delegation: add decode function with an io.Reader

.github/workflows/bench.yml

@@ -1,34 +0,0 @@
-name: go continuous benchmark
-on:
-  push:
-    branches:
-      - main
-
-permissions:
-  contents: write
-  deployments: write
-
-jobs:
-  benchmark:
-    name: Run Go continuous benchmark
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-go@v5
-        with:
-          go-version: "stable"
-      - name: Run benchmark
-        run: go test -v ./... -bench=. -run=xxx -benchmem | tee output.txt
-
-      - name: Store benchmark result
-        uses: benchmark-action/github-action-benchmark@v1
-        with:
-          name: Go Benchmark
-          tool: 'go'
-          output-file-path: output.txt
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          # Push and deploy GitHub pages branch automatically
-          auto-push: true
-          # Show alert with commit comment on detecting possible performance regression
-          alert-threshold: '200%'
-          comment-on-alert: true

.github/workflows/gotest.yml

@@ -7,14 +7,14 @@ jobs:
       fail-fast: false
       matrix:
         os: [ "ubuntu" ]
-        go: [ "1.22.x", "1.23.x", ]
+        go: [ "1.21.x", "1.22.x", "1.23.x", ]
     env:
       COVERAGES: ""
     runs-on: ${{ matrix.os }}-latest
     name: ${{ matrix.os}} (go ${{ matrix.go }})
     steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-go@v5
+      - uses: actions/checkout@v2
+      - uses: actions/setup-go@v2
         with:
           go-version: ${{ matrix.go }}
       - name: Go information
@@ -22,6 +22,6 @@ jobs:
           go version
           go env
       - name: Run tests
-        run: go test -v ./... -tags jwx_es256k
+        run: go test -v ./...
       - name: Check formatted
         run: gofmt -l .

LICENSE.md

@@ -29,7 +29,7 @@ Verbatim copies of both licenses are included below:
 ```
                                  Apache License
                            Version 2.0, January 2004
-                        https://www.apache.org/licenses/
+                        http://www.apache.org/licenses/
 
    TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
 

Readme.md

@@ -1,76 +0,0 @@
-<div align="center">
-  <a href="https://github.com/ucan-wg/go-ucan" target="_blank">
-    <img src="https://raw.githubusercontent.com/ucan-wg/go-ucan/v1/assets/logo.png" alt="go-ucan Logo" height="250"></img>
-  </a>
-
-  <h1 align="center">go-ucan</h1>
-
-  <p>
-    <img src="https://img.shields.io/badge/UCAN-v1.0.0--rc.1-blue" alt="UCAN v1.0.0-rc.1">
-    <a href="https://github.com/ucan-wg/go-ucan/tags">
-        <img alt="GitHub Tag" src="https://img.shields.io/github/v/tag/ucan-wg/go-ucan">
-    </a>
-    <a href="https://github.com/ucan-wg/go-ucan/actions?query=">
-      <img src="https://github.com/ucan-wg/go-ucan/actions/workflows/gotest.yml/badge.svg" alt="Build Status">
-    </a>
-    <a href="https://ucan-wg.github.io/go-ucan/dev/bench/">
-        <img alt="Go benchmarks" src="https://img.shields.io/badge/Benchmarks-go-blue">
-    </a>
-    <a href="https://github.com/ucan-wg/go-ucan/blob/v1/LICENSE.md">
-        <img alt="Apache 2.0 + MIT License" src="https://img.shields.io/badge/License-Apache--2.0+MIT-green">
-    </a>
-    <a href="https://pkg.go.dev/github.com/ucan-wg/go-ucan">
-      <img src="https://img.shields.io/badge/Docs-godoc-blue" alt="Docs">
-    </a>
-    <a href="https://discord.gg/JSyFG6XgVM">
-      <img src="https://img.shields.io/static/v1?label=Discord&message=join%20us!&color=mediumslateblue" alt="Discord">
-    </a>
-  </p>
-</div>
-
-This is a go library to help the next generation of web and decentralized applications make use
-of UCANs in their authorization flows.
-
-User Controlled Authorization Networks (UCANs) are a way of doing authorization where users are fully in control. OAuth is designed for a centralized world, UCAN is the distributed user controlled version.
-
-## Resources
-
-### Specifications
-
-The UCAN specification is separated in multiple sub-spec:
-- [Main specification](https://github.com/ucan-wg/spec)
-- [Delegation](https://github.com/ucan-wg/delegation/tree/v1_ipld)
-- [Invocation](https://github.com/ucan-wg/invocation)
-- [Container](https://github.com/ucan-wg/container)
-
-Not implemented yet:
-- [Revocation](https://github.com/ucan-wg/revocation/tree/first-draft)
-- [Promise](https://github.com/ucan-wg/promise/tree/v1-rc1)
-
-### Talks
-
-- [Decentralizing Auth, and UCAN Too - Brooklyn Zelenka (2023)](https://www.youtube.com/watch?v=MuHfrqw9gQA)
-- [What's New in UCAN 1.0 - Brooklyn Zelenka (2024)](https://www.youtube.com/watch?v=-uohQzZcwF4)
-
-## Status
-
-`go-ucan` currently support the required parts of the UCAN specification: the main specification, delegation and invocation. It leverages the sibling project [`go-did-it`](https://github.com/MetaMask/go-did-it) for easy and extensible DID support.
-
-Besides that, `go-ucan` also includes:
-- support for encrypted values in token's metadata
-
-## Getting Help
-
-For usage questions, usecases, or issues reach out to us in our `go-ucan`
-[Discord channel](https://discord.gg/3EHEQ6M8BC).
-
-We would be happy to try to answer your question or try opening a new issue on
-Github.
-
-## UCAN Gopher
-
-Artwork by [Bruno Monts](https://www.instagram.com/bruno_monts). Thank you [Renee French](http://reneefrench.blogspot.com/) for creating the [Go Gopher](https://blog.golang.org/gopher)
-
-## License
-
-This project is licensed under the double license [Apache 2.0 + MIT](https://github.com/ucan-wg/go-ucan/blob/v1/LICENSE.md).

capability/command/command.go

@@ -16,12 +16,15 @@ var _ fmt.Stringer = (*Command)(nil)
 // by one or more slash-separated Segments of lowercase characters.
 //
 // [Command]: https://github.com/ucan-wg/spec#command
-type Command string
+type Command struct {
+	segments []string
+}
 
-// New creates a validated command from the provided list of segment strings.
-// An error is returned if an invalid Command would be formed
-func New(segments ...string) Command {
-	return Top().Join(segments...)
+// New creates a validated command from the provided list of segment
+// strings.  An error is returned if an invalid Command would be
+// formed
+func New(segments ...string) *Command {
+	return &Command{segments: segments}
 }
 
 // Parse verifies that the provided string contains the required
@@ -29,26 +32,26 @@ func New(segments ...string) Command {
 // Command.
 //
 // [segment structure]: https://github.com/ucan-wg/spec#segment-structure
-func Parse(s string) (Command, error) {
+func Parse(s string) (*Command, error) {
 	if !strings.HasPrefix(s, "/") {
-		return "", ErrRequiresLeadingSlash
+		return nil, ErrRequiresLeadingSlash
 	}
 
 	if len(s) > 1 && strings.HasSuffix(s, "/") {
-		return "", ErrDisallowsTrailingSlash
+		return nil, ErrDisallowsTrailingSlash
 	}
 
 	if s != strings.ToLower(s) {
-		return "", ErrRequiresLowercase
+		return nil, ErrRequiresLowercase
 	}
 
 	// The leading slash will result in the first element from strings.Split
 	// being an empty string which is removed as strings.Join will ignore it.
-	return Command(s), nil
+	return &Command{strings.Split(s, "/")[1:]}, nil
 }
 
 // MustParse is the same as Parse, but panic() if the parsing fail.
-func MustParse(s string) Command {
+func MustParse(s string) *Command {
 	c, err := Parse(s)
 	if err != nil {
 		panic(err)
@@ -56,14 +59,15 @@ func MustParse(s string) Command {
 	return c
 }
 
-// Top is the most powerful capability.
+// [Top] is the most powerful capability.
 //
 // This function returns a Command that is a wildcard and therefore represents the
-// most powerful ability. As such, it should be handled with care and used sparingly.
+// most powerful abilily.  As such it should be handle with care and used
+// sparingly.
 //
 // [Top]: https://github.com/ucan-wg/spec#-aka-top
-func Top() Command {
-	return Command(separator)
+func Top() *Command {
+	return New()
 }
 
 // IsValid returns true if the provided string is a valid UCAN command.
@@ -74,62 +78,18 @@ func IsValid(s string) bool {
 
 // Join appends segments to the end of this command using the required
 // segment separator.
-func (c Command) Join(segments ...string) Command {
-	size := 0
-	for _, s := range segments {
-		size += len(s)
-	}
-	if size == 0 {
-		return c
-	}
-	buf := make([]byte, 0, len(c)+size+len(segments))
-	buf = append(buf, []byte(c)...)
-	for _, s := range segments {
-		if s != "" {
-			if len(buf) > 1 {
-				buf = append(buf, separator...)
-			}
-			buf = append(buf, []byte(s)...)
-		}
-	}
-	return Command(buf)
+func (c *Command) Join(segments ...string) *Command {
+	return &Command{append(c.segments, segments...)}
 }
 
 // Segments returns the ordered segments that comprise the Command as a
 // slice of strings.
-func (c Command) Segments() []string {
-	if c == separator {
-		return nil
-	}
-	return strings.Split(string(c), separator)[1:]
-}
-
-// Covers returns true if the command is identical or a parent of the given other command.
-func (c Command) Covers(other Command) bool {
-	// fast-path, equivalent to the code below (verified with fuzzing)
-	if !strings.HasPrefix(string(other), string(c)) {
-		return false
-	}
-	return c == separator || len(c) == len(other) || other[len(c)] == separator[0]
-
-	/* -------
-
-	otherSegments := other.Segments()
-	if len(otherSegments) < len(c.Segments()) {
-		return false
-	}
-	for i, s := range c.Segments() {
-		if otherSegments[i] != s {
-			return false
-		}
-	}
-	return true
-
-	*/
+func (c *Command) Segments() []string {
+	return c.segments
 }
 
 // String returns the composed representation the command.  This is also
 // the required wire representation (before IPLD encoding occurs.)
-func (c Command) String() string {
-	return string(c)
+func (c *Command) String() string {
+	return "/" + strings.Join(c.segments, "/")
 }

capability/command/command_test.go

@@ -5,7 +5,7 @@ import (
 
 	"github.com/stretchr/testify/require"
 
-	"github.com/ucan-wg/go-ucan/pkg/command"
+	"github.com/ucan-wg/go-ucan/capability/command"
 )
 
 func TestTop(t *testing.T) {
@@ -13,81 +13,73 @@ func TestTop(t *testing.T) {
 }
 
 func TestIsValidCommand(t *testing.T) {
+	t.Parallel()
+
 	t.Run("succeeds when", func(t *testing.T) {
+		t.Parallel()
+
 		for _, testcase := range validTestcases(t) {
+			testcase := testcase
+
 			t.Run(testcase.name, func(t *testing.T) {
+				t.Parallel()
+
 				require.True(t, command.IsValid(testcase.inp))
 			})
 		}
 	})
 
 	t.Run("fails when", func(t *testing.T) {
+		t.Parallel()
+
 		for _, testcase := range invalidTestcases(t) {
+			testcase := testcase
+
 			t.Run(testcase.name, func(t *testing.T) {
+				t.Parallel()
+
 				require.False(t, command.IsValid(testcase.inp))
 			})
 		}
 	})
 }
 
-func TestNew(t *testing.T) {
-	require.Equal(t, command.Top(), command.New())
-	require.Equal(t, "/foo", command.New("foo").String())
-	require.Equal(t, "/foo/bar", command.New("foo", "bar").String())
-	require.Equal(t, "/foo/bar/baz", command.New("foo", "bar/baz").String())
-}
-
 func TestParseCommand(t *testing.T) {
+	t.Parallel()
+
 	t.Run("succeeds when", func(t *testing.T) {
+		t.Parallel()
+
 		for _, testcase := range validTestcases(t) {
+			testcase := testcase
+
 			t.Run(testcase.name, func(t *testing.T) {
+				t.Parallel()
+
 				cmd, err := command.Parse("/elem0/elem1/elem2")
 				require.NoError(t, err)
-				require.NotEmpty(t, cmd)
+				require.NotNil(t, cmd)
 			})
 		}
 	})
 
 	t.Run("fails when", func(t *testing.T) {
+		t.Parallel()
+
 		for _, testcase := range invalidTestcases(t) {
+			testcase := testcase
+
 			t.Run(testcase.name, func(t *testing.T) {
+				t.Parallel()
+
 				cmd, err := command.Parse(testcase.inp)
 				require.ErrorIs(t, err, testcase.err)
-				require.Zero(t, cmd)
+				require.Nil(t, cmd)
 			})
 		}
 	})
 }
 
-func TestEquality(t *testing.T) {
-	require.True(t, command.MustParse("/foo/bar/baz") == command.MustParse("/foo/bar/baz"))
-	require.False(t, command.MustParse("/foo/bar/baz") == command.MustParse("/foo/bar/bazz"))
-	require.False(t, command.MustParse("/foo/bar") == command.MustParse("/foo/bar/baz"))
-}
-
-func TestJoin(t *testing.T) {
-	require.Equal(t, "/foo", command.Top().Join("foo").String())
-	require.Equal(t, "/foo/bar", command.Top().Join("foo/bar").String())
-	require.Equal(t, "/foo/bar", command.Top().Join("foo", "bar").String())
-	require.Equal(t, "/faz/boz/foo/bar", command.MustParse("/faz/boz").Join("foo/bar").String())
-	require.Equal(t, "/faz/boz/foo/bar", command.MustParse("/faz/boz").Join("foo", "bar").String())
-}
-
-func TestSegments(t *testing.T) {
-	require.Empty(t, command.Top().Segments())
-	require.Equal(t, []string{"foo", "bar", "baz"}, command.MustParse("/foo/bar/baz").Segments())
-}
-
-func TestCovers(t *testing.T) {
-	require.True(t, command.MustParse("/foo/bar/baz").Covers(command.MustParse("/foo/bar/baz")))
-	require.True(t, command.MustParse("/foo/bar").Covers(command.MustParse("/foo/bar/baz")))
-	require.False(t, command.MustParse("/foo/bar/baz").Covers(command.MustParse("/foo/bar")))
-	require.True(t, command.MustParse("/").Covers(command.MustParse("/foo")))
-	require.True(t, command.MustParse("/").Covers(command.MustParse("/foo/bar/baz")))
-	require.False(t, command.MustParse("/foo").Covers(command.MustParse("/foo00")))
-	require.False(t, command.MustParse("/foo/bar").Covers(command.MustParse("/foo/bar00")))
-}
-
 type testcase struct {
 	name string
 	inp  string

capability/policy/ipld.go

@@ -9,15 +9,10 @@ import (
 	"github.com/ipld/go-ipld-prime/must"
 	"github.com/ipld/go-ipld-prime/node/basicnode"
 
-	"github.com/ucan-wg/go-ucan/pkg/policy/limits"
-	"github.com/ucan-wg/go-ucan/pkg/policy/selector"
+	"github.com/ucan-wg/go-ucan/capability/policy/selector"
 )
 
 func FromIPLD(node datamodel.Node) (Policy, error) {
-	if err := limits.ValidateIntegerBoundsIPLD(node); err != nil {
-		return nil, fmt.Errorf("policy contains integer values outside safe bounds: %w", err)
-	}
-
 	return statementsFromIPLD("/", node)
 }
 
@@ -66,7 +61,7 @@ func statementFromIPLD(path string, node datamodel.Node) (Statement, error) {
 			if err != nil {
 				return nil, err
 			}
-			return negation{statement: statement}, nil
+			return Not(statement), nil
 
 		case KindAnd, KindOr:
 			arg2, _ := node.LookupByIndex(1)
@@ -81,7 +76,7 @@ func statementFromIPLD(path string, node datamodel.Node) (Statement, error) {
 		}
 	case 3:
 		switch op {
-		case KindEqual, KindNotEqual, KindLessThan, KindLessThanOrEqual, KindGreaterThan, KindGreaterThanOrEqual:
+		case KindEqual, KindLessThan, KindLessThanOrEqual, KindGreaterThan, KindGreaterThanOrEqual:
 			sel, err := arg2AsSelector(op)
 			if err != nil {
 				return nil, err
@@ -98,11 +93,11 @@ func statementFromIPLD(path string, node datamodel.Node) (Statement, error) {
 			if pattern.Kind() != datamodel.Kind_String {
 				return nil, ErrNotAString(combinePath(path, op, 2))
 			}
-			g, err := parseGlob(must.String(pattern))
+			res, err := Like(sel, must.String(pattern))
 			if err != nil {
 				return nil, ErrInvalidPattern(combinePath(path, op, 2), err)
 			}
-			return wildcard{selector: sel, pattern: g}, nil
+			return res, nil
 
 		case KindAll, KindAny:
 			sel, err := arg2AsSelector(op)
@@ -237,7 +232,7 @@ func statementToIPLD(statement Statement) (datamodel.Node, error) {
 		if err != nil {
 			return nil, err
 		}
-		err = listBuilder.AssembleValue().AssignString(string(statement.pattern))
+		err = listBuilder.AssembleValue().AssignString(statement.pattern)
 		if err != nil {
 			return nil, err
 		}

capability/policy/ipld_test.go

@@ -16,36 +16,13 @@ func TestIpldRoundTrip(t *testing.T) {
   ["any", ".tags", 
     ["or", [
       ["==", ".", "news"], 
-      ["==", ".", "press"]
-    ]]
-  ]
-]`
-
-	// must contain all the operators
-	const allOps = `
-[
-  ["and", [
-    ["==", ".foo1", ".bar1"],
-    ["!=", ".foo2", ".bar2"]
-  ]],
-  ["or", [
-    [">", ".foo5", 5.2],
-    [">=", ".foo6", 6.2]
-  ]],
-  ["not", ["like", ".foo7", "*@example.com"]],
-  ["all", ".foo8",
-    ["<", ".foo3", 3]
-  ],
-  ["any", ".foo9",
-    ["<=", ".foo4", 4]
-  ]
+      ["==", ".", "press"]]]
 ]`
 
 	for _, tc := range []struct {
 		name, dagJsonStr string
 	}{
 		{"illustrativeExample", illustrativeExample},
-		{"allOps", allOps},
 	} {
 		nodes, err := ipld.Decode([]byte(tc.dagJsonStr), dagjson.Decode)
 		require.NoError(t, err)

capability/policy/literal/literal.go

@@ -0,0 +1,52 @@
+package literal
+
+import (
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/node/basicnode"
+)
+
+func Node(n ipld.Node) ipld.Node {
+	return n
+}
+
+func Link(cid ipld.Link) ipld.Node {
+	nb := basicnode.Prototype.Link.NewBuilder()
+	nb.AssignLink(cid)
+	return nb.Build()
+}
+
+func Bool(val bool) ipld.Node {
+	nb := basicnode.Prototype.Bool.NewBuilder()
+	nb.AssignBool(val)
+	return nb.Build()
+}
+
+func Int(val int64) ipld.Node {
+	nb := basicnode.Prototype.Int.NewBuilder()
+	nb.AssignInt(val)
+	return nb.Build()
+}
+
+func Float(val float64) ipld.Node {
+	nb := basicnode.Prototype.Float.NewBuilder()
+	nb.AssignFloat(val)
+	return nb.Build()
+}
+
+func String(val string) ipld.Node {
+	nb := basicnode.Prototype.String.NewBuilder()
+	nb.AssignString(val)
+	return nb.Build()
+}
+
+func Bytes(val []byte) ipld.Node {
+	nb := basicnode.Prototype.Bytes.NewBuilder()
+	nb.AssignBytes(val)
+	return nb.Build()
+}
+
+func Null() ipld.Node {
+	nb := basicnode.Prototype.Any.NewBuilder()
+	nb.AssignNull()
+	return nb.Build()
+}

capability/policy/match.go

@@ -0,0 +1,164 @@
+package policy
+
+import (
+	"cmp"
+	"fmt"
+
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/datamodel"
+	"github.com/ipld/go-ipld-prime/must"
+
+	"github.com/ucan-wg/go-ucan/capability/policy/selector"
+)
+
+// Match determines if the IPLD node matches the policy document.
+func Match(policy Policy, node ipld.Node) bool {
+	for _, stmt := range policy {
+		ok := matchStatement(stmt, node)
+		if !ok {
+			return false
+		}
+	}
+	return true
+}
+
+func matchStatement(statement Statement, node ipld.Node) bool {
+	switch statement.Kind() {
+	case KindEqual:
+		if s, ok := statement.(equality); ok {
+			one, _, err := selector.Select(s.selector, node)
+			if err != nil || one == nil {
+				return false
+			}
+			return datamodel.DeepEqual(s.value, one)
+		}
+	case KindGreaterThan:
+		if s, ok := statement.(equality); ok {
+			one, _, err := selector.Select(s.selector, node)
+			if err != nil || one == nil {
+				return false
+			}
+			return isOrdered(s.value, one, gt)
+		}
+	case KindGreaterThanOrEqual:
+		if s, ok := statement.(equality); ok {
+			one, _, err := selector.Select(s.selector, node)
+			if err != nil || one == nil {
+				return false
+			}
+			return isOrdered(s.value, one, gte)
+		}
+	case KindLessThan:
+		if s, ok := statement.(equality); ok {
+			one, _, err := selector.Select(s.selector, node)
+			if err != nil || one == nil {
+				return false
+			}
+			return isOrdered(s.value, one, lt)
+		}
+	case KindLessThanOrEqual:
+		if s, ok := statement.(equality); ok {
+			one, _, err := selector.Select(s.selector, node)
+			if err != nil || one == nil {
+				return false
+			}
+			return isOrdered(s.value, one, lte)
+		}
+	case KindNot:
+		if s, ok := statement.(negation); ok {
+			return !matchStatement(s.statement, node)
+		}
+	case KindAnd:
+		if s, ok := statement.(connective); ok {
+			for _, cs := range s.statements {
+				r := matchStatement(cs, node)
+				if !r {
+					return false
+				}
+			}
+			return true
+		}
+	case KindOr:
+		if s, ok := statement.(connective); ok {
+			if len(s.statements) == 0 {
+				return true
+			}
+			for _, cs := range s.statements {
+				r := matchStatement(cs, node)
+				if r {
+					return true
+				}
+			}
+			return false
+		}
+	case KindLike:
+		if s, ok := statement.(wildcard); ok {
+			one, _, err := selector.Select(s.selector, node)
+			if err != nil || one == nil {
+				return false
+			}
+			v, err := one.AsString()
+			if err != nil {
+				return false
+			}
+			return s.glob.Match(v)
+		}
+	case KindAll:
+		if s, ok := statement.(quantifier); ok {
+			_, many, err := selector.Select(s.selector, node)
+			if err != nil || many == nil {
+				return false
+			}
+			for _, n := range many {
+				ok := matchStatement(s.statement, n)
+				if !ok {
+					return false
+				}
+			}
+			return true
+		}
+	case KindAny:
+		if s, ok := statement.(quantifier); ok {
+			// FIXME: line below return a single node, not many
+			_, many, err := selector.Select(s.selector, node)
+			if err != nil || many == nil {
+				return false
+			}
+			for _, n := range many {
+				ok := matchStatement(s.statement, n)
+				if ok {
+					return true
+				}
+			}
+			return false
+		}
+	}
+	panic(fmt.Errorf("unimplemented statement kind: %s", statement.Kind()))
+}
+
+func isOrdered(expected ipld.Node, actual ipld.Node, satisfies func(order int) bool) bool {
+	if expected.Kind() == ipld.Kind_Int && actual.Kind() == ipld.Kind_Int {
+		a := must.Int(actual)
+		b := must.Int(expected)
+		return satisfies(cmp.Compare(a, b))
+	}
+
+	if expected.Kind() == ipld.Kind_Float && actual.Kind() == ipld.Kind_Float {
+		a, err := actual.AsFloat()
+		if err != nil {
+			panic(fmt.Errorf("extracting node float: %w", err))
+		}
+		b, err := expected.AsFloat()
+		if err != nil {
+			panic(fmt.Errorf("extracting selector float: %w", err))
+		}
+		return satisfies(cmp.Compare(a, b))
+	}
+
+	return false
+}
+
+func gt(order int) bool  { return order == 1 }
+func gte(order int) bool { return order == 0 || order == 1 }
+func lt(order int) bool  { return order == -1 }
+func lte(order int) bool { return order == 0 || order == -1 }

capability/policy/match_test.go

@@ -0,0 +1,492 @@
+package policy
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/ipfs/go-cid"
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/codec/dagjson"
+	cidlink "github.com/ipld/go-ipld-prime/linking/cid"
+	"github.com/ipld/go-ipld-prime/node/basicnode"
+	"github.com/stretchr/testify/require"
+
+	"github.com/ucan-wg/go-ucan/capability/policy/literal"
+	"github.com/ucan-wg/go-ucan/capability/policy/selector"
+)
+
+func TestMatch(t *testing.T) {
+	t.Run("equality", func(t *testing.T) {
+		t.Run("string", func(t *testing.T) {
+			np := basicnode.Prototype.String
+			nb := np.NewBuilder()
+			nb.AssignString("test")
+			nd := nb.Build()
+
+			pol := Policy{Equal(selector.MustParse("."), literal.String("test"))}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+
+			pol = Policy{Equal(selector.MustParse("."), literal.String("test2"))}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+
+			pol = Policy{Equal(selector.MustParse("."), literal.Int(138))}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+		})
+
+		t.Run("int", func(t *testing.T) {
+			np := basicnode.Prototype.Int
+			nb := np.NewBuilder()
+			nb.AssignInt(138)
+			nd := nb.Build()
+
+			pol := Policy{Equal(selector.MustParse("."), literal.Int(138))}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+
+			pol = Policy{Equal(selector.MustParse("."), literal.Int(1138))}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+
+			pol = Policy{Equal(selector.MustParse("."), literal.String("138"))}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+		})
+
+		t.Run("float", func(t *testing.T) {
+			np := basicnode.Prototype.Float
+			nb := np.NewBuilder()
+			nb.AssignFloat(1.138)
+			nd := nb.Build()
+
+			pol := Policy{Equal(selector.MustParse("."), literal.Float(1.138))}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+
+			pol = Policy{Equal(selector.MustParse("."), literal.Float(11.38))}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+
+			pol = Policy{Equal(selector.MustParse("."), literal.String("138"))}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+		})
+
+		t.Run("IPLD Link", func(t *testing.T) {
+			l0 := cidlink.Link{Cid: cid.MustParse("bafybeif4owy5gno5lwnixqm52rwqfodklf76hsetxdhffuxnplvijskzqq")}
+			l1 := cidlink.Link{Cid: cid.MustParse("bafkreifau35r7vi37tvbvfy3hdwvgb4tlflqf7zcdzeujqcjk3rsphiwte")}
+
+			np := basicnode.Prototype.Link
+			nb := np.NewBuilder()
+			nb.AssignLink(l0)
+			nd := nb.Build()
+
+			pol := Policy{Equal(selector.MustParse("."), literal.Link(l0))}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+
+			pol = Policy{Equal(selector.MustParse("."), literal.Link(l1))}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+
+			pol = Policy{Equal(selector.MustParse("."), literal.String("bafybeif4owy5gno5lwnixqm52rwqfodklf76hsetxdhffuxnplvijskzqq"))}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+		})
+
+		t.Run("string in map", func(t *testing.T) {
+			np := basicnode.Prototype.Map
+			nb := np.NewBuilder()
+			ma, _ := nb.BeginMap(1)
+			ma.AssembleKey().AssignString("foo")
+			ma.AssembleValue().AssignString("bar")
+			ma.Finish()
+			nd := nb.Build()
+
+			pol := Policy{Equal(selector.MustParse(".foo"), literal.String("bar"))}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+
+			pol = Policy{Equal(selector.MustParse(".[\"foo\"]"), literal.String("bar"))}
+			ok = Match(pol, nd)
+			require.True(t, ok)
+
+			pol = Policy{Equal(selector.MustParse(".foo"), literal.String("baz"))}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+
+			pol = Policy{Equal(selector.MustParse(".foobar"), literal.String("bar"))}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+		})
+
+		t.Run("string in list", func(t *testing.T) {
+			np := basicnode.Prototype.List
+			nb := np.NewBuilder()
+			la, _ := nb.BeginList(1)
+			la.AssembleValue().AssignString("foo")
+			la.Finish()
+			nd := nb.Build()
+
+			pol := Policy{Equal(selector.MustParse(".[0]"), literal.String("foo"))}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+
+			pol = Policy{Equal(selector.MustParse(".[1]"), literal.String("foo"))}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+		})
+	})
+
+	t.Run("inequality", func(t *testing.T) {
+		t.Run("gt int", func(t *testing.T) {
+			np := basicnode.Prototype.Int
+			nb := np.NewBuilder()
+			nb.AssignInt(138)
+			nd := nb.Build()
+
+			pol := Policy{GreaterThan(selector.MustParse("."), literal.Int(1))}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+		})
+
+		t.Run("gte int", func(t *testing.T) {
+			np := basicnode.Prototype.Int
+			nb := np.NewBuilder()
+			nb.AssignInt(138)
+			nd := nb.Build()
+
+			pol := Policy{GreaterThanOrEqual(selector.MustParse("."), literal.Int(1))}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+
+			pol = Policy{GreaterThanOrEqual(selector.MustParse("."), literal.Int(138))}
+			ok = Match(pol, nd)
+			require.True(t, ok)
+		})
+
+		t.Run("gt float", func(t *testing.T) {
+			np := basicnode.Prototype.Float
+			nb := np.NewBuilder()
+			nb.AssignFloat(1.38)
+			nd := nb.Build()
+
+			pol := Policy{GreaterThan(selector.MustParse("."), literal.Float(1))}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+		})
+
+		t.Run("gte float", func(t *testing.T) {
+			np := basicnode.Prototype.Float
+			nb := np.NewBuilder()
+			nb.AssignFloat(1.38)
+			nd := nb.Build()
+
+			pol := Policy{GreaterThanOrEqual(selector.MustParse("."), literal.Float(1))}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+
+			pol = Policy{GreaterThanOrEqual(selector.MustParse("."), literal.Float(1.38))}
+			ok = Match(pol, nd)
+			require.True(t, ok)
+		})
+
+		t.Run("lt int", func(t *testing.T) {
+			np := basicnode.Prototype.Int
+			nb := np.NewBuilder()
+			nb.AssignInt(138)
+			nd := nb.Build()
+
+			pol := Policy{LessThan(selector.MustParse("."), literal.Int(1138))}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+		})
+
+		t.Run("lte int", func(t *testing.T) {
+			np := basicnode.Prototype.Int
+			nb := np.NewBuilder()
+			nb.AssignInt(138)
+			nd := nb.Build()
+
+			pol := Policy{LessThanOrEqual(selector.MustParse("."), literal.Int(1138))}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+
+			pol = Policy{LessThanOrEqual(selector.MustParse("."), literal.Int(138))}
+			ok = Match(pol, nd)
+			require.True(t, ok)
+		})
+	})
+
+	t.Run("negation", func(t *testing.T) {
+		np := basicnode.Prototype.Bool
+		nb := np.NewBuilder()
+		nb.AssignBool(false)
+		nd := nb.Build()
+
+		pol := Policy{Not(Equal(selector.MustParse("."), literal.Bool(true)))}
+		ok := Match(pol, nd)
+		require.True(t, ok)
+
+		pol = Policy{Not(Equal(selector.MustParse("."), literal.Bool(false)))}
+		ok = Match(pol, nd)
+		require.False(t, ok)
+	})
+
+	t.Run("conjunction", func(t *testing.T) {
+		np := basicnode.Prototype.Int
+		nb := np.NewBuilder()
+		nb.AssignInt(138)
+		nd := nb.Build()
+
+		pol := Policy{
+			And(
+				GreaterThan(selector.MustParse("."), literal.Int(1)),
+				LessThan(selector.MustParse("."), literal.Int(1138)),
+			),
+		}
+		ok := Match(pol, nd)
+		require.True(t, ok)
+
+		pol = Policy{
+			And(
+				GreaterThan(selector.MustParse("."), literal.Int(1)),
+				Equal(selector.MustParse("."), literal.Int(1138)),
+			),
+		}
+		ok = Match(pol, nd)
+		require.False(t, ok)
+
+		pol = Policy{And()}
+		ok = Match(pol, nd)
+		require.True(t, ok)
+	})
+
+	t.Run("disjunction", func(t *testing.T) {
+		np := basicnode.Prototype.Int
+		nb := np.NewBuilder()
+		nb.AssignInt(138)
+		nd := nb.Build()
+
+		pol := Policy{
+			Or(
+				GreaterThan(selector.MustParse("."), literal.Int(138)),
+				LessThan(selector.MustParse("."), literal.Int(1138)),
+			),
+		}
+		ok := Match(pol, nd)
+		require.True(t, ok)
+
+		pol = Policy{
+			Or(
+				GreaterThan(selector.MustParse("."), literal.Int(138)),
+				Equal(selector.MustParse("."), literal.Int(1138)),
+			),
+		}
+		ok = Match(pol, nd)
+		require.False(t, ok)
+
+		pol = Policy{Or()}
+		ok = Match(pol, nd)
+		require.True(t, ok)
+	})
+
+	t.Run("wildcard", func(t *testing.T) {
+		pattern := `Alice\*, Bob*, Carol.`
+
+		for _, s := range []string{
+			"Alice*, Bob, Carol.",
+			"Alice*, Bob, Dan, Erin, Carol.",
+			"Alice*, Bob  , Carol.",
+			"Alice*, Bob*, Carol.",
+		} {
+			func(s string) {
+				t.Run(fmt.Sprintf("pass %s", s), func(t *testing.T) {
+					np := basicnode.Prototype.String
+					nb := np.NewBuilder()
+					nb.AssignString(s)
+					nd := nb.Build()
+
+					statement, err := Like(selector.MustParse("."), pattern)
+					require.NoError(t, err)
+
+					pol := Policy{statement}
+					ok := Match(pol, nd)
+					require.True(t, ok)
+				})
+			}(s)
+		}
+
+		for _, s := range []string{
+			"Alice*, Bob, Carol",
+			"Alice*, Bob*, Carol!",
+			"Alice Cooper, Bob, Carol.",
+			"Alice, Bob, Carol.",
+			" Alice*, Bob, Carol. ",
+		} {
+			func(s string) {
+				t.Run(fmt.Sprintf("fail %s", s), func(t *testing.T) {
+					np := basicnode.Prototype.String
+					nb := np.NewBuilder()
+					nb.AssignString(s)
+					nd := nb.Build()
+
+					statement, err := Like(selector.MustParse("."), pattern)
+					require.NoError(t, err)
+
+					pol := Policy{statement}
+					ok := Match(pol, nd)
+					require.False(t, ok)
+				})
+			}(s)
+		}
+	})
+
+	t.Run("quantification", func(t *testing.T) {
+		buildValueNode := func(v int64) ipld.Node {
+			np := basicnode.Prototype.Map
+			nb := np.NewBuilder()
+			ma, _ := nb.BeginMap(1)
+			ma.AssembleKey().AssignString("value")
+			ma.AssembleValue().AssignInt(v)
+			ma.Finish()
+			return nb.Build()
+		}
+
+		t.Run("all", func(t *testing.T) {
+			np := basicnode.Prototype.List
+			nb := np.NewBuilder()
+			la, _ := nb.BeginList(5)
+			la.AssembleValue().AssignNode(buildValueNode(5))
+			la.AssembleValue().AssignNode(buildValueNode(10))
+			la.AssembleValue().AssignNode(buildValueNode(20))
+			la.AssembleValue().AssignNode(buildValueNode(50))
+			la.AssembleValue().AssignNode(buildValueNode(100))
+			la.Finish()
+			nd := nb.Build()
+
+			pol := Policy{
+				All(
+					selector.MustParse(".[]"),
+					GreaterThan(selector.MustParse(".value"), literal.Int(2)),
+				),
+			}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+
+			pol = Policy{
+				All(
+					selector.MustParse(".[]"),
+					GreaterThan(selector.MustParse(".value"), literal.Int(20)),
+				),
+			}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+		})
+
+		t.Run("any", func(t *testing.T) {
+			np := basicnode.Prototype.List
+			nb := np.NewBuilder()
+			la, _ := nb.BeginList(5)
+			la.AssembleValue().AssignNode(buildValueNode(5))
+			la.AssembleValue().AssignNode(buildValueNode(10))
+			la.AssembleValue().AssignNode(buildValueNode(20))
+			la.AssembleValue().AssignNode(buildValueNode(50))
+			la.AssembleValue().AssignNode(buildValueNode(100))
+			la.Finish()
+			nd := nb.Build()
+
+			pol := Policy{
+				Any(
+					selector.MustParse(".[]"),
+					GreaterThan(selector.MustParse(".value"), literal.Int(60)),
+				),
+			}
+			ok := Match(pol, nd)
+			require.True(t, ok)
+
+			pol = Policy{
+				Any(
+					selector.MustParse(".[]"),
+					GreaterThan(selector.MustParse(".value"), literal.Int(100)),
+				),
+			}
+			ok = Match(pol, nd)
+			require.False(t, ok)
+		})
+	})
+}
+
+func TestPolicyExamples(t *testing.T) {
+	makeNode := func(data string) ipld.Node {
+		nd, err := ipld.Decode([]byte(data), dagjson.Decode)
+		require.NoError(t, err)
+		return nd
+	}
+
+	evaluate := func(statement string, data ipld.Node) bool {
+		// we need to wrap statement with [] to make them a policy
+		policy := fmt.Sprintf("[%s]", statement)
+
+		pol, err := FromDagJson(policy)
+		require.NoError(t, err)
+		return Match(pol, data)
+	}
+
+	t.Run("And", func(t *testing.T) {
+		data := makeNode(`{ "name": "Katie", "age": 35, "nationalities": ["Canadian", "South African"] }`)
+
+		require.True(t, evaluate(`["and", []]`, data))
+		require.True(t, evaluate(`
+["and", [
+  ["==", ".name", "Katie"], 
+  [">=", ".age", 21]
+]]`, data))
+		require.False(t, evaluate(`
+["and", [
+  ["==", ".name", "Katie"], 
+  [">=", ".age", 21], 
+  ["==", ".nationalities", ["American"]]
+]]`, data))
+	})
+
+	t.Run("Or", func(t *testing.T) {
+		data := makeNode(`{ "name": "Katie", "age": 35, "nationalities": ["Canadian", "South African"] }`)
+
+		require.True(t, evaluate(`["or", []]`, data))
+		require.True(t, evaluate(`
+		["or", [
+		  ["==", ".name", "Katie"],
+		  [">", ".age", 45]
+		]]
+		`, data))
+
+	})
+
+	t.Run("Not", func(t *testing.T) {
+		data := makeNode(`{ "name": "Katie", "nationalities": ["Canadian", "South African"] }`)
+
+		require.True(t, evaluate(`
+["not", 
+  ["and", [
+    ["==", ".name", "Katie"], 
+    ["==", ".nationalities", ["American"]]
+  ]]
+]
+`, data))
+	})
+
+	t.Run("All", func(t *testing.T) {
+		data := makeNode(`{"a": [{"b": 1}, {"b": 2}, {"z": [7, 8, 9]}]}`)
+
+		require.False(t, evaluate(`["all", ".a", [">", ".b", 0]]`, data))
+	})
+
+	t.Run("Any", func(t *testing.T) {
+		data := makeNode(`{"a": [{"b": 1}, {"b": 2}, {"z": [7, 8, 9]}]}`)
+
+		require.True(t, evaluate(`["any", ".a", ["==", ".b", 2]]`, data))
+	})
+}

capability/policy/policy.go

@@ -0,0 +1,125 @@
+package policy
+
+// https://github.com/ucan-wg/delegation/blob/4094d5878b58f5d35055a3b93fccda0b8329ebae/README.md#policy
+
+import (
+	"github.com/gobwas/glob"
+	"github.com/ipld/go-ipld-prime"
+
+	"github.com/ucan-wg/go-ucan/capability/policy/selector"
+)
+
+const (
+	KindEqual              = "=="   // implemented by equality
+	KindGreaterThan        = ">"    // implemented by equality
+	KindGreaterThanOrEqual = ">="   // implemented by equality
+	KindLessThan           = "<"    // implemented by equality
+	KindLessThanOrEqual    = "<="   // implemented by equality
+	KindNot                = "not"  // implemented by negation
+	KindAnd                = "and"  // implemented by connective
+	KindOr                 = "or"   // implemented by connective
+	KindLike               = "like" // implemented by wildcard
+	KindAll                = "all"  // implemented by quantifier
+	KindAny                = "any"  // implemented by quantifier
+)
+
+type Policy []Statement
+
+type Statement interface {
+	Kind() string
+}
+
+type equality struct {
+	kind     string
+	selector selector.Selector
+	value    ipld.Node
+}
+
+func (e equality) Kind() string {
+	return e.kind
+}
+
+func Equal(selector selector.Selector, value ipld.Node) Statement {
+	return equality{kind: KindEqual, selector: selector, value: value}
+}
+
+func GreaterThan(selector selector.Selector, value ipld.Node) Statement {
+	return equality{kind: KindGreaterThan, selector: selector, value: value}
+}
+
+func GreaterThanOrEqual(selector selector.Selector, value ipld.Node) Statement {
+	return equality{kind: KindGreaterThanOrEqual, selector: selector, value: value}
+}
+
+func LessThan(selector selector.Selector, value ipld.Node) Statement {
+	return equality{kind: KindLessThan, selector: selector, value: value}
+}
+
+func LessThanOrEqual(selector selector.Selector, value ipld.Node) Statement {
+	return equality{kind: KindLessThanOrEqual, selector: selector, value: value}
+}
+
+type negation struct {
+	statement Statement
+}
+
+func (n negation) Kind() string {
+	return KindNot
+}
+
+func Not(stmt Statement) Statement {
+	return negation{statement: stmt}
+}
+
+type connective struct {
+	kind       string
+	statements []Statement
+}
+
+func (c connective) Kind() string {
+	return c.kind
+}
+
+func And(stmts ...Statement) Statement {
+	return connective{kind: KindAnd, statements: stmts}
+}
+
+func Or(stmts ...Statement) Statement {
+	return connective{kind: KindOr, statements: stmts}
+}
+
+type wildcard struct {
+	selector selector.Selector
+	pattern  string
+	glob     glob.Glob // not serialized
+}
+
+func (n wildcard) Kind() string {
+	return KindLike
+}
+
+func Like(selector selector.Selector, pattern string) (Statement, error) {
+	g, err := glob.Compile(pattern)
+	if err != nil {
+		return nil, err
+	}
+	return wildcard{selector: selector, pattern: pattern, glob: g}, nil
+}
+
+type quantifier struct {
+	kind      string
+	selector  selector.Selector
+	statement Statement
+}
+
+func (n quantifier) Kind() string {
+	return n.kind
+}
+
+func All(selector selector.Selector, statement Statement) Statement {
+	return quantifier{kind: KindAll, selector: selector, statement: statement}
+}
+
+func Any(selector selector.Selector, statement Statement) Statement {
+	return quantifier{kind: KindAny, selector: selector, statement: statement}
+}

capability/policy/selector/parsing.go

@@ -0,0 +1,160 @@
+package selector
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+func Parse(str string) (Selector, error) {
+	if len(str) == 0 {
+		return nil, newParseError("empty selector", str, 0, "")
+	}
+	if string(str[0]) != "." {
+		return nil, newParseError("selector must start with identity segment '.'", str, 0, string(str[0]))
+	}
+
+	col := 0
+	var sel Selector
+	for _, tok := range tokenize(str) {
+		seg := tok
+		opt := strings.HasSuffix(tok, "?")
