delegation: add decode function with an io.Reader

.github/workflows/bench.yml

@@ -1,34 +0,0 @@
-name: go continuous benchmark
-on:
-  push:
-    branches:
-      - v1
-
-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@v4
-        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

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.
@@ -74,35 +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 {
-	return strings.Split(string(c), separator)
+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) {
@@ -13,66 +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())
-}
-
 type testcase struct {
 	name string
 	inp  string

capability/policy/ipld.go

@@ -9,7 +9,7 @@ import (
 	"github.com/ipld/go-ipld-prime/must"
 	"github.com/ipld/go-ipld-prime/node/basicnode"
 
-	"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) {
@@ -61,7 +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)
@@ -93,11 +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)
@@ -232,7 +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

@@ -16,9 +16,7 @@ func TestIpldRoundTrip(t *testing.T) {
   ["any", ".tags", 
     ["or", [
       ["==", ".", "news"], 
-      ["==", ".", "press"]
-    ]]
-  ]
+      ["==", ".", "press"]]]
 ]`
 
 	for _, tc := range []struct {

capability/policy/literal/literal.go

@@ -1,13 +1,20 @@
-// Package literal holds a collection of functions to create IPLD types to use in policies, selector and args.
 package literal
 
 import (
-	"github.com/ipfs/go-cid"
 	"github.com/ipld/go-ipld-prime"
-	cidlink "github.com/ipld/go-ipld-prime/linking/cid"
 	"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)
@@ -38,16 +45,6 @@ func Bytes(val []byte) ipld.Node {
 	return nb.Build()
 }
 
-func Link(link ipld.Link) ipld.Node {
-	nb := basicnode.Prototype.Link.NewBuilder()
-	nb.AssignLink(link)
-	return nb.Build()
-}
-
-func LinkCid(cid cid.Cid) ipld.Node {
-	return Link(cidlink.Link{Cid: cid})
-}
-
 func Null() ipld.Node {
 	nb := basicnode.Prototype.Any.NewBuilder()
 	nb.AssignNull()

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

@@ -2,7 +2,6 @@ package policy
 
 import (
 	"fmt"
-	"strings"
 	"testing"
 
 	"github.com/ipfs/go-cid"
@@ -12,7 +11,8 @@ import (
 	"github.com/ipld/go-ipld-prime/node/basicnode"
 	"github.com/stretchr/testify/require"
 
-	"github.com/ucan-wg/go-ucan/pkg/policy/literal"
+	"github.com/ucan-wg/go-ucan/capability/policy/literal"
+	"github.com/ucan-wg/go-ucan/capability/policy/selector"
 )
 
 func TestMatch(t *testing.T) {
@@ -23,16 +23,16 @@ func TestMatch(t *testing.T) {
 			nb.AssignString("test")
 			nd := nb.Build()
 
-			pol := MustConstruct(Equal(".", literal.String("test")))
-			ok := pol.Match(nd)
+			pol := Policy{Equal(selector.MustParse("."), literal.String("test"))}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 
-			pol = MustConstruct(Equal(".", literal.String("test2")))
-			ok = pol.Match(nd)
+			pol = Policy{Equal(selector.MustParse("."), literal.String("test2"))}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 
-			pol = MustConstruct(Equal(".", literal.Int(138)))
-			ok = pol.Match(nd)
+			pol = Policy{Equal(selector.MustParse("."), literal.Int(138))}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 		})
 
@@ -42,16 +42,16 @@ func TestMatch(t *testing.T) {
 			nb.AssignInt(138)
 			nd := nb.Build()
 
-			pol := MustConstruct(Equal(".", literal.Int(138)))
-			ok := pol.Match(nd)
+			pol := Policy{Equal(selector.MustParse("."), literal.Int(138))}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 
-			pol = MustConstruct(Equal(".", literal.Int(1138)))
-			ok = pol.Match(nd)
+			pol = Policy{Equal(selector.MustParse("."), literal.Int(1138))}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 
-			pol = MustConstruct(Equal(".", literal.String("138")))
-			ok = pol.Match(nd)
+			pol = Policy{Equal(selector.MustParse("."), literal.String("138"))}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 		})
 
@@ -61,16 +61,16 @@ func TestMatch(t *testing.T) {
 			nb.AssignFloat(1.138)
 			nd := nb.Build()
 
-			pol := MustConstruct(Equal(".", literal.Float(1.138)))
-			ok := pol.Match(nd)
+			pol := Policy{Equal(selector.MustParse("."), literal.Float(1.138))}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 
-			pol = MustConstruct(Equal(".", literal.Float(11.38)))
-			ok = pol.Match(nd)
+			pol = Policy{Equal(selector.MustParse("."), literal.Float(11.38))}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 
-			pol = MustConstruct(Equal(".", literal.String("138")))
-			ok = pol.Match(nd)
+			pol = Policy{Equal(selector.MustParse("."), literal.String("138"))}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 		})
 
@@ -83,16 +83,16 @@ func TestMatch(t *testing.T) {
 			nb.AssignLink(l0)
 			nd := nb.Build()
 