+		if opt {
+			seg = tok[0 : len(tok)-1]
+		}
+		switch seg {
+		case ".":
+			if len(sel) > 0 && sel[len(sel)-1].Identity() {
+				return nil, newParseError("selector contains unsupported recursive descent segment: '..'", str, col, tok)
+			}
+			sel = append(sel, Identity)
+		case "[]":
+			sel = append(sel, segment{tok, false, opt, true, nil, "", 0})
+		default:
+			if strings.HasPrefix(seg, "[") && strings.HasSuffix(seg, "]") {
+				lookup := seg[1 : len(seg)-1]
+
+				if indexRegex.MatchString(lookup) { // index
+					idx, err := strconv.Atoi(lookup)
+					if err != nil {
+						return nil, newParseError("invalid index", str, col, tok)
+					}
+					sel = append(sel, segment{str: tok, optional: opt, index: idx})
+				} else if strings.HasPrefix(lookup, "\"") && strings.HasSuffix(lookup, "\"") { // explicit field
+					sel = append(sel, segment{str: tok, optional: opt, field: lookup[1 : len(lookup)-1]})
+				} else if sliceRegex.MatchString(lookup) { // slice [3:5] or [:5] or [3:]
+					var rng []int
+					splt := strings.Split(lookup, ":")
+					if splt[0] == "" {
+						rng = append(rng, 0)
+					} else {
+						i, err := strconv.Atoi(splt[0])
+						if err != nil {
+							return nil, newParseError("invalid slice index", str, col, tok)
+						}
+						rng = append(rng, i)
+					}
+					if splt[1] != "" {
+						i, err := strconv.Atoi(splt[1])
+						if err != nil {
+							return nil, newParseError("invalid slice index", str, col, tok)
+						}
+						rng = append(rng, i)
+					}
+					sel = append(sel, segment{str: tok, optional: opt, slice: rng})
+				} else {
+					return nil, newParseError(fmt.Sprintf("invalid segment: %s", seg), str, col, tok)
+				}
+			} else if fieldRegex.MatchString(seg) {
+				sel = append(sel, segment{str: tok, optional: opt, field: seg[1:]})
+			} else {
+				return nil, newParseError(fmt.Sprintf("invalid segment: %s", seg), str, col, tok)
+			}
+		}
+		col += len(tok)
+	}
+	return sel, nil
+}
+
+func MustParse(sel string) Selector {
+	s, err := Parse(sel)
+	if err != nil {
+		panic(err)
+	}
+	return s
+}
+
+func tokenize(str string) []string {
+	var toks []string
+	col := 0
+	ofs := 0
+	ctx := ""
+
+	for col < len(str) {
+		char := string(str[col])
+
+		if char == "\"" && string(str[col-1]) != "\\" {
+			col++
+			if ctx == "\"" {
+				ctx = ""
+			} else {
+				ctx = "\""
+			}
+			continue
+		}
+
+		if ctx == "\"" {
+			col++
+			continue
+		}
+
+		if char == "." || char == "[" {
+			if ofs < col {
+				toks = append(toks, str[ofs:col])
+			}
+			ofs = col
+		}
+		col++
+	}
+
+	if ofs < col && ctx != "\"" {
+		toks = append(toks, str[ofs:col])
+	}
+
+	return toks
+}
+
+type parseerr struct {
+	msg string
+	src string
+	col int
+	tok string
+}
+
+func (p parseerr) Name() string {
+	return "ParseError"
+}
+
+func (p parseerr) Message() string {
+	return p.msg
+}
+
+func (p parseerr) Column() int {
+	return p.col
+}
+
+func (p parseerr) Error() string {
+	return p.msg
+}
+
+func (p parseerr) Source() string {
+	return p.src
+}
+
+func (p parseerr) Token() string {
+	return p.tok
+}
+
+func newParseError(message string, source string, column int, token string) error {
+	return parseerr{message, source, column, token}
+}

capability/policy/selector/selector.go

@@ -0,0 +1,259 @@
+package selector
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/datamodel"
+	"github.com/ipld/go-ipld-prime/schema"
+)
+
+// Selector describes a UCAN policy selector, as specified here:
+// https://github.com/ucan-wg/delegation/blob/4094d5878b58f5d35055a3b93fccda0b8329ebae/README.md#selectors
+type Selector []segment
+
+func (s Selector) String() string {
+	var res strings.Builder
+	for _, seg := range s {
+		res.WriteString(seg.String())
+	}
+	return res.String()
+}
+
+var Identity = segment{".", true, false, false, nil, "", 0}
+
+var (
+	indexRegex = regexp.MustCompile(`^-?\d+$`)
+	sliceRegex = regexp.MustCompile(`^((\-?\d+:\-?\d*)|(\-?\d*:\-?\d+))$`)
+	fieldRegex = regexp.MustCompile(`^\.[a-zA-Z_]*?$`)
+)
+
+type segment struct {
+	str      string
+	identity bool
+	optional bool
+	iterator bool
+	slice    []int
+	field    string
+	index    int
+}
+
+// String returns the segment's string representation.
+func (s segment) String() string {
+	return s.str
+}
+
+// Identity flags that this selector is the identity selector.
+func (s segment) Identity() bool {
+	return s.identity
+}
+
+// Optional flags that this selector is optional.
+func (s segment) Optional() bool {
+	return s.optional
+}
+
+// Iterator flags that this selector is an iterator segment.
+func (s segment) Iterator() bool {
+	return s.iterator
+}
+
+// Slice flags that this segment targets a range of a slice.
+func (s segment) Slice() []int {
+	return s.slice
+}
+
+// Field is the name of a field in a struct/map.
+func (s segment) Field() string {
+	return s.field
+}
+
+// Index is an index of a slice.
+func (s segment) Index() int {
+	return s.index
+}
+
+// Select uses a selector to extract an IPLD node or set of nodes from the
+// passed subject node.
+func Select(sel Selector, subject ipld.Node) (ipld.Node, []ipld.Node, error) {
+	return resolve(sel, subject, nil)
+}
+
+func resolve(sel Selector, subject ipld.Node, at []string) (ipld.Node, []ipld.Node, error) {
+	cur := subject
+	for i, seg := range sel {
+		if seg.Identity() {
+			continue
+		} else if seg.Iterator() {
+			if cur != nil && cur.Kind() == datamodel.Kind_List {
+				var many []ipld.Node
+				it := cur.ListIterator()
+				for {
+					if it.Done() {
+						break
+					}
+
+					k, v, err := it.Next()
+					if err != nil {
+						return nil, nil, err
+					}
+
+					key := fmt.Sprintf("%d", k)
+					o, m, err := resolve(sel[i+1:], v, append(at[:], key))
+					if err != nil {
+						return nil, nil, err
+					}
+
+					if m != nil {
+						many = append(many, m...)
+					} else {
+						many = append(many, o)
+					}
+				}
+				return nil, many, nil
+			} else if cur != nil && cur.Kind() == datamodel.Kind_Map {
+				var many []ipld.Node
+				it := cur.MapIterator()
+				for {
+					if it.Done() {
+						break
+					}
+
+					k, v, err := it.Next()
+					if err != nil {
+						return nil, nil, err
+					}
+
+					key, _ := k.AsString()
+					o, m, err := resolve(sel[i+1:], v, append(at[:], key))
+					if err != nil {
+						return nil, nil, err
+					}
+
+					if m != nil {
+						many = append(many, m...)
+					} else {
+						many = append(many, o)
+					}
+				}
+				return nil, many, nil
+			} else if seg.Optional() {
+				cur = nil
+			} else {
+				return nil, nil, newResolutionError(fmt.Sprintf("can not iterate over kind: %s", kindString(cur)), at)
+			}
+
+		} else if seg.Field() != "" {
+			at = append(at, seg.Field())
+			if cur != nil && cur.Kind() == datamodel.Kind_Map {
+				n, err := cur.LookupByString(seg.Field())
+				if err != nil {
+					if isMissing(err) {
+						if seg.Optional() {
+							cur = nil
+						} else {
+							return nil, nil, newResolutionError(fmt.Sprintf("object has no field named: %s", seg.Field()), at)
+						}
+					} else {
+						return nil, nil, err
+					}
+				}
+				cur = n
+			} else if seg.Optional() {
+				cur = nil
+			} else {
+				return nil, nil, newResolutionError(fmt.Sprintf("can not access field: %s on kind: %s", seg.Field(), kindString(cur)), at)
+			}
+		} else if seg.Slice() != nil {
+			if cur != nil && cur.Kind() == datamodel.Kind_List {
+				return nil, nil, newResolutionError("list slice selection not yet implemented", at)
+			} else if cur != nil && cur.Kind() == datamodel.Kind_Bytes {
+				return nil, nil, newResolutionError("bytes slice selection not yet implemented", at)
+			} else if seg.Optional() {
+				cur = nil
+			} else {
+				return nil, nil, newResolutionError(fmt.Sprintf("can not index: %s on kind: %s", seg.Field(), kindString(cur)), at)
+			}
+		} else {
+			at = append(at, fmt.Sprintf("%d", seg.Index()))
+			if cur != nil && cur.Kind() == datamodel.Kind_List {
+				idx := int64(seg.Index())
+				if idx < 0 {
+					idx = cur.Length() + idx
+				}
+				if idx < 0 {
+					// necessary until https://github.com/ipld/go-ipld-prime/pull/571
+					// after, isMissing() below will work
+					// TODO: remove
+					return nil, nil, newResolutionError(fmt.Sprintf("index out of bounds: %d", seg.Index()), at)
+				}
+				n, err := cur.LookupByIndex(idx)
+				if err != nil {
+					if isMissing(err) {
+						if seg.Optional() {
+							cur = nil
+						} else {
+							return nil, nil, newResolutionError(fmt.Sprintf("index out of bounds: %d", seg.Index()), at)
+						}
+					} else {
+						return nil, nil, err
+					}
+				}
+				cur = n
+			} else if seg.Optional() {
+				cur = nil
+			} else {
+				return nil, nil, newResolutionError(fmt.Sprintf("can not access field: %s on kind: %s", seg.Field(), kindString(cur)), at)
+			}
+		}
+	}
+
+	return cur, nil, nil
+}
+
+func kindString(n datamodel.Node) string {
+	if n == nil {
+		return "null"
+	}
+	return n.Kind().String()
+}
+
+func isMissing(err error) bool {
+	if _, ok := err.(datamodel.ErrNotExists); ok {
+		return true
+	}
+	if _, ok := err.(schema.ErrNoSuchField); ok {
+		return true
+	}
+	if _, ok := err.(schema.ErrInvalidKey); ok {
+		return true
+	}
+	return false
+}
+
+type resolutionerr struct {
+	msg string
+	at  []string
+}
+
+func (r resolutionerr) Name() string {
+	return "ResolutionError"
+}
+
+func (r resolutionerr) Message() string {
+	return fmt.Sprintf("can not resolve path: .%s", strings.Join(r.at, "."))
+}
+
+func (r resolutionerr) At() []string {
+	return r.at
+}
+
+func (r resolutionerr) Error() string {
+	return r.Message()
+}
+
+func newResolutionError(message string, at []string) error {
+	return resolutionerr{message, at}
+}

capability/policy/selector/selector_test.go

@@ -0,0 +1,499 @@
+package selector
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/codec/dagjson"
+	"github.com/ipld/go-ipld-prime/must"
+	basicnode "github.com/ipld/go-ipld-prime/node/basic"
+	"github.com/ipld/go-ipld-prime/node/bindnode"
+	"github.com/ipld/go-ipld-prime/printer"
+	"github.com/stretchr/testify/require"
+)
+
+func TestParse(t *testing.T) {
+	t.Run("identity", func(t *testing.T) {
+		sel, err := Parse(".")
+		require.NoError(t, err)
+		require.Equal(t, 1, len(sel))
+		require.True(t, sel[0].Identity())
+		require.False(t, sel[0].Optional())
+		require.False(t, sel[0].Iterator())
+		require.Empty(t, sel[0].Slice())
+		require.Empty(t, sel[0].Field())
+		require.Empty(t, sel[0].Index())
+	})
+
+	t.Run("field", func(t *testing.T) {
+		sel, err := Parse(".foo")
+		require.NoError(t, err)
+		require.Equal(t, 1, len(sel))
+		require.False(t, sel[0].Identity())
+		require.False(t, sel[0].Optional())
+		require.False(t, sel[0].Iterator())
+		require.Empty(t, sel[0].Slice())
+		require.Equal(t, sel[0].Field(), "foo")
+		require.Empty(t, sel[0].Index())
+	})
+
+	t.Run("explicit field", func(t *testing.T) {
+		sel, err := Parse(`.["foo"]`)
+		require.NoError(t, err)
+		require.Equal(t, 2, len(sel))
+		require.True(t, sel[0].Identity())
+		require.False(t, sel[0].Optional())
+		require.False(t, sel[0].Iterator())
+		require.Empty(t, sel[0].Slice())
+		require.Empty(t, sel[0].Field())
+		require.Empty(t, sel[0].Index())
+		require.False(t, sel[1].Identity())
+		require.False(t, sel[1].Optional())
+		require.False(t, sel[1].Iterator())
+		require.Empty(t, sel[1].Slice())
+		require.Equal(t, sel[1].Field(), "foo")
+		require.Empty(t, sel[1].Index())
+	})
+
+	t.Run("index", func(t *testing.T) {
+		sel, err := Parse(".[138]")
+		require.NoError(t, err)
+		require.Equal(t, 2, len(sel))
+		require.True(t, sel[0].Identity())
+		require.False(t, sel[0].Optional())
+		require.False(t, sel[0].Iterator())
+		require.Empty(t, sel[0].Slice())
+		require.Empty(t, sel[0].Field())
+		require.Empty(t, sel[0].Index())
+		require.False(t, sel[1].Identity())
+		require.False(t, sel[1].Optional())
+		require.False(t, sel[1].Iterator())
+		require.Empty(t, sel[1].Slice())
+		require.Empty(t, sel[1].Field())
+		require.Equal(t, sel[1].Index(), 138)
+	})
+
+	t.Run("negative index", func(t *testing.T) {
+		sel, err := Parse(".[-138]")
+		require.NoError(t, err)
+		require.Equal(t, 2, len(sel))
+		require.True(t, sel[0].Identity())
+		require.False(t, sel[0].Optional())
+		require.False(t, sel[0].Iterator())
+		require.Empty(t, sel[0].Slice())
+		require.Empty(t, sel[0].Field())
+		require.Empty(t, sel[0].Index())
+		require.False(t, sel[1].Identity())
+		require.False(t, sel[1].Optional())
+		require.False(t, sel[1].Iterator())
+		require.Empty(t, sel[1].Slice())
+		require.Empty(t, sel[1].Field())
+		require.Equal(t, sel[1].Index(), -138)
+	})
+
+	t.Run("iterator", func(t *testing.T) {
+		sel, err := Parse(".[]")
+		require.NoError(t, err)
+		require.Equal(t, 2, len(sel))
+		require.True(t, sel[0].Identity())
+		require.False(t, sel[0].Optional())
+		require.False(t, sel[0].Iterator())
+		require.Empty(t, sel[0].Slice())
+		require.Empty(t, sel[0].Field())
+		require.Empty(t, sel[0].Index())
+		require.False(t, sel[1].Identity())
+		require.False(t, sel[1].Optional())
+		require.True(t, sel[1].Iterator())
+		require.Empty(t, sel[1].Slice())
+		require.Empty(t, sel[1].Field())
+		require.Empty(t, sel[1].Index())
+	})
+
+	t.Run("optional field", func(t *testing.T) {
+		sel, err := Parse(".foo?")
+		require.NoError(t, err)
+		require.Equal(t, 1, len(sel))
+		require.False(t, sel[0].Identity())
+		require.True(t, sel[0].Optional())
+		require.False(t, sel[0].Iterator())
+		require.Empty(t, sel[0].Slice())
+		require.Equal(t, sel[0].Field(), "foo")
+		require.Empty(t, sel[0].Index())
+	})
+
+	t.Run("optional explicit field", func(t *testing.T) {
+		sel, err := Parse(`.["foo"]?`)
+		require.NoError(t, err)
+		require.Equal(t, 2, len(sel))
+		require.True(t, sel[0].Identity())
+		require.False(t, sel[0].Optional())
+		require.False(t, sel[0].Iterator())
+		require.Empty(t, sel[0].Slice())
+		require.Empty(t, sel[0].Field())
+		require.Empty(t, sel[0].Index())
+		require.False(t, sel[1].Identity())
+		require.True(t, sel[1].Optional())
+		require.False(t, sel[1].Iterator())
+		require.Empty(t, sel[1].Slice())
+		require.Equal(t, sel[1].Field(), "foo")
+		require.Empty(t, sel[1].Index())
+	})
+
+	t.Run("optional index", func(t *testing.T) {
+		sel, err := Parse(".[138]?")
+		require.NoError(t, err)
+		require.Equal(t, 2, len(sel))
+		require.True(t, sel[0].Identity())
+		require.False(t, sel[0].Optional())
+		require.False(t, sel[0].Iterator())
+		require.Empty(t, sel[0].Slice())
+		require.Empty(t, sel[0].Field())
+		require.Empty(t, sel[0].Index())
+		require.False(t, sel[1].Identity())
+		require.True(t, sel[1].Optional())
+		require.False(t, sel[1].Iterator())
+		require.Empty(t, sel[1].Slice())
+		require.Empty(t, sel[1].Field())
+		require.Equal(t, sel[1].Index(), 138)
+	})
+
+	t.Run("optional iterator", func(t *testing.T) {
+		sel, err := Parse(".[]?")
+		require.NoError(t, err)
+		require.Equal(t, 2, len(sel))
+		require.True(t, sel[0].Identity())
+		require.False(t, sel[0].Optional())
+		require.False(t, sel[0].Iterator())
+		require.Empty(t, sel[0].Slice())
+		require.Empty(t, sel[0].Field())
+		require.Empty(t, sel[0].Index())
+		require.False(t, sel[1].Identity())
+		require.True(t, sel[1].Optional())
+		require.True(t, sel[1].Iterator())
+		require.Empty(t, sel[1].Slice())
+		require.Empty(t, sel[1].Field())
+		require.Empty(t, sel[1].Index())
+	})
+
+	t.Run("nesting", func(t *testing.T) {
+		str := `.foo.["bar"].[138]?.baz[1:]`
+		sel, err := Parse(str)
+		require.NoError(t, err)
+		printSegments(sel)
+		require.Equal(t, str, sel.String())
+		require.Equal(t, 7, len(sel))
+		require.False(t, sel[0].Identity())
+		require.False(t, sel[0].Optional())
+		require.False(t, sel[0].Iterator())
+		require.Empty(t, sel[0].Slice())
+		require.Equal(t, sel[0].Field(), "foo")
+		require.Empty(t, sel[0].Index())
+		require.True(t, sel[1].Identity())
+		require.False(t, sel[1].Optional())
+		require.False(t, sel[1].Iterator())
+		require.Empty(t, sel[1].Slice())
+		require.Empty(t, sel[1].Field())
+		require.Empty(t, sel[1].Index())
+		require.False(t, sel[2].Identity())
+		require.False(t, sel[2].Optional())
+		require.False(t, sel[2].Iterator())
+		require.Empty(t, sel[2].Slice())
+		require.Equal(t, sel[2].Field(), "bar")
+		require.Empty(t, sel[2].Index())
+		require.True(t, sel[3].Identity())
+		require.False(t, sel[3].Optional())
+		require.False(t, sel[3].Iterator())
+		require.Empty(t, sel[3].Slice())
+		require.Empty(t, sel[3].Field())
+		require.Empty(t, sel[3].Index())
+		require.False(t, sel[4].Identity())
+		require.True(t, sel[4].Optional())
+		require.False(t, sel[4].Iterator())
+		require.Empty(t, sel[4].Slice())
+		require.Empty(t, sel[4].Field())
+		require.Equal(t, sel[4].Index(), 138)
+		require.False(t, sel[5].Identity())
+		require.False(t, sel[5].Optional())
+		require.False(t, sel[5].Iterator())
+		require.Empty(t, sel[5].Slice())
+		require.Equal(t, sel[5].Field(), "baz")
+		require.Empty(t, sel[5].Index())
+		require.False(t, sel[6].Identity())
+		require.False(t, sel[6].Optional())
+		require.False(t, sel[6].Iterator())
+		require.Equal(t, sel[6].Slice(), []int{1})
+		require.Empty(t, sel[6].Field())
+		require.Empty(t, sel[6].Index())
+	})
+
+	t.Run("non dotted", func(t *testing.T) {
+		_, err := Parse("foo")
+		require.NotNil(t, err)
+		fmt.Println(err)
+	})
+
+	t.Run("non quoted", func(t *testing.T) {
+		_, err := Parse(".[foo]")
+		require.NotNil(t, err)
+		fmt.Println(err)
+	})
+}
+
+func printSegments(s Selector) {
+	for i, seg := range s {
+		fmt.Printf("%d: %s\n", i, seg.String())
+	}
+}
+
+func TestSelect(t *testing.T) {
+	type name struct {
+		First  string
+		Middle *string
+		Last   string
+	}
+	type interest struct {
+		Name       string
+		Outdoor    bool
+		Experience int
+	}
+	type user struct {
+		Name          name
+		Age           int
+		Nationalities []string
+		Interests     []interest
+	}
+
+	ts, err := ipld.LoadSchemaBytes([]byte(`
+	  type User struct {
+		  name Name
+			age Int
+			nationalities [String]
+			interests [Interest]
+		}
+		type Name struct {
+			first String
+			middle optional String
+			last String
+		}
+		type Interest struct {
+			name String
+			outdoor Bool
+			experience Int
+		}
+	`))
+	require.NoError(t, err)
+	typ := ts.TypeByName("User")
+
+	am := "Joan"
+	alice := user{
+		Name:          name{First: "Alice", Middle: &am, Last: "Wonderland"},
+		Age:           24,
+		Nationalities: []string{"British"},
+		Interests: []interest{
+			{Name: "Cycling", Outdoor: true, Experience: 4},
+			{Name: "Chess", Outdoor: false, Experience: 2},
+		},
+	}
+	bob := user{
+		Name:          name{First: "Bob", Last: "Builder"},
+		Age:           35,
+		Nationalities: []string{"Canadian", "South African"},
+		Interests: []interest{
+			{Name: "Snowboarding", Outdoor: true, Experience: 8},
+			{Name: "Reading", Outdoor: false, Experience: 25},
+		},
+	}
+
+	anode := bindnode.Wrap(&alice, typ)
+	bnode := bindnode.Wrap(&bob, typ)
+
+	t.Run("identity", func(t *testing.T) {
+		sel, err := Parse(".")
+		require.NoError(t, err)
+
+		one, many, err := Select(sel, anode)
+		require.NoError(t, err)
+		require.NotEmpty(t, one)
+		require.Empty(t, many)
+
+		fmt.Println(printer.Sprint(one))
+
+		age := must.Int(must.Node(one.LookupByString("age")))
+		require.Equal(t, int64(alice.Age), age)
+	})
+
+	t.Run("nested property", func(t *testing.T) {
+		sel, err := Parse(".name.first")
+		require.NoError(t, err)
+
+		one, many, err := Select(sel, anode)
+		require.NoError(t, err)
+		require.NotEmpty(t, one)
+		require.Empty(t, many)
+
+		fmt.Println(printer.Sprint(one))
+
+		name := must.String(one)
+		require.Equal(t, alice.Name.First, name)
+
+		one, many, err = Select(sel, bnode)
+		require.NoError(t, err)
+		require.NotEmpty(t, one)
+		require.Empty(t, many)
+
+		fmt.Println(printer.Sprint(one))
+
+		name = must.String(one)
+		require.Equal(t, bob.Name.First, name)
+	})
+
+	t.Run("optional nested property", func(t *testing.T) {
+		sel, err := Parse(".name.middle?")
+		require.NoError(t, err)
+
+		one, many, err := Select(sel, anode)
+		require.NoError(t, err)
+		require.NotEmpty(t, one)
+		require.Empty(t, many)
+
+		fmt.Println(printer.Sprint(one))
+
+		name := must.String(one)
+		require.Equal(t, *alice.Name.Middle, name)
+
+		one, many, err = Select(sel, bnode)
+		require.NoError(t, err)
+		require.Empty(t, one)
+		require.Empty(t, many)
+	})
+
+	t.Run("not exists", func(t *testing.T) {
+		sel, err := Parse(".name.foo")
+		require.NoError(t, err)
+
+		one, many, err := Select(sel, anode)
+		require.Error(t, err)
+		require.Empty(t, one)
+		require.Empty(t, many)
+
+		fmt.Println(err)
+
+		require.ErrorAs(t, err, &resolutionerr{}, "error was not a resolution error")
+	})
+
+	t.Run("optional not exists", func(t *testing.T) {
+		sel, err := Parse(".name.foo?")
+		require.NoError(t, err)
+
+		one, many, err := Select(sel, anode)
+		require.NoError(t, err)
+		require.Empty(t, one)
+		require.Empty(t, many)
+	})
+
+	t.Run("iterator", func(t *testing.T) {
+		sel, err := Parse(".interests[]")
+		require.NoError(t, err)
+
+		one, many, err := Select(sel, anode)
+		require.NoError(t, err)
+		require.Empty(t, one)
+		require.NotEmpty(t, many)
+
+		for _, n := range many {
+			fmt.Println(printer.Sprint(n))
+		}
+
+		iname := must.String(must.Node(many[0].LookupByString("name")))
+		require.Equal(t, alice.Interests[0].Name, iname)
+
+		iname = must.String(must.Node(many[1].LookupByString("name")))
+		require.Equal(t, alice.Interests[1].Name, iname)
+	})
+
+	t.Run("map iterator", func(t *testing.T) {
+		sel, err := Parse(".interests[0][]")
+		require.NoError(t, err)
+
+		one, many, err := Select(sel, anode)
+		require.NoError(t, err)
+		require.Empty(t, one)
+		require.NotEmpty(t, many)
+
+		for _, n := range many {
+			fmt.Println(printer.Sprint(n))
+		}
+
+		require.Equal(t, alice.Interests[0].Name, must.String(many[0]))
+		require.Equal(t, alice.Interests[0].Experience, int(must.Int(many[2])))
+	})
+}
+
+func FuzzParse(f *testing.F) {
+	selectorCorpus := []string{
+		`.`, `.[]`, `.[]?`, `.[][]?`, `.x`, `.["x"]`, `.[0]`, `.[-1]`, `.[0]`,
+		`.[0]`, `.[0:2]`, `.[1:]`, `.[:2]`, `.[0:2]`, `.[1:]`, `.x?`, `.x?`,
+		`.x?`, `.["x"]?`, `.length?`, `.[4]?`, `.[]`, `.[][]`, `.x`, `.x`, `.x`,
+		`.length`, `.[4]`,
+	}
+	for _, selector := range selectorCorpus {
+		f.Add(selector)
+	}
+	f.Fuzz(func(t *testing.T, selector string) {
+		// only look for panic()
+		_, _ = Parse(selector)
+	})
+}
+
+func FuzzParseAndSelect(f *testing.F) {
+	selectorCorpus := []string{
+		`.`, `.[]`, `.[]?`, `.[][]?`, `.x`, `.["x"]`, `.[0]`, `.[-1]`, `.[0]`,
+		`.[0]`, `.[0:2]`, `.[1:]`, `.[:2]`, `.[0:2]`, `.[1:]`, `.x?`, `.x?`,
+		`.x?`, `.["x"]?`, `.length?`, `.[4]?`, `.[]`, `.[][]`, `.x`, `.x`, `.x`,
+		`.length`, `.[4]`,
+	}
+	subjectCorpus := []string{
+		`{"x":1}`, `[1, 2]`, `null`, `[[1], 2, [3]]`, `{"x": 1 }`, `{"x": 1}`,
+		`[1, 2]`, `[1, 2]`, `"Hi"`, `{"/":{"bytes":"AAE"}`, `[0, 1, 2]`,
+		`[0, 1, 2]`, `[0, 1, 2]`, `"hello"`, `{"/":{"bytes":"AAEC"}}`, `{}`,
+		`null`, `[]`, `{}`, `[1, 2]`, `[0, 1]`, `null`, `[[1], 2, [3]]`, `{}`,
+		`null`, `[]`, `[1, 2]`, `[0, 1]`,
+	}
+	for i := 0; ; i++ {
+		switch {
+		case i < len(selectorCorpus) && i < len(subjectCorpus):
+			f.Add(selectorCorpus[i], subjectCorpus[i])
+			continue
+		case i > len(selectorCorpus):
+			f.Add("", subjectCorpus[i])
+			continue
+		case i > len(subjectCorpus):
+			f.Add(selectorCorpus[i], "")
+			continue
+		}
+		break
+	}
+
+	f.Fuzz(func(t *testing.T, selector, subject string) {
+		sel, err := Parse(selector)
+		if err != nil {
+			t.Skip()
+		}
+
+		np := basicnode.Prototype.Any
+		nb := np.NewBuilder()
+		err = dagjson.Decode(nb, strings.NewReader(subject))
+		if err != nil {
+			t.Skip()
+		}
+		node := nb.Build()
+		if node == nil {
+			t.Skip()
+		}
+
+		// look for panic()
+		_, _, _ = Select(sel, node)
+	})
+}

capability/policy/selector/supported_test.go

@@ -1,15 +1,18 @@
 package selector_test
 
 import (
+	"bytes"
 	"strings"
 	"testing"
 
 	"github.com/ipld/go-ipld-prime"
 	"github.com/ipld/go-ipld-prime/codec/dagjson"
+	"github.com/ipld/go-ipld-prime/datamodel"
 	basicnode "github.com/ipld/go-ipld-prime/node/basic"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/ucan-wg/go-ucan/pkg/policy/selector"
+	"github.com/ucan-wg/go-ucan/capability/policy/selector"
 )
 
 // TestSupported Forms runs tests against the Selector according to the
@@ -23,16 +26,18 @@ func TestSupportedForms(t *testing.T) {
 		Output   string
 	}
 
-	// Pass and return a node
+	// Pass
 	for _, testcase := range []Testcase{
 		{Name: "Identity", Selector: `.`, Input: `{"x":1}`, Output: `{"x":1}`},
 		{Name: "Iterator", Selector: `.[]`, Input: `[1, 2]`, Output: `[1, 2]`},
-		{Name: "Optional Null Iterator", Selector: `.[]?`, Input: `null`, Output: `[]`},
+		{Name: "Optional Null Iterator", Selector: `.[]?`, Input: `null`, Output: `()`},
+		{Name: "Optional Iterator", Selector: `.[][]?`, Input: `[[1], 2, [3]]`, Output: `[1, 3]`},
 		{Name: "Object Key", Selector: `.x`, Input: `{"x": 1 }`, Output: `1`},
 		{Name: "Quoted Key", Selector: `.["x"]`, Input: `{"x": 1}`, Output: `1`},
 		{Name: "Index", Selector: `.[0]`, Input: `[1, 2]`, Output: `1`},
 		{Name: "Negative Index", Selector: `.[-1]`, Input: `[1, 2]`, Output: `2`},
-		{Name: "Bytes Index", Selector: `.[0]`, Input: `{"/":{"bytes":"AAE"}}`, Output: `0`},
+		{Name: "String Index", Selector: `.[0]`, Input: `"Hi"`, Output: `"H"`},
+		{Name: "Bytes Index", Selector: `.[0]`, Input: `{"/":{"bytes":"AAE"}`, Output: `0`},
 		{Name: "Array Slice", Selector: `.[0:2]`, Input: `[0, 1, 2]`, Output: `[0, 1]`},
 		{Name: "Array Slice", Selector: `.[1:]`, Input: `[0, 1, 2]`, Output: `[1, 2]`},
 		{Name: "Array Slice", Selector: `.[:2]`, Input: `[0, 1, 2]`, Output: `[0, 1]`},
@@ -47,16 +52,35 @@ func TestSupportedForms(t *testing.T) {
 			require.NoError(t, err)
 
 			// attempt to select
-			res, err := sel.Select(makeNode(t, tc.Input))
+			node, nodes, err := selector.Select(sel, makeNode(t, tc.Input))
 			require.NoError(t, err)
-			require.NotNil(t, res)
+			require.NotEqual(t, node != nil, len(nodes) > 0) // XOR (only one of node or nodes should be set)
+
+			// make an IPLD List node from a []datamodel.Node
+			if node == nil {
+				nb := basicnode.Prototype.List.NewBuilder()
+				la, err := nb.BeginList(int64(len(nodes)))
+				require.NoError(t, err)
+
+				for _, n := range nodes {
+					// TODO: This code is probably not needed if the Select operation properly prunes nil values - e.g.: Optional Iterator
+					if n == nil {
+						n = datamodel.Null
+					}
+
+					require.NoError(t, la.AssembleValue().AssignNode(n))
+				}
+				require.NoError(t, la.Finish())
+
+				node = nb.Build()
+			}
 
 			exp := makeNode(t, tc.Output)
-			require.True(t, ipld.DeepEqual(exp, res))
+			equalIPLD(t, exp, node)
 		})
 	}
 
-	// No error and return null, as optional
+	// null
 	for _, testcase := range []Testcase{
 		{Name: "Optional Missing Key", Selector: `.x?`, Input: `{}`},
 		{Name: "Optional Null Key", Selector: `.x?`, Input: `null`},
@@ -73,15 +97,19 @@ func TestSupportedForms(t *testing.T) {
 			require.NoError(t, err)
 
 			// attempt to select
-			res, err := sel.Select(makeNode(t, tc.Input))
+			node, nodes, err := selector.Select(sel, makeNode(t, tc.Input))
 			require.NoError(t, err)
-			require.Nil(t, res)
+			// TODO: should Select return a single node which is sometimes a list or null?
+			// require.Equal(t, datamodel.Null, node)
+			assert.Nil(t, node)
+			assert.Empty(t, nodes)
 		})
 	}
 
-	// fail to select and return an error
+	// error
 	for _, testcase := range []Testcase{
 		{Name: "Null Iterator", Selector: `.[]`, Input: `null`},
+		{Name: "Nested Iterator", Selector: `.[][]`, Input: `[[1], 2, [3]]`},
 		{Name: "Missing Key", Selector: `.x`, Input: `{}`},
 		{Name: "Null Key", Selector: `.x`, Input: `null`},
 		{Name: "Array Key", Selector: `.x`, Input: `[]`},
@@ -96,13 +124,31 @@ func TestSupportedForms(t *testing.T) {
 			require.NoError(t, err)
 
 			// attempt to select
-			res, err := sel.Select(makeNode(t, tc.Input))
+			node, nodes, err := selector.Select(sel, makeNode(t, tc.Input))
 			require.Error(t, err)
-			require.Nil(t, res)
+			assert.Nil(t, node)
+			assert.Empty(t, nodes)
 		})
 	}
 }
 
+func equalIPLD(t *testing.T, expected datamodel.Node, actual datamodel.Node) bool {
+	t.Helper()
+
+	exp, act := &bytes.Buffer{}, &bytes.Buffer{}
+	if err := dagjson.Encode(expected, exp); err != nil {
+		return assert.Fail(t, "Failed to encode json for expected IPLD node")
+	}
+
+	if err := dagjson.Encode(actual, act); err != nil {
+		return assert.Fail(t, "Failed to encode JSON for actual IPLD node")
+	}
+
+	require.JSONEq(t, exp.String(), act.String())
+
+	return true
+}
+
 func makeNode(t *testing.T, dagJsonInput string) ipld.Node {
 	t.Helper()
 

delegation/delegatiom_options.go

@@ -0,0 +1,46 @@
+package delegation
+
+// Code generated by github.com/selesy/go-options.  DO NOT EDIT.
+
+import (
+	"github.com/ipld/go-ipld-prime/datamodel"
+	"time"
+)
+
+type Option func(c *config) error
+
+func newConfig(options ...Option) (config, error) {
+	var c config
+	err := applyConfigOptions(&c, options...)
+	return c, err
+}
+
+func applyConfigOptions(c *config, options ...Option) error {
+	for _, o := range options {
+		if err := o(c); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func WithExpiration(o *time.Time) Option {
+	return func(c *config) error {
+		c.Expiration = o
+		return nil
+	}
+}
+
+func WithMeta(o map[string]datamodel.Node) Option {
+	return func(c *config) error {
+		c.Meta = o
+		return nil
+	}
+}
+
+func WithNotBefore(o *time.Time) Option {
+	return func(c *config) error {
+		c.NotBefore = o
+		return nil
+	}
+}

delegation/delegation.go

@@ -0,0 +1,225 @@
+package delegation
+
+import (
+	"crypto/rand"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/ipld/go-ipld-prime/datamodel"
+	"github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/ucan-wg/go-ucan/capability/command"
+	"github.com/ucan-wg/go-ucan/capability/policy"
+	"github.com/ucan-wg/go-ucan/did"
+	"github.com/ucan-wg/go-ucan/internal/envelope"
+	"github.com/ucan-wg/go-ucan/internal/token"
+)
+
+const (
+	Tag = "ucan/dlg@1.0.0-rc.1"
+)
+
+type Delegation struct {
+	envel *envelope.Envelope
+}
+
+//go:generate -command options go run github.com/selesy/go-options
+//go:generate options -type=config -prefix=With -output=delegatiom_options.go -cmp=false -stringer=false -imports=time,github.com/ipld/go-ipld-prime/datamodel
+
+type config struct {
+	Expiration *time.Time
+	Meta       map[string]datamodel.Node
+	NotBefore  *time.Time
+}
+
+func New(privKey crypto.PrivKey, aud did.DID, sub *did.DID, cmd *command.Command, pol policy.Policy, nonce []byte, opts ...Option) (*Delegation, error) {
+	cfg, err := newConfig(opts...)
+	if err != nil {
+		return nil, err
+	}
+
+	issuer, err := did.FromPrivKey(privKey)
+	if err != nil {
+		return nil, err
+	}
+
+	if !aud.Defined() {
+		return nil, fmt.Errorf("%w: %s", token.ErrMissingRequiredDID, "aud")
+	}
+	audience := aud.String()
+
+	var subject *string
+	if sub != nil {
+		s := sub.String()
+		subject = &s
+	}
+
+	policy, err := pol.ToIPLD()
+	if err != nil {
+		return nil, err
+	}
+
+	var meta *token.Map__String__Any
+	if len(cfg.Meta) > 0 {
+		m := token.ToIPLDMapStringAny(cfg.Meta)
+		meta = &m
+	}
+
+	var notBefore *int
+	if cfg.NotBefore != nil {
+		n := int(cfg.NotBefore.Unix())
+		notBefore = &n
+	}
+
+	var expiration *int
+	if cfg.Expiration != nil {
+		e := int(cfg.Expiration.Unix())
+		expiration = &e
+	}
+
+	tkn := &token.Token{
+		Issuer:     issuer.String(),
+		Audience:   &audience,
+		Subject:    subject,
+		Command:    cmd.String(),
+		Policy:     &policy,
+		Nonce:      &nonce,
+		Meta:       meta,
+		NotBefore:  notBefore,
+		Expiration: expiration,
+	}
+
+	envel, err := envelope.New(privKey, tkn, Tag)
+	if err != nil {
+		return nil, err
+	}
+
+	dlg := &Delegation{envel: envel}
+
+	if err := dlg.Validate(); err != nil {
+		return nil, err
+	}
+
+	return dlg, nil
+}
+
+func Root(privKey crypto.PrivKey, aud did.DID, cmd *command.Command, pol policy.Policy, nonce []byte, opts ...Option) (*Delegation, error) {
+	sub, err := did.FromPrivKey(privKey)
+	if err != nil {
+		return nil, err
+	}
+
+	return New(privKey, aud, &sub, cmd, pol, nonce, opts...)
+}
+
+func (d *Delegation) Audience() did.DID {
+	id, _ := did.Parse(*d.envel.TokenPayload().Audience)
+
+	return id
+}
+
+func (d *Delegation) Command() *command.Command {
+	cmd, _ := command.Parse(d.envel.TokenPayload().Command)
+
+	return cmd
+}
+
+func (d *Delegation) IsPowerline() bool {
+	return d.envel.TokenPayload().Subject == nil
+}
+
+func (d *Delegation) IsRoot() bool {
+	return &d.envel.TokenPayload().Issuer == d.envel.TokenPayload().Subject
+}
+
+func (d *Delegation) Issuer() did.DID {
+	id, _ := did.Parse(d.envel.TokenPayload().Issuer)
+
+	return id
+}
+
+func (d *Delegation) Meta() map[string]datamodel.Node {
+	return d.envel.TokenPayload().Meta.Values
+}
+
+func (d *Delegation) Nonce() []byte {
+	return *d.envel.TokenPayload().Nonce
+}
+
+func (d *Delegation) Policy() policy.Policy {
+	pol, _ := policy.FromIPLD(*d.envel.TokenPayload().Policy)
+
+	return pol
+}
+
+func (d *Delegation) Subject() *did.DID {
+	if d.envel.TokenPayload().Subject == nil {
+		return nil
+	}
+
+	id, _ := did.Parse(*d.envel.TokenPayload().Subject)
+
+	return &id
+}
+
+func (d *Delegation) Validate() error {
+	return errors.Join(
+		d.validateDID("iss", &d.envel.TokenPayload().Issuer, false),
+		d.validateDID("aud", d.envel.TokenPayload().Audience, false),
+		d.validateDID("sub", d.envel.TokenPayload().Subject, true),
+		d.validateCommand(),
+		d.validatePolicy(),
+		d.validateNonce(),
+	)
+}
+
+func (d *Delegation) validateCommand() error {
+	_, err := command.Parse(d.envel.TokenPayload().Command)
+
+	return err
+}
+
+func (d *Delegation) validateDID(fieldName string, identity *string, nullableOrOptional bool) error {
+	if identity == nil && !nullableOrOptional {
+		return fmt.Errorf("a required DID is missing: %s", fieldName)
+	}
+
+	id, err := did.Parse(*identity)
+	if err != nil {
+
+	}
+
+	if !id.Defined() && !id.Key() {
+		return fmt.Errorf("a required DID is missing: %s", fieldName)
+	}
+
+	return nil
+}
+
+func (d *Delegation) validateNonce() error {
+	if d.envel.TokenPayload().Nonce == nil || len(*d.envel.TokenPayload().Nonce) < 1 {
+		return fmt.Errorf("nonce is required: must not be nil or empty")
+	}
+
+	return nil
+}
+
+func (d *Delegation) validatePolicy() error {
+	if d.envel.TokenPayload().Policy == nil {
+		return fmt.Errorf("the \"pol\" field is required")
+	}
+
+	_, err := policy.FromIPLD(*d.envel.TokenPayload().Policy)
+
+	return err
+}
+
+func Nonce() ([]byte, error) {
+	nonce := make([]byte, 32)
+
+	if _, err := rand.Read(nonce); err != nil {
+		return nil, err
+	}
+
+	return nonce, nil
+}

delegation/delegation_test.go

@@ -0,0 +1,149 @@
+package delegation_test
+
+import (
+	"crypto/rand"
+	"testing"
+	"time"
+
+	"github.com/ipld/go-ipld-prime/datamodel"
+	"github.com/ipld/go-ipld-prime/node/basicnode"
+	"github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/stretchr/testify/require"
+	"github.com/ucan-wg/go-ucan/capability/command"
+	"github.com/ucan-wg/go-ucan/capability/policy"
+	"github.com/ucan-wg/go-ucan/delegation"
+	"github.com/ucan-wg/go-ucan/did"
+	"gotest.tools/v3/golden"
+)
+
+const (
+	nonce = "6roDhGi0kiNriQAz7J3d+bOeoI/tj8ENikmQNbtjnD0"
+
+	AudiencePrivKeyCfg = "CAESQL1hvbXpiuk2pWr/XFbfHJcZNpJ7S90iTA3wSCTc/BPRneCwPnCZb6c0vlD6ytDWqaOt0HEOPYnqEpnzoBDprSM="
+	AudienceDID        = "did:key:z6Mkq5YmbJcTrPExNDi26imrTCpKhepjBFBSHqrBDN2ArPkv"
+
+	issuerPrivKeyCfg = "CAESQLSql38oDmQXIihFFaYIjb73mwbPsc7MIqn4o8PN4kRNnKfHkw5gRP1IV9b6d0estqkZayGZ2vqMAbhRixjgkDU="
+	issuerDID        = "did:key:z6Mkpzn2n3ZGT2VaqMGSQC3tzmzV4TS9S71iFsDXE1WnoNH2"
+
+	subjectPrivKeyCfg = "CAESQL9RtjZ4dQBeXtvDe53UyvslSd64kSGevjdNiA1IP+hey5i/3PfRXSuDr71UeJUo1fLzZ7mGldZCOZL3gsIQz5c="
+	subjectDID        = "did:key:z6MktA1uBdCpq4uJBqE9jjMiLyxZBg9a6xgPPKJjMqss6Zc2"
+	subJectCmd        = "/foo/bar"
+	subjectPol        = `
+[
+	[
+		"==",
+		".status",
+		"draft"
+	],
+	[
+		"all",
+		".reviewer",
+		[
+			"like",
+			".email",
+			"*@example.com"
+		]
+	],
+	[
+		"any",
+		".tags",
+		[
+			"or",
+			[
+				[
+					"==",
+					".",
+					"news"
+				],
+				[
+					"==",
+					".",
+					"press"
+				]
+			]
+		]
+	]
+]
+`
+)
+
+func TestConstructors(t *testing.T) {
+	t.Parallel()
+
+	privKey := privKey(t, issuerPrivKeyCfg)
+
+	aud, err := did.Parse(AudienceDID)
+
+	sub, err := did.Parse(subjectDID)
+	require.NoError(t, err)
+
+	cmd, err := command.Parse(subJectCmd)
+	require.NoError(t, err)
+
+	pol, err := policy.FromDagJson(subjectPol)
+	require.NoError(t, err)
+
+	exp := time.Time{}
+
+	meta := map[string]datamodel.Node{
+		"foo": basicnode.NewString("fooo"),
+		"bar": basicnode.NewString("barr"),
+	}
+
+	t.Run("New", func(t *testing.T) {
+		dlg, err := delegation.New(privKey, aud, &sub, cmd, pol, []byte(nonce), delegation.WithExpiration(&exp), delegation.WithMeta(meta))
+		require.NoError(t, err)
+
+		data, err := dlg.ToDagJson()
+		require.NoError(t, err)
+
+		t.Log(string(data))
+
+		golden.Assert(t, string(data), "new.dagjson")
+	})
+
+	t.Run("Root", func(t *testing.T) {
+		t.Parallel()
+
+		dlg, err := delegation.Root(privKey, aud, cmd, pol, []byte(nonce), delegation.WithExpiration(&exp), delegation.WithMeta(meta))
+		require.NoError(t, err)
+
+		data, err := dlg.ToDagJson()
+		require.NoError(t, err)
+
+		t.Log(string(data))
+
+		golden.Assert(t, string(data), "root.dagjson")
+	})
+}
+
+func privKey(t *testing.T, privKeyCfg string) crypto.PrivKey {
+	t.Helper()
+
+	privKeyMar, err := crypto.ConfigDecodeKey(privKeyCfg)
+	require.NoError(t, err)
+
+	privKey, err := crypto.UnmarshalPrivateKey(privKeyMar)
+	require.NoError(t, err)
+
+	return privKey
+}
+
+func TestKey(t *testing.T) {
+	t.Skip()
+
+	priv, _, err := crypto.GenerateEd25519Key(rand.Reader)
+	require.NoError(t, err)
+
+	privMar, err := crypto.MarshalPrivateKey(priv)
+	require.NoError(t, err)
+
+	privCfg := crypto.ConfigEncodeKey(privMar)
+	t.Log(privCfg)
+
+	id, err := did.FromPubKey(priv.GetPublic())
+	require.NoError(t, err)
+	t.Log(id)
+
+	t.Fail()
+}

delegation/encoding.go

@@ -0,0 +1,113 @@
+package delegation
+
+import (
+	"fmt"
+	"io"
+
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/codec"
+	"github.com/ipld/go-ipld-prime/codec/dagcbor"
+	"github.com/ipld/go-ipld-prime/codec/dagjson"
+	"github.com/ipld/go-ipld-prime/datamodel"
+
+	"github.com/ucan-wg/go-ucan/internal/envelope"
+)
+
+// Encode marshals a Delegation to the format specified by the provided
+// codec.Encoder.
+func (d *Delegation) Encode(encFn codec.Encoder) ([]byte, error) {
+	node, err := d.ToIPLD()
+	if err != nil {
+		return nil, err
+	}
+
+	return ipld.Encode(node, encFn)
+}
+
+// ToDagCbor marshals the Delegation to the DAG-CBOR format.
+func (d *Delegation) ToDagCbor() ([]byte, error) {
+	return d.Encode(dagcbor.Encode)
+}
+
+// ToDagJson marshals the Delegation to the DAG-JSON format.
+func (d *Delegation) ToDagJson() ([]byte, error) {
+	return d.Encode(dagjson.Encode)
+}
+
+// ToIPLD wraps the Delegation in an IPLD datamodel.Node.
+func (d *Delegation) ToIPLD() (datamodel.Node, error) {
+	return d.envel.Wrap()
+}
+
+// Decode unmarshals the input data using the format specified by the
+// provided codec.Decoder into a Delegation.
+//
+// An error is returned if the conversion fails, or if the resulting
+// Delegation is invalid.
+func Decode(b []byte, decFn codec.Decoder) (*Delegation, error) {
+	node, err := ipld.Decode(b, decFn)
+	if err != nil {
+		return nil, err
+	}
+	return FromIPLD(node)
+}
+
+// DecodeReader is the same as Decode, but accept an io.Reader.
+func DecodeReader(r io.Reader, decFn codec.Decoder) (*Delegation, error) {
+	node, err := ipld.DecodeStreaming(r, decFn)
+	if err != nil {
+		return nil, err
+	}
+	return FromIPLD(node)
+}
+
+// FromDagCbor unmarshals the input data into a Delegation.
+//
+// An error is returned if the conversion fails, or if the resulting
+// Delegation is invalid.
+func FromDagCbor(data []byte) (*Delegation, error) {
+	return Decode(data, dagcbor.Decode)
+}
+
+// FromDagCborReader is the same as FromDagCbor, but accept an io.Reader.
+func FromDagCborReader(r io.Reader) (*Delegation, error) {
+	return DecodeReader(r, dagcbor.Decode)
+}
+
+// FromDagJson unmarshals the input data into a Delegation.
+//
+// An error is returned if the conversion fails, or if the resulting
+// Delegation is invalid.
+func FromDagJson(data []byte) (*Delegation, error) {
+	return Decode(data, dagjson.Decode)
+}
+
+// FromDagJsonReader is the same as FromDagJson, but accept an io.Reader.
+func FromDagJsonReader(r io.Reader) (*Delegation, error) {
+	return DecodeReader(r, dagjson.Decode)
+}
+
+// FromIPLD unwraps a Delegation from the provided IPLD datamodel.Node
+//
+// An error is returned if the conversion fails, or if the resulting
+// Delegation is invalid.
+func FromIPLD(node datamodel.Node) (*Delegation, error) {
+	envel, err := envelope.Unwrap(node)
+	if err != nil {
+		return nil, err
+	}
+
+	if envel.Tag() != Tag {
+		return nil, fmt.Errorf("wrong tag for TokenPayload: received %s but expected %s", envel.Tag(), Tag)
+	}
+
+	dlg := &Delegation{
+		envel: envel,
+	}
+
+	if err := dlg.Validate(); err != nil {
+		return nil, err
+	}
+
+	return dlg, nil
+}

delegation/encoding_test.go

@@ -0,0 +1,101 @@
+package delegation_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"github.com/ucan-wg/go-ucan/delegation"
+)
+
+func TestEncodingRoundTrip(t *testing.T) {
+	const delegationJson = `
+[
+  {
+    "/": {
+      "bytes": "QWr0Pk+sSWE1nszuBMQzggbHX4ofJb8QRdwrLJK/AGCx2p4s/xaCRieomfstDjsV4ezBzX1HARvcoNgdwDQ8Aw"
+    }
+  },
+  {
+    "h": {
+      "/": {
+        "bytes": "NO0BcQ"
+      }
+    },
+    "ucan/dlg@1.0.0-rc.1": {
+      "aud": "did:key:z6Mkpzn2n3ZGT2VaqMGSQC3tzmzV4TS9S71iFsDXE1WnoNH2",
+      "cmd": "/foo/bar",
+      "exp": -62135596800,
+      "iss": "did:key:z6Mkpzn2n3ZGT2VaqMGSQC3tzmzV4TS9S71iFsDXE1WnoNH2",
+      "meta": {
+        "bar": "barr",
+        "foo": "fooo"
+      },
+      "nbf": -62135596800,
+      "nonce": {
+        "/": {
+          "bytes": "X93ORvN1QIXrKPyEP5m5XoVK9VLX9nX8VV/+HlWrp9c"
+        }
+      },
+      "pol": [
+        [
+          "==",
+          ".status",
+          "draft"
+        ],
+        [
+          "all",
+          ".reviewer",
+          [
+            "like",
+            ".email",
+            "*@example.com"
+          ]
+        ],
+        [
+          "any",
+          ".tags",
+          [
+            "or",
+            [
+              [
+                "==",
+                ".",
+                "news"
+              ],
+              [
+                "==",
+                ".",
+                "press"
+              ]
+            ]
+          ]
+        ]
+      ],
+      "sub": "did:key:z6MktA1uBdCpq4uJBqE9jjMiLyxZBg9a6xgPPKJjMqss6Zc2"
+    }
+  }
+]
+`
+	// format:    dagJson   -->   Delegation   -->   dagCbor   -->   Delegation   -->   dagJson
+	// function:        FromDagJson()       ToDagCbor()    FromDagCbor()       ToDagJson()
+
+	p1, err := delegation.FromDagJson([]byte(delegationJson))
+	require.NoError(t, err)
+
+	cborBytes, err := p1.ToDagCbor()
+	require.NoError(t, err)
+	fmt.Println("cborBytes length", len(cborBytes))
+	fmt.Println("cbor", string(cborBytes))
+
+	p2, err := delegation.FromDagCbor(cborBytes)
+	require.NoError(t, err)
+	fmt.Println("read Cbor", p2)
+
+	readJson, err := p2.ToDagJson()
+	require.NoError(t, err)
+	fmt.Println("readJson length", len(readJson))
+	fmt.Println("json: ", string(readJson))
+
+	require.JSONEq(t, delegationJson, string(readJson))
+}

delegation/testdata/new.dagjson

@@ -0,0 +1 @@
+[{"/":{"bytes":"P2lPLfdMuZuc4NPZ0mbozU+/bn5xoWlJsu+Fvaxi4ICYXVJb9/wiTTht3WJEFqjxXLxfTl4BMZF3J1CNvMPqBg"}},{"h":{"/":{"bytes":"NO0BcQ"}},"ucan/dlg@1.0.0-rc.1":{"aud":"did:key:z6Mkq5YmbJcTrPExNDi26imrTCpKhepjBFBSHqrBDN2ArPkv","cmd":"/foo/bar","exp":-62135596800,"iss":"did:key:z6Mkpzn2n3ZGT2VaqMGSQC3tzmzV4TS9S71iFsDXE1WnoNH2","meta":{"bar":"barr","foo":"fooo"},"nonce":{"/":{"bytes":"NnJvRGhHaTBraU5yaVFBejdKM2QrYk9lb0kvdGo4RU5pa21RTmJ0am5EMA"}},"pol":[["==",".status","draft"],["all",".reviewer",["like",".email","*@example.com"]],["any",".tags",["or",[["==",".","news"],["==",".","press"]]]]],"sub":"did:key:z6MktA1uBdCpq4uJBqE9jjMiLyxZBg9a6xgPPKJjMqss6Zc2"}}]

delegation/testdata/root.dagjson

@@ -0,0 +1 @@
+[{"/":{"bytes":"0sjiwG9BOgpezz6qw5UiD+rqOeqFLn4+Qds1PvbnsUBoc3RhF6IVxIeoOXDh1ufv3RHaI/zg4wjYpUwAMpTACw"}},{"h":{"/":{"bytes":"NO0BcQ"}},"ucan/dlg@1.0.0-rc.1":{"aud":"did:key:z6Mkq5YmbJcTrPExNDi26imrTCpKhepjBFBSHqrBDN2ArPkv","cmd":"/foo/bar","exp":-62135596800,"iss":"did:key:z6Mkpzn2n3ZGT2VaqMGSQC3tzmzV4TS9S71iFsDXE1WnoNH2","meta":{"bar":"barr","foo":"fooo"},"nonce":{"/":{"bytes":"NnJvRGhHaTBraU5yaVFBejdKM2QrYk9lb0kvdGo4RU5pa21RTmJ0am5EMA"}},"pol":[["==",".status","draft"],["all",".reviewer",["like",".email","*@example.com"]],["any",".tags",["or",[["==",".","news"],["==",".","press"]]]]],"sub":"did:key:z6Mkpzn2n3ZGT2VaqMGSQC3tzmzV4TS9S71iFsDXE1WnoNH2"}}]

did/crypto.go

@@ -0,0 +1,48 @@
+package did
+
+import (
+	"errors"
+
+	crypto "github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/libp2p/go-libp2p/core/crypto/pb"
+	"github.com/multiformats/go-multicodec"
+	"github.com/multiformats/go-varint"
+)
+
+func FromPrivKey(privKey crypto.PrivKey) (DID, error) {
+	return FromPubKey(privKey.GetPublic())
+}
+
+func FromPubKey(pubKey crypto.PubKey) (DID, error) {
+	code, ok := map[pb.KeyType]multicodec.Code{
+		pb.KeyType_Ed25519:   multicodec.Ed25519Pub,
+		pb.KeyType_RSA:       multicodec.RsaPub,
+		pb.KeyType_Secp256k1: multicodec.Secp256k1Pub,
+		pb.KeyType_ECDSA:     multicodec.Es256,
+	}[pubKey.Type()]
+	if !ok {
+		return Undef, errors.New("Blah")
+	}
+
+	buf := varint.ToUvarint(uint64(code))
+
+	pubBytes, err := pubKey.Raw()
+	if err != nil {
+		return Undef, err
+	}
+
+	return DID{
+		str:  string(append(buf, pubBytes...)),
+		code: uint64(code),
+		key:  true,
+	}, nil
+}
+
+func ToPubKey(s string) (crypto.PubKey, error) {
+	id, err := Parse(s)
+	if err != nil {
+		return nil, err
+	}
+
+	return id.PubKey()
+}

did/crypto_test.go

@@ -0,0 +1,51 @@
+package did_test
+
+import (
+	"testing"
+
+	"github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/stretchr/testify/require"
+	"github.com/ucan-wg/go-ucan/did"
+)
+
+const (
+	exampleDIDStr    = "did:key:z6MkhaXgBZDvotDkL5257faiztiGiC2QtKLGpbnnEGta2doK"
+	examplePubKeyStr = "Lm/M42cB3HkUiODQsXRcweM6TByfzEHGO9ND274JcOY="
+)
+
+func TestFromPubKey(t *testing.T) {
+	t.Parallel()
+
+	id, err := did.FromPubKey(examplePubKey(t))
+	require.NoError(t, err)
+	require.Equal(t, exampleDID(t), id)
+}
+
+func TestToPubKey(t *testing.T) {
+	t.Parallel()
+
+	pubKey, err := did.ToPubKey(exampleDIDStr)
+	require.NoError(t, err)
+	require.Equal(t, examplePubKey(t), pubKey)
+}
+
+func exampleDID(t *testing.T) did.DID {
+	t.Helper()
+
+	id, err := did.Parse(exampleDIDStr)
+	require.NoError(t, err)
+
+	return id
+}
+
+func examplePubKey(t *testing.T) crypto.PubKey {
+	t.Helper()
+
+	pubKeyCfg, err := crypto.ConfigDecodeKey(examplePubKeyStr)
+	require.NoError(t, err)
+
+	pubKey, err := crypto.UnmarshalEd25519PublicKey(pubKeyCfg)
+	require.NoError(t, err)
+
+	return pubKey
+}

did/did.go

@@ -0,0 +1,118 @@
+package did
+
+import (
+	"fmt"
+	"strings"
+
+	crypto "github.com/libp2p/go-libp2p/core/crypto"
+	mbase "github.com/multiformats/go-multibase"
+	"github.com/multiformats/go-multicodec"
+	varint "github.com/multiformats/go-varint"
+)
+
+const Prefix = "did:"
+const KeyPrefix = "did:key:"
+
+const DIDCore = 0x0d1d
+const Ed25519 = 0xed
+const RSA = uint64(multicodec.RsaPub)
+
+var MethodOffset = varint.UvarintSize(uint64(DIDCore))
+
+//
+// [did:key format]: https://w3c-ccg.github.io/did-method-key/
+type DID struct {
+	key  bool
+	code uint64
+	str  string
+}
+
+// Undef can be used to represent a nil or undefined DID, using DID{}
+// directly is also acceptable.
+var Undef = DID{}
+
+func (d DID) Defined() bool {
+	return d.str != ""
+}
+
+func (d DID) Bytes() []byte {
+	if !d.Defined() {
+		return nil
+	}
+	return []byte(d.str)
+}
+
+func (d DID) Code() uint64 {
+	return d.code
+}
+
+func (d DID) DID() DID {
+	return d
+}
+
+func (d DID) Key() bool {
+	return d.key
+}
+
+func (d DID) PubKey() (crypto.PubKey, error) {
+	if !d.key {
+		return nil, fmt.Errorf("unsupported did type: %s", d.String())
+	}
+
+	unmarshaler, ok := map[multicodec.Code]crypto.PubKeyUnmarshaller{
+		multicodec.Ed25519Pub:   crypto.UnmarshalEd25519PublicKey,
+		multicodec.RsaPub:       crypto.UnmarshalRsaPublicKey,
+		multicodec.Secp256k1Pub: crypto.UnmarshalSecp256k1PublicKey,
+		multicodec.Es256:        crypto.UnmarshalECDSAPublicKey,
+	}[multicodec.Code(d.code)]
+	if !ok {
+		return nil, fmt.Errorf("unsupported multicodec: %d", d.code)
+	}
+
+	return unmarshaler(d.Bytes()[varint.UvarintSize(d.code):])
+}
+
+// String formats the decentralized identity document (DID) as a string.
+func (d DID) String() string {
+	if d.key {
+		key, _ := mbase.Encode(mbase.Base58BTC, []byte(d.str))
+		return "did:key:" + key
+	}
+	return "did:" + d.str[MethodOffset:]
+}
+
+func Decode(bytes []byte) (DID, error) {
+	code, _, err := varint.FromUvarint(bytes)
+	if err != nil {
+		return Undef, err
+	}
+	if code == Ed25519 || code == RSA {
+		return DID{str: string(bytes), code: code, key: true}, nil
+	} else if code == DIDCore {
+		return DID{str: string(bytes)}, nil
+	}
+	return Undef, fmt.Errorf("unsupported DID encoding: 0x%x", code)
+}
+
+func Parse(str string) (DID, error) {
+	if !strings.HasPrefix(str, Prefix) {
+		return Undef, fmt.Errorf("must start with 'did:'")
+	}
+
+	if strings.HasPrefix(str, KeyPrefix) {
+		code, bytes, err := mbase.Decode(str[len(KeyPrefix):])
+		if err != nil {
+			return Undef, err
+		}
+		if code != mbase.Base58BTC {
+			return Undef, fmt.Errorf("not Base58BTC encoded")
+		}
+		return Decode(bytes)
+	}
+
+	buf := make([]byte, MethodOffset)
+	varint.PutUvarint(buf, DIDCore)
+	suffix, _ := strings.CutPrefix(str, Prefix)
+	buf = append(buf, suffix...)
+	return DID{str: string(buf), code: DIDCore}, nil
+}

did/did_test.go

@@ -0,0 +1,79 @@
+package did
+
+import (
+	"testing"
+)
+
+func TestParseDIDKey(t *testing.T) {
+	str := "did:key:z6Mkod5Jr3yd5SC7UDueqK4dAAw5xYJYjksy722tA9Boxc4z"
+	d, err := Parse(str)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	if d.String() != str {
+		t.Fatalf("expected %v to equal %v", d.String(), str)
+	}
+}
+
+func TestDecodeDIDKey(t *testing.T) {
+	str := "did:key:z6Mkod5Jr3yd5SC7UDueqK4dAAw5xYJYjksy722tA9Boxc4z"
+	d0, err := Parse(str)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	d1, err := Decode(d0.Bytes())
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	if d1.String() != str {
+		t.Fatalf("expected %v to equal %v", d1.String(), str)
+	}
+}
+
+func TestParseDIDWeb(t *testing.T) {
+	str := "did:web:up.web3.storage"
+	d, err := Parse(str)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	if d.String() != str {
+		t.Fatalf("expected %v to equal %v", d.String(), str)
+	}
+}
+
+func TestDecodeDIDWeb(t *testing.T) {
+	str := "did:web:up.web3.storage"
+	d0, err := Parse(str)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	d1, err := Decode(d0.Bytes())
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	if d1.String() != str {
+		t.Fatalf("expected %v to equal %v", d1.String(), str)
+	}
+}
+
+func TestEquivalence(t *testing.T) {
+	u0 := DID{}
+	u1 := Undef
+	if u0 != u1 {
+		t.Fatalf("undef DID not equivalent")
+	}
+
+	d0, err := Parse("did:key:z6Mkod5Jr3yd5SC7UDueqK4dAAw5xYJYjksy722tA9Boxc4z")
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	d1, err := Parse("did:key:z6Mkod5Jr3yd5SC7UDueqK4dAAw5xYJYjksy722tA9Boxc4z")
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	if d0 != d1 {
+		t.Fatalf("two equivalent DID not equivalent")
+	}
+}

doc.go

@@ -0,0 +1,5 @@
+// Package ucan provides the core functionality required to grant and
+// revoke privileges via [UCAN] tokens.
+//
+// [UCAN]: https://ucan.xyz
+package ucan

go.mod

@@ -1,27 +1,29 @@
 module github.com/ucan-wg/go-ucan
 
-go 1.24.4
+go 1.22.0
 
-toolchain go1.24.5
+toolchain go1.22.4
 
 require (
-	github.com/MetaMask/go-did-it v1.0.0-pre1
-	github.com/avast/retry-go/v4 v4.6.1
-	github.com/ipfs/go-cid v0.5.0
+	github.com/gobwas/glob v0.2.3
+	github.com/ipfs/go-cid v0.4.1
 	github.com/ipld/go-ipld-prime v0.21.0
+	github.com/libp2p/go-libp2p v0.36.2
 	github.com/multiformats/go-multibase v0.2.0
 	github.com/multiformats/go-multicodec v0.9.0
 	github.com/multiformats/go-multihash v0.2.3
 	github.com/multiformats/go-varint v0.0.7
-	github.com/stretchr/testify v1.10.0
-	github.com/ucan-wg/go-varsig v1.0.0
-	golang.org/x/crypto v0.40.0
+	github.com/selesy/go-options v0.0.0-20240912020512-ed2658318e52
+	github.com/stretchr/testify v1.9.0
+	gotest.tools/v3 v3.5.1
 )
 
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.0 // indirect
-	github.com/klauspost/cpuid/v2 v2.2.9 // indirect
+	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.3.0 // indirect
+	github.com/fatih/structtag v1.2.0 // indirect
+	github.com/google/go-cmp v0.6.0 // indirect
+	github.com/klauspost/cpuid/v2 v2.2.8 // indirect
 	github.com/minio/sha256-simd v1.0.1 // indirect
 	github.com/mr-tron/base58 v1.2.0 // indirect
 	github.com/multiformats/go-base32 v0.1.0 // indirect
@@ -29,8 +31,12 @@ require (
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/polydawn/refmt v0.89.0 // indirect
 	github.com/spaolacci/murmur3 v1.1.0 // indirect
-	golang.org/x/sys v0.34.0 // indirect
-	gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
+	golang.org/x/crypto v0.25.0 // indirect
+	golang.org/x/mod v0.21.0 // indirect
+	golang.org/x/sync v0.8.0 // indirect
+	golang.org/x/sys v0.25.0 // indirect
+	golang.org/x/tools v0.25.0 // indirect
+	google.golang.org/protobuf v1.34.2 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	lukechampine.com/blake3 v1.3.0 // indirect
 )

go.sum

@@ -1,34 +1,38 @@
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
-github.com/MetaMask/go-did-it v1.0.0-pre1 h1:NTGAC7z52TwFegEF7c+csUr/6Al1nAo6ValAAxOsjto=
-github.com/MetaMask/go-did-it v1.0.0-pre1/go.mod h1:7m9syDnXFTg5GmUEcydpO4Rs3eYT4McFH7vCw5fp3A4=
-github.com/avast/retry-go/v4 v4.6.1 h1:VkOLRubHdisGrHnTu89g08aQEWEgRU7LVEop3GbIcMk=
-github.com/avast/retry-go/v4 v4.6.1/go.mod h1:V6oF8njAwxJ5gRo1Q7Cxab24xs5NCWZBeaHHBklR8mA=
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/decred/dcrd/crypto/blake256 v1.1.0 h1:zPMNGQCm0g4QTY27fOCorQW7EryeQ/U0x++OzVrdms8=
-github.com/decred/dcrd/crypto/blake256 v1.1.0/go.mod h1:2OfgNZ5wDpcsFmHmCK5gZTPcCXqlm2ArzUIkw9czNJo=
-github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.0 h1:NMZiJj8QnKe1LgsbDayM4UoHwbvwDRwnI3hwNaAHRnc=
-github.com/decred/dcrd/dcrec/secp256k1/v4 v4.4.0/go.mod h1:ZXNYxsqcloTdSy/rNShjYzMhyjf0LaoftYK0p+A3h40=
+github.com/decred/dcrd/crypto/blake256 v1.0.1 h1:7PltbUIQB7u/FfZ39+DGa/ShuMyJ5ilcvdfma9wOH6Y=
+github.com/decred/dcrd/crypto/blake256 v1.0.1/go.mod h1:2OfgNZ5wDpcsFmHmCK5gZTPcCXqlm2ArzUIkw9czNJo=
+github.com/decred/dcrd/dcrec/secp256k1/v4 v4.3.0 h1:rpfIENRNNilwHwZeG5+P150SMrnNEcHYvcCuK6dPZSg=
+github.com/decred/dcrd/dcrec/secp256k1/v4 v4.3.0/go.mod h1:v57UDF4pDQJcEfFUCRop3lJL149eHGSe9Jvczhzjo/0=
+github.com/fatih/structtag v1.2.0 h1:/OdNE99OxoI/PqaW/SuSK9uxxT3f/tcSZgon/ssNSx4=
+github.com/fatih/structtag v1.2.0/go.mod h1:mBJUNpUnHmRKrKlQQlmCrh5PuhftFbNv8Ys4/aAZl94=
 github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
 github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/go-yaml/yaml v2.1.0+incompatible/go.mod h1:w2MrLa16VYP0jy6N7M5kHaCkaLENm+P+Tv+MfurjSw0=
-github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
-github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/gobwas/glob v0.2.3 h1:A4xDbljILXROh+kObIiy5kIaPYD8e96x1tgBhUI5J+Y=
+github.com/gobwas/glob v0.2.3/go.mod h1:d3Ez4x06l9bZtSvzIay5+Yzi0fmZzPgnTbPcKjJAkT8=
+github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
+github.com/google/go-cmp v0.6.0/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
 github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1 h1:EGx4pi6eqNxGaHF6qqu48+N2wcFQ5qg5FXgOdqsJ5d8=
 github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
-github.com/ipfs/go-cid v0.5.0 h1:goEKKhaGm0ul11IHA7I6p1GmKz8kEYniqFopaB5Otwg=
-github.com/ipfs/go-cid v0.5.0/go.mod h1:0L7vmeNXpQpUS9vt+yEARkJ8rOg43DF3iPgn4GIN0mk=
+github.com/ipfs/go-cid v0.4.1 h1:A/T3qGvxi4kpKWWcPC/PgbvDA2bjVLO7n4UeVwnbs/s=
+github.com/ipfs/go-cid v0.4.1/go.mod h1:uQHwDeX4c6CtyrFwdqyhpNcxVewur1M7l7fNU7LKwZk=
 github.com/ipld/go-ipld-prime v0.21.0 h1:n4JmcpOlPDIxBcY037SVfpd1G+Sj1nKZah0m6QH9C2E=
 github.com/ipld/go-ipld-prime v0.21.0/go.mod h1:3RLqy//ERg/y5oShXXdx5YIp50cFGOanyMctpPjsvxQ=
 github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
 github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
-github.com/klauspost/cpuid/v2 v2.2.9 h1:66ze0taIn2H33fBvCkXuv9BmCwDfafmiIVpKV9kKGuY=
-github.com/klauspost/cpuid/v2 v2.2.9/go.mod h1:rqkxqrZ1EhYM9G+hXH7YdowN5R5RGN6NK4QwQ3WMXF8=
+github.com/klauspost/cpuid/v2 v2.2.8 h1:+StwCXwm9PdpiEkPyzBXIy+M9KUb4ODm0Zarf1kS5BM=
+github.com/klauspost/cpuid/v2 v2.2.8/go.mod h1:Lcz8mBdAVJIBVzewtcLocK12l3Y+JytZYpaMropDUws=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
 github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/libp2p/go-buffer-pool v0.1.0 h1:oK4mSFcQz7cTQIfqbe4MIj9gLW+mnanjyFtc6cdF0Y8=
+github.com/libp2p/go-buffer-pool v0.1.0/go.mod h1:N+vh8gMqimBzdKkSMVuydVDq+UV5QTWy5HSiZacSbPg=
+github.com/libp2p/go-libp2p v0.36.2 h1:BbqRkDaGC3/5xfaJakLV/BrpjlAuYqSB0lRvtzL3B/U=
+github.com/libp2p/go-libp2p v0.36.2/go.mod h1:XO3joasRE4Eup8yCTTP/+kX+g92mOgRaadk46LmPhHY=
 github.com/minio/sha256-simd v1.0.1 h1:6kaan5IFmwTNynnKKpDHe6FWHohJOHhCPchzK49dzMM=
 github.com/minio/sha256-simd v1.0.1/go.mod h1:Pz6AKMiUdngCLpeTL/RJY1M9rUuPMYujV5xJjtbRSN8=
 github.com/mr-tron/base58 v1.2.0 h1:T/HDJBh4ZCPbU39/+c3rRvE0uKBQlU27+QI8LJ4t64o=
@@ -37,6 +41,8 @@ github.com/multiformats/go-base32 v0.1.0 h1:pVx9xoSPqEIQG8o+UbAe7DNi51oej1NtK+aG
 github.com/multiformats/go-base32 v0.1.0/go.mod h1:Kj3tFY6zNr+ABYMqeUNeGvkIC/UYgtWibDcT0rExnbI=
 github.com/multiformats/go-base36 v0.2.0 h1:lFsAbNOGeKtuKozrtBsAkSVhv1p9D0/qedU9rQyccr0=
 github.com/multiformats/go-base36 v0.2.0/go.mod h1:qvnKE++v+2MWCfePClUEjE78Z7P2a1UV0xHgWc0hkp4=
+github.com/multiformats/go-multiaddr v0.13.0 h1:BCBzs61E3AGHcYYTv8dqRH43ZfyrqM8RXVPT8t13tLQ=
+github.com/multiformats/go-multiaddr v0.13.0/go.mod h1:sBXrNzucqkFJhvKOiwwLyqamGa/P5EIXNPLovyhQCII=
 github.com/multiformats/go-multibase v0.2.0 h1:isdYCVLvksgWlMW9OZRYJEa9pZETFivncJHmHnnd87g=
 github.com/multiformats/go-multibase v0.2.0/go.mod h1:bFBZX4lKCA/2lyOFSAoKH5SS6oPyjtnzK/XTFDPkNuk=
 github.com/multiformats/go-multicodec v0.9.0 h1:pb/dlPnzee/Sxv/j4PmkDRxCOi3hXTz3IbPKOXWJkmg=
@@ -52,6 +58,8 @@ github.com/polydawn/refmt v0.89.0/go.mod h1:/zvteZs/GwLtCgZ4BL6CBsk9IKIlexP43ObX
 github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/selesy/go-options v0.0.0-20240912020512-ed2658318e52 h1:poNWlojS+o3229ZuatLMzK9wFiLuLxo7O170Edggs0o=
+github.com/selesy/go-options v0.0.0-20240912020512-ed2658318e52/go.mod h1:Cn8TrnJWCWd3dAmejFTpLN8tNVNKNoVVlZzL8ux5EWQ=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/smartystreets/assertions v1.2.0 h1:42S6lae5dvLc7BrLu/0ugRtcFVjoJNMC/N3yZFZkDFs=
 github.com/smartystreets/assertions v1.2.0/go.mod h1:tcbTF8ujkAEcZ8TElKY+i30BzYlVhC/LOxJk7iOWnoo=
@@ -59,29 +67,39 @@ github.com/smartystreets/goconvey v1.7.2 h1:9RBaZCeXEQ3UselpuwUQHltGVXvdwm6cv1hg
 github.com/smartystreets/goconvey v1.7.2/go.mod h1:Vw0tHAZW6lzCRk3xgdin6fKYcG+G3Pg9vgXWeJpQFMM=
 github.com/spaolacci/murmur3 v1.1.0 h1:7c1g84S4BPRrfL5Xrdp6fOJ206sU9y293DDHaoy0bLI=
 github.com/spaolacci/murmur3 v1.1.0/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
-github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
-github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
-github.com/ucan-wg/go-varsig v1.0.0 h1:Hrc437Zg+B5Eoajg+qZQZI3Q3ocPyjlnp3/Bz9ZnlWw=
-github.com/ucan-wg/go-varsig v1.0.0/go.mod h1:Sakln6IPooDPH+ClQ0VvR09TuwUhHcfLqcPiPkMZGh0=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/urfave/cli v1.22.10/go.mod h1:Gos4lmkARVdJ6EkW0WaNv/tZAAMe9V7XWyB60NtXRu0=
 github.com/warpfork/go-wish v0.0.0-20220906213052-39a1cc7a02d0 h1:GDDkbFiaK8jsSDJfjId/PEGEShv6ugrt4kYsC5UIDaQ=
 github.com/warpfork/go-wish v0.0.0-20220906213052-39a1cc7a02d0/go.mod h1:x6AKhvSSexNrVSrViXSHUEbICjmGXhtgABaHIySUSGw=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.40.0 h1:r4x+VvoG5Fm+eJcxMaY8CQM7Lb0l1lsmjGBQ6s8BfKM=
-golang.org/x/crypto v0.40.0/go.mod h1:Qr1vMER5WyS2dfPHAlsOj01wgLbsyWtFn/aY+5+ZdxY=
+golang.org/x/crypto v0.25.0 h1:ypSNr+bnYL2YhwoMt2zPxHFmbAN1KZs/njMG3hxUp30=
+golang.org/x/crypto v0.25.0/go.mod h1:T+wALwcMOSE0kXgUAnPAHqTLW+XHgcELELW8VaDgm/M=
+golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56 h1:2dVuKD2vS7b0QIHQbpyTISPd0LeHDbnYEryqj5Q1ug8=
+golang.org/x/exp v0.0.0-20240719175910-8a7402abbf56/go.mod h1:M4RDyNAINzryxdtnbRXRL/OHtkFuWGRjvuhBJpk2IlY=
+golang.org/x/mod v0.21.0 h1:vvrHzRwRfVKSiLrG+d4FMl/Qi4ukBCE6kZlTUkDYRT0=
+golang.org/x/mod v0.21.0/go.mod h1:6SkKJ3Xj0I0BrPOZoBy3bdMptDDU9oJrpohJ3eWZ1fY=
 golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/sync v0.8.0 h1:3NFvSEYkUoMifnESzZl15y791HH1qU2xm6eCJU5ZPXQ=
+golang.org/x/sync v0.8.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.34.0 h1:H5Y5sJ2L2JRdyv7ROF1he/lPdvFsd0mJHFw2ThKHxLA=
-golang.org/x/sys v0.34.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
+golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.25.0 h1:r+8e+loiHxRqhXVl6ML1nO3l1+oFoWbnlu2Ehimmi34=
+golang.org/x/sys v0.25.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/tools v0.0.0-20190328211700-ab21143f2384/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+golang.org/x/tools v0.25.0 h1:oFU9pkj/iJgs+0DT+VMHrx+oBKs/LJMV+Uvg78sl+fE=
+golang.org/x/tools v0.25.0/go.mod h1:/vtpO8WL1N9cQC3FN5zPqb//fRXskFHbLKk4OW1Q7rg=
+google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
+google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
-gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gotest.tools/v3 v3.5.1 h1:EENdUnS3pdur5nybKYIh2Vfgc8IUNBjxDPSjtiJcOzU=
+gotest.tools/v3 v3.5.1/go.mod h1:isy3WKz7GK6uNw/sbHzfKBLvlvXwUyV06n6brMxxopU=
 lukechampine.com/blake3 v1.3.0 h1:sJ3XhFINmHSrYCgl958hscfIa3bw8x4DqMP3u1YvoYE=
 lukechampine.com/blake3 v1.3.0/go.mod h1:0OFRp7fBtAylGVCO40o87sbupkyIGgbpv1+M1k1LM6k=

internal/cmd/token/main.go

@@ -0,0 +1,54 @@
+package main
+
+import (
+	"bytes"
+	"log/slog"
+	"os"
+
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/node/bindnode"
+)
+
+const header = `// Code generated by internal/cmd/token - DO NOT EDIT.
+
+package token
+
+import "github.com/ipld/go-ipld-prime/datamodel"
+
+`
+
+func main() {
+	slog.Info("Generating Go types for token.ipldsch")
+
+	if err := Run(); err != nil {
+		slog.Error(err.Error())
+		slog.Error("Finished but failed to generate and write token_gen.go")
+
+		os.Exit(1)
+	}
+
+	slog.Info("Finished generating and writing token_gen.go")
+	os.Exit(0)
+}
+
+func Run() error {
+	schema, err := os.ReadFile("token.ipldsch")
+	if err != nil {
+		return err
+	}
+
+	slog.Debug(string(schema))
+
+	typeSystem, err := ipld.LoadSchemaBytes(schema)
+	if err != nil {
+		return err
+	}
+
+	buf := bytes.NewBufferString(header)
+
+	if err := bindnode.ProduceGoTypes(buf, typeSystem); err != nil {
+		return err
+	}
+
+	return os.WriteFile("token_gen.go", buf.Bytes(), 0o600)
+}

internal/envelope/envelope.go

@@ -0,0 +1,309 @@
+package envelope
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/ipld/go-ipld-prime/codec/dagcbor"
+	"github.com/ipld/go-ipld-prime/datamodel"
+	"github.com/ipld/go-ipld-prime/fluent/qp"
+	"github.com/ipld/go-ipld-prime/node/basicnode"
+	"github.com/ipld/go-ipld-prime/node/bindnode"
+	crypto "github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/libp2p/go-libp2p/core/crypto/pb"
+	"github.com/ucan-wg/go-ucan/did"
+	"github.com/ucan-wg/go-ucan/internal/token"
+	"github.com/ucan-wg/go-ucan/internal/varsig"
+)
+
+// [Envelope] is a signed enclosure for a UCAN v1 Token.
+//
+// While the types and functions in this package are not exported,
+// the names used for types, fields, variables, etc generally use the
+// names from the specification
+//
+// [Envelope]: https://github.com/ucan-wg/spec#envelope
+type Envelope struct {
+	signature  []byte
+	sigPayload *sigPayload
+}
+
+// New creates an Envelope containing a VarsigHeader and Signature for
+// the data resulting from wrapping the provided Token in an IPLD
+// datamodel.Node and encoding it using DAG-CBOR.
+func New(privKey crypto.PrivKey, token *token.Token, tag string) (*Envelope, error) {
+	sigPayload, err := newSigPayload(privKey.Type(), token, tag)
+	if err != nil {
+		return nil, err
+	}
+
+	cbor, err := sigPayload.cbor()
+	if err != nil {
+		return nil, err
+	}
+
+	signature, err := privKey.Sign(cbor)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Envelope{
+		signature:  signature,
+		sigPayload: sigPayload,
+	}, nil
+}
+
+// Wrap is syntactic sugar for creating an Envelope and wrapping it as an
+// IPLD datamodel.Node in a single operation.
+//
+// Since the Envelope itself isn't returned, use this method only when
+// the IPLD datamodel.Node is used directly.  If the Envelope is also
+// required, use New followed by Envelope.Wrap to avoid the need to
+// unwrap the newly created datamodel.Node.
+func Wrap(privKey crypto.PrivKey, token *token.Token, tag string) (datamodel.Node, error) {
+	env, err := New(privKey, token, tag)
+	if err != nil {
+		return nil, err
+	}
+
+	return env.Wrap()
+}
+
+// Unwrap attempts to crate an Envelope from a datamodel.Node
+//
+// There are lots of ways that this can fail and therefore there are
+// an almost excessive number of check included here and while
+// attempting to extract the token.Token from one of the inner IPLD
+// nodes.
+func Unwrap(node datamodel.Node) (*Envelope, error) {
+	signatureNode, err := node.LookupByIndex(0)
+	if err != nil {
+		return nil, err
+	}
+
+	signature, err := signatureNode.AsBytes()
+	if err != nil {
+		return nil, err
+	}
+
+	sigPayloadNode, err := node.LookupByIndex(1)
+	if err != nil {
+		return nil, err
+	}
+
+	sigPayload, err := unwrapSigPayload(sigPayloadNode)
+	if err != nil {
+		return nil, err
+	}
+
+	envel := &Envelope{
+		signature:  signature,
+		sigPayload: sigPayload,
+	}
+
+	if ok, err := envel.Verify(); !ok || err != nil {
+		return nil, fmt.Errorf("envelope was not signed by issuer")
+	}
+
+	return envel, nil
+}
+
+// Signature returns the cryptographic signature of the Envelope's
+// SigPayload.
+func (e *Envelope) Signature() []byte {
+	return e.signature
+}
+
+// Tag returns the key that's used to reference the TokenPayload within
+// this Envelope.
+func (e *Envelope) Tag() string {
+	return e.sigPayload.tag
+}
+
+// TokenPayload returns the *token.Token enclosed within this Envelope.
+func (e *Envelope) TokenPayload() *token.Token {
+	return e.sigPayload.tokenPayload
+}
+
+// VarsigHeader is an accessor that returns the [VarsigHeader] from the
+// underlying [SigPayload] from the [Envelope].
+//
+// [Envelope]: https://github.com/ucan-wg/spec#envelope
+// [SigPayload]: https://github.com/ucan-wg/spec#envelope
+// [VarsigHeader]: https://github.com/ucan-wg/spec#envelope
+func (e *Envelope) VarsigHeader() []byte {
+	return e.sigPayload.varsigHeader
+}
+
+// Verify checks that the [Envelope]'s signature is correct for the
+// data created by encoding the SigPayload as DAG-CBOR and the public
+// key passed as the only argument.
+//
+// Note that for Delegation and Invocation tokens, the public key
+// is retrieved from the DID's method specific identifier for the
+// Issuer field.
+//
+// [Envelope]: https://github.com/ucan-wg/spec#envelope
+func (e *Envelope) Verify() (bool, error) {
+	pubKey, err := did.ToPubKey(e.sigPayload.tokenPayload.Issuer)
+	if err != nil {
+		return false, err
+	}
+
+	cbor, err := e.sigPayload.cbor()
+	if err != nil {
+		return false, err
+	}
+
+	return pubKey.Verify(cbor, e.signature)
+}
+
+// Wrap encodes the Envelope as an IPLD datamodel.Node.
+func (e *Envelope) Wrap() (datamodel.Node, error) {
+	spn, err := e.sigPayload.wrap()
+	if err != nil {
+		return nil, err
+	}
+
+	return qp.BuildList(basicnode.Prototype.Any, 2, func(la datamodel.ListAssembler) {
+		qp.ListEntry(la, qp.Bytes(e.signature))
+		qp.ListEntry(la, qp.Node(spn))
+	})
+}
+
+//
+// The types below are strictly to make it easier to Wrap and Unwrap the
+// Envelope with an IPLD datamodel.Node.  The Envelope itself provides
+// accessors to the internals of these types.
+//
+
+type sigPayload struct {
+	varsigHeader []byte
+	tokenPayload *token.Token
+	tag          string
+}
+
+func newSigPayload(keyType pb.KeyType, token *token.Token, tag string) (*sigPayload, error) {
+	varsigHeader, err := varsig.Encode(keyType)
+	if err != nil {
+		return nil, err
+	}
+
+	return &sigPayload{
+		varsigHeader: varsigHeader,
+		tokenPayload: token,
+		tag:          tag,
+	}, nil
+}
+
+func unwrapSigPayload(node datamodel.Node) (*sigPayload, error) {
+	// Normally we could look up the VarsigHeader and TokenPayload using
+	// node.LookupByString() - this works for the "h" key used for the
+	// VarsigHeader but not for the TokenPayload's key (tag) as all we
+	// know is that it starts with "ucan/" and as explained below, must
+	// decode to a schema.TypedNode for the representation provided by the
+	// token.Prototype().
+	// vvv
+	mi := node.MapIterator()
+	if mi == nil {
+		return nil, fmt.Errorf("the SigPayload node is not a map: %s", node.Kind().String())
+	}
+
+	var (
+		hdrNode datamodel.Node
+		tknNode datamodel.Node
+		tag     string
+	)
+
+	keyCount := 0
+
+	for !mi.Done() {
+		k, v, err := mi.Next()
+		if err != nil {
+			return nil, err
+		}
+
+		kStr, err := k.AsString()
+		if err != nil {
+			return nil, fmt.Errorf("the SigPayload keys are not strings: %w", err)
+		}
+
+		keyCount++
+
+		if kStr == "h" {
+			hdrNode = v
+
+			continue
+		}
+
+		if strings.HasPrefix(kStr, "ucan/") {
+			tknNode = v
+			tag = kStr
+		}
+	}
+
+	if keyCount != 2 {
+		return nil, fmt.Errorf("the SigPayload map should have exactly two keys: %d", keyCount)
+	}
+	// ^^^
+
+	// Replaces the datamodel.Node in tokenPayloadNode with a
+	// schema.TypedNode so that we can cast it to a *token.Token after
+	// unwrapping it.