-			pol := MustConstruct(Equal(".", literal.Link(l0)))
-			ok := pol.Match(nd)
+			pol := Policy{Equal(selector.MustParse("."), literal.Link(l0))}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 
-			pol = MustConstruct(Equal(".", literal.Link(l1)))
-			ok = pol.Match(nd)
+			pol = Policy{Equal(selector.MustParse("."), literal.Link(l1))}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 
-			pol = MustConstruct(Equal(".", literal.String("bafybeif4owy5gno5lwnixqm52rwqfodklf76hsetxdhffuxnplvijskzqq")))
-			ok = pol.Match(nd)
+			pol = Policy{Equal(selector.MustParse("."), literal.String("bafybeif4owy5gno5lwnixqm52rwqfodklf76hsetxdhffuxnplvijskzqq"))}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 		})
 
@@ -105,20 +105,20 @@ func TestMatch(t *testing.T) {
 			ma.Finish()
 			nd := nb.Build()
 
-			pol := MustConstruct(Equal(".foo", literal.String("bar")))
-			ok := pol.Match(nd)
+			pol := Policy{Equal(selector.MustParse(".foo"), literal.String("bar"))}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 
-			pol = MustConstruct(Equal(".[\"foo\"]", literal.String("bar")))
-			ok = pol.Match(nd)
+			pol = Policy{Equal(selector.MustParse(".[\"foo\"]"), literal.String("bar"))}
+			ok = Match(pol, nd)
 			require.True(t, ok)
 
-			pol = MustConstruct(Equal(".foo", literal.String("baz")))
-			ok = pol.Match(nd)
+			pol = Policy{Equal(selector.MustParse(".foo"), literal.String("baz"))}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 
-			pol = MustConstruct(Equal(".foobar", literal.String("bar")))
-			ok = pol.Match(nd)
+			pol = Policy{Equal(selector.MustParse(".foobar"), literal.String("bar"))}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 		})
 
@@ -130,12 +130,12 @@ func TestMatch(t *testing.T) {
 			la.Finish()
 			nd := nb.Build()
 
-			pol := MustConstruct(Equal(".[0]", literal.String("foo")))
-			ok := pol.Match(nd)
+			pol := Policy{Equal(selector.MustParse(".[0]"), literal.String("foo"))}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 
-			pol = MustConstruct(Equal(".[1]", literal.String("foo")))
-			ok = pol.Match(nd)
+			pol = Policy{Equal(selector.MustParse(".[1]"), literal.String("foo"))}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 		})
 	})
@@ -147,8 +147,8 @@ func TestMatch(t *testing.T) {
 			nb.AssignInt(138)
 			nd := nb.Build()
 
-			pol := MustConstruct(GreaterThan(".", literal.Int(1)))
-			ok := pol.Match(nd)
+			pol := Policy{GreaterThan(selector.MustParse("."), literal.Int(1))}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 		})
 
@@ -158,12 +158,12 @@ func TestMatch(t *testing.T) {
 			nb.AssignInt(138)
 			nd := nb.Build()
 
-			pol := MustConstruct(GreaterThanOrEqual(".", literal.Int(1)))
-			ok := pol.Match(nd)
+			pol := Policy{GreaterThanOrEqual(selector.MustParse("."), literal.Int(1))}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 
-			pol = MustConstruct(GreaterThanOrEqual(".", literal.Int(138)))
-			ok = pol.Match(nd)
+			pol = Policy{GreaterThanOrEqual(selector.MustParse("."), literal.Int(138))}
+			ok = Match(pol, nd)
 			require.True(t, ok)
 		})
 
@@ -173,8 +173,8 @@ func TestMatch(t *testing.T) {
 			nb.AssignFloat(1.38)
 			nd := nb.Build()
 
-			pol := MustConstruct(GreaterThan(".", literal.Float(1)))
-			ok := pol.Match(nd)
+			pol := Policy{GreaterThan(selector.MustParse("."), literal.Float(1))}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 		})
 
@@ -184,12 +184,12 @@ func TestMatch(t *testing.T) {
 			nb.AssignFloat(1.38)
 			nd := nb.Build()
 
-			pol := MustConstruct(GreaterThanOrEqual(".", literal.Float(1)))
-			ok := pol.Match(nd)
+			pol := Policy{GreaterThanOrEqual(selector.MustParse("."), literal.Float(1))}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 
-			pol = MustConstruct(GreaterThanOrEqual(".", literal.Float(1.38)))
-			ok = pol.Match(nd)
+			pol = Policy{GreaterThanOrEqual(selector.MustParse("."), literal.Float(1.38))}
+			ok = Match(pol, nd)
 			require.True(t, ok)
 		})
 
@@ -199,8 +199,8 @@ func TestMatch(t *testing.T) {
 			nb.AssignInt(138)
 			nd := nb.Build()
 
-			pol := MustConstruct(LessThan(".", literal.Int(1138)))
-			ok := pol.Match(nd)
+			pol := Policy{LessThan(selector.MustParse("."), literal.Int(1138))}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 		})
 
@@ -210,12 +210,12 @@ func TestMatch(t *testing.T) {
 			nb.AssignInt(138)
 			nd := nb.Build()
 