+	// vvv
+	nb := token.Prototype().Representation().NewBuilder()
+
+	err := nb.AssignNode(tknNode)
+	if err != nil {
+		return nil, err
+	}
+
+	tknNode = nb.Build()
+	// ^^^
+
+	tokenPayload := bindnode.Unwrap(tknNode)
+	if tokenPayload == nil {
+		return nil, errors.New("failed to Unwrap the TokenPayload")
+	}
+
+	tkn, ok := tokenPayload.(*token.Token)
+	if !ok {
+		return nil, errors.New("failed to assert the TokenPayload type as *token.Token")
+	}
+
+	hdr, err := hdrNode.AsBytes()
+	if err != nil {
+		return nil, err
+	}
+
+	return &sigPayload{
+		varsigHeader: hdr,
+		tokenPayload: tkn,
+		tag:          tag,
+	}, nil
+}
+
+func (sp *sigPayload) cbor() ([]byte, error) {
+	node, err := sp.wrap()
+	if err != nil {
+		return nil, err
+	}
+
+	buf := &bytes.Buffer{}
+	if err = dagcbor.Encode(node, buf); err != nil {
+		return nil, err
+	}
+
+	return buf.Bytes(), nil
+}
+
+func (sp *sigPayload) wrap() (datamodel.Node, error) {
+	tpn := bindnode.Wrap(sp.tokenPayload, token.Prototype().Type())
+
+	return qp.BuildMap(basicnode.Prototype.Any, 2, func(ma datamodel.MapAssembler) {
+		qp.MapEntry(ma, "h", qp.Bytes(sp.varsigHeader))
+		qp.MapEntry(ma, sp.tag, qp.Node(tpn.Representation()))
+	})
+}

internal/envelope/envelope_test.go

@@ -0,0 +1,200 @@
+package envelope_test
+
+import (
+	"encoding/base64"
+	"testing"
+
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/codec/dagcbor"
+	"github.com/ipld/go-ipld-prime/codec/dagjson"
+	"github.com/ipld/go-ipld-prime/datamodel"
+	"github.com/ipld/go-ipld-prime/fluent/qp"
+	"github.com/ipld/go-ipld-prime/node/basicnode"
+	crypto "github.com/libp2p/go-libp2p/core/crypto"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"github.com/ucan-wg/go-ucan/did"
+	"github.com/ucan-wg/go-ucan/internal/envelope"
+	"github.com/ucan-wg/go-ucan/internal/token"
+	"gotest.tools/v3/golden"
+)
+
+const (
+	exampleDID             = "did:key:z6MkpuK2Amsu1RqcLGgmHHQHhvmeXCCBVsM4XFSg2cCyg4Nh"
+	examplePrivKeyCfg      = "CAESQP9v2uqECTuIi45dyg3znQvsryvf2IXmOF/6aws6aCehm0FVrj0zHR5RZSDxWNjcpcJqsGym3sjCungX9Zt5oA4="
+	exampleSignatureStr    = "PZV6A2aI7n+MlyADqcqmWhkuyNrgUCDz+qSLSnI9bpasOwOhKUTx95m5Nu5CO/INa1LqzHGioD9+PVf6qdtTBg"
+	exampleTag             = "ucan/example@v1.0.0-rc.1"
+	exampleVarsigHeaderStr = "NO0BcQ"
+
+	invalidSignatureStr = "PZV6A2aI7n+MlyADqcqmWhkuyNrgUCDz+qSLSnI9bpasOwOhKUTx95m5Nu5CO/INa1LqzHGioD9+PVf6qdtTBK"
+
+	exampleDAGCBORFilename = "example.dagcbor"
+	exampleDAGJSONFilename = "example.dagjson"
+)
+
+func TestNew(t *testing.T) {
+	t.Parallel()
+
+	envel := exampleEnvelope(t)
+	assert.NotZero(t, envel)
+
+	assert.Equal(t, exampleSignature(t), envel.Signature())
+	assert.Equal(t, exampleTag, envel.Tag())
+	assert.Equal(t, exampleVarsigHeader(t), envel.VarsigHeader())
+	assert.EqualValues(t, exampleGoldenTokenPayload(t), envel.TokenPayload())
+}
+
+func TestWrap(t *testing.T) {
+	t.Parallel()
+
+	node, err := envelope.Wrap(examplePrivKey(t), exampleToken(t), exampleTag)
+	require.NoError(t, err)
+
+	cbor, err := ipld.Encode(node, dagcbor.Encode)
+	require.NoError(t, err)
+
+	golden.AssertBytes(t, cbor, exampleDAGCBORFilename)
+
+	json, err := ipld.Encode(node, dagjson.Encode)
+	require.NoError(t, err)
+
+	golden.Assert(t, string(json), exampleDAGJSONFilename)
+}
+
+func TestEnvelope_Verify(t *testing.T) {
+	t.Parallel()
+
+	t.Run("valid signature by issuer", func(t *testing.T) {
+		t.Parallel()
+
+		envel := exampleEnvelope(t)
+		ok, err := envel.Verify()
+		require.NoError(t, err)
+		assert.True(t, ok)
+	})
+
+	t.Run("invalid signature by wrong issuer", func(t *testing.T) {
+		t.Parallel()
+
+		envel, err := envelope.Unwrap(invalidNodeFromGolden(t))
+		require.NoError(t, err)
+
+		ok, _ := envel.Verify()
+		assert.False(t, ok)
+	})
+}
+
+func TestEnvelope_Wrap(t *testing.T) {
+	t.Parallel()
+
+	envel := exampleEnvelope(t)
+
+	node, err := envel.Wrap()
+	require.NoError(t, err)
+
+	cbor, err := ipld.Encode(node, dagcbor.Encode)
+	require.NoError(t, err)
+
+	assert.Equal(t, golden.Get(t, exampleDAGCBORFilename), cbor)
+}
+
+func exampleGoldenEnvelope(t *testing.T) *envelope.Envelope {
+	t.Helper()
+
+	envel, err := envelope.Unwrap(exampleGoldenNode(t))
+	require.NoError(t, err)
+
+	return envel
+}
+
+func exampleGoldenNode(t *testing.T) datamodel.Node {
+	t.Helper()
+
+	cbor := golden.Get(t, exampleDAGCBORFilename)
+
+	node, err := ipld.Decode(cbor, dagcbor.Decode)
+	require.NoError(t, err)
+
+	return node
+}
+
+func exampleGoldenTokenPayload(t *testing.T) *token.Token {
+	t.Helper()
+
+	return exampleGoldenEnvelope(t).TokenPayload()
+}
+
+func examplePrivKey(t *testing.T) crypto.PrivKey {
+	t.Helper()
+
+	privKeyEnc, err := crypto.ConfigDecodeKey(examplePrivKeyCfg)
+	require.NoError(t, err)
+
+	privKey, err := crypto.UnmarshalPrivateKey(privKeyEnc)
+	require.NoError(t, err)
+
+	return privKey
+}
+
+func exampleEnvelope(t *testing.T) *envelope.Envelope {
+	t.Helper()
+
+	envel, err := envelope.New(examplePrivKey(t), exampleToken(t), exampleTag)
+	require.NoError(t, err)
+
+	return envel
+}
+
+func examplePubKey(t *testing.T) crypto.PubKey {
+	t.Helper()
+
+	return examplePrivKey(t).GetPublic()
+}
+
+func exampleSignature(t *testing.T) []byte {
+	t.Helper()
+
+	sig, err := base64.RawStdEncoding.DecodeString(exampleSignatureStr)
+	require.NoError(t, err)
+
+	return sig
+}
+
+func exampleToken(t *testing.T) *token.Token {
+	t.Helper()
+
+	id, err := did.FromPubKey(examplePubKey(t))
+	require.NoError(t, err)
+
+	return &token.Token{
+		Issuer: id.String(),
+	}
+}
+
+func exampleVarsigHeader(t *testing.T) []byte {
+	t.Helper()
+
+	hdr, err := base64.RawStdEncoding.DecodeString(exampleVarsigHeaderStr)
+	require.NoError(t, err)
+
+	return hdr
+}
+
+func invalidNodeFromGolden(t *testing.T) datamodel.Node {
+	t.Helper()
+
+	invalidSig, err := base64.RawStdEncoding.DecodeString(invalidSignatureStr)
+	require.NoError(t, err)
+
+	envelNode := exampleGoldenNode(t)
+	sigPayloadNode, err := envelNode.LookupByIndex(1)
+	require.NoError(t, err)
+
+	node, err := qp.BuildList(basicnode.Prototype.Any, 2, func(la datamodel.ListAssembler) {
+		qp.ListEntry(la, qp.Bytes(invalidSig))
+		qp.ListEntry(la, qp.Node(sigPayloadNode))
+	})
+	require.NoError(t, err)
+
+	return node
+}

internal/envelope/testdata/example.dagcbor

@@ -0,0 +1 @@
+‚X@=•zfˆîŒ— ©Ê¦Z.ÈÚàP óú¤‹Jr=n–¬;¡)Dñ÷™¹6îB;ò

internal/envelope/testdata/example.dagjson

@@ -0,0 +1,20 @@
+[
+  {
+    "/": {
+      "bytes": "PZV6A2aI7n+MlyADqcqmWhkuyNrgUCDz+qSLSnI9bpasOwOhKUTx95m5Nu5CO/INa1LqzHGioD9+PVf6qdtTBg"
+    }
+  },
+  {
+    "h": {
+      "/": {
+        "bytes": "NO0BcQ"
+      }
+    },
+    "ucan/example@v1.0.0-rc.1": {
+      "cmd": "",
+      "exp": null,
+      "iss": "did:key:z6MkpuK2Amsu1RqcLGgmHHQHhvmeXCCBVsM4XFSg2cCyg4Nh",
+      "sub": null
+    }
+  }
+]

internal/token/conversion.go

@@ -0,0 +1,24 @@
+package token
+
+import (
+	"github.com/ipld/go-ipld-prime/datamodel"
+)
+
+func ToIPLDMapStringAny(m map[string]datamodel.Node) Map__String__Any {
+	keys := make([]string, len(m))
+	i := 0
+
+	for k := range m {
+		keys[i] = k
+		i++
+	}
+
+	return Map__String__Any{
+		Keys:   keys,
+		Values: m,
+	}
+}
+
+func FromIPLDMapStringAny(m Map__String__Any) map[string]datamodel.Node {
+	return m.Values
+}

internal/token/doc.go

@@ -0,0 +1,33 @@
+// Package token provides a generic model of the [TokenPayload] required
+// within an Envelope.
+//
+// # Field requirements
+//
+// While the Token object represents the wire format of both a UCAN
+// Delegation token and a UCAN Invocation token, the delegation and
+// invocation packages are, respectively, responsible for making sure
+// required fields are included when creating a new Token or when
+// validating the contents of an Envelope as it's received from
+// another party.  The following table shows the current (as of
+// 2024-09-11) relationship between optional and nullable fields in
+// the delegation and invocation views and the payload model:
+//
+//	| Name  |     Delegation      |     Invocation      |  Token   |
+//	|       | Required | Nullable | Required | Nullable |          |
+//	| ----- | -------- | -------- | -------- | -------- | -------- |
+//	| iss   | Yes      | No       | Yes      | No       |          |
+//	| aud   | Yes      | No       | No       | N/A      | Optional |
+//	| sub   | Yes      | Yes      | Yes      | No       | Nullable |
+//	| cmd   | Yes      | No       | Yes      | No       |          |
+//	| pol   | Yes      | No       | X        | X        | Optional |
+//	| nonce | Yes      | No       | No       | N/A      | Optional |
+//	| meta  | No       | N/A      | No       | N/A      | Optional |
+//	| nbf   | No       | N/A      | X        | X        | Optional |
+//	| exp   | Yes      | Yes      | Yes      | Yes      |          |
+//	| args  | X        | X        | Yes      | No       | Optional |
+//	| prf   | X        | X        | Yes      | No       | Optional |
+//	| iat   | X        | X        | No       | N/A      | Optional |
+//	| cause | X        | X        | No       | N/A      | Optional |
+//
+// [TokenPayload]: https://github.com/ucan-wg/spec?tab=readme-ov-file#envelope
+package token

internal/token/errors.go

@@ -0,0 +1,11 @@
+package token
+
+import "errors"
+
+var ErrFailedSchemaLoad = errors.New("failed to load IPLD Schema")
+
+var ErrNoSchemaType = errors.New("schema does not contain type")
+
+var ErrNodeNotToken = errors.New("IPLD node is not a Token")
+
+var ErrMissingRequiredDID = errors.New("a required DID is missing")

internal/token/schema.go

@@ -0,0 +1,46 @@
+package token
+
+import (
+	_ "embed"
+	"fmt"
+	"sync"
+
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/node/bindnode"
+	"github.com/ipld/go-ipld-prime/schema"
+)
+
+const tokenTypeName = "Token"
+
+//go:embed token.ipldsch
+var schemaBytes []byte
+
+var (
+	once sync.Once
+	ts   *schema.TypeSystem
+	err  error
+)
+
+func mustLoadSchema() *schema.TypeSystem {
+	once.Do(func() {
+		ts, err = ipld.LoadSchemaBytes(schemaBytes)
+	})
+	if err != nil {
+		panic(fmt.Errorf("%w: %w", ErrFailedSchemaLoad, err))
+	}
+
+	tknType := ts.TypeByName(tokenTypeName)
+	if tknType == nil {
+		panic(fmt.Errorf("%w: %s", ErrNoSchemaType, tokenTypeName))
+	}
+
+	return ts
+}
+
+func tokenType() schema.Type {
+	return mustLoadSchema().TypeByName(tokenTypeName)
+}
+
+func Prototype() schema.TypedPrototype {
+	return bindnode.Prototype((*Token)(nil), tokenType())
+}

internal/token/schema_test.go

@@ -0,0 +1,84 @@
+package token_test
+
+import (
+	_ "embed"
+	"fmt"
+	"testing"
+
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/codec/dagcbor"
+	"github.com/ipld/go-ipld-prime/codec/dagjson"
+	"github.com/stretchr/testify/require"
+	"github.com/ucan-wg/go-ucan/internal/token"
+)
+
+//go:embed token.ipldsch
+var schemaBytes []byte
+
+func TestSchemaRoundTrip(t *testing.T) {
+	const delegationJson = `
+{
+  "aud":"did:key:def456",
+  "cmd":"/foo/bar",
+  "exp":123456,
+  "iss":"did:key:abc123",
+  "meta":{
+    "bar":"baaar",
+    "foo":"fooo"
+  },
+  "nbf":123456,
+  "nonce":{
+    "/":{
+      "bytes":"c3VwZXItcmFuZG9t"
+    }
+  },
+  "pol":[
+    ["==", ".status", "draft"],
+    ["all", ".reviewer", [
+		["like", ".email", "*@example.com"]]
+	],
+    ["any", ".tags", [ 
+		["or", [
+			["==", ".", "news"], 
+			["==", ".", "press"]]
+      ]]
+	]
+  ],
+  "sub":""
+}
+`
+	// format:    dagJson --> IPLD node --> token --> dagCbor --> IPLD node   -->   dagJson
+	// function:                     Unwrap()   Wrap()
+
+	n1, err := ipld.DecodeUsingPrototype([]byte(delegationJson), dagjson.Decode, token.Prototype())
+	require.NoError(t, err)
+
+	cborBytes, err := ipld.Encode(n1, dagcbor.Encode)
+	require.NoError(t, err)
+	fmt.Println("cborBytes length", len(cborBytes))
+	fmt.Println("cbor", string(cborBytes))
+
+	n2, err := ipld.DecodeUsingPrototype(cborBytes, dagcbor.Decode, token.Prototype())
+	require.NoError(t, err)
+	fmt.Println("read Cbor", n2)
+
+	t1, err := token.Unwrap(n2)
+	require.NoError(t, err)
+
+	n3 := t1.Wrap()
+
+	readJson, err := ipld.Encode(n3, dagjson.Encode)
+	require.NoError(t, err)
+	fmt.Println("readJson length", len(readJson))
+	fmt.Println("json: ", string(readJson))
+
+	require.JSONEq(t, delegationJson, string(readJson))
+}
+
+func BenchmarkSchemaLoad(b *testing.B) {
+	b.ReportAllocs()
+
+	for i := 0; i < b.N; i++ {
+		_, _ = ipld.LoadSchemaBytes(schemaBytes)
+	}
+}

internal/token/token.go

@@ -0,0 +1,33 @@
+package token
+
+import (
+	"github.com/ipld/go-ipld-prime/datamodel"
+	"github.com/ipld/go-ipld-prime/node/bindnode"
+)
+
+//go:generate go run ../cmd/token/...
+
+// Unwrap creates a Token from an arbitrary IPLD node or returns an
+// error if at least the required model fields are not present.
+//
+// It is the responsibility of the Delegation and Invocation views
+// to further validate the presence of the required fields and the
+// content as needed.
+func Unwrap(node datamodel.Node) (*Token, error) {
+	iface := bindnode.Unwrap(node)
+	if iface == nil {
+		return nil, ErrNodeNotToken
+	}
+
+	tkn, ok := iface.(*Token)
+	if !ok {
+		return nil, ErrNodeNotToken
+	}
+
+	return tkn, nil
+}
+
+// Wrap creates an IPLD node representing the Token.
+func (t *Token) Wrap() datamodel.Node {
+	return bindnode.Wrap(t, tokenType())
+}

internal/token/token.ipldsch

@@ -0,0 +1,63 @@
+
+type CID string
+
+type Command string
+
+type DID string
+
+# Field requirements:
+#
+# | Name  |     Delegation      |     Invocation      |  Token   |
+# |       | Required | Nullable | Required | Nullable |          |
+# | ----- | -------- | -------- | -------- | -------- | -------- |
+# | iss   | Yes      | No       | Yes      | No       |          |
+# | aud   | Yes      | No       | No       | N/A      | Optional |
+# | sub   | Yes      | Yes      | Yes      | No       | Nullable |
+# | cmd   | Yes      | No       | Yes      | No       |          |
+# | pol   | Yes      | No       | X        | X        | Optional |
+# | nonce | Yes      | No       | No       | N/A      | Optional |
+# | meta  | No       | N/A      | No       | N/A      | Optional |
+# | nbf   | No       | N/A      | X        | X        | Optional |
+# | exp   | Yes      | Yes      | Yes      | Yes      | Nullable |
+# | args  | X        | X        | Yes      | No       | Optional |
+# | prf   | X        | X        | Yes      | No       | Optional |
+# | iat   | X        | X        | No       | N/A      | Optional |
+# | cause | X        | X        | No       | N/A      | Optional |
+
+type Token struct {
+    # Issuer DID (sender)
+    issuer DID (rename "iss")
+    # Audience DID (receiver)
+    audience optional DID (rename "aud")
+    # Principal that the chain is about (the Subject)
+    subject nullable DID (rename "sub")
+
+    # The Command to eventually invoke
+    command Command (rename "cmd")
+
+    # The delegation policy
+    # It doesn't seem possible to represent it with a schema.
+    policy optional Any (rename "pol")
+
+    # The invocation's arguments
+    arguments optional {String: Any} (rename "args")
+
+    # Delegations that prove the chain of authority
+    Proofs optional [CID] (rename "prf")
+
+    # A unique, random nonce
+    nonce optional Bytes
+    
+    # Arbitrary Metadata
+    meta optional {String : Any}
+
+    # "Not before" UTC Unix Timestamp in seconds (valid from), 53-bits integer
+    notBefore optional Int (rename "nbf")
+    # The timestamp at which the delegation becomes invalid
+    expiration nullable Int (rename "exp")
+    # The timestamp at which the invocation was created
+    issuedAt optional Int
+
+    # An optional CID of the receipt that enqueued this invocation
+    cause optional CID
+}

internal/token/token_gen.go

@@ -0,0 +1,31 @@
+// Code generated by internal/cmd/token - DO NOT EDIT.
+
+package token
+
+import "github.com/ipld/go-ipld-prime/datamodel"
+
+type Map struct {
+	Keys   []string
+	Values map[string]datamodel.Node
+}
+type List []datamodel.Node
+type Map__String__Any struct {
+	Keys   []string
+	Values map[string]datamodel.Node
+}
+type List__CID []string
+type Token struct {
+	Issuer     string
+	Audience   *string
+	Subject    *string
+	Command    string
+	Policy     *datamodel.Node
+	Arguments  *Map__String__Any
+	Proofs     *List__CID
+	Nonce      *[]uint8
+	Meta       *Map__String__Any
+	NotBefore  *int
+	Expiration *int
+	IssuedAt   *int
+	Cause      *string
+}

internal/token/token_test.go

@@ -0,0 +1,55 @@
+package token_test
+
+import (
+	"testing"
+
+	"github.com/ipld/go-ipld-prime"
+	"github.com/ipld/go-ipld-prime/codec/dagjson"
+	"github.com/stretchr/testify/require"
+	"github.com/ucan-wg/go-ucan/internal/token"
+)
+
+func TestEncode(t *testing.T) {
+	t.Parallel()
+
+	tkn := &token.Token{}
+
+	node := tkn.Wrap()
+
+	json, err := ipld.Encode(node, dagjson.Encode)
+	require.NoError(t, err)
+
+	t.Log(string(json))
+
+	t.Fail()
+}
+
+func TestPrototype(t *testing.T) {
+	t.Parallel()
+
+	tkn := &token.Token{
+		Issuer: "blah",
+	}
+	n1 := tkn.Wrap()
+	json, err := ipld.Encode(n1, dagjson.Encode)
+	require.NoError(t, err)
+
+	t.Log(string(json))
+
+	n2, err := ipld.Decode(json, dagjson.Decode)
+	require.NoError(t, err)
+
+	nb := token.Prototype().Representation().NewBuilder()
+	require.NoError(t, nb.AssignNode(n2))
+
+	n3 := nb.Build()
+
+	tkn2, err := token.Unwrap(n3)
+	require.NoError(t, err)
+
+	t.Log(tkn2)
+
+	require.Equal(t, tkn, tkn2)
+
+	t.Fail()
+}

internal/tools/tools.go

@@ -0,0 +1,7 @@
+//go:build tools
+
+package tools
+
+import (
+	_ "github.com/selesy/go-options"
+)

internal/varsig/varsig.go

@@ -0,0 +1,134 @@
+// Package varsig implements the portion of the [varsig specification]
+// that's needed for the UCAN [Envelope].
+//
+// While the [Envelope] specification has a field that's labelled
+// "VarsigHeader", this field is actually the prefix, header and segments
+// of the body excluding the signature itself (which is a different field
+// in the [Envelope]).
+//
+// Given that [go-ucan] supports a limited number of public key types,
+// and that the signature isn't part of the resulting field, the values
+// that are used are constants.  Note that for key types that are fully
+// specified in the [did:key], the [VarsigHeader] field isn't technically
+// needed and could theoretically conflict with the DID.
+//
+// Treating these values as constants has no impact when issuing or
+// delegating tokens.  When decoding tokens, simply matching the strings
+// will allow us to detect errors but won't provide as much detail (e.g.
+// we can't indicate that the signature was incorrectly generated from
+// a DAG-JSON encoding.)
+//
+// [varsig specification]: https://github.com/ChainAgnostic/varsig
+// [Envelope]:https://github.com/ucan-wg/spec#envelope
+// [go-ucan]: https://github.com/ucan-wg/go-ucan
+package varsig
+
+import (
+	"encoding/base64"
+	"encoding/binary"
+	"errors"
+	"fmt"
+
+	"github.com/libp2p/go-libp2p/core/crypto/pb"
+	"github.com/multiformats/go-multicodec"
+)
+
+const (
+	Prefix = 0x34
+)
+
+// ErrUnknownHeader is returned when it's not possible to decode the
+// provided string into a libp2p public key type.
+var ErrUnknownHeader = errors.New("could not decode unknown header")
+
+// ErrUnknownKeyType is returned when value provided is not a valid
+// libp2p public key type.
+var ErrUnknownKeyType = errors.New("could not encode unsupported key type")
+
+var (
+	decMap = headerToKeyType()
+	encMap = keyTypeToHeader()
+)
+
+// Decode returns either the pb.KeyType associated with the provided Header
+// or an error.
+//
+// Currently, only the four key types supported by the [go-libp2p/core/crypto]
+// library are supported.
+//
+// [go-libp2p/core/crypto]: github.com/libp2p/go-libp2p/core/crypto
+func Decode(header []byte) (pb.KeyType, error) {
+	keyType, ok := decMap[base64.RawStdEncoding.EncodeToString(header)]
+	if !ok {
+		return -1, fmt.Errorf("%w: %s", ErrUnknownHeader, header)
+	}
+
+	return keyType, nil
+}
+
+// Encode returns either the header associated with the provided pb.KeyType
+// or an error indicating the header was unknown.
+//
+// Currently, only the four key types supported by the [go-libp2p/core/crypto]
+// library are supported.
+//
+// [go-libp2p/core/crypto]: github.com/libp2p/go-libp2p/core/crypto
+func Encode(keyType pb.KeyType) ([]byte, error) {
+	header, ok := encMap[keyType]
+	if !ok {
+		return nil, fmt.Errorf("%w: %s", ErrUnknownKeyType, keyType.String())
+	}
+
+	return []byte(header), nil
+}
+
+func keyTypeToHeader() map[pb.KeyType][]byte {
+	const rsaSigLen = 0x100
+
+	return map[pb.KeyType][]byte{
+		pb.KeyType_RSA: header(
+			Prefix,
+			multicodec.RsaPub,
+			multicodec.Sha2_256,
+			rsaSigLen,
+			multicodec.DagCbor,
+		),
+		pb.KeyType_Ed25519: header(
+			Prefix,
+			multicodec.Ed25519Pub,
+			multicodec.DagCbor,
+		),
+		pb.KeyType_Secp256k1: header(
+			Prefix,
+			multicodec.Secp256k1Pub,
+			multicodec.Sha2_256,
+			multicodec.DagCbor,
+		),
+		pb.KeyType_ECDSA: header(
+			Prefix,
+			multicodec.Es256,
+			multicodec.Sha2_256,
+			multicodec.DagCbor,
+		),
+	}
+}
+
+func headerToKeyType() map[string]pb.KeyType {
+	out := make(map[string]pb.KeyType, len(encMap))
+
+	for keyType, header := range encMap {
+		out[base64.RawStdEncoding.EncodeToString(header)] = keyType
+	}
+
+	return out
+}
+
+func header(vals ...multicodec.Code) []byte {
+	var buf []byte
+
+	for _, val := range vals {
+		buf = binary.AppendUvarint(buf, uint64(val))
+	}
+
+	return buf
+}

internal/varsig/varsig_test.go

@@ -0,0 +1,51 @@
+package varsig_test
+
+import (
+	"encoding/base64"
+	"fmt"
+	"testing"
+
+	"github.com/libp2p/go-libp2p/core/crypto/pb"
+	"github.com/stretchr/testify/assert"
+
+	"github.com/ucan-wg/go-ucan/internal/varsig"
+)
+
+func TestDecode(t *testing.T) {
+	t.Parallel()
+
+	notAHeader := base64.RawStdEncoding.EncodeToString([]byte("not a header"))
+	keyType, err := varsig.Decode([]byte(notAHeader))
+	assert.Equal(t, pb.KeyType(-1), keyType)
+	assert.ErrorIs(t, err, varsig.ErrUnknownHeader)
+}
+
+func ExampleDecode() {
+	hdr, err := base64.RawStdEncoding.DecodeString("NIUkEoACcQ")
+	if err != nil {
+		fmt.Println(err.Error())
+
+		return
+	}
+
+	keyType, _ := varsig.Decode(hdr)
+	fmt.Println(keyType.String())
+	// Output:
+	// RSA
+}
+
+func TestEncode(t *testing.T) {
+	t.Parallel()
+
+	header, err := varsig.Encode(pb.KeyType(99))
+	assert.Nil(t, header)
+	assert.ErrorIs(t, err, varsig.ErrUnknownKeyType)
+}
+
+func ExampleEncode() {
+	header, _ := varsig.Encode(pb.KeyType_RSA)
+	fmt.Println(base64.RawStdEncoding.EncodeToString(header))
+
+	// Output:
+	// NIUkEoACcQ
+}

pkg/args/args.go

@@ -1,187 +0,0 @@
-// Package args provides the type that represents the Arguments passed to
-// a command within an invocation.Token as well as a convenient Add method
-// to incrementally build the underlying map.
-package args
-
-import (
-	"errors"
-	"fmt"
-	"iter"
-	"sort"
-	"strings"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/fluent/qp"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-	"github.com/ipld/go-ipld-prime/printer"
-
-	"github.com/ucan-wg/go-ucan/pkg/policy/limits"
-	"github.com/ucan-wg/go-ucan/pkg/policy/literal"
-)
-
-var ErrNotFound = errors.New("key not found in meta")
-
-// Args are the Command's arguments when an invocation Token is processed by the executor.
-// This also serves as a way to construct the underlying IPLD data with minimum allocations
-// and transformations, while hiding the IPLD complexity from the caller.
-type Args struct {
-	// This type must be compatible with the IPLD type represented by the IPLD
-	// schema { String : Any }.
-
-	Keys   []string
-	Values map[string]ipld.Node
-}
-
-// New returns a pointer to an initialized Args value.
-func New() *Args {
-	return &Args{
-		Values: map[string]ipld.Node{},
-	}
-}
-
-// GetNode retrieves a value as a raw IPLD node.
-// Returns ErrNotFound if the given key is missing.
-func (a *Args) GetNode(key string) (ipld.Node, error) {
-	v, ok := a.Values[key]
-	if !ok {
-		return nil, ErrNotFound
-	}
-	return v, nil
-}
-
-// Add inserts a key/value pair in the Args set.
-//
-// Accepted types for val are any CBOR compatible type, or directly IPLD values.
-func (a *Args) Add(key string, val any) error {
-	if _, ok := a.Values[key]; ok {
-		return fmt.Errorf("duplicate key %q", key)
-	}
-
-	node, err := literal.Any(val)
-	if err != nil {
-		return err
-	}
-
-	if err := limits.ValidateIntegerBoundsIPLD(node); err != nil {
-		return fmt.Errorf("value for key %q: %w", key, err)
-	}
-
-	a.Values[key] = node
-	a.Keys = append(a.Keys, key)
-
-	return nil
-}
-
-type Iterator interface {
-	Iter() iter.Seq2[string, ipld.Node]
-}
-
-// Include merges the provided arguments into the existing arguments.
-//
-// If duplicate keys are encountered, the new value is silently dropped
-// without causing an error.
-func (a *Args) Include(other Iterator) {
-	for key, value := range other.Iter() {
-		if _, ok := a.Values[key]; ok {
-			// don't overwrite
-			continue
-		}
-		a.Values[key] = value
-		a.Keys = append(a.Keys, key)
-	}
-}
-
-// Len return the number of arguments.
-func (a *Args) Len() int {
-	return len(a.Keys)
-}
-
-// Iter iterates over the args key/values
-func (a *Args) Iter() iter.Seq2[string, ipld.Node] {
-	return func(yield func(string, ipld.Node) bool) {
-		for _, key := range a.Keys {
-			if !yield(key, a.Values[key]) {
-				return
-			}
-		}
-	}
-}
-
-// ToIPLD wraps an instance of an Args with an ipld.Node.
-func (a *Args) ToIPLD() (ipld.Node, error) {
-	sort.Strings(a.Keys)
-
-	return qp.BuildMap(basicnode.Prototype.Any, int64(len(a.Keys)), func(ma datamodel.MapAssembler) {
-		for _, key := range a.Keys {
-			qp.MapEntry(ma, key, qp.Node(a.Values[key]))
-		}
-	})
-}
-
-// Equals tells if two Args hold the same values.
-func (a *Args) Equals(other *Args) bool {
-	if len(a.Keys) != len(other.Keys) {
-		return false
-	}
-	if len(a.Values) != len(other.Values) {
-		return false
-	}
-	for _, key := range a.Keys {
-		if !ipld.DeepEqual(a.Values[key], other.Values[key]) {
-			return false
-		}
-	}
-	return true
-}
-
-func (a *Args) String() string {
-	sort.Strings(a.Keys)
-
-	buf := strings.Builder{}
-	buf.WriteString("{")
-
-	for _, key := range a.Keys {
-		buf.WriteString("\n\t")
-		buf.WriteString(key)
-		buf.WriteString(": ")
-		buf.WriteString(strings.ReplaceAll(printer.Sprint(a.Values[key]), "\n", "\n\t"))
-		buf.WriteString(",")
-	}
-
-	if len(a.Keys) > 0 {
-		buf.WriteString("\n")
-	}
-	buf.WriteString("}")
-
-	return buf.String()
-}
-
-// ReadOnly returns a read-only version of Args.
-func (a *Args) ReadOnly() ReadOnly {
-	return ReadOnly{args: a}
-}
-
-// Clone makes a deep copy.
-func (a *Args) Clone() *Args {
-	res := &Args{
-		Keys:   make([]string, len(a.Keys)),
-		Values: make(map[string]ipld.Node, len(a.Values)),
-	}
-	copy(res.Keys, a.Keys)
-	for k, v := range a.Values {
-		res.Values[k] = v
-	}
-	return res
-}
-
-// Validate checks that all values in the Args are valid according to UCAN specs
-func (a *Args) Validate() error {
-	for key, value := range a.Values {
-		if err := limits.ValidateIntegerBoundsIPLD(value); err != nil {
-			return fmt.Errorf("value for key %q: %w", key, err)
-		}
-	}
-
-	return nil
-}

pkg/args/args_test.go

@@ -1,297 +0,0 @@
-package args_test
-
-import (
-	"maps"
-	"sync"
-	"testing"
-
-	"github.com/ipfs/go-cid"
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/codec/dagcbor"
-	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-	"github.com/ipld/go-ipld-prime/schema"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/ucan-wg/go-ucan/pkg/args"
-	"github.com/ucan-wg/go-ucan/pkg/policy/limits"
-	"github.com/ucan-wg/go-ucan/pkg/policy/literal"
-)
-
-func TestArgs(t *testing.T) {
-	t.Parallel()
-
-	const (
-		intKey    = "intKey"
-		mapKey    = "mapKey"
-		nilKey    = "nilKey"
-		boolKey   = "boolKey"
-		linkKey   = "linkKey"
-		listKey   = "listKey"
-		nodeKey   = "nodeKey"
-		uintKey   = "uintKey"
-		bytesKey  = "bytesKey"
-		floatKey  = "floatKey"
-		stringKey = "stringKey"
-	)
-
-	const (
-		expIntVal    = int64(-42)
-		expBoolVal   = true
-		expUintVal   = uint(42)
-		expStringVal = "stringVal"
-	)
-
-	var (
-		expMapVal = map[string]string{"keyOne": "valOne", "keyTwo": "valTwo"}
-		// expNilVal = (map[string]string)(nil)
-		expLinkVal  = cid.MustParse("bafzbeigai3eoy2ccc7ybwjfz5r3rdxqrinwi4rwytly24tdbh6yk7zslrm")
-		expListVal  = []string{"elem1", "elem2", "elem3"}
-		expNodeVal  = literal.String("nodeVal")
-		expBytesVal = []byte{0xde, 0xad, 0xbe, 0xef}
-		expFloatVal = 42.0
-	)
-
-	argsIn := args.New()
-
-	for _, a := range []struct {
-		key string
-		val any
-	}{
-		{key: intKey, val: expIntVal},
-		{key: mapKey, val: expMapVal},
-		// {key:  nilKey, val: expNilVal},
-		{key: boolKey, val: expBoolVal},
-		{key: linkKey, val: expLinkVal},
-		{key: listKey, val: expListVal},
-		{key: uintKey, val: expUintVal},
-		{key: nodeKey, val: expNodeVal},
-		{key: bytesKey, val: expBytesVal},
-		{key: floatKey, val: expFloatVal},
-		{key: stringKey, val: expStringVal},
-	} {
-		require.NoError(t, argsIn.Add(a.key, a.val))
-	}
-
-	// Round-trip to DAG-CBOR
-	argsOut := roundTripThroughDAGCBOR(t, argsIn)
-	assert.ElementsMatch(t, argsIn.Keys, argsOut.Keys)
-	assert.Equal(t, argsIn.Values, argsOut.Values)
-
-	actMapVal := map[string]string{}
-	mit := argsOut.Values[mapKey].MapIterator()
-
-	for !mit.Done() {
-		k, v, err := mit.Next()
-		require.NoError(t, err)
-		ks := must(k.AsString())
-		vs := must(v.AsString())
-		actMapVal[ks] = vs
-	}
-
-	actListVal := []string{}
-	lit := argsOut.Values[listKey].ListIterator()
-
-	for !lit.Done() {
-		_, v, err := lit.Next()
-		require.NoError(t, err)
-		vs := must(v.AsString())
-
-		actListVal = append(actListVal, vs)
-	}
-
-	assert.Equal(t, expIntVal, must(argsOut.Values[intKey].AsInt()))
-	assert.Equal(t, expMapVal, actMapVal) // TODO: special accessor
-	// TODO: the nil map comes back empty (but the right type)
-	// assert.Equal(t, expNilVal, actNilVal)
-	assert.Equal(t, expBoolVal, must(argsOut.Values[boolKey].AsBool()))
-	assert.Equal(t, expLinkVal.String(), must(argsOut.Values[linkKey].AsLink()).(datamodel.Link).String()) // TODO: special accessor
-	assert.Equal(t, expListVal, actListVal)                                                                // TODO: special accessor
-	assert.Equal(t, expNodeVal, argsOut.Values[nodeKey])
-	assert.Equal(t, expUintVal, uint(must(argsOut.Values[uintKey].AsInt())))
-	assert.Equal(t, expBytesVal, must(argsOut.Values[bytesKey].AsBytes()))
-	assert.Equal(t, expFloatVal, must(argsOut.Values[floatKey].AsFloat()))
-	assert.Equal(t, expStringVal, must(argsOut.Values[stringKey].AsString()))
-}
-
-func TestArgs_Include(t *testing.T) {
-	t.Parallel()
-
-	argsIn := args.New()
-	require.NoError(t, argsIn.Add("key1", "val1"))
-	require.NoError(t, argsIn.Add("key2", "val2"))
-
-	argsOther := args.New()
-	require.NoError(t, argsOther.Add("key2", "valOther")) // This should not overwrite key2 above
-	require.NoError(t, argsOther.Add("key3", "val3"))
-	require.NoError(t, argsOther.Add("key4", "val4"))
-
-	argsIn.Include(argsOther)
-
-	assert.Len(t, argsIn.Values, 4)
-	assert.Equal(t, "val1", must(argsIn.Values["key1"].AsString()))
-	assert.Equal(t, "val2", must(argsIn.Values["key2"].AsString()))
-	assert.Equal(t, "val3", must(argsIn.Values["key3"].AsString()))
-	assert.Equal(t, "val4", must(argsIn.Values["key4"].AsString()))
-}
-
-func TestIterCloneEquals(t *testing.T) {
-	a := args.New()
-
-	require.NoError(t, a.Add("foo", "bar"))
-	require.NoError(t, a.Add("baz", 1234))
-
-	expected := map[string]ipld.Node{
-		"foo": basicnode.NewString("bar"),
-		"baz": basicnode.NewInt(1234),
-	}
-
-	// args -> iter
-	require.Equal(t, expected, maps.Collect(a.Iter()))
-
-	// readonly -> iter
-	ro := a.ReadOnly()
-	require.Equal(t, expected, maps.Collect(ro.Iter()))
-
-	// args -> clone -> iter
-	clone := a.Clone()
-	require.Equal(t, expected, maps.Collect(clone.Iter()))
-
-	// readonly -> WriteableClone -> iter
-	wclone := ro.WriteableClone()
-	require.Equal(t, expected, maps.Collect(wclone.Iter()))
-
-	require.True(t, a.Equals(wclone))
-	require.True(t, ro.Equals(wclone.ReadOnly()))
-}
-
-func TestInclude(t *testing.T) {
-	a1 := args.New()
-
-	require.NoError(t, a1.Add("samekey", "bar"))
-	require.NoError(t, a1.Add("baz", 1234))
-
-	a2 := args.New()
-
-	require.NoError(t, a2.Add("samekey", "othervalue")) // check no overwrite
-	require.NoError(t, a2.Add("otherkey", 1234))
-
-	a1.Include(a2)
-
-	require.Equal(t, map[string]ipld.Node{
-		"samekey":  basicnode.NewString("bar"),
-		"baz":      basicnode.NewInt(1234),
-		"otherkey": basicnode.NewInt(1234),
-	}, maps.Collect(a1.Iter()))
-}
-
-func TestArgsIntegerBounds(t *testing.T) {
-	t.Parallel()
-
-	tests := []struct {
-		name    string
-		key     string
-		val     int64
-		wantErr string
-	}{
-		{
-			name: "valid int",
-			key:  "valid",
-			val:  42,
-		},
-		{
-			name: "max safe integer",
-			key:  "max",
-			val:  limits.MaxInt53,
-		},
-		{
-			name: "min safe integer",
-			key:  "min",
-			val:  limits.MinInt53,
-		},
-		{
-			name:    "exceeds max safe integer",
-			key:     "tooBig",
-			val:     limits.MaxInt53 + 1,
-			wantErr: "exceeds safe integer bounds",
-		},
-		{
-			name:    "below min safe integer",
-			key:     "tooSmall",
-			val:     limits.MinInt53 - 1,
-			wantErr: "exceeds safe integer bounds",
-		},
-		{
-			name:    "duplicate key",
-			key:     "duplicate",
-			val:     42,
-			wantErr: "duplicate key",
-		},
-	}
-
-	a := args.New()
-	require.NoError(t, a.Add("duplicate", 1)) // tests duplicate key
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			err := a.Add(tt.key, tt.val)
-			if tt.wantErr != "" {
-				require.Error(t, err)
-				require.Contains(t, err.Error(), tt.wantErr)
-			} else {
-				require.NoError(t, err)
-				val, err := a.GetNode(tt.key)
-				require.NoError(t, err)
-				i, err := val.AsInt()
-				require.NoError(t, err)
-				require.Equal(t, tt.val, i)
-			}
-		})
-	}
-}
-
-const (
-	argsSchema = "type Args { String : Any }"
-	argsName   = "Args"
-)
-
-var (
-	once      sync.Once
-	ts        *schema.TypeSystem
-	errSchema error
-)
-
-func argsType() schema.Type {
-	once.Do(func() {
-		ts, errSchema = ipld.LoadSchemaBytes([]byte(argsSchema))
-	})
-	if errSchema != nil {
-		panic(errSchema)
-	}
-
-	return ts.TypeByName(argsName)
-}
-
-func roundTripThroughDAGCBOR(t *testing.T, argsIn *args.Args) *args.Args {
-	t.Helper()
-
-	node, err := argsIn.ToIPLD()
-	require.NoError(t, err)
-
-	data, err := ipld.Encode(node, dagcbor.Encode)
-	require.NoError(t, err)
-
-	var argsOut args.Args
-	_, err = ipld.Unmarshal(data, dagcbor.Decode, &argsOut, argsType())
-	require.NoError(t, err)
-
-	return &argsOut
-}
-
-func must[T any](t T, err error) T {
-	if err != nil {
-		panic(err)
-	}
-	return t
-}

pkg/args/builder.go

@@ -1,71 +0,0 @@
-package args
-
-import (
-	"errors"
-
-	"github.com/ipld/go-ipld-prime"
-)
-
-// Builder allows the fluid construction of an Args.
-type Builder struct {
-	args *Args
-	errs error
-}
-
-// NewBuilder returns a Builder which will assemble the Args.
-func NewBuilder() *Builder {
-	return &Builder{
-		args: New(),
-	}
-}
-
-// Add inserts a new key/val into the Args being assembled while collecting
-// any errors caused by duplicate keys.
-func (b *Builder) Add(key string, val any) *Builder {
-	b.errs = errors.Join(b.errs, b.args.Add(key, val))
-
-	return b
-}
-
-// Build returns the assembled Args or an error containing a list of
-// errors encountered while trying to build the Args.
-func (b *Builder) Build() (*Args, error) {
-	if b.errs != nil {
-		return nil, b.errs
-	}
-
-	return b.args, nil
-}
-
-// BuildIPLD is the same as Build except it takes the additional step of
-// converting the Args to an ipld.Node.
-func (b *Builder) BuildIPLD() (ipld.Node, error) {
-	args, err := b.Build()
-	if err != nil {
-		return nil, err
-	}
-
-	return args.ToIPLD()
-}
-
-// MustBuild is the same as Build except it panics if an error occurs.
-func (b *Builder) MustBuild() *Args {
-	args, err := b.Build()
-
-	if err != nil {
-		panic(b.errs)
-	}
-
-	return args
-}
-
-// MustBuildIPLD is the same as BuildIPLD except it panics if an error
-// occurs.
-func (b *Builder) MustBuildIPLD() ipld.Node {
-	node, err := b.BuildIPLD()
-	if err != nil {
-		panic(err)
-	}
-
-	return node
-}

pkg/args/builder_test.go

@@ -1,82 +0,0 @@
-package args_test
-
-import (
-	"testing"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-
-	"github.com/ucan-wg/go-ucan/pkg/args"
-)
-
-func TestBuilder_XXX(t *testing.T) {
-	t.Parallel()
-
-	const (
-		keyOne = "key1"
-		valOne = "string"
-		keyTwo = "key2"
-		valTwo = 42
-	)
-
-	exp := args.New()
-	exp.Add(keyOne, valOne)
-	exp.Add(keyTwo, valTwo)
-
-	expNode, err := exp.ToIPLD()
-	require.NoError(t, err)
-
-	disjointKeys := args.NewBuilder().
-		Add(keyOne, valOne).
-		Add(keyTwo, valTwo)
-
-	duplicateKeys := args.NewBuilder().
-		Add(keyOne, valOne).
-		Add(keyTwo, valTwo).
-		Add(keyOne, "oh no!")
-
-	t.Run("MustBuild succeeds with disjoint keys", func(t *testing.T) {
-		t.Parallel()
-
-		var act *args.Args
-
-		require.NotPanics(t, func() {
-			act = disjointKeys.MustBuild()
-		})
-		assert.Equal(t, exp, act)
-	})
-
-	t.Run("MustBuild fails with duplicate keys", func(t *testing.T) {
-		t.Parallel()
-
-		var act *args.Args
-
-		require.Panics(t, func() {
-			act = duplicateKeys.MustBuild()
-		})
-		assert.Nil(t, act)
-	})
-
-	t.Run("MustBuildIPLD succeeds with disjoint keys", func(t *testing.T) {
-		t.Parallel()
-
-		var act ipld.Node
-
-		require.NotPanics(t, func() {
-			act = disjointKeys.MustBuildIPLD()
-		})
-		assert.Equal(t, expNode, act)
-	})
-
-	t.Run("MustBuildIPLD fails with duplicate keys", func(t *testing.T) {
-		t.Parallel()
-
-		var act ipld.Node
-
-		require.Panics(t, func() {
-			act = duplicateKeys.MustBuildIPLD()
-		})
-		assert.Nil(t, act)
-	})
-}

pkg/args/readonly.go

@@ -1,39 +0,0 @@
-package args
-
-import (
-	"iter"
-
-	"github.com/ipld/go-ipld-prime"
-)
-
-type ReadOnly struct {
-	args *Args
-}
-
-func (r ReadOnly) GetNode(key string) (ipld.Node, error) {
-	return r.args.GetNode(key)
-}
-
-func (r ReadOnly) Len() int {
-	return r.args.Len()
-}
-
-func (r ReadOnly) Iter() iter.Seq2[string, ipld.Node] {
-	return r.args.Iter()
-}
-
-func (r ReadOnly) ToIPLD() (ipld.Node, error) {
-	return r.args.ToIPLD()
-}
-
-func (r ReadOnly) Equals(other ReadOnly) bool {
-	return r.args.Equals(other.args)
-}
-
-func (r ReadOnly) String() string {
-	return r.args.String()
-}
-
-func (r ReadOnly) WriteableClone() *Args {
-	return r.args.Clone()
-}

pkg/container/Readme.md

@@ -1,88 +0,0 @@
-# Token container
-
-The specification has been promoted to https://github.com/ucan-wg/container.
-
-## Why do I need that?
-
-Some common situation asks to package multiple tokens together:
-- calling a service requires sending an invocation, alongside the matching delegations
-- sending a series of revocations
-- \<insert your application specific scenario here>
-
-The UCAN specification defines how a single token is serialized (envelope with signature, IPLD encoded as Dag-cbor), but it's entirely left open how to package multiple tokens together. To be clear, this is a correct thing to do for a specification, as different ways equally valid to solve that problem exists and can coexist. Any wire format holding a list of bytes would do (cbor, json, csv ...).
-
-**go-ucan** however, provide an opinionated implementation, which may or may not work in your situation. 
-
-Some experiment has been done over which format is appropriate, and two have been selected:
-- **DAG-CBOR** of a list of bytes, as a low overhead option
-- **CAR** file, as a somewhat common ways to cary arbitrary blocks of data
-
-Notably, **compression is not included**, even though it does work reasonably well. This is because your transport medium might already do it, or should.
-
-## Wire format consideration
-
-Several possible formats have been explored:
-- CAR files (binary or base64)
-- DAG-CBOR (binary or base64)
-
-Additionally, gzip and deflate compression has been experimented with.
-
-Below are the results in terms of storage used, as percentage and byte overhead over the raw tokens:
-
-| Token count | car | carBase64 | carGzip | carGzipBase64 | cbor | cborBase64 | cborGzip | cborGzipBase64 | cborFlate | cborFlateBase64 |
-|-------------|-----|-----------|---------|---------------|------|------------|----------|----------------|-----------|-----------------|
-| 1           | 15  | 54        | 7       | 42            | 0    | 35         | \-8      | 22             | \-12      | 16              |
-| 2           | 12  | 49        | \-12    | 15            | 0    | 34         | \-25     | 0              | \-28      | \-3             |
-| 3           | 11  | 48        | \-21    | 4             | 0    | 34         | \-32     | \-10           | \-34      | \-11            |
-| 4           | 10  | 47        | \-26    | \-1           | 0    | 34         | \-36     | \-15           | \-37      | \-17            |
-| 5           | 10  | 47        | \-28    | \-4           | 0    | 34         | \-38     | \-18           | \-40      | \-20            |
-| 6           | 10  | 47        | \-30    | \-7           | 0    | 34         | \-40     | \-20           | \-40      | \-20            |
-| 7           | 10  | 46        | \-31    | \-8           | 0    | 34         | \-41     | \-21           | \-42      | \-22            |
-| 8           | 9   | 46        | \-32    | \-10          | 0    | 34         | \-42     | \-22           | \-42      | \-23            |
-| 9           | 9   | 46        | \-33    | \-11          | 0    | 34         | \-43     | \-23           | \-43      | \-24            |
-| 10          | 9   | 46        | \-34    | \-12          | 0    | 34         | \-43     | \-25           | \-44      | \-25            |
-
-![Overhead %](img/overhead_percent.png)
-
-| Token count | car | carBase64 | carGzip | carGzipBase64 | cbor | cborBase64 | cborGzip | cborGzipBase64 | cborFlate | cborFlateBase64 |
-|-------------|-----|-----------|---------|---------------|------|------------|----------|----------------|-----------|-----------------|
-| 1           | 64  | 226       | 29      | 178           | 4    | 146        | \-35     | 94             | \-52      | 70              |
-| 2           | 102 | 412       | \-107   | 128           | 7    | 288        | \-211    | 0              | \-234     | \-32            |
-| 3           | 140 | 602       | \-270   | 58            | 10   | 430        | \-405    | \-126          | \-429     | \-146           |
-| 4           | 178 | 792       | \-432   | \-28          | 13   | 572        | \-602    | \-252          | \-617     | \-288           |
-| 5           | 216 | 978       | \-582   | \-94          | 16   | 714        | \-805    | \-386          | \-839     | \-418           |
-| 6           | 254 | 1168      | \-759   | \-176         | 19   | 856        | \-1001   | \-508          | \-1018    | \-520           |
-| 7           | 292 | 1358      | \-908   | \-246         | 22   | 998        | \-1204   | \-634          | \-1229    | \-650           |
-| 8           | 330 | 1544      | \-1085  | \-332         | 25   | 1140       | \-1398   | \-756          | \-1423    | \-792           |
-| 9           | 368 | 1734      | \-1257  | \-414         | 28   | 1282       | \-1614   | \-894          | \-1625    | \-930           |
-| 10          | 406 | 1924      | \-1408  | \-508         | 31   | 1424       | \-1804   | \-1040         | \-1826    | \-1060          |
-
-![img.png](img/overhead_bytes.png)
-
-Following is the performance aspect, with CPU usage and memory allocation:
-
-|                 | Write ns/op | Read ns/op | Write B/op | Read B/op | Write allocs/op | Read allocs/op |
-|-----------------|-------------|------------|------------|-----------|-----------------|----------------|
-| car             | 8451        | 1474630    | 17928      | 149437    | 59              | 2631           |
-| carBase64       | 16750       | 1437678    | 24232      | 151502    | 61              | 2633           |
-| carGzip         | 320253      | 1581412    | 823887     | 192272    | 76              | 2665           |
-| carGzipBase64   | 343305      | 1486269    | 828782     | 198543    | 77              | 2669           |
-| cbor            | 6419        | 1301554    | 16368      | 138891    | 25              | 2534           |
-| cborBase64      | 12860       | 1386728    | 20720      | 140962    | 26              | 2536           |
-| cborGzip        | 310106      | 1379146    | 822742     | 182003    | 42              | 2585           |
-| cborGzipBase64  | 317001      | 1462548    | 827640     | 189283    | 43              | 2594           |
-| cborFlate       | 327112      | 1555007    | 822473     | 181537    | 40              | 2591           |
-| cborFlateBase64 | 311276      | 1456562    | 826042     | 188665    | 41              | 2596           |
-
-(BEWARE: logarithmic scale)
-
-![img.png](img/cpu.png)
-![img_1.png](img/alloc_byte.png)
-![img_2.png](img/alloc_count.png)
-
-Conclusion:
-- CAR files are heavy for this usage, notably because they carry the CIDs of the tokens
-- compression works quite well and warrants its usage even with a single token
-- DAG-CBOR outperform CAR files everywhere, and comes with a tiny ~3 bytes per token overhead.
-
-**Formats beside DAG-CBOR and CAR, with or without base64, have been removed. They are in the git history though.**

pkg/container/car.go

@@ -1,263 +0,0 @@
-package container
-
-import (
-	"bufio"
-	"bytes"
-	"encoding/binary"
-	"fmt"
-	"io"
-	"iter"
-
-	"github.com/ipfs/go-cid"
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/codec/dagcbor"
-	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/fluent/qp"
-	cidlink "github.com/ipld/go-ipld-prime/linking/cid"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-)
-
-/*
-	Note: below is essentially a re-implementation of the CAR file v1 read and write.
-	This exists here for two reasons:
-		- go-car's API forces to go through an IPLD getter or through a blockstore API
-		- generally, go-car is a very complex and large dependency
-*/
-
-// EmptyCid is a "zero" Cid: zero-length "identity" multihash with "raw" codec
-// It can be used to have at least one root in a CARv1 file (making it legal), yet
-// denote that it can be ignored.
-var EmptyCid = cid.MustParse([]byte{01, 55, 00, 00})
-
-type carBlock struct {
-	c    cid.Cid
-	data []byte
-}
-
-// writeCar writes a CARv1 file containing the blocks from the iterator.
-// If no roots are provided, a single EmptyCid is used as root to make the file
-// spec compliant.
-func writeCar(w io.Writer, roots []cid.Cid, blocks iter.Seq2[carBlock, error]) error {
-	if len(roots) == 0 {
-		roots = []cid.Cid{EmptyCid}
-	}
-	h := carHeader{
-		Roots:   roots,
-		Version: 1,
-	}
-	hb, err := h.Write()
-	if err != nil {
-		return err
-	}
-	err = ldWrite(w, hb)
-	if err != nil {
-		return err
-	}
-
-	for block, err := range blocks {
-		if err != nil {
-			return err
-		}
-		err = ldWrite(w, block.c.Bytes(), block.data)
-		if err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-// readCar reads a CARv1 file from the reader, and return a block iterator.
-// Roots are ignored.
-func readCar(r io.Reader) (roots []cid.Cid, blocks iter.Seq2[carBlock, error], err error) {
-	br := bufio.NewReader(r)
-
-	hb, err := ldRead(br)
-	if err != nil {
-		return nil, nil, err
-	}
-	h, err := readHeader(hb)
-	if err != nil {
-		return nil, nil, err
-	}
-	if h.Version != 1 {
-		return nil, nil, fmt.Errorf("invalid car version: %d", h.Version)
-	}
-
-	return h.Roots, func(yield func(block carBlock, err error) bool) {
-		for {
-			block, err := readBlock(br)
-			if err == io.EOF {
-				return
-			}
-			if err != nil {
-				if !yield(carBlock{}, err) {
-					return
-				}
-			}
-			if !yield(block, nil) {
-				return
-			}
-		}
-	}, nil
-}
-
-// readBlock reads a section from the reader and decode a (cid+data) block.
-func readBlock(r *bufio.Reader) (carBlock, error) {
-	raw, err := ldRead(r)
-	if err != nil {
-		return carBlock{}, err
-	}
-
-	n, c, err := cid.CidFromReader(bytes.NewReader(raw))
-	if err != nil {
-		return carBlock{}, err
-	}
-	data := raw[n:]
-
-	// integrity check
-	hashed, err := c.Prefix().Sum(data)
-	if err != nil {
-		return carBlock{}, err
-	}
-
-	if !hashed.Equals(c) {
-		return carBlock{}, fmt.Errorf("mismatch in content integrity, name: %s, data: %s", c, hashed)
-	}
-
-	return carBlock{c: c, data: data}, nil
-}
-
-// maxAllowedSectionSize dictates the maximum number of bytes that a CARv1 header
-// or section is allowed to occupy without causing a decode to error.
-// This cannot be supplied as an option, only adjusted as a global. You should
-// use v2#NewReader instead since it allows for options to be passed in.
-var maxAllowedSectionSize uint = 32 << 20 // 32MiB
-
-// ldRead performs a length-delimited read of a section from the reader.
-// A section is composed of an uint length followed by the data.
-func ldRead(r *bufio.Reader) ([]byte, error) {
-	if _, err := r.Peek(1); err != nil { // no more blocks, likely clean io.EOF
-		return nil, err
-	}
-
-	l, err := binary.ReadUvarint(r)
-	if err != nil {
-		if err == io.EOF {
-			return nil, io.ErrUnexpectedEOF // don't silently pretend this is a clean EOF
-		}
-		return nil, err
-	}
-	if l == 0 {
-		return nil, fmt.Errorf("invalid zero size section")
-	}
-
-	if l > uint64(maxAllowedSectionSize) { // Don't OOM
-		return nil, fmt.Errorf("malformed car; header is bigger than MaxAllowedSectionSize")
-	}
-
-	buf := make([]byte, l)
-	if _, err := io.ReadFull(r, buf); err != nil {
-		if err == io.EOF {
-			// we should be able to read the promised bytes, this is not normal
-			return nil, io.ErrUnexpectedEOF
-		}
-		return nil, err
-	}
-
-	return buf, nil
-}
-
-// ldWrite performs a length-delimited write of a section on the writer.
-// A section is composed of an uint length followed by the data.
-func ldWrite(w io.Writer, d ...[]byte) error {
-	var sum uint64
-	for _, s := range d {
-		sum += uint64(len(s))
-	}
-
-	buf := make([]byte, 8)
-	n := binary.PutUvarint(buf, sum)
-	_, err := w.Write(buf[:n])
-	if err != nil {
-		return err
-	}
-
-	for _, s := range d {
-		_, err = w.Write(s)
-		if err != nil {
-			return err
-		}
-	}
-
-	return nil
-}
-
-type carHeader struct {
-	Roots   []cid.Cid
-	Version uint64
-}
-
-const rootsKey = "roots"
-const versionKey = "version"
-
-func readHeader(data []byte) (*carHeader, error) {
-	var header carHeader
-
-	nd, err := ipld.Decode(data, dagcbor.Decode)
-	if err != nil {
-		return nil, err
-	}
-	if nd.Length() != 2 {
-		return nil, fmt.Errorf("malformed car header")
-	}
-	rootsNd, err := nd.LookupByString(rootsKey)
-	if err != nil {
-		return nil, fmt.Errorf("malformed car header")
-	}
-	it := rootsNd.ListIterator()
-	if it == nil {
-		return nil, fmt.Errorf("malformed car header")
-	}
-	header.Roots = make([]cid.Cid, 0, rootsNd.Length())
-	for !it.Done() {
-		_, nd, err := it.Next()
-		if err != nil {
-			return nil, err
-		}
-		lk, err := nd.AsLink()
-		if err != nil {
-			return nil, err
-		}
-		switch lk := lk.(type) {
-		case cidlink.Link:
-			header.Roots = append(header.Roots, lk.Cid)
-		default:
-			return nil, fmt.Errorf("malformed car header")
-		}
-	}
-	versionNd, err := nd.LookupByString(versionKey)
-	if err != nil {
-		return nil, fmt.Errorf("malformed car header")
-	}
-	version, err := versionNd.AsInt()
-	if err != nil {
-		return nil, fmt.Errorf("malformed car header")
-	}
-	header.Version = uint64(version)
-	return &header, nil
-}
-
-func (ch *carHeader) Write() ([]byte, error) {
-	nd, err := qp.BuildMap(basicnode.Prototype.Any, 2, func(ma datamodel.MapAssembler) {
-		qp.MapEntry(ma, rootsKey, qp.List(int64(len(ch.Roots)), func(la datamodel.ListAssembler) {
-			for _, root := range ch.Roots {
-				qp.ListEntry(la, qp.Link(cidlink.Link{Cid: root}))
-			}
-		}))
-		qp.MapEntry(ma, versionKey, qp.Int(1))
-	})
-	if err != nil {
-		return nil, err
-	}
-	return ipld.Encode(nd, dagcbor.Encode)
-}

pkg/container/car_test.go

@@ -1,85 +0,0 @@
-package container
-
-import (
-	"bytes"
-	"os"
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-func TestCarRoundTrip(t *testing.T) {
-	// this car file is a complex and legal CARv1 file
-	original, err := os.ReadFile("testdata/sample-v1.car")
-	require.NoError(t, err)
-
-	roots, it, err := readCar(bytes.NewReader(original))
-	require.NoError(t, err)
-
-	var blks []carBlock
-	for blk, err := range it {
-		require.NoError(t, err)
-		blks = append(blks, blk)
-	}
-
-	require.Len(t, blks, 1049)
-
-	buf := bytes.NewBuffer(nil)
-
-	err = writeCar(buf, roots, func(yield func(carBlock, error) bool) {
-		for _, blk := range blks {
-			if !yield(blk, nil) {
-				return
-			}
-		}
-	})
-	require.NoError(t, err)
-
-	// Bytes equal after the round-trip
-	require.Equal(t, original, buf.Bytes())
-}
-
-func FuzzCarRoundTrip(f *testing.F) {
-	// Note: this fuzzing is somewhat broken.
-	// After some time, the fuzzer discover that a varint can be serialized in different
-	// ways that lead to the same integer value. This means that the CAR format can have
-	// multiple legal binary representation for the exact same data, which is what we are
-	// trying to detect here. Ideally, the format would be stricter, but that's how things
-	// are.
-
-	example, err := os.ReadFile("testdata/sample-v1.car")
-	require.NoError(f, err)
-
-	f.Add(example)
-
-	f.Fuzz(func(t *testing.T, data []byte) {
-		roots, blocksIter, err := readCar(bytes.NewReader(data))
-		if err != nil {
-			// skip invalid binary
-			t.Skip()
-		}
-
-		// reading all the blocks, which force reading and verifying the full file
-		var blocks []carBlock
-		for block, err := range blocksIter {
-			if err != nil {
-				// error reading, invalid data
-				t.Skip()
-			}
-			blocks = append(blocks, block)
-		}
-
-		var buf bytes.Buffer
-		err = writeCar(&buf, roots, func(yield func(carBlock, error) bool) {
-			for _, blk := range blocks {
-				if !yield(blk, nil) {
-					return
-				}
-			}
-		})
-		require.NoError(t, err)
-
-		// test if the round-trip produce a byte-equal CAR
-		require.Equal(t, data, buf.Bytes())
-	})
-}

pkg/container/containertest/Base64StdPaddingGzipped

@@ -1 +0,0 @@
-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

pkg/container/containertest/Base64URLGzipped

@@ -1 +0,0 @@
-PH4sIAAAAAAAA_5zW65MU1f3HcS7-hB8igpfIgqUxCqLC0tfTfUADMzs7M87ObubaOzMEsM-lp6eb6Zmee49GvEKwVBQRgygIUVHLCwoqoJAAikCQaJRICCqFGPCCcXVFoaBMJbukKs929h94P3nV-ZzvSg2XrEkV9u7kwFW3J6bv7bj7tflfrjm4e8_grc7Dke4jPx6c_Mm87olH_O9Of35_59-X7z2xe056dKx7156F074aOXzCcemCRe-Y4T3n3v7SNV-fdd4qVfcLA48NPDbwArtYxqo1mcxJT2ebmWZmUgE3s09jtUxqMsmQKSZ1ptRBu5lF0WK75ZbawpVO25NW2rLtfgG5XFZKtlwBr1GPVfyKU9YjZS_BOEv0yVouNxmpBUxr-TH6osmv4Uyx-L9NM5PUWqLtmqTohbQnkWp1i5JlxiOWLxAFAdaJeU13Z0gwWsN2AOdzc267A6tz5uDmGTPvUH-pNVfUOWU6CBfLqP9ZkqUl9fc6w3KqRmTVUDWGB1BiiKoDCBhJptRABAuCxrJY0zHPQBZjbLCY8hKCVBOplbMwDXbdsO9O4ZT5m20fTPywBymh3HfTBjDl5MzlT65xpm15kC4-f_2hlTtKyQUbrj78wBPfjn1e3T9i7OmuEfmt25d4z_q2K_0H36lRiw_9NbK0Szy0d3A_kPKuFk6qOYqVTSCj2uGNknxdT0BN0Etlqklxr8QaSqzF468oQl-R0oo7rztKQaK5crqzmMq7vOV4uh4jFZ2zPIrfFL0hS_ZYOFikDSA1ku1FAqJEZIRUA2gMy0OeY4EOKGVlHmCDIgZKKhYhp2NKGQR5YvBYZAWVp4j0Io1b4N905xU_e_SJj1-4pAfpbefa207fnMit_9XP39xxw7D3Fk0bH7vs09W_3uwcG3Vk5Nxv14yYP2Zj7lLPQ01Nnw0bsmXTssuZprL6-dX3zB3U9NH9q8_tB1KhgwUG8gA54HH5OcMyW1vqjmLnO11GNB0Ph6ut8WI1zAbdSMv2FclKhWK2riCS9trFvDvmd3tC0bpo8SAeC5QExZfiO3LeIOuKePkGkBrJnkEiWJYlnjEg1nhERSKouowIUgEvGUTGRBN5Ims6QiyVZVUwNIp4GUNOxr1I199x4OH_y6103Q-3DOhBuhYw1x1Y9eHYjejREfahp2Z9SNaqo83Xb0yff-mFr3_srFg7at3FV2aEy28atv2p8zbc-313YOQ3y65gm1Z9MHzdipHm0H4gFYmaLrQGWjpFLp4ICmagamWKHI560tlAsoa1uNcotoQKWj7fGuvz3Ck1v5hJgvZQJGYIKTlcFrypWocVLHPuEC_oWa2e0M3OVsen-BuZuwayZ-YOckQARDJ4TLAsChqUdVHVOBkA1pA5GVKGkaiqA04CDISiIcoUMhRjCHuRmjJraxO7f_ji-PiTE3pf0g83F4Zc-hF4-7uTV4XPG7xw986TC__2_qlnjrf9OLDrrKfeXioPGvtN0-NHRv8OHh7_5fzP1V3Lt40Zar-z-c3Vtx5O54b0AykTCrGsVS1iKmkdapQ1q6lqKWkV2gD1J3MIY09SlHw5O6yHgn1FqnoTLU66YobsbASoKq46rmoka2c8LomNkHBFYH2VVldNa-GTQgNIjWR7kTiVAIYRsYEFTcMCgpDqogw4TFXGwKqmYaACRtMJ4ClmEDAQFaHAYAbSXqRXxt9z8fIVxXOXjpjI9SDtXIkK6MJ3T6xbv-WuN7azi9K8UGl5a1t056x9G6fgxJJ5g03lSBk_O2juXV0Lnh2kVHfIwcqrKw-9dboId5X-eU5__iRPLhyxMsF03C9ZnWYKtRfZajIbUDjb68k7XFG2UL5adKesKOwrku42qkgrRaK2lI1jYJaMelnpaLf9RhW0sfmUrjk-FymaAcHBDSA1ku1FYjVeBBpGBqUCpjIUKdI5TuAwwqqhiQAAyvAQ6BoDBCgiwSCizMsSQhzfi_SP-2K_-PGE9saxTzMze5Dy-z0P7Di679olRys3fzdIXbZgbpvy0Krm5oXnnP_1w9yzj0yF8_64bCjzW2H22feEv48NLk6_8UD32fWPNvlf_CS18OUB_UDSE1WcaNUKSsqx_SjA-zNeLYI4T0cybfM4pbMg4AknnbbOetjqK1K-blcKUt4DWcNrVBzBIiJ2fGE7W8gCKZbI4WhBy4KkP9MWhA0gNZL9LxJLVMQhA_KEkTAjEkbnBZFILMQGQRLPi5gSpAOqEShqqoFFWZA4jCHoRRLeO9XcMqtwy7p35cd6kIY99snirRBtnvqcHN9benz4hCuG3LJt9bafZki7thTP_mHpi5PGXfbY6N1Nm68Z992tLD51S-q5DR98dsnhAbNSNzwZvOr_-4FUTdpy0XIjlg0nZSHkqaneUBVUCylgZEtmwQ3LhZrhR3WtkrX7PHegSpISVKtKuCYFyu11s5pK6FHbR112BNtsIZUOt1fSHVIuLzYydw1kz8ydoGqUF4nBizIHZYFyog5ZLHCU0QwEOZGROVEiusr824blDCgBSSIMgGdO8ClPP7KYPJnsQIeKG3uQrnz5teFvvD98hrrOc3nrmK3rn9s_-09PjBzaddOwxDl3Hz1xfEx810uPhvYcbL3sL9dNWjnuxamjXnCFEheAP29i5nXf3tGf6y7r6qwrJZfHlLyGLCvuWCf05Qp6JGDYBaNWqnvS5bKN_VRBVaWvSDnJBG4lHBEAl05yIccVIHZabmmLBttdobSjaKY3FRY9alvY42oAqZFsL5KKCAaEQkMlokgpyzKijhlRpaIoGZClCLCU1ahOIGQhFWSDQwLLqkhlzrwkvOH-ScEtSw68Omr87B6kpYWRa185WbvuC8u8aMC0i1pXbHeO72P9982fsHhh2xbf8WGe0y5Zq-wAk3YenZ05evG93MzVAx78aXJlxr1r2hce7A9Srqh6jIIVjNU7INENUg7Tqmz7tFBb2pfy-oq6zxuOOO0kWo27-3yC58tCwi900DxOtpk-k2txFCfuCGKllnOscqVk-W0N1dmoFcw3coI3kO1FElVWYhiiGhzgCS-xPES6zFKVAZxgyIAXJZWjAOsygppAEG_8Z-wIQZzai7Ri5eyp3V8981nL9fET_woAAP__svLMp3sQAAA

pkg/container/containertest/containertest.go

@@ -1,21 +0,0 @@
-package containertest
-
-import _ "embed"
-
-//go:embed Base64StdPadding
-var Base64StdPadding string
-
-//go:embed Base64StdPaddingGzipped
-var Base64StdPaddingGzipped string
-
-//go:embed Base64URL
-var Base64URL string
-
-//go:embed Base64URLGzipped
-var Base64URLGzipped string
-
-//go:embed Bytes
-var Bytes []byte
-
-//go:embed BytesGzipped
-var BytesGzipped []byte

pkg/container/packaging.go

@@ -1,118 +0,0 @@
-package container
-
-import (
-	"compress/gzip"
-	"encoding/base64"
-	"errors"
-	"fmt"
-	"io"
-)
-
-const containerVersionTag = "ctn-v1"
-
-type header byte
-
-const (
-	headerRawBytes             = header(0x40)
-	headerBase64StdPadding     = header(0x42)
-	headerBase64URL            = header(0x43)
-	headerRawBytesGzip         = header(0x4D)
-	headerBase64StdPaddingGzip = header(0x4F)
-	headerBase64URLGzip        = header(0x50)
-)
-
-func (h header) encoder(w io.Writer) *payloadWriter {
-	res := &payloadWriter{rawWriter: w, writer: w, header: h}
-
-	switch h {
-	case headerBase64StdPadding, headerBase64StdPaddingGzip:
-		b64Writer := base64.NewEncoder(base64.StdEncoding, res.writer)
-		res.writer = b64Writer
-		res.closers = append([]io.Closer{b64Writer}, res.closers...)
-	case headerBase64URL, headerBase64URLGzip:
-		b64Writer := base64.NewEncoder(base64.RawURLEncoding, res.writer)
-		res.writer = b64Writer
-		res.closers = append([]io.Closer{b64Writer}, res.closers...)
-	}
-
-	switch h {
-	case headerRawBytesGzip, headerBase64StdPaddingGzip, headerBase64URLGzip:
-		gzipWriter := gzip.NewWriter(res.writer)
-		res.writer = gzipWriter
-		res.closers = append([]io.Closer{gzipWriter}, res.closers...)
-	}
-
-	return res
-}
-
-func payloadDecoder(r io.Reader) (io.Reader, error) {
-	headerBuf := make([]byte, 1)
-	_, err := r.Read(headerBuf)
-	if err != nil {
-		return nil, err
-	}
-	h := header(headerBuf[0])
-
-	switch h {
-	case headerRawBytes,
-		headerBase64StdPadding,
-		headerBase64URL,
-		headerRawBytesGzip,
-		headerBase64StdPaddingGzip,
-		headerBase64URLGzip:
-	default:
-		return nil, fmt.Errorf("unknown container header")
-	}
-
-	switch h {
-	case headerBase64StdPadding, headerBase64StdPaddingGzip:
-		r = base64.NewDecoder(base64.StdEncoding, r)
-	case headerBase64URL, headerBase64URLGzip:
-		r = base64.NewDecoder(base64.RawURLEncoding, r)
-	}
-
-	switch h {
-	case headerRawBytesGzip, headerBase64StdPaddingGzip, headerBase64URLGzip:
-		gzipReader, err := gzip.NewReader(r)
-		if err != nil {
-			return nil, err
-		}
-		r = gzipReader
-	}
-
-	return r, nil
-}
-
-var _ io.WriteCloser = &payloadWriter{}
-
-// payloadWriter is tasked with two things:
-// - prepend the header byte
-// - call Close() on all the underlying io.Writer
-type payloadWriter struct {
-	rawWriter   io.Writer
-	writer      io.Writer
-	header      header
-	headerWrote bool
-	closers     []io.Closer
-}
-
-func (w *payloadWriter) Write(p []byte) (n int, err error) {
-	if !w.headerWrote {
-		_, err := w.rawWriter.Write([]byte{byte(w.header)})
-		if err != nil {
-			return 0, err
-		}
-		w.headerWrote = true
-	}
-	return w.writer.Write(p)
-}
-
-func (w *payloadWriter) Close() error {
-	var errs error
-	for _, closer := range w.closers {
-		if err := closer.Close(); err != nil {
-			errs = errors.Join(errs, err)
-		}
-	}
-	return errs
-}

pkg/container/reader.go

@@ -1,235 +0,0 @@
-package container
-
-import (
-	"bytes"
-	"fmt"
-	"io"
-	"iter"
-	"strings"
-
-	"github.com/ipfs/go-cid"
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/codec/cbor"
-	"github.com/ipld/go-ipld-prime/datamodel"
-
-	"github.com/ucan-wg/go-ucan/token"
-	"github.com/ucan-wg/go-ucan/token/delegation"
-	"github.com/ucan-wg/go-ucan/token/invocation"
-)
-
-var ErrNotFound = fmt.Errorf("not found")
-var ErrMultipleInvocations = fmt.Errorf("multiple invocations")
-
-// Reader is a token container reader. It exposes the tokens conveniently decoded.
-type Reader map[cid.Cid]bundle
-
-type bundle struct {
-	sealed []byte
-	token  token.Token
-}
-
-// FromBytes decodes a container from a []byte
-func FromBytes(data []byte) (Reader, error) {
-	return FromReader(bytes.NewReader(data))
-}
-
-// FromString decodes a container from a string
-func FromString(s string) (Reader, error) {
-	return FromReader(strings.NewReader(s))
-}
-
-// FromReader decodes a container from an io.Reader.
-func FromReader(r io.Reader) (Reader, error) {
-	payload, err := payloadDecoder(r)
-	if err != nil {
-		return nil, err
-	}
-
-	n, err := ipld.DecodeStreaming(payload, cbor.Decode)
-	if err != nil {
-		return nil, err
-	}
-	if n.Kind() != datamodel.Kind_Map {
-		return nil, fmt.Errorf("invalid container format: expected map")
-	}
-	if n.Length() != 1 {
-		return nil, fmt.Errorf("invalid container format: expected single version key")
-	}
-
-	// get the first (and only) key-value pair
-	it := n.MapIterator()
-	key, tokensNode, err := it.Next()
-	if err != nil {
-		return nil, err
-	}
-
-	version, err := key.AsString()
-	if err != nil {
-		return nil, fmt.Errorf("invalid container format: version must be string")
-	}
-	if version != containerVersionTag {
-		return nil, fmt.Errorf("unsupported container version: %s", version)
-	}
-
-	if tokensNode.Kind() != datamodel.Kind_List {
-		return nil, fmt.Errorf("invalid container format: tokens must be a list")
-	}
-
-	ctn := make(Reader, tokensNode.Length())
-	it2 := tokensNode.ListIterator()
-	for !it2.Done() {
-		_, val, err := it2.Next()
-		if err != nil {
-			return nil, err
-		}
-		data, err := val.AsBytes()
-		if err != nil {
-			return nil, err
-		}
-		err = ctn.addToken(data)
-		if err != nil {
-			return nil, err
-		}
-	}
-	return ctn, nil
-}
-
-// GetToken returns an arbitrary decoded token, from its CID.
-// If not found, ErrNotFound is returned.
-func (ctn Reader) GetToken(cid cid.Cid) (token.Token, error) {
-	bndl, ok := ctn[cid]
-	if !ok {
-		return nil, ErrNotFound
-	}
-	return bndl.token, nil
-}
-
-// GetSealed returns an arbitrary sealed token, from its CID.
-// If not found, ErrNotFound is returned.
-func (ctn Reader) GetSealed(cid cid.Cid) ([]byte, error) {
-	bndl, ok := ctn[cid]
-	if !ok {
-		return nil, ErrNotFound
-	}
-	return bndl.sealed, nil
-}
-
-// GetAllTokens return all the tokens in the container.
-func (ctn Reader) GetAllTokens() iter.Seq[token.Bundle] {
-	return func(yield func(token.Bundle) bool) {
-		for c, bndl := range ctn {
-			if !yield(token.Bundle{
-				Cid:     c,
-				Decoded: bndl.token,
-				Sealed:  bndl.sealed,
-			}) {
-				return
-			}
-		}
-	}
-}
-
-// GetDelegation is the same as GetToken but only return a delegation.Token, with the right type.
-// If not found, delegation.ErrDelegationNotFound is returned.
-func (ctn Reader) GetDelegation(cid cid.Cid) (*delegation.Token, error) {
-	tkn, err := ctn.GetToken(cid)
-	if err != nil { // only ErrNotFound expected
-		return nil, delegation.ErrDelegationNotFound
-	}
-	if tkn, ok := tkn.(*delegation.Token); ok {
-		return tkn, nil
-	}
-	return nil, delegation.ErrDelegationNotFound
-}
-
-// GetDelegationBundle is the same as GetToken but only return a delegation.Bundle, with the right type.
-// If not found, delegation.ErrDelegationNotFound is returned.
-func (ctn Reader) GetDelegationBundle(cid cid.Cid) (*delegation.Bundle, error) {
-	bndl, ok := ctn[cid]
-	if !ok {
-		return nil, delegation.ErrDelegationNotFound
-	}
-	if tkn, ok := bndl.token.(*delegation.Token); ok {
-		return &delegation.Bundle{
-			Cid:     cid,
-			Decoded: tkn,
-			Sealed:  bndl.sealed,
-		}, nil
-	}
-	return nil, delegation.ErrDelegationNotFound
-}
-
-// GetAllDelegations returns all the delegation.Token in the container.
-func (ctn Reader) GetAllDelegations() iter.Seq[*delegation.Bundle] {
-	return func(yield func(*delegation.Bundle) bool) {
-		for c, bndl := range ctn {
-			if t, ok := bndl.token.(*delegation.Token); ok {
-				if !yield(&delegation.Bundle{
-					Cid:     c,
-					Decoded: t,
-					Sealed:  bndl.sealed,
-				}) {
-					return
-				}
-			}
-		}
-	}
-}
-
-// GetInvocation returns a single invocation.Token.
-// If none are found, ErrNotFound is returned.
-// If more than one invocation exists, ErrMultipleInvocations is returned.
-func (ctn Reader) GetInvocation() (*invocation.Token, error) {
-	var res *invocation.Token
-	for _, bndl := range ctn {
-		if inv, ok := bndl.token.(*invocation.Token); ok {
-			if res != nil {
-				return nil, ErrMultipleInvocations
-			}
-			res = inv
-		}
-	}
-	if res == nil {
-		return nil, ErrNotFound
-	}
-	return res, nil
-}
-
-// GetAllInvocations returns all the invocation.Token in the container.
-func (ctn Reader) GetAllInvocations() iter.Seq[invocation.Bundle] {
-	return func(yield func(invocation.Bundle) bool) {
-		for c, bndl := range ctn {
-			if t, ok := bndl.token.(*invocation.Token); ok {
-				if !yield(invocation.Bundle{
-					Cid:     c,
-					Decoded: t,
-					Sealed:  bndl.sealed,
-				}) {
-					return
-				}
-			}
-		}
-	}
-}
-
-func (ctn Reader) addToken(data []byte) error {
-	tkn, c, err := token.FromSealed(data)
-	if err != nil {
-		return err
-	}
-	ctn[c] = bundle{
-		sealed: data,
-		token:  tkn,
-	}
-	return nil
-}
-
-// ToWriter convert a container Reader into a Writer.
-// Most likely, you only want to use this in tests for convenience.
-func (ctn Reader) ToWriter() Writer {
-	writer := NewWriter()
-	for _, bndl := range ctn {
-		writer.AddSealed(bndl.sealed)
-	}
-	return writer
-}

pkg/container/serial_test.go

@@ -1,243 +0,0 @@
-package container
-
-import (
-	"bytes"
-	"crypto/rand"
-	"fmt"
-	"io"
-	"strings"
-	"testing"
-	"time"
-
-	"github.com/MetaMask/go-did-it"
-	"github.com/MetaMask/go-did-it/controller/did-key"
-	"github.com/MetaMask/go-did-it/crypto/ed25519"
-	"github.com/ipfs/go-cid"
-	"github.com/stretchr/testify/require"
-
-	"github.com/ucan-wg/go-ucan/pkg/command"
-	"github.com/ucan-wg/go-ucan/pkg/policy"
-	"github.com/ucan-wg/go-ucan/pkg/policy/literal"
-	"github.com/ucan-wg/go-ucan/token/delegation"
-)
-
-func TestContainerRoundTrip(t *testing.T) {
-	for _, tc := range []struct {
-		name           string
-		expectedHeader header
-		writer         any
-	}{
-		{"Bytes", headerRawBytes, Writer.ToBytes},
-		{"BytesWriter", headerRawBytes, Writer.ToBytesWriter},
-		{"BytesGzipped", headerRawBytesGzip, Writer.ToBytesGzipped},
-		{"BytesGzippedWriter", headerRawBytesGzip, Writer.ToBytesGzippedWriter},
-		{"Base64StdPadding", headerBase64StdPadding, Writer.ToBase64StdPadding},
-		{"Base64StdPaddingWriter", headerBase64StdPadding, Writer.ToBase64StdPaddingWriter},
-		{"Base64StdPaddingGzipped", headerBase64StdPaddingGzip, Writer.ToBase64StdPaddingGzipped},
-		{"Base64StdPaddingGzippedWriter", headerBase64StdPaddingGzip, Writer.ToBase64StdPaddingGzippedWriter},
-		{"Base64URL", headerBase64URL, Writer.ToBase64URL},
-		{"Base64URLWriter", headerBase64URL, Writer.ToBase64URLWriter},
-		{"Base64URLGzipped", headerBase64URLGzip, Writer.ToBase64URLGzipped},
-		{"Base64URLGzipWriter", headerBase64URLGzip, Writer.ToBase64URLGzipWriter},
-	} {
-		t.Run(tc.name, func(t *testing.T) {
-			tokens := make(map[cid.Cid]*delegation.Token)
-			var dataSize int
-
-			writer := NewWriter()
-
-			for i := 0; i < 10; i++ {
-				dlg, c, data := randToken()
-				writer.AddSealed(data)
-				tokens[c] = dlg
-				dataSize += len(data)
-			}
-
-			var reader Reader
-			var serialLen int
-
-			switch fn := tc.writer.(type) {
-			case func(ctn Writer, w io.Writer) error:
-				buf := bytes.NewBuffer(nil)
-				err := fn(writer, buf)
-				require.NoError(t, err)
-				serialLen = buf.Len()
-
-				h, err := buf.ReadByte()
-				require.NoError(t, err)
-				require.Equal(t, byte(tc.expectedHeader), h)
-				err = buf.UnreadByte()
-				require.NoError(t, err)
-
-				reader, err = FromReader(bytes.NewReader(buf.Bytes()))
-				require.NoError(t, err)
-
-			case func(ctn Writer) ([]byte, error):
-				b, err := fn(writer)
-				require.NoError(t, err)
-				serialLen = len(b)
-
-				require.Equal(t, byte(tc.expectedHeader), b[0])
-
-				reader, err = FromBytes(b)
-				require.NoError(t, err)
-
-			case func(ctn Writer) (string, error):
-				s, err := fn(writer)
-				require.NoError(t, err)
-				serialLen = len(s)
-
-				require.Equal(t, byte(tc.expectedHeader), s[0])
-
-				reader, err = FromString(s)
-				require.NoError(t, err)
-			}
-
-			t.Logf("data size %d, container size %d, overhead: %d%%, %d bytes",
-				dataSize, serialLen, int(float32(serialLen-dataSize)/float32(dataSize)*100.0), serialLen-dataSize)
-
-			for c, dlg := range tokens {
-				tknRead, err := reader.GetToken(c)
-				require.NoError(t, err)
-
-				// require.Equal fails as time.Time holds a wall time that is going to be
-				// different, even if it represents the same event.
-				// We need to do the following instead.
-
-				dlgRead := tknRead.(*delegation.Token)
-				require.Equal(t, dlg.Issuer(), dlgRead.Issuer())
-				require.Equal(t, dlg.Audience(), dlgRead.Audience())
-				require.Equal(t, dlg.Subject(), dlgRead.Subject())
-				require.Equal(t, dlg.Command(), dlgRead.Command())
-				require.Equal(t, dlg.Policy(), dlgRead.Policy())
-				require.Equal(t, dlg.Nonce(), dlgRead.Nonce())
-				require.True(t, dlg.Meta().Equals(dlgRead.Meta()))
-				if dlg.NotBefore() != nil {
-					// within 1s as the original value gets truncated to seconds when serialized
-					require.WithinDuration(t, *dlg.NotBefore(), *dlgRead.NotBefore(), time.Second)
-				}
-				if dlg.Expiration() != nil {
-					// within 1s as the original value gets truncated to seconds when serialized
-					require.WithinDuration(t, *dlg.Expiration(), *dlgRead.Expiration(), time.Second)
-				}
-			}
-		})
-	}
-}
-
-func BenchmarkContainerSerialisation(b *testing.B) {
-	var duration strings.Builder
-	var allocByte strings.Builder
-	var allocCount strings.Builder
-
-	for _, builder := range []strings.Builder{duration, allocByte, allocCount} {
-		builder.WriteString("car\tcarBase64\tcarGzip\tcarGzipBase64\tcbor\tcborBase64\tcborGzip\tcborGzipBase64\tcborFlate\tcborFlateBase64\n")
-	}
-
-	for _, tc := range []struct {
-		name   string
-		writer func(ctn Writer, w io.Writer) error
-		reader func(io.Reader) (Reader, error)
-	}{
-		{"Bytes", Writer.ToBytesWriter, FromReader},
-		{"BytesGzipped", Writer.ToBytesGzippedWriter, FromReader},
-		{"Base64StdPadding", Writer.ToBase64StdPaddingWriter, FromReader},
-		{"Base64StdPaddingGzipped", Writer.ToBase64StdPaddingGzippedWriter, FromReader},
-		{"Base64URL", Writer.ToBase64URLWriter, FromReader},
-		{"Base64URLGzip", Writer.ToBase64URLGzipWriter, FromReader},
-	} {
-		writer := NewWriter()
-
-		for i := 0; i < 10; i++ {
-			_, _, data := randToken()
-			writer.AddSealed(data)
-		}
-
-		buf := bytes.NewBuffer(nil)
-		_ = tc.writer(writer, buf)
-
-		b.Run(tc.name+"_write", func(b *testing.B) {
-			b.ReportAllocs()
-			for i := 0; i < b.N; i++ {
-				buf := bytes.NewBuffer(nil)
-				_ = tc.writer(writer, buf)
-			}
-		})
-
-		b.Run(tc.name+"_read", func(b *testing.B) {
-			b.ReportAllocs()
-			for i := 0; i < b.N; i++ {
-				_, _ = tc.reader(bytes.NewReader(buf.Bytes()))
-			}
-		})
-	}
-}
-
-func randDID() (ed25519.PrivateKey, did.DID) {
-	_, privKey, err := ed25519.GenerateKeyPair()
-	if err != nil {
-		panic(err)
-	}
-	d := didkeyctl.FromPrivateKey(privKey)
-	return privKey, d
-}
-
-func randomString(length int) string {
-	b := make([]byte, length/2+1)
-	_, _ = rand.Read(b)
-	return fmt.Sprintf("%x", b)[0:length]
-}
-
-func randToken() (*delegation.Token, cid.Cid, []byte) {
-	priv, iss := randDID()
-	_, aud := randDID()
-	cmd := command.New("foo", "bar")
-	pol := policy.MustConstruct(
-		policy.All(".[]",
-			policy.GreaterThan(".value", literal.Int(2)),
-		),
-	)
-
-	opts := []delegation.Option{
-		delegation.WithExpiration(time.Now().Add(time.Hour)),
-	}
-	for i := 0; i < 3; i++ {
-		opts = append(opts, delegation.WithMeta(randomString(8), randomString(10)))
-	}
-
-	t, err := delegation.Root(iss, aud, cmd, pol, opts...)