-			pol := MustConstruct(LessThanOrEqual(".", literal.Int(1138)))
-			ok := pol.Match(nd)
+			pol := Policy{LessThanOrEqual(selector.MustParse("."), literal.Int(1138))}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 
-			pol = MustConstruct(LessThanOrEqual(".", literal.Int(138)))
-			ok = pol.Match(nd)
+			pol = Policy{LessThanOrEqual(selector.MustParse("."), literal.Int(138))}
+			ok = Match(pol, nd)
 			require.True(t, ok)
 		})
 	})
@@ -226,12 +226,12 @@ func TestMatch(t *testing.T) {
 		nb.AssignBool(false)
 		nd := nb.Build()
 
-		pol := MustConstruct(Not(Equal(".", literal.Bool(true))))
-		ok := pol.Match(nd)
+		pol := Policy{Not(Equal(selector.MustParse("."), literal.Bool(true)))}
+		ok := Match(pol, nd)
 		require.True(t, ok)
 
-		pol = MustConstruct(Not(Equal(".", literal.Bool(false))))
-		ok = pol.Match(nd)
+		pol = Policy{Not(Equal(selector.MustParse("."), literal.Bool(false)))}
+		ok = Match(pol, nd)
 		require.False(t, ok)
 	})
 
@@ -241,26 +241,26 @@ func TestMatch(t *testing.T) {
 		nb.AssignInt(138)
 		nd := nb.Build()
 
-		pol := MustConstruct(
+		pol := Policy{
 			And(
-				GreaterThan(".", literal.Int(1)),
-				LessThan(".", literal.Int(1138)),
+				GreaterThan(selector.MustParse("."), literal.Int(1)),
+				LessThan(selector.MustParse("."), literal.Int(1138)),
 			),
-		)
-		ok := pol.Match(nd)
+		}
+		ok := Match(pol, nd)
 		require.True(t, ok)
 
-		pol = MustConstruct(
+		pol = Policy{
 			And(
-				GreaterThan(".", literal.Int(1)),
-				Equal(".", literal.Int(1138)),
+				GreaterThan(selector.MustParse("."), literal.Int(1)),
+				Equal(selector.MustParse("."), literal.Int(1138)),
 			),
-		)
-		ok = pol.Match(nd)
+		}
+		ok = Match(pol, nd)
 		require.False(t, ok)
 
-		pol = MustConstruct(And())
-		ok = pol.Match(nd)
+		pol = Policy{And()}
+		ok = Match(pol, nd)
 		require.True(t, ok)
 	})
 
@@ -270,26 +270,26 @@ func TestMatch(t *testing.T) {
 		nb.AssignInt(138)
 		nd := nb.Build()
 
-		pol := MustConstruct(
+		pol := Policy{
 			Or(
-				GreaterThan(".", literal.Int(138)),
-				LessThan(".", literal.Int(1138)),
+				GreaterThan(selector.MustParse("."), literal.Int(138)),
+				LessThan(selector.MustParse("."), literal.Int(1138)),
 			),
-		)
-		ok := pol.Match(nd)
+		}
+		ok := Match(pol, nd)
 		require.True(t, ok)
 
-		pol = MustConstruct(
+		pol = Policy{
 			Or(
-				GreaterThan(".", literal.Int(138)),
-				Equal(".", literal.Int(1138)),
+				GreaterThan(selector.MustParse("."), literal.Int(138)),
+				Equal(selector.MustParse("."), literal.Int(1138)),
 			),
-		)
-		ok = pol.Match(nd)
+		}
+		ok = Match(pol, nd)
 		require.False(t, ok)
 
-		pol = MustConstruct(Or())
-		ok = pol.Match(nd)
+		pol = Policy{Or()}
+		ok = Match(pol, nd)
 		require.True(t, ok)
 	})
 
@@ -309,8 +309,11 @@ func TestMatch(t *testing.T) {
 					nb.AssignString(s)
 					nd := nb.Build()
 
-					pol := MustConstruct(Like(".", pattern))
-					ok := pol.Match(nd)
+					statement, err := Like(selector.MustParse("."), pattern)
+					require.NoError(t, err)
+
+					pol := Policy{statement}
+					ok := Match(pol, nd)
 					require.True(t, ok)
 				})
 			}(s)
@@ -330,8 +333,11 @@ func TestMatch(t *testing.T) {
 					nb.AssignString(s)
 					nd := nb.Build()
 
-					pol := MustConstruct(Like(".", pattern))
-					ok := pol.Match(nd)
+					statement, err := Like(selector.MustParse("."), pattern)
+					require.NoError(t, err)
+
+					pol := Policy{statement}
+					ok := Match(pol, nd)
 					require.False(t, ok)
 				})
 			}(s)
@@ -361,12 +367,22 @@ func TestMatch(t *testing.T) {
 			la.Finish()
 			nd := nb.Build()
 
-			pol := MustConstruct(All(".[]", GreaterThan(".value", literal.Int(2))))
-			ok := pol.Match(nd)
+			pol := Policy{
+				All(
+					selector.MustParse(".[]"),
+					GreaterThan(selector.MustParse(".value"), literal.Int(2)),
+				),
+			}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 
-			pol = MustConstruct(All(".[]", GreaterThan(".value", literal.Int(20))))
-			ok = pol.Match(nd)
+			pol = Policy{
+				All(
+					selector.MustParse(".[]"),
+					GreaterThan(selector.MustParse(".value"), literal.Int(20)),
+				),
+			}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 		})
 
@@ -382,12 +398,22 @@ func TestMatch(t *testing.T) {
 			la.Finish()
 			nd := nb.Build()
 
-			pol := MustConstruct(Any(".[]", GreaterThan(".value", literal.Int(60))))
-			ok := pol.Match(nd)
+			pol := Policy{
+				Any(
+					selector.MustParse(".[]"),
+					GreaterThan(selector.MustParse(".value"), literal.Int(60)),
+				),
+			}
+			ok := Match(pol, nd)
 			require.True(t, ok)
 
-			pol = MustConstruct(Any(".[]", GreaterThan(".value", literal.Int(100))))
-			ok = pol.Match(nd)
+			pol = Policy{
+				Any(
+					selector.MustParse(".[]"),
+					GreaterThan(selector.MustParse(".value"), literal.Int(100)),
+				),
+			}
+			ok = Match(pol, nd)
 			require.False(t, ok)
 		})
 	})
@@ -406,7 +432,7 @@ func TestPolicyExamples(t *testing.T) {
 
 		pol, err := FromDagJson(policy)
 		require.NoError(t, err)
-		return pol.Match(data)
+		return Match(pol, data)
 	}
 
 	t.Run("And", func(t *testing.T) {
@@ -464,152 +490,3 @@ func TestPolicyExamples(t *testing.T) {
 		require.True(t, evaluate(`["any", ".a", ["==", ".b", 2]]`, data))
 	})
 }
-
-func FuzzMatch(f *testing.F) {
-	// Policy + Data examples
-	f.Add([]byte(`[["==", ".status", "draft"]]`), []byte(`{"status": "draft"}`))
-	f.Add([]byte(`[["all", ".reviewer", ["like", ".email", "*@example.com"]]]`), []byte(`{"reviewer": [{"email": "alice@example.com"}, {"email": "bob@example.com"}]}`))
-	f.Add([]byte(`[["any", ".tags", ["or", [["==", ".", "news"], ["==", ".", "press"]]]]]`), []byte(`{"tags": ["news", "press"]}`))
-	f.Add([]byte(`[["==", ".name", "Alice"]]`), []byte(`{"name": "Alice"}`))
-	f.Add([]byte(`[[">", ".age", 30]]`), []byte(`{"age": 31}`))
-	f.Add([]byte(`[["<=", ".height", 180]]`), []byte(`{"height": 170}`))
-	f.Add([]byte(`[["not", ["==", ".status", "inactive"]]]`), []byte(`{"status": "active"}`))
-	f.Add([]byte(`[["and", [["==", ".role", "admin"], [">=", ".experience", 5]]]]`), []byte(`{"role": "admin", "experience": 6}`))
-	f.Add([]byte(`[["or", [["==", ".department", "HR"], ["==", ".department", "Finance"]]]]`), []byte(`{"department": "HR"}`))
-	f.Add([]byte(`[["like", ".email", "*@company.com"]]`), []byte(`{"email": "user@company.com"}`))
-	f.Add([]byte(`[["all", ".projects", [">", ".budget", 10000]]]`), []byte(`{"projects": [{"budget": 15000}, {"budget": 8000}]}`))
-	f.Add([]byte(`[["any", ".skills", ["==", ".", "Go"]]]`), []byte(`{"skills": ["Go", "Python", "JavaScript"]}`))
-	f.Add(
-		[]byte(`[["and", [
-			["==", ".name", "Bob"],
-			["or", [[">", ".age", 25],["==", ".status", "active"]]],
-			["all", ".tasks", ["==", ".completed", true]]
-		]]]`),
-		[]byte(`{
-			"name": "Bob",
-			"age": 26,
-			"status": "active",
-			"tasks": [{"completed": true}, {"completed": true}, {"completed": false}]
-		}`),
-	)
-
-	f.Fuzz(func(t *testing.T, policyBytes []byte, dataBytes []byte) {
-		policyNode, err := ipld.Decode(policyBytes, dagjson.Decode)
-		if err != nil {
-			t.Skip()
-		}
-
-		dataNode, err := ipld.Decode(dataBytes, dagjson.Decode)
-		if err != nil {
-			t.Skip()
-		}
-
-		// policy node -> policy object
-		policy, err := FromIPLD(policyNode)
-		if err != nil {
-			t.Skip()
-		}
-
-		policy.Match(dataNode)
-	})
-}
-
-func TestPolicyFilter(t *testing.T) {
-	pol := MustConstruct(
-		Any(".http", And(
-			Equal(".method", literal.String("GET")),
-			Equal(".path", literal.String("/foo")),
-		)),
-		Equal(".http", literal.String("foobar")),
-		All(".jsonrpc.foo", Or(
-			Not(Equal(".bar", literal.String("foo"))),
-			Equal(".", literal.String("foo")),
-			Like(".boo", "abcd"),
-			Like(".boo", "*bcd"),
-		)),
-	)
-
-	for _, tc := range []struct {
-		path     string
-		expected Policy
-	}{
-		{
-			path: "http",
-			expected: MustConstruct(
-				Any(".http", And(
-					Equal(".method", literal.String("GET")),
-					Equal(".path", literal.String("/foo")),
-				)),
-				Equal(".http", literal.String("foobar")),
-			),
-		},
-		{
-			path: "http,method",
-			expected: MustConstruct(
-				Any(".http", And(
-					Equal(".method", literal.String("GET")),
-				)),
-			),
-		},
-		{
-			path: "http,path",
-			expected: MustConstruct(
-				Any(".http", And(
-					Equal(".path", literal.String("/foo")),
-				)),
-			),
-		},
-		{
-			path:     "http,foo",
-			expected: Policy{},
-		},
-		{
-			path: "jsonrpc",
-			expected: MustConstruct(
-				All(".jsonrpc.foo", Or(
-					Not(Equal(".bar", literal.String("foo"))),
-					Equal(".", literal.String("foo")),
-					Like(".boo", "abcd"),
-					Like(".boo", "*bcd"),
-				)),
-			),
-		},
-		{
-			path:     "jsonrpc,baz",
-			expected: Policy{},
-		},
-		{
-			path: "jsonrpc,foo",
-			expected: MustConstruct(
-				All(".jsonrpc.foo", Or(
-					Not(Equal(".bar", literal.String("foo"))),
-					Equal(".", literal.String("foo")),
-					Like(".boo", "abcd"),
-					Like(".boo", "*bcd"),
-				)),
-			),
-		},
-		{
-			path: "jsonrpc,foo,bar",
-			expected: MustConstruct(
-				All(".jsonrpc.foo", Or(
-					Not(Equal(".bar", literal.String("foo"))),
-				)),
-			),
-		},
-		{
-			path: "jsonrpc,foo,boo",
-			expected: MustConstruct(
-				All(".jsonrpc.foo", Or(
-					Like(".boo", "abcd"),
-					Like(".boo", "*bcd"),
-				)),
-			),
-		},
-	} {
-		t.Run(tc.path, func(t *testing.T) {
-			res := pol.Filter(strings.Split(tc.path, ",")...)
-			require.Equal(t, tc.expected.String(), res.String())
-		})
-	}
-}