-	if err != nil {
-		panic(err)
-	}
-	b, c, err := t.ToSealed(priv)
-	if err != nil {
-		panic(err)
-	}
-	return t, c, b
-}
-
-func FuzzContainerRead(f *testing.F) {
-	// Generate a corpus
-	for tokenCount := 0; tokenCount < 10; tokenCount++ {
-		writer := NewWriter()
-		for i := 0; i < tokenCount; i++ {
-			_, _, data := randToken()
-			writer.AddSealed(data)
-		}
-		data, err := writer.ToBytes()
-		require.NoError(f, err)
-
-		f.Add(data)
-	}
-
-	f.Fuzz(func(t *testing.T, data []byte) {
-		start := time.Now()
-
-		// search for panics
-		_, _ = FromBytes(data)
-
-		if time.Since(start) > 100*time.Millisecond {
-			panic("too long")
-		}
-	})
-}

pkg/container/writer.go

@@ -1,139 +0,0 @@
-package container
-
-import (
-	"bytes"
-	"io"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/codec/cbor"
-	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/fluent/qp"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-)
-
-// Writer is a token container writer. It provides a convenient way to aggregate and serialize tokens together.
-type Writer map[string]struct{}
-
-func NewWriter() Writer {
-	return make(Writer)
-}
-
-// AddSealed includes a "sealed" token (serialized with a ToSealed* function) in the container.
-func (ctn Writer) AddSealed(data []byte) {
-	ctn[string(data)] = struct{}{}
-}
-
-// ToBytes encode the container into raw bytes.
-func (ctn Writer) ToBytes() ([]byte, error) {
-	return ctn.toBytes(headerRawBytes)
-}
-
-// ToBytesWriter is the same as ToBytes, but with an io.Writer.
-func (ctn Writer) ToBytesWriter(w io.Writer) error {
-	return ctn.toWriter(headerRawBytes, w)
-}
-
-// ToBytesGzipped encode the container into gzipped bytes.
-func (ctn Writer) ToBytesGzipped() ([]byte, error) {
-	return ctn.toBytes(headerRawBytesGzip)
-}
-
-// ToBytesGzippedWriter is the same as ToBytesGzipped, but with an io.Writer.
-func (ctn Writer) ToBytesGzippedWriter(w io.Writer) error {
-	return ctn.toWriter(headerRawBytesGzip, w)
-}
-
-// ToBase64StdPadding encode the container into a base64 string, with standard encoding and padding.
-func (ctn Writer) ToBase64StdPadding() (string, error) {
-	return ctn.toString(headerBase64StdPadding)
-}
-
-// ToBase64StdPaddingWriter is the same as ToBase64StdPadding, but with an io.Writer.
-func (ctn Writer) ToBase64StdPaddingWriter(w io.Writer) error {
-	return ctn.toWriter(headerBase64StdPadding, w)
-}
-
-// ToBase64StdPaddingGzipped encode the container into a pre-gzipped base64 string, with standard encoding and padding.
-func (ctn Writer) ToBase64StdPaddingGzipped() (string, error) {
-	return ctn.toString(headerBase64StdPaddingGzip)
-}
-
-// ToBase64StdPaddingGzippedWriter is the same as ToBase64StdPaddingGzipped, but with an io.Writer.
-func (ctn Writer) ToBase64StdPaddingGzippedWriter(w io.Writer) error {
-	return ctn.toWriter(headerBase64StdPaddingGzip, w)
-}
-
-// ToBase64URL encode the container into base64 string, with URL-safe encoding and no padding.
-func (ctn Writer) ToBase64URL() (string, error) {
-	return ctn.toString(headerBase64URL)
-}
-
-// ToBase64URLWriter is the same as ToBase64URL, but with an io.Writer.
-func (ctn Writer) ToBase64URLWriter(w io.Writer) error {
-	return ctn.toWriter(headerBase64URL, w)
-}
-
-// ToBase64URLGzipped encode the container into pre-gzipped base64 string, with URL-safe encoding and no padding.
-func (ctn Writer) ToBase64URLGzipped() (string, error) {
-	return ctn.toString(headerBase64URLGzip)
-}
-
-// ToBase64URLGzipWriter is the same as ToBase64URL, but with an io.Writer.
-func (ctn Writer) ToBase64URLGzipWriter(w io.Writer) error {
-	return ctn.toWriter(headerBase64URLGzip, w)
-}
-
-func (ctn Writer) toBytes(header header) ([]byte, error) {
-	var buf bytes.Buffer
-	err := ctn.toWriter(header, &buf)
-	if err != nil {
-		return nil, err
-	}
-	return buf.Bytes(), nil
-}
-
-func (ctn Writer) toString(header header) (string, error) {
-	var buf bytes.Buffer
-	err := ctn.toWriter(header, &buf)
-	if err != nil {
-		return "", err
-	}
-	return buf.String(), nil
-}
-
-func (ctn Writer) toWriter(header header, w io.Writer) (err error) {
-	encoder := header.encoder(w)
-
-	defer func() {
-		err = encoder.Close()
-	}()
-	node, err := qp.BuildMap(basicnode.Prototype.Any, 1, func(ma datamodel.MapAssembler) {
-		qp.MapEntry(ma, containerVersionTag, qp.List(int64(len(ctn)), func(la datamodel.ListAssembler) {
-			for data, _ := range ctn {
-				qp.ListEntry(la, qp.Bytes([]byte(data)))
-			}
-		}))
-	})
-	if err != nil {
-		return err
-	}
-
-	return ipld.EncodeStreaming(encoder, node, cbor.Encode)
-}
-
-// ToReader convert a container Writer into a Reader.
-// Most likely, you only want to use this in tests for convenience.
-// This is not optimized and can panic.
-func (ctn Writer) ToReader() Reader {
-	data, err := ctn.ToBytes()
-	if err != nil {
-		panic(err)
-	}
-
-	reader, err := FromBytes(data)
-	if err != nil {
-		panic(err)
-	}
-
-	return reader
-}

pkg/container/writer_test.go

@@ -1,18 +0,0 @@
-package container
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-func TestWriterDedup(t *testing.T) {
-	ctn := NewWriter()
-
-	_, _, sealed := randToken()
-	ctn.AddSealed(sealed)
-	require.Len(t, ctn, 1)
-
-	ctn.AddSealed(sealed)
-	require.Len(t, ctn, 1)
-}

pkg/meta/meta.go

@@ -1,265 +0,0 @@
-package meta
-
-import (
-	"errors"
-	"fmt"
-	"iter"
-	"sort"
-	"strings"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/printer"
-
-	"github.com/ucan-wg/go-ucan/pkg/policy/literal"
-	"github.com/ucan-wg/go-ucan/pkg/secretbox"
-)
-
-var ErrNotFound = errors.New("key not found in meta")
-
-var ErrNotEncryptable = errors.New("value of this type cannot be encrypted")
-
-// Meta is a container for meta key-value pairs in a UCAN token.
-// This also serves as a way to construct the underlying IPLD data with minimum allocations
-// and transformations, while hiding the IPLD complexity from the caller.
-type Meta struct {
-	// This type must be compatible with the IPLD type represented by the IPLD
-	// schema { String : Any }.
-
-	Keys   []string
-	Values map[string]ipld.Node
-}
-
-// NewMeta constructs a new Meta.
-func NewMeta() *Meta {
-	return &Meta{Values: map[string]ipld.Node{}}
-}
-
-// GetBool retrieves a value as a bool.
-// Returns ErrNotFound if the given key is missing.
-// Returns datamodel.ErrWrongKind if the value has the wrong type.
-func (m *Meta) GetBool(key string) (bool, error) {
-	v, ok := m.Values[key]
-	if !ok {
-		return false, ErrNotFound
-	}
-	return v.AsBool()
-}
-
-// GetString retrieves a value as a string.
-// Returns ErrNotFound if the given key is missing.
-// Returns datamodel.ErrWrongKind if the value has the wrong type.
-func (m *Meta) GetString(key string) (string, error) {
-	v, ok := m.Values[key]
-	if !ok {
-		return "", ErrNotFound
-	}
-	return v.AsString()
-}
-
-// GetEncryptedString decorates GetString and decrypt its output with the given symmetric encryption key.
-func (m *Meta) GetEncryptedString(key string, encryptionKey []byte) (string, error) {
-	v, err := m.GetBytes(key)
-	if err != nil {
-		return "", err
-	}
-
-	decrypted, err := secretbox.DecryptStringWithKey(v, encryptionKey)
-	if err != nil {
-		return "", err
-	}
-
-	return string(decrypted), nil
-}
-
-// GetInt64 retrieves a value as an int64.
-// Returns ErrNotFound if the given key is missing.
-// Returns datamodel.ErrWrongKind if the value has the wrong type.
-func (m *Meta) GetInt64(key string) (int64, error) {
-	v, ok := m.Values[key]
-	if !ok {
-		return 0, ErrNotFound
-	}
-	return v.AsInt()
-}
-
-// GetFloat64 retrieves a value as a float64.
-// Returns ErrNotFound if the given key is missing.
-// Returns datamodel.ErrWrongKind if the value has the wrong type.
-func (m *Meta) GetFloat64(key string) (float64, error) {
-	v, ok := m.Values[key]
-	if !ok {
-		return 0, ErrNotFound
-	}
-	return v.AsFloat()
-}
-
-// GetBytes retrieves a value as a []byte.
-// Returns ErrNotFound if the given key is missing.
-// Returns datamodel.ErrWrongKind if the value has the wrong type.
-func (m *Meta) GetBytes(key string) ([]byte, error) {
-	v, ok := m.Values[key]
-	if !ok {
-		return nil, ErrNotFound
-	}
-	return v.AsBytes()
-}
-
-// GetEncryptedBytes decorates GetBytes and decrypt its output with the given symmetric encryption key.
-func (m *Meta) GetEncryptedBytes(key string, encryptionKey []byte) ([]byte, error) {
-	v, err := m.GetBytes(key)
-	if err != nil {
-		return nil, err
-	}
-
-	decrypted, err := secretbox.DecryptStringWithKey(v, encryptionKey)
-	if err != nil {
-		return nil, err
-	}
-
-	return decrypted, nil
-}
-
-// GetNode retrieves a value as a raw IPLD node.
-// Returns ErrNotFound if the given key is missing.
-func (m *Meta) GetNode(key string) (ipld.Node, error) {
-	v, ok := m.Values[key]
-	if !ok {
-		return nil, ErrNotFound
-	}
-	return v, nil
-}
-
-// Add adds a key/value pair in the meta set.
-// Accepted types for val are any CBOR compatible type, or directly IPLD values.
-func (m *Meta) Add(key string, val any) error {
-	if _, ok := m.Values[key]; ok {
-		return fmt.Errorf("duplicate key %q", key)
-	}
-
-	node, err := literal.Any(val)
-	if err != nil {
-		return err
-	}
-
-	m.Keys = append(m.Keys, key)
-	m.Values[key] = node
-
-	return nil
-}
-
-// AddEncrypted adds a key/value pair in the meta set.
-// The value is encrypted with the given encryptionKey.
-// Accepted types for the value are: string, []byte.
-// The ciphertext will be 40 bytes larger than the plaintext due to encryption overhead.
-func (m *Meta) AddEncrypted(key string, val any, encryptionKey []byte) error {
-	var encrypted []byte
-	var err error
-
-	switch val := val.(type) {
-	case string:
-		encrypted, err = secretbox.EncryptWithKey([]byte(val), encryptionKey)
-		if err != nil {
-			return err
-		}
-	case []byte:
-		encrypted, err = secretbox.EncryptWithKey(val, encryptionKey)
-		if err != nil {
-			return err
-		}
-	default:
-		return ErrNotEncryptable
-	}
-
-	return m.Add(key, encrypted)
-}
-
-type Iterator interface {
-	Iter() iter.Seq2[string, ipld.Node]
-}
-
-// Include merges the provided meta into the existing one.
-//
-// If duplicate keys are encountered, the new value is silently dropped
-// without causing an error.
-func (m *Meta) Include(other Iterator) {
-	for key, value := range other.Iter() {
-		if _, ok := m.Values[key]; ok {
-			// don't overwrite
-			continue
-		}
-		m.Values[key] = value
-		m.Keys = append(m.Keys, key)
-	}
-}
-
-// Len returns the number of key/values.
-func (m *Meta) Len() int {
-	return len(m.Values)
-}
-
-// Iter iterates over the meta key/values
-func (m *Meta) Iter() iter.Seq2[string, ipld.Node] {
-	return func(yield func(string, ipld.Node) bool) {
-		for _, key := range m.Keys {
-			if !yield(key, m.Values[key]) {
-				return
-			}
-		}
-	}
-}
-
-// Equals tells if two Meta hold the same key/values.
-func (m *Meta) Equals(other *Meta) bool {
-	if len(m.Keys) != len(other.Keys) {
-		return false
-	}
-	if len(m.Values) != len(other.Values) {
-		return false
-	}
-	for _, key := range m.Keys {
-		if !ipld.DeepEqual(m.Values[key], other.Values[key]) {
-			return false
-		}
-	}
-	return true
-}
-
-func (m *Meta) String() string {
-	sort.Strings(m.Keys)
-
-	buf := strings.Builder{}
-	buf.WriteString("{")
-
-	for key, node := range m.Values {
-		buf.WriteString("\n\t")
-		buf.WriteString(key)
-		buf.WriteString(": ")
-		buf.WriteString(strings.ReplaceAll(printer.Sprint(node), "\n", "\n\t"))
-		buf.WriteString(",")
-	}
-
-	if len(m.Values) > 0 {
-		buf.WriteString("\n")
-	}
-	buf.WriteString("}")
-
-	return buf.String()
-}
-
-// ReadOnly returns a read-only version of Meta.
-func (m *Meta) ReadOnly() ReadOnly {
-	return ReadOnly{meta: m}
-}
-
-// Clone makes a deep copy.
-func (m *Meta) Clone() *Meta {
-	res := &Meta{
-		Keys:   make([]string, len(m.Keys)),
-		Values: make(map[string]ipld.Node, len(m.Values)),
-	}
-	copy(res.Keys, m.Keys)
-	for k, v := range m.Values {
-		res.Values[k] = v
-	}
-	return res
-}

pkg/meta/meta_test.go

@@ -1,130 +0,0 @@
-package meta_test
-
-import (
-	"crypto/rand"
-	"maps"
-	"testing"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-	"github.com/stretchr/testify/require"
-
-	"github.com/ucan-wg/go-ucan/pkg/meta"
-)
-
-func TestMeta_Add(t *testing.T) {
-	t.Parallel()
-
-	type Unsupported struct{}
-
-	t.Run("error if not primitive or Node", func(t *testing.T) {
-		t.Parallel()
-
-		err := (&meta.Meta{}).Add("invalid", &Unsupported{})
-		require.Error(t, err)
-	})
-
-	t.Run("encrypted meta", func(t *testing.T) {
-		t.Parallel()
-
-		key := make([]byte, 32)
-		_, err := rand.Read(key)
-		require.NoError(t, err)
-
-		m := meta.NewMeta()
-
-		// string encryption
-		err = m.AddEncrypted("secret", "hello world", key)
-		require.NoError(t, err)
-
-		_, err = m.GetString("secret")
-		require.Error(t, err) // the ciphertext is saved as []byte instead of string
-
-		decrypted, err := m.GetEncryptedString("secret", key)
-		require.NoError(t, err)
-		require.Equal(t, "hello world", decrypted)
-
-		// bytes encryption
-		originalBytes := make([]byte, 128)
-		_, err = rand.Read(originalBytes)
-		require.NoError(t, err)
-		err = m.AddEncrypted("secret-bytes", originalBytes, key)
-		require.NoError(t, err)
-
-		encryptedBytes, err := m.GetBytes("secret-bytes")
-		require.NoError(t, err)
-		require.NotEqual(t, originalBytes, encryptedBytes)
-
-		decryptedBytes, err := m.GetEncryptedBytes("secret-bytes", key)
-		require.NoError(t, err)
-		require.Equal(t, originalBytes, decryptedBytes)
-
-		// error cases
-		t.Run("error on unsupported type", func(t *testing.T) {
-			err := m.AddEncrypted("invalid", 123, key)
-			require.ErrorIs(t, err, meta.ErrNotEncryptable)
-		})
-
-		t.Run("error on invalid key size", func(t *testing.T) {
-			err := m.AddEncrypted("invalid", "test", []byte("short-key"))
-			require.Error(t, err)
-			require.Contains(t, err.Error(), "invalid key size")
-		})
-
-		t.Run("error on nil key", func(t *testing.T) {
-			err := m.AddEncrypted("invalid", "test", nil)
-			require.Error(t, err)
-			require.Contains(t, err.Error(), "encryption key is required")
-		})
-	})
-}
-
-func TestIterCloneEquals(t *testing.T) {
-	m := meta.NewMeta()
-
-	require.NoError(t, m.Add("foo", "bar"))
-	require.NoError(t, m.Add("baz", 1234))
-
-	expected := map[string]ipld.Node{
-		"foo": basicnode.NewString("bar"),
-		"baz": basicnode.NewInt(1234),
-	}
-
-	// meta -> iter
-	require.Equal(t, expected, maps.Collect(m.Iter()))
-
-	// readonly -> iter
-	ro := m.ReadOnly()
-	require.Equal(t, expected, maps.Collect(ro.Iter()))
-
-	// meta -> clone -> iter
-	clone := m.Clone()
-	require.Equal(t, expected, maps.Collect(clone.Iter()))
-
-	// readonly -> WriteableClone -> iter
-	wclone := ro.WriteableClone()
-	require.Equal(t, expected, maps.Collect(wclone.Iter()))
-
-	require.True(t, m.Equals(wclone))
-	require.True(t, ro.Equals(wclone.ReadOnly()))
-}
-
-func TestInclude(t *testing.T) {
-	m1 := meta.NewMeta()
-
-	require.NoError(t, m1.Add("samekey", "bar"))
-	require.NoError(t, m1.Add("baz", 1234))
-
-	m2 := meta.NewMeta()
-
-	require.NoError(t, m2.Add("samekey", "othervalue")) // check no overwrite
-	require.NoError(t, m2.Add("otherkey", 1234))
-
-	m1.Include(m2)
-
-	require.Equal(t, map[string]ipld.Node{
-		"samekey":  basicnode.NewString("bar"),
-		"baz":      basicnode.NewInt(1234),
-		"otherkey": basicnode.NewInt(1234),
-	}, maps.Collect(m1.Iter()))
-}

pkg/meta/readonly.go

@@ -1,64 +0,0 @@
-package meta
-
-import (
-	"iter"
-
-	"github.com/ipld/go-ipld-prime"
-)
-
-// ReadOnly wraps a Meta into a read-only facade.
-type ReadOnly struct {
-	meta *Meta
-}
-
-func (r ReadOnly) GetBool(key string) (bool, error) {
-	return r.meta.GetBool(key)
-}
-
-func (r ReadOnly) GetString(key string) (string, error) {
-	return r.meta.GetString(key)
-}
-
-func (r ReadOnly) GetEncryptedString(key string, encryptionKey []byte) (string, error) {
-	return r.meta.GetEncryptedString(key, encryptionKey)
-}
-
-func (r ReadOnly) GetInt64(key string) (int64, error) {
-	return r.meta.GetInt64(key)
-}
-
-func (r ReadOnly) GetFloat64(key string) (float64, error) {
-	return r.meta.GetFloat64(key)
-}
-
-func (r ReadOnly) GetBytes(key string) ([]byte, error) {
-	return r.meta.GetBytes(key)
-}
-
-func (r ReadOnly) GetEncryptedBytes(key string, encryptionKey []byte) ([]byte, error) {
-	return r.meta.GetEncryptedBytes(key, encryptionKey)
-}
-
-func (r ReadOnly) GetNode(key string) (ipld.Node, error) {
-	return r.meta.GetNode(key)
-}
-
-func (r ReadOnly) Len() int {
-	return r.meta.Len()
-}
-
-func (r ReadOnly) Iter() iter.Seq2[string, ipld.Node] {
-	return r.meta.Iter()
-}
-
-func (r ReadOnly) Equals(other ReadOnly) bool {
-	return r.meta.Equals(other.meta)
-}
-
-func (r ReadOnly) String() string {
-	return r.meta.String()
-}
-
-func (r ReadOnly) WriteableClone() *Meta {
-	return r.meta.Clone()
-}

pkg/policy/glob.go

@@ -1,79 +0,0 @@
-package policy
-
-import "fmt"
-
-type glob string
-
-// parseGlob ensures that the pattern conforms to the spec: only '*' and escaped '\*' are allowed.
-func parseGlob(pattern string) (glob, error) {
-	for i := 0; i < len(pattern); i++ {
-		if pattern[i] == '*' {
-			continue
-		}
-		if pattern[i] == '\\' && i+1 < len(pattern) && pattern[i+1] == '*' {
-			i++ // skip the escaped '*'
-			continue
-		}
-		if pattern[i] == '\\' && i+1 < len(pattern) {
-			i++ // skip the escaped character
-			continue
-		}
-		if pattern[i] == '\\' {
-			return "", fmt.Errorf("invalid escape sequence")
-		}
-	}
-
-	return glob(pattern), nil
-}
-
-func mustParseGlob(pattern string) glob {
-	g, err := parseGlob(pattern)
-	if err != nil {
-		panic(err)
-	}
-	return g
-}
-
-// Match matches a string against the glob pattern with * wildcards, handling escaped '\*' literals.
-func (pattern glob) Match(str string) bool {
-	// i is the index for the pattern
-	// j is the index for the string
-	var i, j int
-
-	// starIdx keeps track of the position of the last * in the pattern.
-	// matchIdx keeps track of the position in the string where the last * matched.
-	var starIdx, matchIdx int = -1, -1
-
-	for j < len(str) {
-		if i < len(pattern) && (pattern[i] == str[j] || pattern[i] == '\\' && i+1 < len(pattern) && pattern[i+1] == str[j]) {
-			// characters match or if there's an escaped character that matches
-			if pattern[i] == '\\' {
-				// skip the escape character
-				i++
-			}
-			i++
-			j++
-		} else if i < len(pattern) && pattern[i] == '*' {
-			// there's a * wildcard in the pattern
-			starIdx = i
-			matchIdx = j
-			i++
-		} else if starIdx != -1 {
-			// there's a previous * wildcard, backtrack
-			i = starIdx + 1
-			matchIdx++
-			j = matchIdx
-		} else {
-			// no match found
-			return false
-		}
-	}
-
-	// check for remaining characters in the pattern
-	for i < len(pattern) && pattern[i] == '*' {
-		i++
-	}
-
-	// the entire pattern is processed, it's a match
-	return i == len(pattern)
-}

pkg/policy/glob_test.go

@@ -1,73 +0,0 @@
-package policy
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-func TestSimpleGlobMatch(t *testing.T) {
-	tests := []struct {
-		pattern string
-		str     string
-		matches bool
-	}{
-		// Basic matching
-		{"*", "anything", true},
-		{"a*", "abc", true},
-		{"*c", "abc", true},
-		{"a*c", "abc", true},
-		{"a*c", "abxc", true},
-		{"a*c", "ac", true},
-		{"a*c", "a", false},
-		{"a*c", "ab", false},
-
-		// Escaped characters
-		{"a\\*c", "a*c", true},
-		{"a\\*c", "abc", false},
-
-		// Mixed wildcards and literals
-		{"a*b*c", "abc", true},
-		{"a*b*c", "aXbYc", true},
-		{"a*b*c", "aXbY", false},
-		{"a*b*c", "abYc", true},
-		{"a*b*c", "aXbc", true},
-		{"a*b*c", "aXbYcZ", false},
-
-		// Edge cases
-		{"", "", true},
-		{"", "a", false},
-		{"*", "", true},
-		{"*", "a", true},
-		{"\\*", "*", true},
-		{"\\*", "a", false},
-
-		// Specified test cases
-		{"Alice\\*, Bob*, Carol.", "Alice*, Bob, Carol.", true},
-		{"Alice\\*, Bob*, Carol.", "Alice*, Bob, Dan, Erin, Carol.", true},
-		{"Alice\\*, Bob*, Carol.", "Alice*, Bob  , Carol.", true},
-		{"Alice\\*, Bob*, Carol.", "Alice*, Bob*, Carol.", true},
-		{"Alice\\*, Bob*, Carol.", "Alice*, Bob, Carol", false},
-		{"Alice\\*, Bob*, Carol.", "Alice*, Bob*, Carol!", false},
-		{"Alice\\*, Bob*, Carol.", "Alice, Bob, Carol.", false},
-		{"Alice\\*, Bob*, Carol.", "Alice Cooper, Bob, Carol.", false},
-		{"Alice\\*, Bob*, Carol.", " Alice*, Bob, Carol. ", false},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.pattern+"_"+tt.str, func(t *testing.T) {
-			g, err := parseGlob(tt.pattern)
-			require.NoError(t, err)
-			require.Equal(t, tt.matches, g.Match(tt.str))
-		})
-	}
-}
-
-func BenchmarkGlob(b *testing.B) {
-	b.ReportAllocs()
-
-	for i := 0; i < b.N; i++ {
-		g := mustParseGlob("Alice\\*, Bob*, Carol.")
-		g.Match("Alice*, Bob*, Carol!")
-	}
-}

pkg/policy/limits/int.go

@@ -1,49 +0,0 @@
-package limits
-
-import (
-	"fmt"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/must"
-)
-
-const (
-	// MaxInt53 represents the maximum safe integer in JavaScript (2^53 - 1)
-	MaxInt53 int64 = 9007199254740991
-	// MinInt53 represents the minimum safe integer in JavaScript (-2^53 + 1)
-	MinInt53 int64 = -9007199254740991
-)
-
-func ValidateIntegerBoundsIPLD(node ipld.Node) error {
-	switch node.Kind() {
-	case ipld.Kind_Int:
-		val := must.Int(node)
-		if val > MaxInt53 || val < MinInt53 {
-			return fmt.Errorf("integer value %d exceeds safe bounds", val)
-		}
-	case ipld.Kind_List:
-		it := node.ListIterator()
-		for !it.Done() {
-			_, v, err := it.Next()
-			if err != nil {
-				return err
-			}
-			if err := ValidateIntegerBoundsIPLD(v); err != nil {
-				return err
-			}
-		}
-	case ipld.Kind_Map:
-		it := node.MapIterator()
-		for !it.Done() {
-			_, v, err := it.Next()
-			if err != nil {
-				return err
-			}
-			if err := ValidateIntegerBoundsIPLD(v); err != nil {
-				return err
-			}
-		}
-	}
-
-	return nil
-}

pkg/policy/limits/int_test.go

@@ -1,82 +0,0 @@
-package limits
-
-import (
-	"testing"
-
-	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/fluent/qp"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-	"github.com/stretchr/testify/require"
-)
-
-func TestValidateIntegerBoundsIPLD(t *testing.T) {
-	buildMap := func() datamodel.Node {
-		nb := basicnode.Prototype.Any.NewBuilder()
-		qp.Map(1, func(ma datamodel.MapAssembler) {
-			qp.MapEntry(ma, "foo", qp.Int(MaxInt53+1))
-		})(nb)
-		return nb.Build()
-	}
-
-	buildList := func() datamodel.Node {
-		nb := basicnode.Prototype.Any.NewBuilder()
-		qp.List(1, func(la datamodel.ListAssembler) {
-			qp.ListEntry(la, qp.Int(MinInt53-1))
-		})(nb)
-		return nb.Build()
-	}
-
-	tests := []struct {
-		name    string
-		input   datamodel.Node
-		wantErr bool
-	}{
-		{
-			name:    "valid int",
-			input:   basicnode.NewInt(42),
-			wantErr: false,
-		},
-		{
-			name:    "max safe int",
-			input:   basicnode.NewInt(MaxInt53),
-			wantErr: false,
-		},
-		{
-			name:    "min safe int",
-			input:   basicnode.NewInt(MinInt53),
-			wantErr: false,
-		},
-		{
-			name:    "above MaxInt53",
-			input:   basicnode.NewInt(MaxInt53 + 1),
-			wantErr: true,
-		},
-		{
-			name:    "below MinInt53",
-			input:   basicnode.NewInt(MinInt53 - 1),
-			wantErr: true,
-		},
-		{
-			name:    "nested map with invalid int",
-			input:   buildMap(),
-			wantErr: true,
-		},
-		{
-			name:    "nested list with invalid int",
-			input:   buildList(),
-			wantErr: true,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			err := ValidateIntegerBoundsIPLD(tt.input)
-			if tt.wantErr {
-				require.Error(t, err)
-				require.Contains(t, err.Error(), "exceeds safe bounds")
-			} else {
-				require.NoError(t, err)
-			}
-		})
-	}
-}

pkg/policy/literal/literal.go

@@ -1,205 +0,0 @@
-// Package literal holds a collection of functions to create IPLD types to use in policies, selector and args.
-package literal
-
-import (
-	"fmt"
-	"reflect"
-	"sort"
-
-	"github.com/ipfs/go-cid"
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/fluent/qp"
-	cidlink "github.com/ipld/go-ipld-prime/linking/cid"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-
-	"github.com/ucan-wg/go-ucan/pkg/policy/limits"
-)
-
-var Bool = basicnode.NewBool
-var Int = basicnode.NewInt
-var Float = basicnode.NewFloat
-var String = basicnode.NewString
-var Bytes = basicnode.NewBytes
-var Link = basicnode.NewLink
-
-func LinkCid(cid cid.Cid) ipld.Node {
-	return Link(cidlink.Link{Cid: cid})
-}
-
-func Null() ipld.Node {
-	nb := basicnode.Prototype.Any.NewBuilder()
-	nb.AssignNull()
-	return nb.Build()
-}
-
-// Map creates an IPLD node from a map[string]any
-func Map[T any](m map[string]T) (ipld.Node, error) {
-	return qp.BuildMap(basicnode.Prototype.Any, int64(len(m)), func(ma datamodel.MapAssembler) {
-		// deterministic iteration
-		keys := make([]string, 0, len(m))
-		for key := range m {
-			keys = append(keys, key)
-		}
-		sort.Strings(keys)
-		for _, key := range keys {
-			qp.MapEntry(ma, key, anyAssemble(m[key]))
-		}
-	})
-}
-
-// List creates an IPLD node from a []any
-func List[T any](l []T) (ipld.Node, error) {
-	return qp.BuildList(basicnode.Prototype.Any, int64(len(l)), func(la datamodel.ListAssembler) {
-		for _, val := range l {
-			qp.ListEntry(la, anyAssemble(val))
-		}
-	})
-}
-
-// Any creates an IPLD node from any value
-// If possible, use another dedicated function for your type for performance.
-func Any(v any) (res ipld.Node, err error) {
-	// some fast path
-	switch val := v.(type) {
-	case bool:
-		return basicnode.NewBool(val), nil
-	case string:
-		return basicnode.NewString(val), nil
-	case int:
-		i := int64(val)
-		if i > limits.MaxInt53 || i < limits.MinInt53 {
-			return nil, fmt.Errorf("integer value %d exceeds safe integer bounds", i)
-		}
-		return basicnode.NewInt(i), nil
-	case int8:
-		return basicnode.NewInt(int64(val)), nil
-	case int16:
-		return basicnode.NewInt(int64(val)), nil
-	case int32:
-		return basicnode.NewInt(int64(val)), nil
-	case int64:
-		if val > limits.MaxInt53 || val < limits.MinInt53 {
-			return nil, fmt.Errorf("integer value %d exceeds safe integer bounds", val)
-		}
-		return basicnode.NewInt(val), nil
-	case uint:
-		return basicnode.NewInt(int64(val)), nil
-	case uint8:
-		return basicnode.NewInt(int64(val)), nil
-	case uint16:
-		return basicnode.NewInt(int64(val)), nil
-	case uint32:
-		return basicnode.NewInt(int64(val)), nil
-	case uint64:
-		if val > uint64(limits.MaxInt53) {
-			return nil, fmt.Errorf("unsigned integer value %d exceeds safe integer bounds", val)
-		}
-		return basicnode.NewInt(int64(val)), nil
-	case float32:
-		return basicnode.NewFloat(float64(val)), nil
-	case float64:
-		return basicnode.NewFloat(val), nil
-	case []byte:
-		return basicnode.NewBytes(val), nil
-	case datamodel.Node:
-		return val, nil
-	case cid.Cid:
-		return LinkCid(val), nil
-	default:
-	}
-
-	builder := basicnode.Prototype__Any{}.NewBuilder()
-
-	defer func() {
-		if r := recover(); r != nil {
-			err = fmt.Errorf("%v", r)
-			res = nil
-		}
-	}()
-
-	anyAssemble(v)(builder)
-
-	return builder.Build(), nil
-}
-
-func anyAssemble(val any) qp.Assemble {
-	var rt reflect.Type
-	var rv reflect.Value
-
-	// support for recursive calls, staying in reflection land
-	if cast, ok := val.(reflect.Value); ok {
-		rt = cast.Type()
-		rv = cast
-	} else {
-		rt = reflect.TypeOf(val)
-		rv = reflect.ValueOf(val)
-	}
-
-	// we need to dereference in some cases, to get the real value type
-	if rt.Kind() == reflect.Ptr || rt.Kind() == reflect.Interface {
-		rv = rv.Elem()
-		rt = rv.Type()
-	}
-
-	switch rt.Kind() {
-	case reflect.Array:
-		if rt.Elem().Kind() == reflect.Uint8 {
-			panic("bytes array are not supported yet")
-		}
-		return qp.List(int64(rv.Len()), func(la datamodel.ListAssembler) {
-			for i := range rv.Len() {
-				qp.ListEntry(la, anyAssemble(rv.Index(i)))
-			}
-		})
-	case reflect.Slice:
-		if rt.Elem().Kind() == reflect.Uint8 {
-			return qp.Bytes(val.([]byte))
-		}
-		return qp.List(int64(rv.Len()), func(la datamodel.ListAssembler) {
-			for i := range rv.Len() {
-				qp.ListEntry(la, anyAssemble(rv.Index(i)))
-			}
-		})
-	case reflect.Map:
-		if rt.Key().Kind() != reflect.String {
-			break
-		}
-		// deterministic iteration
-		keys := rv.MapKeys()
-		sort.Slice(keys, func(i, j int) bool {
-			return keys[i].String() < keys[j].String()
-		})
-		return qp.Map(int64(rv.Len()), func(ma datamodel.MapAssembler) {
-			for _, key := range keys {
-				qp.MapEntry(ma, key.String(), anyAssemble(rv.MapIndex(key)))
-			}
-		})
-	case reflect.Bool:
-		return qp.Bool(rv.Bool())
-	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
-		i := rv.Int()
-		if i > limits.MaxInt53 || i < limits.MinInt53 {
-			panic(fmt.Sprintf("integer %d exceeds safe bounds", i))
-		}
-		return qp.Int(i)
-	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64:
-		u := rv.Uint()
-		if u > uint64(limits.MaxInt53) {
-			panic(fmt.Sprintf("unsigned integer %d exceeds safe bounds", u))
-		}
-		return qp.Int(int64(u))
-	case reflect.Float32, reflect.Float64:
-		return qp.Float(rv.Float())
-	case reflect.String:
-		return qp.String(rv.String())
-	case reflect.Struct:
-		if rt == reflect.TypeOf(cid.Cid{}) {
-			c := rv.Interface().(cid.Cid)
-			return qp.Link(cidlink.Link{Cid: c})
-		}
-	default:
-	}
-
-	panic(fmt.Sprintf("unsupported type %T", val))
-}

pkg/policy/literal/literal_test.go

@@ -1,314 +0,0 @@
-package literal
-
-import (
-	"testing"
-
-	"github.com/ipfs/go-cid"
-	"github.com/ipld/go-ipld-prime/datamodel"
-	cidlink "github.com/ipld/go-ipld-prime/linking/cid"
-	"github.com/ipld/go-ipld-prime/printer"
-	"github.com/stretchr/testify/require"
-
-	"github.com/ucan-wg/go-ucan/pkg/policy/limits"
-)
-
-func TestList(t *testing.T) {
-	n, err := List([]int{1, 2, 3})
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_List, n.Kind())
-	require.Equal(t, int64(3), n.Length())
-	require.Equal(t, `list{
-	0: int{1}
-	1: int{2}
-	2: int{3}
-}`, printer.Sprint(n))
-
-	n, err = List([][]int{{1, 2, 3}, {4, 5, 6}})
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_List, n.Kind())
-	require.Equal(t, int64(2), n.Length())
-	require.Equal(t, `list{
-	0: list{
-		0: int{1}
-		1: int{2}
-		2: int{3}
-	}
-	1: list{
-		0: int{4}
-		1: int{5}
-		2: int{6}
-	}
-}`, printer.Sprint(n))
-}
-
-func TestMap(t *testing.T) {
-	n, err := Map(map[string]any{
-		"bool":   true,
-		"string": "foobar",
-		"bytes":  []byte{1, 2, 3, 4},
-		"int":    1234,
-		"uint":   uint(12345),
-		"float":  1.45,
-		"slice":  []int{1, 2, 3},
-		"array":  [2]int{1, 2},
-		"map": map[string]any{
-			"foo": "bar",
-			"foofoo": map[string]string{
-				"barbar": "foo",
-			},
-		},
-		"link": cid.MustParse("bafzbeigai3eoy2ccc7ybwjfz5r3rdxqrinwi4rwytly24tdbh6yk7zslrm"),
-	})
-	require.NoError(t, err)
-
-	v, err := n.LookupByString("bool")
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Bool, v.Kind())
-	require.Equal(t, true, must(v.AsBool()))
-
-	v, err = n.LookupByString("string")
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_String, v.Kind())
-	require.Equal(t, "foobar", must(v.AsString()))
-
-	v, err = n.LookupByString("bytes")
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Bytes, v.Kind())
-	require.Equal(t, []byte{1, 2, 3, 4}, must(v.AsBytes()))
-
-	v, err = n.LookupByString("int")
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Int, v.Kind())
-	require.Equal(t, int64(1234), must(v.AsInt()))
-
-	v, err = n.LookupByString("uint")
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Int, v.Kind())
-	require.Equal(t, int64(12345), must(v.AsInt()))
-
-	v, err = n.LookupByString("float")
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Float, v.Kind())
-	require.Equal(t, 1.45, must(v.AsFloat()))
-
-	v, err = n.LookupByString("slice")
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_List, v.Kind())
-	require.Equal(t, int64(3), v.Length())
-	require.Equal(t, `list{
-	0: int{1}
-	1: int{2}
-	2: int{3}
-}`, printer.Sprint(v))
-
-	v, err = n.LookupByString("array")
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_List, v.Kind())
-	require.Equal(t, int64(2), v.Length())
-	require.Equal(t, `list{
-	0: int{1}
-	1: int{2}
-}`, printer.Sprint(v))
-
-	v, err = n.LookupByString("map")
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Map, v.Kind())
-	require.Equal(t, int64(2), v.Length())
-	require.Equal(t, `map{
-	string{"foo"}: string{"bar"}
-	string{"foofoo"}: map{
-		string{"barbar"}: string{"foo"}
-	}
-}`, printer.Sprint(v))
-
-	v, err = n.LookupByString("link")
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Link, v.Kind())
-	asLink, err := v.AsLink()
-	require.NoError(t, err)
-	require.True(t, asLink.(cidlink.Link).Equals(cid.MustParse("bafzbeigai3eoy2ccc7ybwjfz5r3rdxqrinwi4rwytly24tdbh6yk7zslrm")))
-}
-
-func TestAny(t *testing.T) {
-	data := map[string]any{
-		"bool":   true,
-		"string": "foobar",
-		"bytes":  []byte{1, 2, 3, 4},
-		"int":    1234,
-		"uint":   uint(12345),
-		"float":  1.45,
-		"slice":  []int{1, 2, 3},
-		"array":  [2]int{1, 2},
-		"map": map[string]any{
-			"foo": "bar",
-			"foofoo": map[string]string{
-				"barbar": "foo",
-			},
-		},
-		"link": cid.MustParse("bafzbeigai3eoy2ccc7ybwjfz5r3rdxqrinwi4rwytly24tdbh6yk7zslrm"),
-		"func": func() {},
-	}
-
-	v, err := Any(data["bool"])
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Bool, v.Kind())
-	require.Equal(t, true, must(v.AsBool()))
-
-	v, err = Any(data["string"])
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_String, v.Kind())
-	require.Equal(t, "foobar", must(v.AsString()))
-
-	v, err = Any(data["bytes"])
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Bytes, v.Kind())
-	require.Equal(t, []byte{1, 2, 3, 4}, must(v.AsBytes()))
-
-	v, err = Any(data["int"])
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Int, v.Kind())
-	require.Equal(t, int64(1234), must(v.AsInt()))
-
-	v, err = Any(data["uint"])
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Int, v.Kind())
-	require.Equal(t, int64(12345), must(v.AsInt()))
-
-	v, err = Any(data["float"])
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Float, v.Kind())
-	require.Equal(t, 1.45, must(v.AsFloat()))
-
-	v, err = Any(data["slice"])
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_List, v.Kind())
-	require.Equal(t, int64(3), v.Length())
-	require.Equal(t, `list{
-	0: int{1}
-	1: int{2}
-	2: int{3}
-}`, printer.Sprint(v))
-
-	v, err = Any(data["array"])
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_List, v.Kind())
-	require.Equal(t, int64(2), v.Length())
-	require.Equal(t, `list{
-	0: int{1}
-	1: int{2}
-}`, printer.Sprint(v))
-
-	v, err = Any(data["map"])
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Map, v.Kind())
-	require.Equal(t, int64(2), v.Length())
-	require.Equal(t, `map{
-	string{"foo"}: string{"bar"}
-	string{"foofoo"}: map{
-		string{"barbar"}: string{"foo"}
-	}
-}`, printer.Sprint(v))
-
-	v, err = Any(data["link"])
-	require.NoError(t, err)
-	require.Equal(t, datamodel.Kind_Link, v.Kind())
-	asLink, err := v.AsLink()
-	require.NoError(t, err)
-	require.True(t, asLink.(cidlink.Link).Equals(cid.MustParse("bafzbeigai3eoy2ccc7ybwjfz5r3rdxqrinwi4rwytly24tdbh6yk7zslrm")))
-
-	_, err = Any(data["func"])
-	require.Error(t, err)
-}
-
-func BenchmarkAny(b *testing.B) {
-	b.Run("bool", func(b *testing.B) {
-		b.ReportAllocs()
-
-		for n := 0; n < b.N; n++ {
-			_, _ = Any(true)
-		}
-	})
-
-	b.Run("string", func(b *testing.B) {
-		b.ReportAllocs()
-		for n := 0; n < b.N; n++ {
-			_, _ = Any("foobar")
-		}
-	})
-
-	b.Run("bytes", func(b *testing.B) {
-		b.ReportAllocs()
-		for n := 0; n < b.N; n++ {
-			_, _ = Any([]byte{1, 2, 3, 4})
-		}
-	})
-
-	b.Run("map", func(b *testing.B) {
-		b.ReportAllocs()
-		for n := 0; n < b.N; n++ {
-			_, _ = Any(map[string]any{
-				"foo": "bar",
-				"foofoo": map[string]string{
-					"barbar": "foo",
-				},
-			})
-		}
-	})
-}
-
-func TestAnyAssembleIntegerOverflow(t *testing.T) {
-	tests := []struct {
-		name      string
-		input     interface{}
-		shouldErr bool
-	}{
-		{
-			name:      "valid int",
-			input:     42,
-			shouldErr: false,
-		},
-		{
-			name:      "max safe int",
-			input:     limits.MaxInt53,
-			shouldErr: false,
-		},
-		{
-			name:      "min safe int",
-			input:     limits.MinInt53,
-			shouldErr: false,
-		},
-		{
-			name:      "overflow int",
-			input:     int64(limits.MaxInt53 + 1),
-			shouldErr: true,
-		},
-		{
-			name:      "underflow int",
-			input:     int64(limits.MinInt53 - 1),
-			shouldErr: true,
-		},
-		{
-			name:      "overflow uint",
-			input:     uint64(limits.MaxInt53 + 1),
-			shouldErr: true,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			_, err := Any(tt.input)
-			if tt.shouldErr {
-				require.Error(t, err)
-			} else {
-				require.NoError(t, err)
-			}
-		})
-	}
-}
-
-func must[T any](t T, err error) T {
-	if err != nil {
-		panic(err)
-	}
-	return t
-}

pkg/policy/match.go

@@ -1,306 +0,0 @@
-package policy
-
-import (
-	"cmp"
-	"fmt"
-	"math"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/must"
-)
-
-// Match determines if the IPLD node satisfies the policy.
-// The first Statement failing to match is returned as well.
-func (p Policy) Match(node datamodel.Node) (bool, Statement) {
-	for _, stmt := range p {
-		res, leaf := matchStatement(stmt, node)
-		switch res {
-		case matchResultNoData, matchResultFalse:
-			return false, leaf
-		case matchResultOptionalNoData, matchResultTrue:
-			// continue
-		}
-	}
-	return true, nil
-}
-
-// PartialMatch returns false IIF one non-optional Statement has the corresponding data and doesn't match.