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

@@ -2,18 +2,10 @@ package selector
 
 import (
 	"fmt"
-	"regexp"
 	"strconv"
 	"strings"
 )
 
-var (
-	identity   = Selector{segment{str: ".", identity: true}}
-	indexRegex = regexp.MustCompile(`^-?\d+$`)
-	sliceRegex = regexp.MustCompile(`^((\-?\d+:\-?\d*)|(\-?\d*:\-?\d+))$`)
-	fieldRegex = regexp.MustCompile(`^\.[a-zA-Z_]*?$`)
-)
-
 func Parse(str string) (Selector, error) {
 	if len(str) == 0 {
 		return nil, newParseError("empty selector", str, 0, "")
@@ -21,9 +13,6 @@ func Parse(str string) (Selector, error) {
 	if string(str[0]) != "." {
 		return nil, newParseError("selector must start with identity segment '.'", str, 0, string(str[0]))
 	}
-	if str == "." {
-		return identity, nil
-	}
 
 	col := 0
 	var sel Selector
@@ -38,9 +27,9 @@ func Parse(str string) (Selector, error) {
 			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})
+			sel = append(sel, Identity)
 		case "[]":
-			sel = append(sel, segment{str: tok, optional: opt, iterator: true})
+			sel = append(sel, segment{tok, false, opt, true, nil, "", 0})
 		default:
 			if strings.HasPrefix(seg, "[") && strings.HasSuffix(seg, "]") {
 				lookup := seg[1 : len(seg)-1]

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

@@ -313,7 +313,7 @@ func TestSelect(t *testing.T) {
 		sel, err := Parse(".")
 		require.NoError(t, err)
 
-		one, many, err := sel.Select(anode)
+		one, many, err := Select(sel, anode)
 		require.NoError(t, err)
 		require.NotEmpty(t, one)
 		require.Empty(t, many)
@@ -328,7 +328,7 @@ func TestSelect(t *testing.T) {
 		sel, err := Parse(".name.first")
 		require.NoError(t, err)
 
-		one, many, err := sel.Select(anode)
+		one, many, err := Select(sel, anode)
 		require.NoError(t, err)
 		require.NotEmpty(t, one)
 		require.Empty(t, many)
@@ -338,7 +338,7 @@ func TestSelect(t *testing.T) {
 		name := must.String(one)
 		require.Equal(t, alice.Name.First, name)
 
-		one, many, err = sel.Select(bnode)
+		one, many, err = Select(sel, bnode)
 		require.NoError(t, err)
 		require.NotEmpty(t, one)
 		require.Empty(t, many)
@@ -353,7 +353,7 @@ func TestSelect(t *testing.T) {
 		sel, err := Parse(".name.middle?")
 		require.NoError(t, err)
 
-		one, many, err := sel.Select(anode)
+		one, many, err := Select(sel, anode)
 		require.NoError(t, err)
 		require.NotEmpty(t, one)
 		require.Empty(t, many)
@@ -363,7 +363,7 @@ func TestSelect(t *testing.T) {
 		name := must.String(one)
 		require.Equal(t, *alice.Name.Middle, name)
 
-		one, many, err = sel.Select(bnode)
+		one, many, err = Select(sel, bnode)
 		require.NoError(t, err)
 		require.Empty(t, one)
 		require.Empty(t, many)
@@ -373,7 +373,7 @@ func TestSelect(t *testing.T) {
 		sel, err := Parse(".name.foo")
 		require.NoError(t, err)
 
-		one, many, err := sel.Select(anode)
+		one, many, err := Select(sel, anode)
 		require.Error(t, err)
 		require.Empty(t, one)
 		require.Empty(t, many)
@@ -387,7 +387,7 @@ func TestSelect(t *testing.T) {
 		sel, err := Parse(".name.foo?")
 		require.NoError(t, err)
 
-		one, many, err := sel.Select(anode)
+		one, many, err := Select(sel, anode)
 		require.NoError(t, err)
 		require.Empty(t, one)
 		require.Empty(t, many)
@@ -397,7 +397,7 @@ func TestSelect(t *testing.T) {
 		sel, err := Parse(".interests[]")
 		require.NoError(t, err)
 
-		one, many, err := sel.Select(anode)
+		one, many, err := Select(sel, anode)
 		require.NoError(t, err)
 		require.Empty(t, one)
 		require.NotEmpty(t, many)
@@ -417,7 +417,7 @@ func TestSelect(t *testing.T) {
 		sel, err := Parse(".interests[0][]")
 		require.NoError(t, err)
 
-		one, many, err := sel.Select(anode)
+		one, many, err := Select(sel, anode)
 		require.NoError(t, err)
 		require.Empty(t, one)
 		require.NotEmpty(t, many)
@@ -431,32 +431,6 @@ func TestSelect(t *testing.T) {
 	})
 }
 
-func TestMatch(t *testing.T) {
-	for _, tc := range []struct {
-		sel       string
-		path      []string
-		want      bool
-		remaining []string
-	}{
-		{sel: ".foo.bar", path: []string{"foo", "bar"}, want: true, remaining: []string{}},
-		{sel: ".foo.bar", path: []string{"foo"}, want: true, remaining: []string{}},
-		{sel: ".foo.bar", path: []string{"foo", "bar", "baz"}, want: true, remaining: []string{"baz"}},
-		{sel: ".foo.bar", path: []string{"foo", "faa"}, want: false},
-		{sel: ".foo.[]", path: []string{"foo", "faa"}, want: false},
-		{sel: ".foo.[]", path: []string{"foo"}, want: true, remaining: []string{}},
-		{sel: ".foo.bar?", path: []string{"foo"}, want: true, remaining: []string{}},
-		{sel: ".foo.bar?", path: []string{"foo", "bar"}, want: true, remaining: []string{}},
-		{sel: ".foo.bar?", path: []string{"foo", "baz"}, want: false},
-	} {
-		t.Run(tc.sel, func(t *testing.T) {
-			sel := MustParse(tc.sel)
-			res, remain := sel.MatchPath(tc.path...)
-			require.Equal(t, tc.want, res)
-			require.EqualValues(t, tc.remaining, remain)
-		})
-	}
-}
-
 func FuzzParse(f *testing.F) {
 	selectorCorpus := []string{
 		`.`, `.[]`, `.[]?`, `.[][]?`, `.x`, `.["x"]`, `.[0]`, `.[-1]`, `.[0]`,
@@ -520,6 +494,6 @@ func FuzzParseAndSelect(f *testing.F) {
 		}
 
 		// look for panic()
-		_, _, _ = sel.Select(node)
+		_, _, _ = Select(sel, node)
 	})
 }

capability/policy/selector/supported_test.go

@@ -12,7 +12,7 @@ import (
 	"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
@@ -30,14 +30,14 @@ func TestSupportedForms(t *testing.T) {
 	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: "String Index", Selector: `.[0]`, Input: `"Hi"`, Output: `"H"`},
-		{Name: "Bytes Index", Selector: `.[0]`, Input: `{"/":{"bytes":"AAE"}}`, Output: `0`},
+		{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]`},
@@ -52,7 +52,7 @@ func TestSupportedForms(t *testing.T) {
 			require.NoError(t, err)
 
 			// attempt to select
-			node, nodes, err := sel.Select(makeNode(t, tc.Input))
+			node, nodes, err := selector.Select(sel, makeNode(t, tc.Input))
 			require.NoError(t, err)
 			require.NotEqual(t, node != nil, len(nodes) > 0) // XOR (only one of node or nodes should be set)
 
@@ -97,7 +97,7 @@ func TestSupportedForms(t *testing.T) {
 			require.NoError(t, err)
 
 			// attempt to select
-			node, nodes, err := sel.Select(makeNode(t, tc.Input))
+			node, nodes, err := selector.Select(sel, makeNode(t, tc.Input))
 			require.NoError(t, err)
 			// TODO: should Select return a single node which is sometimes a list or null?
 			// require.Equal(t, datamodel.Null, node)
@@ -124,7 +124,7 @@ func TestSupportedForms(t *testing.T) {
 			require.NoError(t, err)
 