-// If the data is missing or the non-optional Statement is matching, true is returned.
-//
-// This allows performing the policy checking in multiple steps, and find immediately if a Statement already failed.
-// A final call to Match is necessary to make sure that the policy is fully matched, with no missing data
-// (apart from optional values).
-//
-// The first Statement failing to match is returned as well.
-func (p Policy) PartialMatch(node datamodel.Node) (bool, Statement) {
-	for _, stmt := range p {
-		res, leaf := matchStatement(stmt, node)
-		switch res {
-		case matchResultFalse:
-			return false, leaf
-		case matchResultNoData, matchResultOptionalNoData, matchResultTrue:
-			// continue
-		}
-	}
-	return true, nil
-}
-
-type matchResult int8
-
-const (
-	matchResultTrue           matchResult = iota // statement has data and resolve to true
-	matchResultFalse                             // statement has data and resolve to false
-	matchResultNoData                            // statement has no data
-	matchResultOptionalNoData                    // statement has no data and is optional
-)
-
-// matchStatement evaluate the policy against the given ipld.Node and returns:
-// - matchResultTrue: if the selector matched and the statement evaluated to true.
-// - matchResultFalse: if the selector matched and the statement evaluated to false.
-// - matchResultNoData: if the selector didn't match the expected data.
-// For matchResultTrue and matchResultNoData, the leaf-most (innermost) statement failing to be true is returned,
-// as well as the corresponding root-most encompassing statement.
-func matchStatement(cur Statement, node ipld.Node) (_ matchResult, leafMost Statement) {
-	var boolToRes = func(v bool) (matchResult, Statement) {
-		if v {
-			return matchResultTrue, nil
-		} else {
-			return matchResultFalse, cur
-		}
-	}
-
-	switch cur.Kind() {
-	case KindEqual:
-		if s, ok := cur.(equality); ok {
-			res, err := s.selector.Select(node)
-			if err != nil {
-				return matchResultNoData, cur
-			}
-			if res == nil { // optional selector didn't match
-				return matchResultOptionalNoData, nil
-			}
-			return boolToRes(datamodel.DeepEqual(s.value, res))
-		}
-	case KindNotEqual:
-		if s, ok := cur.(equality); ok {
-			res, err := s.selector.Select(node)
-			if err != nil {
-				return matchResultNoData, cur
-			}
-			if res == nil { // optional selector didn't match
-				return matchResultOptionalNoData, nil
-			}
-			return boolToRes(!datamodel.DeepEqual(s.value, res))
-		}
-	case KindGreaterThan:
-		if s, ok := cur.(equality); ok {
-			res, err := s.selector.Select(node)
-			if err != nil {
-				return matchResultNoData, cur
-			}
-			if res == nil { // optional selector didn't match
-				return matchResultOptionalNoData, nil
-			}
-			return boolToRes(isOrdered(s.value, res, gt))
-		}
-	case KindGreaterThanOrEqual:
-		if s, ok := cur.(equality); ok {
-			res, err := s.selector.Select(node)
-			if err != nil {
-				return matchResultNoData, cur
-			}
-			if res == nil { // optional selector didn't match
-				return matchResultOptionalNoData, nil
-			}
-			return boolToRes(isOrdered(s.value, res, gte))
-		}
-	case KindLessThan:
-		if s, ok := cur.(equality); ok {
-			res, err := s.selector.Select(node)
-			if err != nil {
-				return matchResultNoData, cur
-			}
-			if res == nil { // optional selector didn't match
-				return matchResultOptionalNoData, nil
-			}
-			return boolToRes(isOrdered(s.value, res, lt))
-		}
-	case KindLessThanOrEqual:
-		if s, ok := cur.(equality); ok {
-			res, err := s.selector.Select(node)
-			if err != nil {
-				return matchResultNoData, cur
-			}
-			if res == nil { // optional selector didn't match
-				return matchResultOptionalNoData, nil
-			}
-			return boolToRes(isOrdered(s.value, res, lte))
-		}
-	case KindNot:
-		if s, ok := cur.(negation); ok {
-			res, leaf := matchStatement(s.statement, node)
-			switch res {
-			case matchResultNoData, matchResultOptionalNoData:
-				return res, leaf
-			case matchResultTrue:
-				return matchResultFalse, cur
-			case matchResultFalse:
-				return matchResultTrue, nil
-			}
-		}
-	case KindAnd:
-		if s, ok := cur.(connective); ok {
-			for _, cs := range s.statements {
-				res, leaf := matchStatement(cs, node)
-				switch res {
-				case matchResultNoData, matchResultOptionalNoData:
-					return res, leaf
-				case matchResultTrue:
-					// continue
-				case matchResultFalse:
-					return matchResultFalse, leaf
-				}
-			}
-			return matchResultTrue, nil
-		}
-	case KindOr:
-		if s, ok := cur.(connective); ok {
-			if len(s.statements) == 0 {
-				return matchResultTrue, nil
-			}
-			for _, cs := range s.statements {
-				res, leaf := matchStatement(cs, node)
-				switch res {
-				case matchResultNoData, matchResultOptionalNoData:
-					return res, leaf
-				case matchResultTrue:
-					return matchResultTrue, leaf
-				case matchResultFalse:
-					// continue
-				}
-			}
-			return matchResultFalse, cur
-		}
-	case KindLike:
-		if s, ok := cur.(wildcard); ok {
-			res, err := s.selector.Select(node)
-			if err != nil {
-				return matchResultNoData, cur
-			}
-			if res == nil { // optional selector didn't match
-				return matchResultOptionalNoData, nil
-			}
-			v, err := res.AsString()
-			if err != nil {
-				return matchResultFalse, cur // not a string
-			}
-			return boolToRes(s.pattern.Match(v))
-		}
-	case KindAll:
-		if s, ok := cur.(quantifier); ok {
-			res, err := s.selector.Select(node)
-			if err != nil {
-				return matchResultNoData, cur
-			}
-			if res == nil {
-				return matchResultOptionalNoData, nil
-			}
-			it := res.ListIterator()
-			if it == nil {
-				return matchResultFalse, cur // not a list
-			}
-			for !it.Done() {
-				_, v, err := it.Next()
-				if err != nil {
-					panic("should never happen")
-				}
-				matchRes, leaf := matchStatement(s.statement, v)
-				switch matchRes {
-				case matchResultNoData, matchResultOptionalNoData:
-					return matchRes, leaf
-				case matchResultTrue:
-					// continue
-				case matchResultFalse:
-					return matchResultFalse, leaf
-				}
-			}
-			return matchResultTrue, nil
-		}
-	case KindAny:
-		if s, ok := cur.(quantifier); ok {
-			res, err := s.selector.Select(node)
-			if err != nil {
-				return matchResultNoData, cur
-			}
-			if res == nil {
-				return matchResultOptionalNoData, nil
-			}
-			it := res.ListIterator()
-			if it == nil {
-				return matchResultFalse, cur // not a list
-			}
-			for !it.Done() {
-				_, v, err := it.Next()
-				if err != nil {
-					panic("should never happen")
-				}
-				matchRes, leaf := matchStatement(s.statement, v)
-				switch matchRes {
-				case matchResultNoData, matchResultOptionalNoData:
-					return matchRes, leaf
-				case matchResultTrue:
-					return matchResultTrue, nil
-				case matchResultFalse:
-					// continue
-				}
-			}
-			return matchResultFalse, cur
-		}
-	}
-	panic(fmt.Errorf("unimplemented statement kind: %s", cur.Kind()))
-}
-
-// isOrdered compares two IPLD nodes and returns true if they satisfy the given ordering function.
-// It supports comparison of integers and floats, returning false for:
-//   - Nodes of different or unsupported kinds
-//   - Integer values outside JavaScript's safe integer bounds (±2^53-1)
-//   - Non-finite floating point values (NaN or ±Inf)
-//
-// The satisfies parameter is a function that interprets the comparison result:
-//   - For ">" it returns true when order is 1
-//   - For ">=" it returns true when order is 0 or 1
-//   - For "<" it returns true when order is -1
-//   - For "<=" it returns true when order is -1 or 0
-func isOrdered(expected ipld.Node, actual ipld.Node, satisfies func(order int) bool) bool {
-	if expected.Kind() == ipld.Kind_Int && actual.Kind() == ipld.Kind_Int {
-		a := must.Int(actual)
-		b := must.Int(expected)
-
-		return satisfies(cmp.Compare(a, b))
-	}
-
-	if expected.Kind() == ipld.Kind_Float && actual.Kind() == ipld.Kind_Float {
-		a, err := actual.AsFloat()
-		if err != nil {
-			panic(fmt.Errorf("extracting node float: %w", err))
-		}
-		b, err := expected.AsFloat()
-		if err != nil {
-			panic(fmt.Errorf("extracting selector float: %w", err))
-		}
-
-		if math.IsInf(a, 0) || math.IsNaN(a) || math.IsInf(b, 0) || math.IsNaN(b) {
-			return false
-		}
-
-		return satisfies(cmp.Compare(a, b))
-	}
-
-	return false
-}
-
-func gt(order int) bool  { return order == 1 }
-func gte(order int) bool { return order == 0 || order == 1 }
-func lt(order int) bool  { return order == -1 }
-func lte(order int) bool { return order == 0 || order == -1 }

pkg/policy/policy.go

@@ -1,254 +0,0 @@
-package policy
-
-// https://github.com/ucan-wg/delegation/blob/4094d5878b58f5d35055a3b93fccda0b8329ebae/README.md#policy
-
-import (
-	"fmt"
-	"strings"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/codec/dagjson"
-
-	selpkg "github.com/ucan-wg/go-ucan/pkg/policy/selector"
-)
-
-const (
-	KindEqual              = "=="   // implemented by equality
-	KindNotEqual           = "!="   // implemented by equality
-	KindGreaterThan        = ">"    // implemented by equality
-	KindGreaterThanOrEqual = ">="   // implemented by equality
-	KindLessThan           = "<"    // implemented by equality
-	KindLessThanOrEqual    = "<="   // implemented by equality
-	KindNot                = "not"  // implemented by negation
-	KindAnd                = "and"  // implemented by connective
-	KindOr                 = "or"   // implemented by connective
-	KindLike               = "like" // implemented by wildcard
-	KindAll                = "all"  // implemented by quantifier
-	KindAny                = "any"  // implemented by quantifier
-)
-
-type Policy []Statement
-
-type Constructor func() (Statement, error)
-
-func Construct(cstors ...Constructor) (Policy, error) {
-	stmts, err := assemble(cstors)
-	if err != nil {
-		return nil, err
-	}
-	return stmts, nil
-}
-
-func MustConstruct(cstors ...Constructor) Policy {
-	pol, err := Construct(cstors...)
-	if err != nil {
-		panic(err)
-	}
-	return pol
-}
-
-func (p Policy) String() string {
-	if len(p) == 0 {
-		return "[]"
-	}
-	childs := make([]string, len(p))
-	for i, statement := range p {
-		childs[i] = strings.ReplaceAll(statement.String(), "\n", "\n  ")
-	}
-	return fmt.Sprintf("[\n  %s\n]", strings.Join(childs, ",\n  "))
-}
-
-type Statement interface {
-	Kind() string
-	String() string
-}
-
-type equality struct {
-	kind     string
-	selector selpkg.Selector
-	value    ipld.Node
-}
-
-func (e equality) Kind() string {
-	return e.kind
-}
-
-func (e equality) String() string {
-	child, err := ipld.Encode(e.value, dagjson.Encode)
-	if err != nil {
-		return "ERROR: INVALID VALUE"
-	}
-	return fmt.Sprintf(`["%s", "%s", %s]`, e.kind, e.selector, strings.ReplaceAll(string(child), "\n", "\n  "))
-}
-
-func Equal(selector string, value ipld.Node) Constructor {
-	return func() (Statement, error) {
-		sel, err := selpkg.Parse(selector)
-		return equality{kind: KindEqual, selector: sel, value: value}, err
-	}
-}
-
-func NotEqual(selector string, value ipld.Node) Constructor {
-	return func() (Statement, error) {
-		sel, err := selpkg.Parse(selector)
-		return equality{kind: KindNotEqual, selector: sel, value: value}, err
-	}
-}
-
-func GreaterThan(selector string, value ipld.Node) Constructor {
-	return func() (Statement, error) {
-		sel, err := selpkg.Parse(selector)
-		return equality{kind: KindGreaterThan, selector: sel, value: value}, err
-	}
-}
-
-func GreaterThanOrEqual(selector string, value ipld.Node) Constructor {
-	return func() (Statement, error) {
-		sel, err := selpkg.Parse(selector)
-		return equality{kind: KindGreaterThanOrEqual, selector: sel, value: value}, err
-	}
-}
-
-func LessThan(selector string, value ipld.Node) Constructor {
-	return func() (Statement, error) {
-		sel, err := selpkg.Parse(selector)
-		return equality{kind: KindLessThan, selector: sel, value: value}, err
-	}
-}
-
-func LessThanOrEqual(selector string, value ipld.Node) Constructor {
-	return func() (Statement, error) {
-		sel, err := selpkg.Parse(selector)
-		return equality{kind: KindLessThanOrEqual, selector: sel, value: value}, err
-	}
-}
-
-type negation struct {
-	statement Statement
-}
-
-func (n negation) Kind() string {
-	return KindNot
-}
-
-func (n negation) String() string {
-	child := n.statement.String()
-	return fmt.Sprintf(`["%s", %s]`, n.Kind(), strings.ReplaceAll(child, "\n", "\n  "))
-}
-
-func Not(cstor Constructor) Constructor {
-	return func() (Statement, error) {
-		stmt, err := cstor()
-		return negation{statement: stmt}, err
-	}
-}
-
-type connective struct {
-	kind       string
-	statements []Statement
-}
-
-func (c connective) Kind() string {
-	return c.kind
-}
-
-func (c connective) String() string {
-	childs := make([]string, len(c.statements))
-	for i, statement := range c.statements {
-		childs[i] = strings.ReplaceAll(statement.String(), "\n", "\n  ")
-	}
-	return fmt.Sprintf("[\"%s\", [\n  %s\n]]", c.kind, strings.Join(childs, ",\n  "))
-}
-
-func And(cstors ...Constructor) Constructor {
-	return func() (Statement, error) {
-		stmts, err := assemble(cstors)
-		if err != nil {
-			return nil, err
-		}
-		return connective{kind: KindAnd, statements: stmts}, nil
-	}
-}
-
-func Or(cstors ...Constructor) Constructor {
-	return func() (Statement, error) {
-		stmts, err := assemble(cstors)
-		if err != nil {
-			return nil, err
-		}
-		return connective{kind: KindOr, statements: stmts}, nil
-	}
-}
-
-type wildcard struct {
-	selector selpkg.Selector
-	pattern  glob
-}
-
-func (n wildcard) Kind() string {
-	return KindLike
-}
-
-func (n wildcard) String() string {
-	return fmt.Sprintf(`["%s", "%s", "%s"]`, n.Kind(), n.selector, n.pattern)
-}
-
-func Like(selector string, pattern string) Constructor {
-	return func() (Statement, error) {
-		g, err := parseGlob(pattern)
-		if err != nil {
-			return nil, err
-		}
-		sel, err := selpkg.Parse(selector)
-		return wildcard{selector: sel, pattern: g}, err
-	}
-}
-
-type quantifier struct {
-	kind      string
-	selector  selpkg.Selector
-	statement Statement
-}
-
-func (n quantifier) Kind() string {
-	return n.kind
-}
-
-func (n quantifier) String() string {
-	child := n.statement.String()
-	return fmt.Sprintf("[\"%s\", \"%s\",\n  %s\n]", n.Kind(), n.selector, strings.ReplaceAll(child, "\n", "\n  "))
-}
-
-func All(selector string, cstor Constructor) Constructor {
-	return func() (Statement, error) {
-		stmt, err := cstor()
-		if err != nil {
-			return nil, err
-		}
-		sel, err := selpkg.Parse(selector)
-		return quantifier{kind: KindAll, selector: sel, statement: stmt}, err
-	}
-}
-
-func Any(selector string, cstor Constructor) Constructor {
-	return func() (Statement, error) {
-		stmt, err := cstor()
-		if err != nil {
-			return nil, err
-		}
-		sel, err := selpkg.Parse(selector)
-		return quantifier{kind: KindAny, selector: sel, statement: stmt}, err
-	}
-}
-
-func assemble(cstors []Constructor) ([]Statement, error) {
-	stmts := make([]Statement, 0, len(cstors))
-	for _, cstor := range cstors {
-		stmt, err := cstor()
-		if err != nil {
-			return nil, err
-		}
-		stmts = append(stmts, stmt)
-	}
-	return stmts, nil
-}

pkg/policy/policy_test.go

@@ -1,95 +0,0 @@
-package policy_test
-
-import (
-	"fmt"
-	"testing"
-
-	"github.com/stretchr/testify/require"
-
-	"github.com/ucan-wg/go-ucan/pkg/policy"
-	"github.com/ucan-wg/go-ucan/pkg/policy/literal"
-)
-
-func ExamplePolicy() {
-	pol := policy.MustConstruct(
-		policy.Equal(".status", literal.String("draft")),
-		policy.All(".reviewer",
-			policy.Like(".email", "*@example.com"),
-		),
-		policy.Any(".tags", policy.Or(
-			policy.Equal(".", literal.String("news")),
-			policy.Equal(".", literal.String("press")),
-		)),
-	)
-
-	fmt.Println(pol)
-
-	// Output:
-	// [
-	//   ["==", ".status", "draft"],
-	//   ["all", ".reviewer",
-	//     ["like", ".email", "*@example.com"]
-	//   ],
-	//   ["any", ".tags",
-	//     ["or", [
-	//       ["==", ".", "news"],
-	//       ["==", ".", "press"]
-	//     ]]
-	//   ]
-	// ]
-}
-
-func ExamplePolicy_accumulate() {
-	var statements []policy.Constructor
-
-	statements = append(statements, policy.Equal(".status", literal.String("draft")))
-
-	statements = append(statements, policy.All(".reviewer",
-		policy.Like(".email", "*@example.com"),
-	))
-
-	statements = append(statements, policy.Any(".tags", policy.Or(
-		policy.Equal(".", literal.String("news")),
-		policy.Equal(".", literal.String("press")),
-	)))
-
-	pol := policy.MustConstruct(statements...)
-
-	fmt.Println(pol)
-
-	// Output:
-	// [
-	//   ["==", ".status", "draft"],
-	//   ["all", ".reviewer",
-	//     ["like", ".email", "*@example.com"]
-	//   ],
-	//   ["any", ".tags",
-	//     ["or", [
-	//       ["==", ".", "news"],
-	//       ["==", ".", "press"]
-	//     ]]
-	//   ]
-	// ]
-}
-
-func TestConstruct(t *testing.T) {
-	pol, err := policy.Construct(
-		policy.Equal(".status", literal.String("draft")),
-		policy.All(".reviewer",
-			policy.Like(".email", "*@example.com"),
-		),
-	)
-	require.NoError(t, err)
-	require.NotNil(t, pol)
-
-	// check if errors cascade correctly
-	pol, err = policy.Construct(
-		policy.Equal(".status", literal.String("draft")),
-		policy.All(".reviewer", policy.Or(
-			policy.Like(".email", "*@example.com"),
-			policy.Like(".", "\\"), // invalid pattern
-		)),
-	)
-	require.Error(t, err)
-	require.Nil(t, pol)
-}

pkg/policy/policytest/spec.go

@@ -1,67 +0,0 @@
-package policytest
-
-import (
-	"github.com/ipld/go-ipld-prime"
-
-	"github.com/ucan-wg/go-ucan/pkg/args"
-	"github.com/ucan-wg/go-ucan/pkg/policy"
-	"github.com/ucan-wg/go-ucan/pkg/policy/literal"
-)
-
-// EmptyPolicy provides a Policy with no statements.
-var EmptyPolicy = policy.Policy{}
-
-// SpecPolicy provides a  valid Policy containing the statements that are included
-// in the second code block of the [Validation] section of the delegation specification.
-//
-// [Validation]: https://github.com/ucan-wg/delegation/tree/v1_ipld#validation
-var SpecPolicy = policy.MustConstruct(
-	policy.Equal(".from", literal.String("alice@example.com")),
-	policy.Any(".to", policy.Like(".", "*@example.com")),
-)
-
-// TODO: Replace the URL for [Validation] above when the delegation
-//       specification has been finished/merged.
-
-// SpecValidArguments provides valid, instantiated Arguments containing
-// the key/value pairs that are included in portion of the second code block
-// of the [Validation] section of the delegation specification.
-//
-// [Validation]: https://github.com/ucan-wg/delegation/tree/v1_ipld#validation
-var SpecValidArguments = args.NewBuilder().
-	Add("from", "alice@example.com").
-	Add("to", []string{
-		"bob@example.com",
-		"carol@not.example.com",
-	}).
-	Add("title", "Coffee").
-	Add("body", "Still on for coffee").
-	MustBuild()
-
-var specValidArgumentsIPLD = mustIPLD(SpecValidArguments)
-
-// SpecInvalidArguments provides invalid, instantiated Arguments containing
-// the key/value pairs that are included in portion of the second code block
-// of the [Validation] section of the delegation specification.
-//
-// [Validation]: https://github.com/ucan-wg/delegation/tree/v1_ipld#validation
-var SpecInvalidArguments = args.NewBuilder().
-	Add("from", "alice@example.com").
-	Add("to", []string{
-		"bob@null.com",
-		"carol@elsewhere.example.com",
-	}).
-	Add("title", "Coffee").
-	Add("body", "Still on for coffee").
-	MustBuild()
-
-var specInvalidArgumentsIPLD = mustIPLD(SpecInvalidArguments)
-
-func mustIPLD(args *args.Args) ipld.Node {
-	node, err := args.ToIPLD()
-	if err != nil {
-		panic(err)
-	}
-
-	return node
-}

pkg/policy/policytest/spec_test.go

@@ -1,32 +0,0 @@
-package policytest
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/assert"
-)
-
-// TestInvocationValidation applies the example policy to the second
-// example arguments as defined in the [Validation] section of the
-// invocation specification.
-//
-// [Validation]: https://github.com/ucan-wg/delegation/tree/v1_ipld#validation
-func TestInvocationValidationSpecExamples(t *testing.T) {
-	t.Parallel()
-
-	t.Run("with passing args", func(t *testing.T) {
-		t.Parallel()
-
-		exec, stmt := SpecPolicy.Match(specValidArgumentsIPLD)
-		assert.True(t, exec)
-		assert.Nil(t, stmt)
-	})
-
-	t.Run("fails on recipients (second statement)", func(t *testing.T) {
-		t.Parallel()
-
-		exec, stmt := SpecPolicy.Match(specInvalidArgumentsIPLD)
-		assert.False(t, exec)
-		assert.NotNil(t, stmt)
-	})
-}

pkg/policy/selector/parsing.go

@@ -1,209 +0,0 @@
-package selector
-
-import (
-	"fmt"
-	"math"
-	"regexp"
-	"strconv"
-	"strings"
-
-	"github.com/ucan-wg/go-ucan/pkg/policy/limits"
-)
-
-var (
-	indexRegex = regexp.MustCompile(`^-?\d+$`)
-	sliceRegex = regexp.MustCompile(`^((\-?\d+:\-?\d*)|(\-?\d*:\-?\d+))$`)
-
-	// Field name requirements:
-	// - Must start with ASCII letter, Unicode letter, or underscore
-	// - Can contain:
-	//   - ASCII letters (a-z, A-Z)
-	//   - ASCII digits (0-9)
-	//   - Unicode letters (\p{L})
-	//   - Dollar sign ($)
-	//   - Underscore (_)
-	//   - Hyphen (-)
-	fieldRegex = regexp.MustCompile(`^\.[a-zA-Z_\p{L}][a-zA-Z0-9$_\p{L}\-]*$`)
-)
-
-func Parse(str string) (Selector, error) {
-	if len(str) == 0 {
-		return nil, newParseError("empty selector", str, 0, "")
-	}
-	if string(str[0]) != "." {
-		return nil, newParseError("selector must start with identity segment '.'", str, 0, string(str[0]))
-	}
-	if str == "." {
-		return Selector{segment{str: ".", identity: true}}, nil
-	}
-	if str == ".?" {
-		return Selector{segment{str: ".?", identity: true, optional: true}}, nil
-	}
-
-	col := 0
-	var sel Selector
-	for _, tok := range tokenize(str) {
-		seg := tok
-		opt := strings.HasSuffix(tok, "?")
-		if opt {
-			seg = strings.TrimRight(tok, "?")
-		}
-		switch {
-		case seg == ".":
-			if len(sel) > 0 && sel[len(sel)-1].Identity() {
-				return nil, newParseError("selector contains unsupported recursive descent segment: '..'", str, col, tok)
-			}
-			sel = append(sel, segment{str: ".", identity: true})
-
-		case seg == "[]":
-			sel = append(sel, segment{str: tok, optional: opt, iterator: true})
-
-		case strings.HasPrefix(seg, "[") && strings.HasSuffix(seg, "]"):
-			lookup := seg[1 : len(seg)-1]
-
-			switch {
-			// index, [123]
-			case indexRegex.MatchString(lookup):
-				idx, err := strconv.Atoi(lookup)
-				if err != nil {
-					return nil, newParseError("invalid index", str, col, tok)
-				}
-				if int64(idx) > limits.MaxInt53 || int64(idx) < limits.MinInt53 {
-					return nil, newParseError(fmt.Sprintf("index %d exceeds safe integer bounds", idx), str, col, tok)
-				}
-				sel = append(sel, segment{str: tok, optional: opt, index: idx})
-
-			// explicit field, ["abcd"]
-			case strings.HasPrefix(lookup, "\"") && strings.HasSuffix(lookup, "\""):
-				fieldName := lookup[1 : len(lookup)-1]
-				if strings.Contains(fieldName, ":") {
-					return nil, newParseError(fmt.Sprintf("invalid segment: %s", seg), str, col, tok)
-				}
-				sel = append(sel, segment{str: tok, optional: opt, field: fieldName})
-
-			// slice [3:5] or [:5] or [3:], also negative numbers
-			case sliceRegex.MatchString(lookup):
-				var rng [2]int64
-				splt := strings.Split(lookup, ":")
-				if splt[0] == "" {
-					rng[0] = math.MinInt
-				} else {
-					i, err := strconv.ParseInt(splt[0], 10, 0)
-					if err != nil {
-						return nil, newParseError("invalid slice index", str, col, tok)
-					}
-					if i > limits.MaxInt53 || i < limits.MinInt53 {
-						return nil, newParseError(fmt.Sprintf("slice index %d exceeds safe integer bounds", i), str, col, tok)
-					}
-					rng[0] = i
-				}
-				if splt[1] == "" {
-					rng[1] = math.MaxInt
-				} else {
-					i, err := strconv.ParseInt(splt[1], 10, 0)
-					if err != nil {
-						return nil, newParseError("invalid slice index", str, col, tok)
-					}
-					if i > limits.MaxInt53 || i < limits.MinInt53 {
-						return nil, newParseError(fmt.Sprintf("slice index %d exceeds safe integer bounds", i), str, col, tok)
-					}
-					rng[1] = i
-				}
-				sel = append(sel, segment{str: tok, optional: opt, slice: rng[:]})
-
-			default:
-				return nil, newParseError(fmt.Sprintf("invalid segment: %s", seg), str, col, tok)
-			}
-
-		case fieldRegex.MatchString(seg):
-			sel = append(sel, segment{str: tok, optional: opt, field: seg[1:]})
-		default:
-			return nil, newParseError(fmt.Sprintf("invalid segment: %s", seg), str, col, tok)
-		}
-		col += len(tok)
-	}
-	return sel, nil
-}
-
-func MustParse(sel string) Selector {
-	s, err := Parse(sel)
-	if err != nil {
-		panic(err)
-	}
-	return s
-}
-
-func tokenize(str string) []string {
-	var toks []string
-	col := 0
-	ofs := 0
-	ctx := ""
-
-	for col < len(str) {
-		char := string(str[col])
-
-		if char == "\"" && string(str[col-1]) != "\\" {
-			col++
-			if ctx == "\"" {
-				ctx = ""
-			} else {
-				ctx = "\""
-			}
-			continue
-		}
-
-		if ctx == "\"" {
-			col++
-			continue
-		}
-
-		if char == "." || char == "[" {
-			if ofs < col {
-				toks = append(toks, str[ofs:col])
-			}
-			ofs = col
-		}
-		col++
-	}
-
-	if ofs < col && ctx != "\"" {
-		toks = append(toks, str[ofs:col])
-	}
-
-	return toks
-}
-
-type parseErr struct {
-	msg string
-	src string
-	col int
-	tok string
-}
-
-func (p parseErr) Name() string {
-	return "ParseError"
-}
-
-func (p parseErr) Message() string {
-	return p.msg
-}
-
-func (p parseErr) Column() int {
-	return p.col
-}
-
-func (p parseErr) Error() string {
-	return p.msg
-}
-
-func (p parseErr) Source() string {
-	return p.src
-}
-
-func (p parseErr) Token() string {
-	return p.tok
-}
-
-func newParseError(message string, source string, column int, token string) error {
-	return parseErr{message, source, column, token}
-}

pkg/policy/selector/parsing_test.go

@@ -1,641 +0,0 @@
-package selector
-
-import (
-	"fmt"
-	"math"
-	"testing"
-
-	"github.com/stretchr/testify/require"
-
-	"github.com/ucan-wg/go-ucan/pkg/policy/limits"
-)
-
-func TestParse(t *testing.T) {
-	t.Run("identity", func(t *testing.T) {
-		sel, err := Parse(".")
-		require.NoError(t, err)
-		require.Equal(t, 1, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-	})
-
-	t.Run("dotted field name", func(t *testing.T) {
-		sel, err := Parse(".foo")
-		require.NoError(t, err)
-		require.Equal(t, 1, len(sel))
-		require.False(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Equal(t, sel[0].Field(), "foo")
-		require.Empty(t, sel[0].Index())
-
-		sel, err = Parse(".foo_bar")
-		require.NoError(t, err)
-		require.Equal(t, 1, len(sel))
-		require.False(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Equal(t, sel[0].Field(), "foo_bar")
-		require.Empty(t, sel[0].Index())
-
-		sel, err = Parse(".foo-bar")
-		require.NoError(t, err)
-		require.Equal(t, 1, len(sel))
-		require.False(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Equal(t, sel[0].Field(), "foo-bar")
-		require.Empty(t, sel[0].Index())
-
-		sel, err = Parse(".foo*bar")
-		require.ErrorContains(t, err, "invalid segment")
-	})
-
-	t.Run("explicit field", func(t *testing.T) {
-		sel, err := Parse(`.["foo"]`)
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Empty(t, sel[1].Slice())
-		require.Equal(t, sel[1].Field(), "foo")
-		require.Empty(t, sel[1].Index())
-	})
-
-	t.Run("iterator, collection value", func(t *testing.T) {
-		sel, err := Parse(".[]")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.True(t, sel[1].Iterator())
-		require.Empty(t, sel[1].Slice())
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-	})
-
-	t.Run("index", func(t *testing.T) {
-		sel, err := Parse(".[138]")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Empty(t, sel[1].Slice())
-		require.Empty(t, sel[1].Field())
-		require.Equal(t, sel[1].Index(), 138)
-	})
-
-	t.Run("negative index", func(t *testing.T) {
-		sel, err := Parse(".[-138]")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Empty(t, sel[1].Slice())
-		require.Empty(t, sel[1].Field())
-		require.Equal(t, sel[1].Index(), -138)
-	})
-
-	t.Run("List slice", func(t *testing.T) {
-		sel, err := Parse(".[7:11]")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Equal(t, sel[1].Slice(), []int64{7, 11})
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-
-		sel, err = Parse(".[2:]")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Equal(t, sel[1].Slice(), []int64{2, math.MaxInt})
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-
-		sel, err = Parse(".[:42]")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Equal(t, sel[1].Slice(), []int64{math.MinInt, 42})
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-
-		sel, err = Parse(".[0:-2]")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Equal(t, sel[1].Slice(), []int64{0, -2})
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-	})
-
-	t.Run("optional identity", func(t *testing.T) {
-		sel, err := Parse(".?")
-		require.NoError(t, err)
-		require.Equal(t, 1, len(sel))
-		require.True(t, sel[0].Identity())
-		require.True(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-	})
-
-	t.Run("optional dotted field name", func(t *testing.T) {
-		sel, err := Parse(".foo?")
-		require.NoError(t, err)
-		require.Equal(t, 1, len(sel))
-		require.False(t, sel[0].Identity())
-		require.True(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Equal(t, sel[0].Field(), "foo")
-		require.Empty(t, sel[0].Index())
-	})
-
-	t.Run("optional explicit field", func(t *testing.T) {
-		sel, err := Parse(`.["foo"]?`)
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.True(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Empty(t, sel[1].Slice())
-		require.Equal(t, sel[1].Field(), "foo")
-		require.Empty(t, sel[1].Index())
-	})
-
-	t.Run("optional iterator", func(t *testing.T) {
-		sel, err := Parse(".[]?")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.True(t, sel[1].Optional())
-		require.True(t, sel[1].Iterator())
-		require.Empty(t, sel[1].Slice())
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-	})
-
-	t.Run("optional index", func(t *testing.T) {
-		sel, err := Parse(".[138]?")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.True(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Empty(t, sel[1].Slice())
-		require.Empty(t, sel[1].Field())
-		require.Equal(t, sel[1].Index(), 138)
-	})
-
-	t.Run("optional negative index", func(t *testing.T) {
-		sel, err := Parse(".[-138]?")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.True(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Empty(t, sel[1].Slice())
-		require.Empty(t, sel[1].Field())
-		require.Equal(t, sel[1].Index(), -138)
-	})
-
-	t.Run("optional list slice", func(t *testing.T) {
-		sel, err := Parse(".[7:11]?")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.True(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Equal(t, sel[1].Slice(), []int64{7, 11})
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-
-		sel, err = Parse(".[2:]?")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.True(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Equal(t, sel[1].Slice(), []int64{2, math.MaxInt})
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-
-		sel, err = Parse(".[:42]?")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.True(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Equal(t, sel[1].Slice(), []int64{math.MinInt, 42})
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-
-		sel, err = Parse(".[0:-2]?")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.True(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Equal(t, sel[1].Slice(), []int64{0, -2})
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-	})
-
-	t.Run("idempotent optional", func(t *testing.T) {
-		sel, err := Parse(".foo???")
-		require.NoError(t, err)
-		require.Equal(t, 1, len(sel))
-		require.False(t, sel[0].Identity())
-		require.True(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Equal(t, sel[0].Field(), "foo")
-		require.Empty(t, sel[0].Index())
-	})
-
-	t.Run("deny multi dot", func(t *testing.T) {
-		_, err := Parse("..")
-		require.Error(t, err)
-	})
-
-	t.Run("nesting", func(t *testing.T) {
-		str := `.foo.["bar"].[138]?.baz[1:]`
-		sel, err := Parse(str)
-		require.NoError(t, err)
-		require.Equal(t, str, sel.String())
-		require.Equal(t, 7, len(sel))
-		require.False(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Equal(t, sel[0].Field(), "foo")
-		require.Empty(t, sel[0].Index())
-		require.True(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Empty(t, sel[1].Slice())
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-		require.False(t, sel[2].Identity())
-		require.False(t, sel[2].Optional())
-		require.False(t, sel[2].Iterator())
-		require.Empty(t, sel[2].Slice())
-		require.Equal(t, sel[2].Field(), "bar")
-		require.Empty(t, sel[2].Index())
-		require.True(t, sel[3].Identity())
-		require.False(t, sel[3].Optional())
-		require.False(t, sel[3].Iterator())
-		require.Empty(t, sel[3].Slice())
-		require.Empty(t, sel[3].Field())
-		require.Empty(t, sel[3].Index())
-		require.False(t, sel[4].Identity())
-		require.True(t, sel[4].Optional())
-		require.False(t, sel[4].Iterator())
-		require.Empty(t, sel[4].Slice())
-		require.Empty(t, sel[4].Field())
-		require.Equal(t, sel[4].Index(), 138)
-		require.False(t, sel[5].Identity())
-		require.False(t, sel[5].Optional())
-		require.False(t, sel[5].Iterator())
-		require.Empty(t, sel[5].Slice())
-		require.Equal(t, sel[5].Field(), "baz")
-		require.Empty(t, sel[5].Index())
-		require.False(t, sel[6].Identity())
-		require.False(t, sel[6].Optional())
-		require.False(t, sel[6].Iterator())
-		require.Equal(t, sel[6].Slice(), []int64{1, math.MaxInt})
-		require.Empty(t, sel[6].Field())
-		require.Empty(t, sel[6].Index())
-	})
-
-	t.Run("non dotted", func(t *testing.T) {
-		_, err := Parse("foo")
-		require.NotNil(t, err)
-	})
-
-	t.Run("non quoted", func(t *testing.T) {
-		_, err := Parse(".[foo]")
-		require.NotNil(t, err)
-	})
-
-	t.Run("slice with negative start and positive end", func(t *testing.T) {
-		sel, err := Parse(".[0:-2]")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Equal(t, sel[1].Slice(), []int64{0, -2})
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-	})
-
-	t.Run("slice with start greater than end", func(t *testing.T) {
-		sel, err := Parse(".[5:2]")
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Equal(t, sel[1].Slice(), []int64{5, 2})
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-	})
-
-	t.Run("slice on string", func(t *testing.T) {
-		sel, err := Parse(`.["foo"].[1:3]`)
-		require.NoError(t, err)
-		require.Equal(t, 4, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Empty(t, sel[1].Slice())
-		require.Equal(t, sel[1].Field(), "foo")
-		require.Empty(t, sel[1].Index())
-		require.True(t, sel[2].Identity())
-		require.False(t, sel[2].Optional())
-		require.False(t, sel[2].Iterator())
-		require.Empty(t, sel[2].Slice())
-		require.Empty(t, sel[2].Field())
-		require.Empty(t, sel[2].Index())
-		require.False(t, sel[3].Identity())
-		require.False(t, sel[3].Optional())
-		require.False(t, sel[3].Iterator())
-		require.Equal(t, sel[3].Slice(), []int64{1, 3})
-		require.Empty(t, sel[3].Field())
-		require.Empty(t, sel[3].Index())
-	})
-
-	t.Run("slice on array", func(t *testing.T) {
-		sel, err := Parse(`.[1:3]`)
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Equal(t, sel[1].Slice(), []int64{1, 3})
-		require.Empty(t, sel[1].Field())
-		require.Empty(t, sel[1].Index())
-	})
-
-	t.Run("index on array", func(t *testing.T) {
-		sel, err := Parse(`.[1]`)
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Empty(t, sel[1].Slice())
-		require.Empty(t, sel[1].Field())
-		require.Equal(t, sel[1].Index(), 1)
-	})
-
-	t.Run("invalid slice on object", func(t *testing.T) {
-		_, err := Parse(`.["foo":"bar"]`)
-		require.Error(t, err)
-		require.Contains(t, err.Error(), "invalid segment")
-	})
-
-	t.Run("index on object", func(t *testing.T) {
-		sel, err := Parse(`.["foo"]`)
-		require.NoError(t, err)
-		require.Equal(t, 2, len(sel))
-		require.True(t, sel[0].Identity())
-		require.False(t, sel[0].Optional())
-		require.False(t, sel[0].Iterator())
-		require.Empty(t, sel[0].Slice())
-		require.Empty(t, sel[0].Field())
-		require.Empty(t, sel[0].Index())
-		require.False(t, sel[1].Identity())
-		require.False(t, sel[1].Optional())
-		require.False(t, sel[1].Iterator())
-		require.Empty(t, sel[1].Slice())
-		require.Equal(t, sel[1].Field(), "foo")
-		require.Empty(t, sel[1].Index())
-	})
-
-	t.Run("slice with non-integer start", func(t *testing.T) {
-		_, err := Parse(".[foo:3]")
-		require.Error(t, err)
-	})
-
-	t.Run("slice with non-integer end", func(t *testing.T) {
-		_, err := Parse(".[1:bar]")
-		require.Error(t, err)
-	})
-
-	t.Run("index with non-integer", func(t *testing.T) {
-		_, err := Parse(".[foo]")
-		require.Error(t, err)
-	})
-
-	t.Run("extended field names", func(t *testing.T) {
-		validFields := []string{
-			".basic",
-			".user_name",
-			".user-name",
-			".userName$special",
-			".αβγ",        // Greek letters
-			".użytkownik", // Polish characters
-			".用户",         // Chinese characters
-			".사용자",        // Korean characters
-			"._private",
-			".number123",
-			".camelCase",
-			".snake_case",
-			".kebab-case",
-			".mixed_kebab-case",
-			".with$dollar",
-			".MIXED_Case_123",
-			".unicodeø",
-		}
-
-		for _, field := range validFields {
-			sel, err := Parse(field)
-			require.NoError(t, err, "field: %s", field)
-			require.NotNil(t, sel)
-		}
-
-		invalidFields := []string{
-			".123number",         // Can't start with digit
-			".@special",          // @ not allowed
-			".space name",        // No spaces
-			".#hashtag",          // No #
-			".name!",             // No !
-			".{brackets}",        // No brackets
-			".name/with/slashes", // No slashes
-		}
-
-		for _, field := range invalidFields {
-			sel, err := Parse(field)
-			require.Error(t, err, "field: %s", field)
-			require.Nil(t, sel)
-		}
-	})
-
-	t.Run("integer overflow", func(t *testing.T) {
-		sel, err := Parse(fmt.Sprintf(".[%d]", limits.MaxInt53+1))
-		require.Error(t, err)
-		require.Nil(t, sel)
-
-		sel, err = Parse(fmt.Sprintf(".[%d]", limits.MinInt53-1))
-		require.Error(t, err)
-		require.Nil(t, sel)
-
-		// Test slice overflow
-		sel, err = Parse(fmt.Sprintf(".[%d:42]", limits.MaxInt53+1))
-		require.Error(t, err)
-		require.Nil(t, sel)
-
-		sel, err = Parse(fmt.Sprintf(".[1:%d]", limits.MaxInt53+1))
-		require.Error(t, err)
-		require.Nil(t, sel)
-	})
-}

pkg/policy/selector/selector.go

@@ -1,342 +0,0 @@
-package selector
-
-import (
-	"fmt"
-	"math"
-	"strconv"
-	"strings"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/fluent/qp"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-)
-
-// Selector describes a UCAN policy selector, as specified here:
-// https://github.com/ucan-wg/delegation/blob/4094d5878b58f5d35055a3b93fccda0b8329ebae/README.md#selectors
-type Selector []segment
-
-// Select perform the selection described by the selector on the input IPLD DAG.
-// Select can return:
-//   - exactly one matched IPLD node
-//   - a resolutionErr error if not being able to resolve to a node
-//   - nil and no errors, if the selector couldn't match on an optional segment (with ?).
-func (s Selector) Select(subject ipld.Node) (ipld.Node, error) {
-	return resolve(s, subject, nil)
-}
-
-func (s Selector) String() string {
-	var res strings.Builder
-	for _, seg := range s {
-		res.WriteString(seg.String())
-	}
-	return res.String()
-}
-
-type segment struct {
-	str      string
-	identity bool
-	optional bool
-	iterator bool
-	slice    []int64 // either 0-length or 2-length
-	field    string
-	index    int
-}
-
-// String returns the segment's string representation.
-func (s segment) String() string {
-	return s.str
-}
-
-// Identity flags that this selector is the identity selector.
-func (s segment) Identity() bool {
-	return s.identity
-}
-
-// Optional flags that this selector is optional.
-func (s segment) Optional() bool {
-	return s.optional
-}
-
-// Iterator flags that this selector is an iterator segment.
-func (s segment) Iterator() bool {
-	return s.iterator
-}
-
-// Slice flags that this segment targets a range of a slice.
-func (s segment) Slice() []int64 {
-	return s.slice
-}
-
-// Field is the name of a field in a struct/map.
-func (s segment) Field() string {
-	return s.field
-}
-
-// Index is an index of a slice.
-func (s segment) Index() int {
-	return s.index
-}
-
-func resolve(sel Selector, subject ipld.Node, at []string) (ipld.Node, error) {
-	errIfNotOptional := func(s segment, err error) error {
-		if !s.Optional() {
-			return err
-		}
-		return nil
-	}
-
-	cur := subject
-	for _, seg := range sel {
-		// 1st level: handle the different segment types (iterator, field, slice, index)
-		// 2nd level: handle different node kinds (list, map, string, bytes)
-		switch {
-		case seg.Identity():
-			continue
-
-		case seg.Iterator():
-			switch {
-			case cur == nil || cur.Kind() == datamodel.Kind_Null:
-				if seg.Optional() {
-					// build an empty list
-					n, _ := qp.BuildList(basicnode.Prototype.Any, 0, func(_ datamodel.ListAssembler) {})
-					return n, nil
-				}
-				return nil, newResolutionError(fmt.Sprintf("can not iterate over kind: %s", kindString(cur)), at)
-
-			case cur.Kind() == datamodel.Kind_List:
-				// iterators are no-op on list
-				continue
-
-			case cur.Kind() == datamodel.Kind_Map:
-				// iterators on maps collect the values
-				nd, err := qp.BuildList(basicnode.Prototype.Any, cur.Length(), func(l datamodel.ListAssembler) {
-					it := cur.MapIterator()
-					for !it.Done() {
-						_, v, err := it.Next()
-						if err != nil {
-							// recovered by BuildList
-							// Error is bubbled up, but should never occur as we already checked the type,
-							// and are using the iterator correctly.