 			// attempt to select
-			node, nodes, err := sel.Select(makeNode(t, tc.Input))
+			node, nodes, err := selector.Select(sel, makeNode(t, tc.Input))
 			require.Error(t, err)
 			assert.Nil(t, node)
 			assert.Empty(t, nodes)

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

@@ -1,17 +1,19 @@
 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"
-	"gotest.tools/v3/golden"
-
+	"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"
-	"github.com/ucan-wg/go-ucan/pkg/command"
-	"github.com/ucan-wg/go-ucan/pkg/policy"
-	"github.com/ucan-wg/go-ucan/token/delegation"
+	"gotest.tools/v3/golden"
 )
 
 const (
@@ -63,9 +65,6 @@ const (
 	]
 ]
 `
-
-	newCID  = "zdpuAn9JgGPvnt2WCmTaKktZdbuvcVGTg9bUT5kQaufwUtZ6e"
-	rootCID = "zdpuAkgGmUp5JrXvehGuuw9JA8DLQKDaxtK3R8brDQQVC2i5X"
 )
 
 func TestConstructors(t *testing.T) {
@@ -84,20 +83,18 @@ func TestConstructors(t *testing.T) {
 	pol, err := policy.FromDagJson(subjectPol)
 	require.NoError(t, err)
 
-	exp, err := time.Parse(time.RFC3339, "2200-01-01T00:00:00Z")
-	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) {
-		tkn, err := delegation.New(privKey, aud, cmd, pol,
-			delegation.WithNonce([]byte(nonce)),
-			delegation.WithSubject(sub),
-			delegation.WithExpiration(exp),
-			delegation.WithMeta("foo", "fooo"),
-			delegation.WithMeta("bar", "barr"),
-		)
+		dlg, err := delegation.New(privKey, aud, &sub, cmd, pol, []byte(nonce), delegation.WithExpiration(&exp), delegation.WithMeta(meta))
 		require.NoError(t, err)
 
-		data, err := tkn.ToDagJson(privKey)
+		data, err := dlg.ToDagJson()
 		require.NoError(t, err)
 
 		t.Log(string(data))
@@ -108,15 +105,10 @@ func TestConstructors(t *testing.T) {
 	t.Run("Root", func(t *testing.T) {
 		t.Parallel()
 
-		tkn, err := delegation.Root(privKey, aud, cmd, pol,
-			delegation.WithNonce([]byte(nonce)),
-			delegation.WithExpiration(exp),
-			delegation.WithMeta("foo", "fooo"),
-			delegation.WithMeta("bar", "barr"),
-		)
+		dlg, err := delegation.Root(privKey, aud, cmd, pol, []byte(nonce), delegation.WithExpiration(&exp), delegation.WithMeta(meta))
 		require.NoError(t, err)
 
-		data, err := tkn.ToDagJson(privKey)
+		data, err := dlg.ToDagJson()
 		require.NoError(t, err)
 
 		t.Log(string(data))
@@ -125,7 +117,9 @@ func TestConstructors(t *testing.T) {
 	})
 }
 
-func privKey(t require.TestingT, privKeyCfg string) crypto.PrivKey {
+func privKey(t *testing.T, privKeyCfg string) crypto.PrivKey {
+	t.Helper()
+
 	privKeyMar, err := crypto.ConfigDecodeKey(privKeyCfg)
 	require.NoError(t, err)
 
@@ -134,3 +128,22 @@ func privKey(t require.TestingT, privKeyCfg string) crypto.PrivKey {
 
 	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/did.go

@@ -116,11 +116,3 @@ func Parse(str string) (DID, error) {
 	buf = append(buf, suffix...)
 	return DID{str: string(buf), code: DIDCore}, nil
 }
-
-func MustParse(str string) DID {
-	did, err := Parse(str)
-	if err != nil {
-		panic(err)
-	}
-	return did
-}

did/did_test.go

@@ -2,8 +2,6 @@ package did
 
 import (
 	"testing"
-
-	"github.com/stretchr/testify/require"
 )
 
 func TestParseDIDKey(t *testing.T) {
@@ -17,18 +15,6 @@ func TestParseDIDKey(t *testing.T) {
 	}
 }
 
-func TestMustParseDIDKey(t *testing.T) {
-	str := "did:key:z6Mkod5Jr3yd5SC7UDueqK4dAAw5xYJYjksy722tA9Boxc4z"
-	require.NotPanics(t, func() {
-		d := MustParse(str)
-		require.Equal(t, str, d.String())
-	})
-	str = "did:key:z7Mkod5Jr3yd5SC7UDueqK4dAAw5xYJYjksy722tA9Boxc4z"
-	require.Panics(t, func() {
-		MustParse(str)
-	})
-}
-
 func TestDecodeDIDKey(t *testing.T) {
 	str := "did:key:z6Mkod5Jr3yd5SC7UDueqK4dAAw5xYJYjksy722tA9Boxc4z"
 	d0, err := Parse(str)