-							// This is verified with fuzzing.
-							panic(err)
-						}
-						qp.ListEntry(l, qp.Node(v))
-					}
-				})
-				if err != nil {
-					panic("should never happen")
-				}
-				return nd, nil
-
-			default:
-				return nil, newResolutionError(fmt.Sprintf("can not iterate over kind: %s", kindString(cur)), at)
-			}
-
-		case seg.Field() != "":
-			at = append(at, seg.Field())
-			switch {
-			case cur == nil:
-				err := newResolutionError(fmt.Sprintf("can not access field: %s on kind: %s", seg.Field(), kindString(cur)), at)
-				return nil, errIfNotOptional(seg, err)
-
-			case cur.Kind() == datamodel.Kind_Map:
-				n, err := cur.LookupByString(seg.Field())
-				if err != nil {
-					// the only possible error is missing field as we already check the type
-					if seg.Optional() {
-						cur = nil
-					} else {
-						return nil, newResolutionError(fmt.Sprintf("object has no field named: %s", seg.Field()), at)
-					}
-				} else {
-					cur = n
-				}
-
-			default:
-				err := newResolutionError(fmt.Sprintf("can not access field: %s on kind: %s", seg.Field(), kindString(cur)), at)
-				return nil, errIfNotOptional(seg, err)
-			}
-
-		case len(seg.Slice()) > 0:
-			if cur == nil {
-				err := newResolutionError(fmt.Sprintf("can not slice on kind: %s", kindString(cur)), at)
-				return nil, errIfNotOptional(seg, err)
-			}
-
-			slice := seg.Slice()
-
-			switch cur.Kind() {
-			case datamodel.Kind_List:
-				start, end := resolveSliceIndices(slice, cur.Length())
-				sliced, err := qp.BuildList(basicnode.Prototype.Any, end-start, func(l datamodel.ListAssembler) {
-					for i := start; i < end; i++ {
-						item, err := cur.LookupByIndex(i)
-						if err != nil {
-							// recovered by BuildList
-							// Error is bubbled up, but should never occur as we already checked the type and boundaries
-							// This is verified with fuzzing.
-							panic(err)
-						}
-						qp.ListEntry(l, qp.Node(item))
-					}
-				})
-				if err != nil {
-					panic("should never happen")
-				}
-				cur = sliced
-
-			case datamodel.Kind_Bytes:
-				b, _ := cur.AsBytes()
-				start, end := resolveSliceIndices(slice, int64(len(b)))
-				cur = basicnode.NewBytes(b[start:end])
-
-			case datamodel.Kind_String:
-				str, _ := cur.AsString()
-				runes := []rune(str)
-				start, end := resolveSliceIndices(slice, int64(len(runes)))
-				cur = basicnode.NewString(string(runes[start:end]))
-
-			default:
-				return nil, newResolutionError(fmt.Sprintf("can not slice on kind: %s", kindString(cur)), at)
-			}
-
-		default: // Index()
-			at = append(at, strconv.Itoa(seg.Index()))
-
-			if cur == nil {
-				err := newResolutionError(fmt.Sprintf("can not access index: %d on kind: %s", seg.Index(), kindString(cur)), at)
-				return nil, errIfNotOptional(seg, err)
-			}
-
-			idx := seg.Index()
-			switch cur.Kind() {
-			case datamodel.Kind_List:
-				if idx < 0 {
-					idx = int(cur.Length()) + idx
-				}
-				if idx < 0 || idx >= int(cur.Length()) {
-					err := newResolutionError(fmt.Sprintf("index out of bounds: %d", seg.Index()), at)
-					return nil, errIfNotOptional(seg, err)
-				}
-				cur, _ = cur.LookupByIndex(int64(idx))
-
-			case datamodel.Kind_Bytes:
-				b, _ := cur.AsBytes()
-				if idx < 0 {
-					idx = len(b) + idx
-				}
-				if idx < 0 || idx >= len(b) {
-					err := newResolutionError(fmt.Sprintf("index %d out of bounds for bytes of length %d", seg.Index(), len(b)), at)
-					return nil, errIfNotOptional(seg, err)
-				}
-				cur = basicnode.NewInt(int64(b[idx]))
-
-			default:
-				return nil, newResolutionError(fmt.Sprintf("can not access index: %d on kind: %s", seg.Index(), kindString(cur)), at)
-			}
-		}
-	}
-
-	// segment exhausted, we return where we are
-	return cur, nil
-}
-
-// resolveSliceIndices resolves the start and end indices for slicing a list or byte array.
-//
-// It takes the slice indices from the selector segment and the length of the list or byte array,
-// and returns the resolved start and end indices. Negative indices are supported.
-//
-// Parameters:
-//   - slice: The slice indices from the selector segment.
-//   - length: The length of the list or byte array being sliced.
-//
-// Returns:
-//   - start: The resolved start index for slicing.
-//   - end: The resolved **excluded** end index for slicing.
-func resolveSliceIndices(slice []int64, length int64) (start int64, end int64) {
-	if len(slice) != 2 {
-		panic("should always be 2-length")
-	}
-
-	start, end = slice[0], slice[1]
-
-	// adjust boundaries
-	switch {
-	case slice[0] == math.MinInt:
-		start = 0
-	case slice[0] < 0:
-		// Check for potential overflow before adding
-		if -slice[0] > length {
-			start = 0
-		} else {
-			start = length + slice[0]
-		}
-	}
-
-	switch {
-	case slice[1] == math.MaxInt:
-		end = length
-	case slice[1] < 0:
-		// Check for potential overflow before adding
-		if -slice[1] > length {
-			end = 0
-		} else {
-			end = length + slice[1]
-		}
-	}
-
-	// backward iteration is not allowed, shortcut to an empty result
-	if start >= end {
-		start, end = 0, 0
-		return
-	}
-
-	// clamp out of bound
-	if start < 0 {
-		start = 0
-	}
-	if start > length {
-		start = length
-	}
-	if end < 0 {
-		end = 0
-	}
-	if end > length {
-		end = length
-	}
-
-	return
-}
-
-func kindString(n datamodel.Node) string {
-	if n == nil {
-		return "null"
-	}
-	return n.Kind().String()
-}
-
-type resolutionErr struct {
-	msg string
-	at  []string
-}
-
-func (r resolutionErr) Name() string {
-	return "ResolutionError"
-}
-
-func (r resolutionErr) Message() string {
-	return fmt.Sprintf("can not resolve path: .%s", strings.Join(r.at, "."))
-}
-
-func (r resolutionErr) At() []string {
-	return r.at
-}
-
-func (r resolutionErr) Error() string {
-	return r.Message()
-}
-
-func newResolutionError(message string, at []string) error {
-	return resolutionErr{message, at}
-}

pkg/policy/selector/selector_test.go

@@ -1,413 +0,0 @@
-package selector
-
-import (
-	"errors"
-	"math"
-	"strings"
-	"testing"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/codec/dagjson"
-	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/fluent/qp"
-	"github.com/ipld/go-ipld-prime/must"
-	basicnode "github.com/ipld/go-ipld-prime/node/basic"
-	"github.com/ipld/go-ipld-prime/node/bindnode"
-	"github.com/stretchr/testify/require"
-)
-
-func TestSelect(t *testing.T) {
-	type name struct {
-		First  string
-		Middle *string
-		Last   string
-	}
-	type interest struct {
-		Name       string
-		Outdoor    bool
-		Experience int
-	}
-	type user struct {
-		Name          name
-		Age           int
-		Nationalities []string
-		Interests     []interest
-	}
-
-	ts, err := ipld.LoadSchemaBytes([]byte(`
-	  type User struct {
-		  name Name
-			age Int
-			nationalities [String]
-			interests [Interest]
-		}
-		type Name struct {
-			first String
-			middle optional String
-			last String
-		}
-		type Interest struct {
-			name String
-			outdoor Bool
-			experience Int
-		}
-	`))
-	require.NoError(t, err)
-	typ := ts.TypeByName("User")
-
-	am := "Joan"
-	alice := user{
-		Name:          name{First: "Alice", Middle: &am, Last: "Wonderland"},
-		Age:           24,
-		Nationalities: []string{"British"},
-		Interests: []interest{
-			{Name: "Cycling", Outdoor: true, Experience: 4},
-			{Name: "Chess", Outdoor: false, Experience: 2},
-		},
-	}
-	bob := user{
-		Name:          name{First: "Bob", Last: "Builder"},
-		Age:           35,
-		Nationalities: []string{"Canadian", "South African"},
-		Interests: []interest{
-			{Name: "Snowboarding", Outdoor: true, Experience: 8},
-			{Name: "Reading", Outdoor: false, Experience: 25},
-		},
-	}
-
-	anode := bindnode.Wrap(&alice, typ)
-	bnode := bindnode.Wrap(&bob, typ)
-
-	t.Run("identity", func(t *testing.T) {
-		sel, err := Parse(".")
-		require.NoError(t, err)
-
-		res, err := sel.Select(anode)
-		require.NoError(t, err)
-		require.NotEmpty(t, res)
-
-		age := must.Int(must.Node(res.LookupByString("age")))
-		require.Equal(t, int64(alice.Age), age)
-	})
-
-	t.Run("nested property", func(t *testing.T) {
-		sel, err := Parse(".name.first")
-		require.NoError(t, err)
-
-		res, err := sel.Select(anode)
-		require.NoError(t, err)
-		require.NotEmpty(t, res)
-
-		name := must.String(res)
-		require.Equal(t, alice.Name.First, name)
-
-		res, err = sel.Select(bnode)
-		require.NoError(t, err)
-		require.NotEmpty(t, res)
-
-		name = must.String(res)
-		require.Equal(t, bob.Name.First, name)
-	})
-
-	t.Run("optional nested property", func(t *testing.T) {
-		sel, err := Parse(".name.middle?")
-		require.NoError(t, err)
-
-		res, err := sel.Select(anode)
-		require.NoError(t, err)
-		require.NotEmpty(t, res)
-
-		name := must.String(res)
-		require.Equal(t, *alice.Name.Middle, name)
-
-		res, err = sel.Select(bnode)
-		require.NoError(t, err)
-		require.Empty(t, res)
-	})
-
-	t.Run("not exists", func(t *testing.T) {
-		sel, err := Parse(".name.foo")
-		require.NoError(t, err)
-
-		res, err := sel.Select(anode)
-		require.Error(t, err)
-		require.Empty(t, res)
-
-		require.ErrorAs(t, err, &resolutionErr{}, "error should be a resolution error")
-	})
-
-	t.Run("optional not exists", func(t *testing.T) {
-		sel, err := Parse(".name.foo?")
-		require.NoError(t, err)
-
-		one, err := sel.Select(anode)
-		require.NoError(t, err)
-		require.Empty(t, one)
-	})
-
-	t.Run("iterator", func(t *testing.T) {
-		sel, err := Parse(".interests[]")
-		require.NoError(t, err)
-
-		res, err := sel.Select(anode)
-		require.NoError(t, err)
-		require.NotEmpty(t, res)
-
-		iname := must.String(must.Node(must.Node(res.LookupByIndex(0)).LookupByString("name")))
-		require.Equal(t, alice.Interests[0].Name, iname)
-
-		iname = must.String(must.Node(must.Node(res.LookupByIndex(1)).LookupByString("name")))
-		require.Equal(t, alice.Interests[1].Name, iname)
-	})
-
-	t.Run("slice on string", func(t *testing.T) {
-		sel, err := Parse(`.[1:3]`)
-		require.NoError(t, err)
-
-		node := basicnode.NewString("hello")
-		res, err := sel.Select(node)
-		require.NoError(t, err)
-		require.NotEmpty(t, res)
-
-		str, err := res.AsString()
-		require.NoError(t, err)
-		require.Equal(t, "el", str) // assert sliced substring
-	})
-
-	t.Run("out of bounds slicing", func(t *testing.T) {
-		node, err := qp.BuildList(basicnode.Prototype.Any, 3, func(la datamodel.ListAssembler) {
-			qp.ListEntry(la, qp.Int(1))
-			qp.ListEntry(la, qp.Int(2))
-			qp.ListEntry(la, qp.Int(3))
-		})
-		require.NoError(t, err)
-
-		sel, err := Parse(`.[10:20]`)
-		require.NoError(t, err)
-
-		res, err := sel.Select(node)
-		require.NoError(t, err)
-		require.NotEmpty(t, res)
-		require.Equal(t, int64(0), res.Length())
-
-		_, err = res.LookupByIndex(0)
-		require.ErrorIs(t, err, datamodel.ErrNotExists{}) // assert empty result for out of bounds slice
-	})
-
-	t.Run("backward slicing", func(t *testing.T) {
-		node, err := qp.BuildList(basicnode.Prototype.Any, 3, func(la datamodel.ListAssembler) {
-			qp.ListEntry(la, qp.Int(1))
-			qp.ListEntry(la, qp.Int(2))
-			qp.ListEntry(la, qp.Int(3))
-		})
-		require.NoError(t, err)
-
-		sel, err := Parse(`.[5:2]`)
-		require.NoError(t, err)
-
-		res, err := sel.Select(node)
-		require.NoError(t, err)
-		require.NotEmpty(t, res)
-		require.Equal(t, int64(0), res.Length())
-
-		_, err = res.LookupByIndex(0)
-		require.ErrorIs(t, err, datamodel.ErrNotExists{}) // assert empty result for backward slice
-	})
-
-	t.Run("slice with negative index", func(t *testing.T) {
-		node, err := qp.BuildList(basicnode.Prototype.Any, 3, func(la datamodel.ListAssembler) {
-			qp.ListEntry(la, qp.Int(1))
-			qp.ListEntry(la, qp.Int(2))
-			qp.ListEntry(la, qp.Int(3))
-		})
-		require.NoError(t, err)
-
-		sel, err := Parse(`.[0:-1]`)
-		require.NoError(t, err)
-
-		res, err := sel.Select(node)
-		require.NoError(t, err)
-		require.NotEmpty(t, res)
-
-		val, err := res.LookupByIndex(1)
-		require.NoError(t, err)
-		require.Equal(t, 2, int(must.Int(val))) // Assert sliced value at index 1
-	})
-
-	t.Run("slice on bytes", func(t *testing.T) {
-		sel, err := Parse(`.[1:3]`)
-		require.NoError(t, err)
-
-		node := basicnode.NewBytes([]byte{0x01, 0x02, 0x03, 0x04, 0x05})
-		res, err := sel.Select(node)
-		require.NoError(t, err)
-		require.NotEmpty(t, res)
-
-		bytes, err := res.AsBytes()
-		require.NoError(t, err)
-		require.Equal(t, []byte{0x02, 0x03}, bytes) // assert sliced bytes
-	})
-
-	t.Run("index on bytes", func(t *testing.T) {
-		sel, err := Parse(`.[2]`)
-		require.NoError(t, err)
-
-		node := basicnode.NewBytes([]byte{0x01, 0x02, 0x03, 0x04, 0x05})
-		res, err := sel.Select(node)
-		require.NoError(t, err)
-		require.NotEmpty(t, res)
-
-		val, err := res.AsInt()
-		require.NoError(t, err)
-		require.Equal(t, int64(0x03), val) // assert indexed byte value
-	})
-
-	t.Run("out of bounds slicing on bytes", func(t *testing.T) {
-		sel, err := Parse(`.[10:20]`)
-		require.NoError(t, err)
-
-		node := basicnode.NewBytes([]byte{0x01, 0x02, 0x03})
-		res, err := sel.Select(node)
-		require.NoError(t, err)
-		require.NotNil(t, res)
-
-		bytes, err := res.AsBytes()
-		require.NoError(t, err)
-		require.Empty(t, bytes) // assert empty result for out of bounds slice
-	})
-
-	t.Run("out of bounds indexing on bytes", func(t *testing.T) {
-		sel, err := Parse(`.[10]`)
-		require.NoError(t, err)
-
-		node := basicnode.NewBytes([]byte{0x01, 0x02, 0x03})
-		_, err = sel.Select(node)
-		require.Error(t, err)
-		require.Contains(t, err.Error(), "can not resolve path: .10") // assert error for out of bounds index
-	})
-}
-
-func FuzzParse(f *testing.F) {
-	selectorCorpus := []string{
-		`.`, `.[]`, `.[]?`, `.[][]?`, `.x`, `.["x"]`, `.[0]`, `.[-1]`, `.[0]`,
-		`.[0]`, `.[0:2]`, `.[1:]`, `.[:2]`, `.[0:2]`, `.[1:]`, `.x?`, `.x?`,
-		`.x?`, `.["x"]?`, `.length?`, `.[4]?`, `.[]`, `.[][]`, `.x`, `.x`, `.x`,
-		`.length`, `.[4]`,
-	}
-	for _, selector := range selectorCorpus {
-		f.Add(selector)
-	}
-	f.Fuzz(func(t *testing.T, selector string) {
-		// only look for panic()
-		_, _ = Parse(selector)
-	})
-}
-
-func FuzzParseAndSelect(f *testing.F) {
-	selectorCorpus := []string{
-		`.`, `.[]`, `.[]?`, `.[][]?`, `.x`, `.["x"]`, `.[0]`, `.[-1]`, `.[0]`,
-		`.[0]`, `.[0:2]`, `.[1:]`, `.[:2]`, `.[0:2]`, `.[1:]`, `.x?`, `.x?`,
-		`.x?`, `.["x"]?`, `.length?`, `.[4]?`, `.[]`, `.[][]`, `.x`, `.x`, `.x`,
-		`.length`, `.[4]`,
-	}
-	subjectCorpus := []string{
-		`{"x":1}`, `[1, 2]`, `null`, `[[1], 2, [3]]`, `{"x": 1 }`, `{"x": 1}`,
-		`[1, 2]`, `[1, 2]`, `"Hi"`, `{"/":{"bytes":"AAE"}`, `[0, 1, 2]`,
-		`[0, 1, 2]`, `[0, 1, 2]`, `"hello"`, `{"/":{"bytes":"AAEC"}}`, `{}`,
-		`null`, `[]`, `{}`, `[1, 2]`, `[0, 1]`, `null`, `[[1], 2, [3]]`, `{}`,
-		`null`, `[]`, `[1, 2]`, `[0, 1]`,
-	}
-	for i := 0; ; i++ {
-		switch {
-		case i < len(selectorCorpus) && i < len(subjectCorpus):
-			f.Add(selectorCorpus[i], subjectCorpus[i])
-			continue
-		case i > len(selectorCorpus):
-			f.Add("", subjectCorpus[i])
-			continue
-		case i > len(subjectCorpus):
-			f.Add(selectorCorpus[i], "")
-			continue
-		}
-		break
-	}
-
-	f.Fuzz(func(t *testing.T, selector, subject string) {
-		sel, err := Parse(selector)
-		if err != nil {
-			t.Skip()
-		}
-
-		np := basicnode.Prototype.Any
-		nb := np.NewBuilder()
-		err = dagjson.Decode(nb, strings.NewReader(subject))
-		if err != nil {
-			t.Skip()
-		}
-		node := nb.Build()
-		if node == nil {
-			t.Skip()
-		}
-
-		// look for panic()
-		_, err = sel.Select(node)
-		if err != nil && !errors.As(err, &resolutionErr{}) {
-			// not normal, we should only have resolution errors
-			t.Fatal(err)
-		}
-	})
-}
-
-func TestResolveSliceIndices(t *testing.T) {
-	tests := []struct {
-		name      string
-		slice     []int64
-		length    int64
-		wantStart int64
-		wantEnd   int64
-	}{
-		{
-			name:      "normal case",
-			slice:     []int64{1, 3},
-			length:    5,
-			wantStart: 1,
-			wantEnd:   3,
-		},
-		{
-			name:      "negative indices",
-			slice:     []int64{-2, -1},
-			length:    5,
-			wantStart: 3,
-			wantEnd:   4,
-		},
-		{
-			name:      "overflow protection negative start",
-			slice:     []int64{math.MinInt64, 3},
-			length:    5,
-			wantStart: 0,
-			wantEnd:   3,
-		},
-		{
-			name:      "overflow protection negative end",
-			slice:     []int64{0, math.MinInt64},
-			length:    5,
-			wantStart: 0,
-			wantEnd:   0,
-		},
-		{
-			name:      "max bounds",
-			slice:     []int64{0, math.MaxInt64},
-			length:    5,
-			wantStart: 0,
-			wantEnd:   5,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			start, end := resolveSliceIndices(tt.slice, tt.length)
-			require.Equal(t, tt.wantStart, start)
-			require.Equal(t, tt.wantEnd, end)
-		})
-	}
-}

pkg/secretbox/secretbox.go

@@ -1,90 +0,0 @@
-package secretbox
-
-import (
-	"crypto/rand"
-	"errors"
-	"fmt"
-	"io"
-
-	"golang.org/x/crypto/nacl/secretbox"
-)
-
-const keySize = 32 // secretbox allows only 32-byte keys
-
-var ErrShortCipherText = errors.New("ciphertext too short")
-var ErrNoEncryptionKey = errors.New("encryption key is required")
-var ErrInvalidKeySize = errors.New("invalid key size: must be 32 bytes")
-var ErrZeroKey = errors.New("encryption key cannot be all zeros")
-
-// GenerateKey generates a random 32-byte key to be used by EncryptWithKey and DecryptWithKey
-func GenerateKey() ([]byte, error) {
-	key := make([]byte, keySize)
-	if _, err := io.ReadFull(rand.Reader, key); err != nil {
-		return nil, fmt.Errorf("failed to generate key: %w", err)
-	}
-	return key, nil
-}
-
-// EncryptWithKey encrypts data using NaCl's secretbox with the provided key.
-// 40 bytes of overhead (24-byte nonce + 16-byte MAC) are added to the plaintext size.
-func EncryptWithKey(data, key []byte) ([]byte, error) {
-	if err := validateKey(key); err != nil {
-		return nil, err
-	}
-
-	var secretKey [keySize]byte
-	copy(secretKey[:], key)
-
-	// Generate 24 bytes of random data as nonce
-	var nonce [24]byte
-	if _, err := io.ReadFull(rand.Reader, nonce[:]); err != nil {
-		return nil, err
-	}
-
-	// Encrypt and authenticate data
-	encrypted := secretbox.Seal(nonce[:], data, &nonce, &secretKey)
-	return encrypted, nil
-}
-
-// DecryptStringWithKey decrypts data using secretbox with the provided key
-func DecryptStringWithKey(data, key []byte) ([]byte, error) {
-	if err := validateKey(key); err != nil {
-		return nil, err
-	}
-
-	if len(data) < 24 {
-		return nil, ErrShortCipherText
-	}
-
-	var secretKey [keySize]byte
-	copy(secretKey[:], key)
-
-	var nonce [24]byte
-	copy(nonce[:], data[:24])
-
-	decrypted, ok := secretbox.Open(nil, data[24:], &nonce, &secretKey)
-	if !ok {
-		return nil, errors.New("decryption failed")
-	}
-
-	return decrypted, nil
-}
-
-func validateKey(key []byte) error {
-	if key == nil {
-		return ErrNoEncryptionKey
-	}
-
-	if len(key) != keySize {
-		return ErrInvalidKeySize
-	}
-
-	// check if key is all zeros
-	for _, b := range key {
-		if b != 0 {
-			return nil
-		}
-	}
-
-	return ErrZeroKey
-}

pkg/secretbox/secretbox_test.go

@@ -1,144 +0,0 @@
-package secretbox
-
-import (
-	"bytes"
-	"crypto/rand"
-	"testing"
-
-	"github.com/stretchr/testify/require"
-)
-
-func TestSecretBoxEncryption(t *testing.T) {
-	t.Parallel()
-
-	key := make([]byte, keySize) // generate random 32-byte key
-	_, errKey := rand.Read(key)
-	require.NoError(t, errKey)
-
-	tests := []struct {
-		name    string
-		data    []byte
-		key     []byte
-		wantErr error
-	}{
-		{
-			name: "valid encryption/decryption",
-			data: []byte("hello world"),
-			key:  key,
-		},
-		{
-			name:    "nil key returns error",
-			data:    []byte("hello world"),
-			key:     nil,
-			wantErr: ErrNoEncryptionKey,
-		},
-		{
-			name: "empty data",
-			data: []byte{},
-			key:  key,
-		},
-		{
-			name:    "invalid key size",
-			data:    []byte("hello world"),
-			key:     make([]byte, 16), // Only 32 bytes allowed now
-			wantErr: ErrInvalidKeySize,
-		},
-		{
-			name:    "zero key returns error",
-			data:    []byte("hello world"),
-			key:     make([]byte, keySize),
-			wantErr: ErrZeroKey,
-		},
-	}
-
-	for _, tt := range tests {
-		tt := tt
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-
-			encrypted, err := EncryptWithKey(tt.data, tt.key)
-			if tt.wantErr != nil {
-				require.ErrorIs(t, err, tt.wantErr)
-				return
-			}
-			require.NoError(t, err)
-
-			// Verify encrypted data is different and includes nonce
-			require.Greater(t, len(encrypted), 24) // At least nonce size
-			if len(tt.data) > 0 {
-				require.NotEqual(t, tt.data, encrypted[24:]) // Ignore nonce prefix
-			}
-
-			decrypted, err := DecryptStringWithKey(encrypted, tt.key)
-			require.NoError(t, err)
-			require.True(t, bytes.Equal(tt.data, decrypted))
-		})
-	}
-}
-
-func TestDecryptionErrors(t *testing.T) {
-	t.Parallel()
-
-	key := make([]byte, keySize)
-	_, err := rand.Read(key)
-	require.NoError(t, err)
-
-	// Create valid encrypted data for tampering tests
-	validData := []byte("test message")
-	encrypted, err := EncryptWithKey(validData, key)
-	require.NoError(t, err)
-
-	tests := []struct {
-		name   string
-		data   []byte
-		key    []byte
-		errMsg string
-	}{
-		{
-			name:   "short ciphertext",
-			data:   make([]byte, 23), // Less than nonce size
-			key:    key,
-			errMsg: "ciphertext too short",
-		},
-		{
-			name:   "invalid ciphertext",
-			data:   make([]byte, 24), // Just nonce size
-			key:    key,
-			errMsg: "decryption failed",
-		},
-		{
-			name:   "tampered ciphertext",
-			data:   tamperWithBytes(encrypted),
-			key:    key,
-			errMsg: "decryption failed",
-		},
-		{
-			name:   "missing key",
-			data:   encrypted,
-			key:    nil,
-			errMsg: "encryption key is required",
-		},
-	}
-
-	for _, tt := range tests {
-		tt := tt
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-
-			_, err := DecryptStringWithKey(tt.data, tt.key)
-			require.Error(t, err)
-			require.Contains(t, err.Error(), tt.errMsg)
-		})
-	}
-}
-
-// tamperWithBytes modifies a byte in the encrypted data to simulate tampering
-func tamperWithBytes(data []byte) []byte {
-	if len(data) < 25 { // Need at least nonce + 1 byte
-		return data
-	}
-	tampered := make([]byte, len(data))
-	copy(tampered, data)
-	tampered[24] ^= 0x01 // Modify first byte after nonce
-	return tampered
-}

token/delegation/delegation.go

@@ -1,285 +0,0 @@
-// Package delegation implements the UCAN [delegation] specification with
-// an immutable Token type as well as methods to convert the Token to and
-// from the [envelope]-enclosed, signed and DAG-CBOR-encoded form that
-// should most commonly be used for transport and storage.
-//
-// [delegation]: https://github.com/ucan-wg/delegation/tree/v1_ipld
-// [envelope]: https://github.com/ucan-wg/spec#envelope
-package delegation
-
-// TODO: change the "delegation" link above when the specification is merged
-
-import (
-	"encoding/base64"
-	"errors"
-	"fmt"
-	"strings"
-	"time"
-
-	"github.com/MetaMask/go-did-it"
-
-	"github.com/ucan-wg/go-ucan/pkg/command"
-	"github.com/ucan-wg/go-ucan/pkg/meta"
-	"github.com/ucan-wg/go-ucan/pkg/policy"
-	"github.com/ucan-wg/go-ucan/token/internal/nonce"
-	"github.com/ucan-wg/go-ucan/token/internal/parse"
-)
-
-// Token is an immutable type that holds the fields of a UCAN delegation.
-type Token struct {
-	// Issuer DID (sender)
-	issuer did.DID
-	// Audience DID (receiver)
-	audience did.DID
-	// Principal that the chain is about (the Subject)
-	subject did.DID
-	// The Command to eventually invoke
-	command command.Command
-	// The delegation policy
-	policy policy.Policy
-	// A unique, random nonce
-	nonce []byte
-	// Arbitrary Metadata
-	meta *meta.Meta
-	// "Not before" UTC Unix Timestamp in seconds (valid from), 53-bits integer
-	notBefore *time.Time
-	// The timestamp at which the Invocation becomes invalid
-	expiration *time.Time
-}
-
-// New creates a validated delegation Token from the provided parameters and options.
-// This is typically used to delegate a given power to another agent.
-//
-// You can read it as "(issuer) allows (audience) to perform (cmd+pol) on (subject)".
-func New(iss did.DID, aud did.DID, cmd command.Command, pol policy.Policy, sub did.DID, opts ...Option) (*Token, error) {
-	tkn := &Token{
-		issuer:   iss,
-		audience: aud,
-		subject:  sub,
-		command:  cmd,
-		policy:   pol,
-		meta:     meta.NewMeta(),
-		nonce:    nil,
-	}
-
-	for _, opt := range opts {
-		if err := opt(tkn); err != nil {
-			return nil, err
-		}
-	}
-
-	var err error
-	if len(tkn.nonce) == 0 {
-		tkn.nonce, err = nonce.Generate()
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	if err := tkn.validate(); err != nil {
-		return nil, err
-	}
-
-	return tkn, nil
-}
-
-// Root creates a validated UCAN delegation Token from the provided parameters and options.
-// This is typically used to create and give power to an agent.
-//
-// You can read it as "(issuer) allows (audience) to perform (cmd+pol) on itself".
-func Root(iss did.DID, aud did.DID, cmd command.Command, pol policy.Policy, opts ...Option) (*Token, error) {
-	return New(iss, aud, cmd, pol, iss, opts...)
-}
-
-// Powerline creates a validated UCAN delegation Token from the provided parameters and options.
-//
-// Powerline is a pattern for automatically delegating all future delegations to another agent regardless of Subject.
-// This is a very powerful pattern, use it only if you understand it.
-// Powerline delegations MUST NOT be used as the root delegation to a resource
-//
-// A very common use case for Powerline is providing a stable DID across multiple agents (e.g. representing a user with
-// multiple devices). This enables the automatic sharing of authority across their devices without needing to share keys
-// or set up a threshold scheme. It is also flexible, since a Powerline delegation MAY be revoked.
-//
-// You can read it as "(issuer) allows (audience) to perform (cmd+pol) on anything".
-func Powerline(iss did.DID, aud did.DID, cmd command.Command, pol policy.Policy, opts ...Option) (*Token, error) {
-	return New(iss, aud, cmd, pol, nil, opts...)
-}
-
-// Issuer returns the did.DID representing the Token's issuer.
-func (t *Token) Issuer() did.DID {
-	return t.issuer
-}
-
-// Audience returns the did.DID representing the Token's audience.
-func (t *Token) Audience() did.DID {
-	return t.audience
-}
-
-// Subject returns the did.DID representing the Token's subject.
-//
-// This field may be did.Undef for delegations that are [Powerlined] but
-// must be equal to the value returned by the Issuer method for root
-// tokens.
-func (t *Token) Subject() did.DID {
-	return t.subject
-}
-
-// Command returns the capability's command.Command.
-func (t *Token) Command() command.Command {
-	return t.command
-}
-
-// Policy returns the capability's policy.Policy.
-func (t *Token) Policy() policy.Policy {
-	return t.policy
-}
-
-// Nonce returns the random Nonce encapsulated in this Token.
-func (t *Token) Nonce() []byte {
-	return t.nonce
-}
-
-// Meta returns the Token's metadata.
-func (t *Token) Meta() meta.ReadOnly {
-	return t.meta.ReadOnly()
-}
-
-// NotBefore returns the time at which the Token becomes "active".
-func (t *Token) NotBefore() *time.Time {
-	return t.notBefore
-}
-
-// Expiration returns the time at which the Token expires.
-func (t *Token) Expiration() *time.Time {
-	return t.expiration
-}
-
-// IsRoot tells if the token is a root delegation.
-func (t *Token) IsRoot() bool {
-	return t.issuer.Equal(t.subject)
-}
-
-// IsPowerline tells if the token is a powerline delegation.
-func (t *Token) IsPowerline() bool {
-	return t.subject == nil
-}
-
-// IsValidNow verifies that the token can be used at the current time, based on expiration or "not before" fields.
-// This does NOT do any other kind of verifications.
-func (t *Token) IsValidNow() bool {
-	return t.IsValidAt(time.Now())
-}
-
-// IsValidNow verifies that the token can be used at the given time, based on expiration or "not before" fields.
-// This does NOT do any other kind of verifications.
-func (t *Token) IsValidAt(ti time.Time) bool {
-	if t.expiration != nil && ti.After(*t.expiration) {
-		return false
-	}
-	if t.notBefore != nil && ti.Before(*t.notBefore) {
-		return false
-	}
-	return true
-}
-
-func (t *Token) String() string {
-	var res strings.Builder
-
-	var kind string
-	switch {
-	case t.issuer == t.subject:
-		kind = " (root delegation)"
-	case t.subject == nil:
-		kind = " (powerline delegation)"
-	default:
-		kind = " (normal delegation)"
-	}
-
-	res.WriteString(fmt.Sprintf("Issuer: %s\n", t.Issuer()))
-	res.WriteString(fmt.Sprintf("Audience: %s\n", t.Audience()))
-	res.WriteString(fmt.Sprintf("Subject: %s%s\n", t.Subject(), kind))
-	res.WriteString(fmt.Sprintf("Command: %s\n", t.Command()))
-	res.WriteString(fmt.Sprintf("Policy: %s\n", t.Policy()))
-	res.WriteString(fmt.Sprintf("Nonce: %s\n", base64.StdEncoding.EncodeToString(t.Nonce())))
-	res.WriteString(fmt.Sprintf("Meta: %s\n", t.Meta()))
-	res.WriteString(fmt.Sprintf("NotBefore: %v\n", t.NotBefore()))
-	res.WriteString(fmt.Sprintf("Expiration: %v", t.Expiration()))
-
-	return res.String()
-}
-
-func (t *Token) validate() error {
-	var errs error
-
-	requiredDID := func(id did.DID, fieldname string) {
-		if id == nil {
-			errs = errors.Join(errs, fmt.Errorf(`a valid did is required for %s: %s`, fieldname, id.String()))
-		}
-	}
-
-	requiredDID(t.issuer, "Issuer")
-	requiredDID(t.audience, "Audience")
-
-	if len(t.nonce) < 12 {
-		errs = errors.Join(errs, fmt.Errorf("token nonce too small"))
-	}
-
-	return errs
-}
-
-// tokenFromModel build a decoded view of the raw IPLD data.
-// This function also serves as validation.
-func tokenFromModel(m tokenPayloadModel) (*Token, error) {
-	var (
-		tkn Token
-		err error
-	)
-
-	tkn.issuer, err = did.Parse(m.Iss)
-	if err != nil {
-		return nil, fmt.Errorf("parse iss: %w", err)
-	}
-
-	if tkn.audience, err = did.Parse(m.Aud); err != nil {
-		return nil, fmt.Errorf("parse audience: %w", err)
-	}
-
-	if tkn.subject, err = parse.OptionalDID(m.Sub); err != nil {
-		return nil, fmt.Errorf("parse subject: %w", err)
-	}
-
-	if tkn.command, err = command.Parse(m.Cmd); err != nil {
-		return nil, fmt.Errorf("parse command: %w", err)
-	}
-
-	if tkn.policy, err = policy.FromIPLD(m.Pol); err != nil {
-		return nil, fmt.Errorf("parse policy: %w", err)
-	}
-
-	if len(m.Nonce) == 0 {
-		return nil, fmt.Errorf("nonce is required")
-	}
-	tkn.nonce = m.Nonce
-
-	tkn.meta = m.Meta
-	if tkn.meta == nil {
-		tkn.meta = meta.NewMeta()
-	}
-
-	tkn.notBefore, err = parse.OptionalTimestamp(m.Nbf)
-	if err != nil {
-		return nil, fmt.Errorf("parse notBefore: %w", err)
-	}
-
-	tkn.expiration, err = parse.OptionalTimestamp(m.Exp)
-	if err != nil {
-		return nil, fmt.Errorf("parse expiration: %w", err)
-	}
-
-	if err := tkn.validate(); err != nil {
-		return nil, err
-	}
-
-	return &tkn, nil
-}

token/delegation/delegation.ipldsch

@@ -1,29 +0,0 @@
-type DID string
-
-# The Delegation payload MUST describe the authorization claims, who is involved, and its validity period.
-type Payload struct {
-    # Issuer DID (sender)
-    iss DID
-    # Audience DID (receiver)
-    aud DID
-    # Principal that the chain is about (the Subject)
-    sub optional DID
-
-    # The Command to eventually invoke
-    cmd String
-
-    # The delegation policy
-    # It doesn't seem possible to represent it with a schema.
-    pol Any
-
-    # A unique, random nonce
-    nonce Bytes
-
-    # Arbitrary Metadata
-    meta optional {String : Any}
-
-    # "Not before" UTC Unix Timestamp in seconds (valid from), 53-bits integer
-    nbf optional Int
-    # The timestamp at which the Invocation becomes invalid
-    exp nullable Int
-}

token/delegation/delegation_test.go

@@ -1,213 +0,0 @@
-package delegation_test
-
-import (
-	_ "embed"
-	"encoding/base64"
-	"testing"
-	"time"
-
-	"github.com/MetaMask/go-did-it/didtest"
-	"github.com/stretchr/testify/require"
-
-	"github.com/ucan-wg/go-ucan/pkg/command"
-	"github.com/ucan-wg/go-ucan/pkg/policy"
-	"github.com/ucan-wg/go-ucan/token/delegation"
-)
-
-//go:embed testdata/new.dagjson
-var newDagJson []byte
-
-//go:embed testdata/powerline.dagjson
-var powerlineDagJson []byte
-
-//go:embed testdata/root.dagjson
-var rootDagJson []byte
-
-const (
-	nonce = "6roDhGi0kiNriQAz7J3d+bOeoI/tj8ENikmQNbtjnD0"
-
-	subJectCmd = "/foo/bar"
-	subjectPol = `
-[
-  ["==", ".status", "draft"],
-  ["all", ".reviewer",
-    ["like", ".email", "*@example.com"]
-  ],
-  ["any", ".tags",
-    ["or", [
-      ["==", ".", "news"],
-      ["==", ".", "press"]
-    ]]
-  ]
-]
-`
-
-	aesKey = "xQklMmNTnVrmaPBq/0pwV5fEwuv/iClF5HWak9MsgI8="
-)
-
-func TestConstructors(t *testing.T) {
-	t.Parallel()
-
-	cmd, err := command.Parse(subJectCmd)
-	require.NoError(t, err)
-
-	pol, err := policy.FromDagJson(subjectPol)
-	require.NoError(t, err)
-
-	exp, err := time.Parse(time.RFC3339, "2200-01-01T00:00:00Z")
-	require.NoError(t, err)
-
-	t.Run("New", func(t *testing.T) {
-		tkn, err := delegation.New(didtest.PersonaAlice.DID(), didtest.PersonaBob.DID(), cmd, pol, didtest.PersonaCarol.DID(),
-			delegation.WithNonce([]byte(nonce)),
-			delegation.WithExpiration(exp),
-			delegation.WithMeta("foo", "fooo"),
-			delegation.WithMeta("bar", "barr"),
-		)
-		require.NoError(t, err)
-
-		require.False(t, tkn.IsRoot())
-		require.False(t, tkn.IsPowerline())
-
-		data, err := tkn.ToDagJson(didtest.PersonaAlice.PrivKey())
-		require.NoError(t, err)
-
-		require.Equal(t, newDagJson, data)
-	})
-
-	t.Run("Root", func(t *testing.T) {
-		tkn, err := delegation.Root(didtest.PersonaAlice.DID(), didtest.PersonaBob.DID(), cmd, pol,
-			delegation.WithNonce([]byte(nonce)),
-			delegation.WithExpiration(exp),
-			delegation.WithMeta("foo", "fooo"),
-			delegation.WithMeta("bar", "barr"),
-		)
-		require.NoError(t, err)
-
-		require.True(t, tkn.IsRoot())
-		require.False(t, tkn.IsPowerline())
-
-		data, err := tkn.ToDagJson(didtest.PersonaAlice.PrivKey())
-		require.NoError(t, err)
-
-		require.Equal(t, rootDagJson, data)
-	})
-
-	t.Run("Powerline", func(t *testing.T) {
-		tkn, err := delegation.Powerline(didtest.PersonaAlice.DID(), didtest.PersonaBob.DID(), cmd, pol,
-			delegation.WithNonce([]byte(nonce)),
-			delegation.WithExpiration(exp),
-			delegation.WithMeta("foo", "fooo"),
-			delegation.WithMeta("bar", "barr"),
-		)
-		require.NoError(t, err)
-
-		require.False(t, tkn.IsRoot())
-		require.True(t, tkn.IsPowerline())
-
-		data, err := tkn.ToDagJson(didtest.PersonaAlice.PrivKey())
-		require.NoError(t, err)
-
-		require.Equal(t, powerlineDagJson, data)
-	})
-}
-
-func TestEncryptedMeta(t *testing.T) {
-	t.Parallel()
-
-	cmd, err := command.Parse(subJectCmd)
-	require.NoError(t, err)
-	pol, err := policy.FromDagJson(subjectPol)
-	require.NoError(t, err)
-
-	encryptionKey, err := base64.StdEncoding.DecodeString(aesKey)
-	require.NoError(t, err)
-	require.Len(t, encryptionKey, 32)
-
-	tests := []struct {
-		name        string
-		key         string
-		value       string
-		expectError bool
-	}{
-		{
-			name:  "simple string",
-			key:   "secret1",
-			value: "hello world",
-		},
-		{
-			name:  "empty string",
-			key:   "secret2",
-			value: "",
-		},
-		{
-			name:  "special characters",
-			key:   "secret3",
-			value: "!@#$%^&*()_+-=[]{}|;:,.<>?",
-		},
-		{
-			name:  "unicode characters",
-			key:   "secret4",
-			value: "Hello, 世界! 👋",
-		},
-	}
-
-	for _, tt := range tests {
-		tt := tt
-		t.Run(tt.name, func(t *testing.T) {
-			t.Parallel()
-
-			tkn, err := delegation.Root(didtest.PersonaAlice.DID(), didtest.PersonaBob.DID(), cmd, pol,
-				delegation.WithEncryptedMetaString(tt.key, tt.value, encryptionKey),
-			)
-			require.NoError(t, err)
-
-			data, err := tkn.ToDagCbor(didtest.PersonaAlice.PrivKey())
-			require.NoError(t, err)
-
-			decodedTkn, _, err := delegation.FromSealed(data)
-			require.NoError(t, err)
-
-			_, err = decodedTkn.Meta().GetString(tt.key)
-			require.Error(t, err)
-
-			decrypted, err := decodedTkn.Meta().GetEncryptedString(tt.key, encryptionKey)
-			require.NoError(t, err)
-			// Verify the decrypted value is equal to the original
-			require.Equal(t, tt.value, decrypted)
-
-			// Try to decrypt with wrong key
-			wrongKey := make([]byte, 32)
-			_, err = decodedTkn.Meta().GetEncryptedString(tt.key, wrongKey)
-			require.Error(t, err)
-		})
-	}
-
-	t.Run("multiple encrypted values in the same token", func(t *testing.T) {
-		values := map[string]string{
-			"secret1": "value1",
-			"secret2": "value2",
-			"secret3": "value3",
-		}
-		var opts []delegation.Option
-		for k, v := range values {
-			opts = append(opts, delegation.WithEncryptedMetaString(k, v, encryptionKey))
-		}
-
-		// Create token with multiple encrypted values
-		tkn, err := delegation.Root(didtest.PersonaAlice.DID(), didtest.PersonaBob.DID(), cmd, pol, opts...)
-		require.NoError(t, err)
-
-		data, err := tkn.ToDagCbor(didtest.PersonaAlice.PrivKey())
-		require.NoError(t, err)
-
-		decodedTkn, _, err := delegation.FromSealed(data)
-		require.NoError(t, err)
-
-		for k, v := range values {
-			decrypted, err := decodedTkn.Meta().GetEncryptedString(k, encryptionKey)
-			require.NoError(t, err)
-			require.Equal(t, v, decrypted)
-		}
-	})
-}