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

@@ -1,15 +1,19 @@
 module github.com/ucan-wg/go-ucan
 
-go 1.23
+go 1.22.0
+
+toolchain go1.22.4
 
 require (
+	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 v0.36.3
+	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/selesy/go-options v0.0.0-20240912020512-ed2658318e52
 	github.com/stretchr/testify v1.9.0
 	gotest.tools/v3 v3.5.1
 )
@@ -17,7 +21,8 @@ require (
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.3.0 // indirect
-	github.com/google/go-cmp v0.5.9 // 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
@@ -27,9 +32,11 @@ require (
 	github.com/polydawn/refmt v0.89.0 // indirect
 	github.com/spaolacci/murmur3 v1.1.0 // indirect
 	golang.org/x/crypto v0.25.0 // indirect
-	golang.org/x/sys v0.22.0 // 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/check.v1 v1.0.0-20190902080502-41f04d3bba15 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	lukechampine.com/blake3 v1.3.0 // indirect
 )

go.sum

@@ -6,11 +6,15 @@ github.com/decred/dcrd/crypto/blake256 v1.0.1 h1:7PltbUIQB7u/FfZ39+DGa/ShuMyJ5il
 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 v0.4.1 h1:A/T3qGvxi4kpKWWcPC/PgbvDA2bjVLO7n4UeVwnbs/s=
@@ -27,8 +31,8 @@ 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 v0.36.3 h1:NHz30+G7D8Y8YmznrVZZla0ofVANrvBl2c+oARfMeDQ=
-github.com/libp2p/go-libp2p v0.36.3/go.mod h1:4Y5vFyCUiJuluEPmpnKYf6WFx5ViKPUYs/ixe9ANFZ8=
+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=
@@ -54,6 +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=
@@ -71,18 +77,23 @@ 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 v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.22.0 h1:RI27ohtqKCnwULzJLqkv897zojh5/DwS/ENaMzUOaWI=
-golang.org/x/sys v0.22.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+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=

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

@@ -24,6 +24,7 @@
 package varsig
 
 import (
+	"encoding/base64"
 	"encoding/binary"
 	"errors"
 	"fmt"
@@ -57,7 +58,7 @@ var (
 //
 // [go-libp2p/core/crypto]: github.com/libp2p/go-libp2p/core/crypto
 func Decode(header []byte) (pb.KeyType, error) {
-	keyType, ok := decMap[string(header)]
+	keyType, ok := decMap[base64.RawStdEncoding.EncodeToString(header)]
 	if !ok {
 		return -1, fmt.Errorf("%w: %s", ErrUnknownHeader, header)
 	}
@@ -81,10 +82,10 @@ func Encode(keyType pb.KeyType) ([]byte, error) {
 	return []byte(header), nil
 }
 
-func keyTypeToHeader() map[pb.KeyType]string {
+func keyTypeToHeader() map[pb.KeyType][]byte {
 	const rsaSigLen = 0x100
 
-	return map[pb.KeyType]string{
+	return map[pb.KeyType][]byte{
 		pb.KeyType_RSA: header(
 			Prefix,
 			multicodec.RsaPub,
@@ -116,18 +117,18 @@ func headerToKeyType() map[string]pb.KeyType {
 	out := make(map[string]pb.KeyType, len(encMap))
 
 	for keyType, header := range encMap {
-		out[header] = keyType
+		out[base64.RawStdEncoding.EncodeToString(header)] = keyType
 	}
 
 	return out
 }
 
-func header(vals ...multicodec.Code) string {
+func header(vals ...multicodec.Code) []byte {
 	var buf []byte
 
 	for _, val := range vals {
 		buf = binary.AppendUvarint(buf, uint64(val))
 	}
 
-	return string(buf)
+	return buf
 }

internal/varsig/varsig_test.go

@@ -8,7 +8,7 @@ import (
 	"github.com/libp2p/go-libp2p/core/crypto/pb"
 	"github.com/stretchr/testify/assert"
 
-	"github.com/ucan-wg/go-ucan/token/internal/varsig"
+	"github.com/ucan-wg/go-ucan/internal/varsig"
 )
 
 func TestDecode(t *testing.T) {

pkg/container/Readme.md

@@ -1,86 +0,0 @@
-# Token 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

@@ -1,78 +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) {
-	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/reader.go

@@ -1,122 +0,0 @@
-package container
-
-import (
-	"encoding/base64"
-	"fmt"
-	"io"
-
-	"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/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")
-
-// Reader is a token container reader. It exposes the tokens conveniently decoded.
-type Reader map[cid.Cid]token.Token
-
-// 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) {
-	tkn, ok := ctn[cid]
-	if !ok {
-		return nil, ErrNotFound
-	}
-	return tkn, nil
-}
-
-// GetDelegation is the same as GetToken but only return a delegation.Token, with the right type.
-func (ctn Reader) GetDelegation(cid cid.Cid) (*delegation.Token, error) {
-	tkn, err := ctn.GetToken(cid)
-	if err != nil {
-		return nil, err
-	}
-	if tkn, ok := tkn.(*delegation.Token); ok {
-		return tkn, nil
-	}
-	return nil, fmt.Errorf("not a delegation token")
-}
-
-// GetInvocation returns the first found invocation.Token.
-// If none are found, ErrNotFound is returned.
-func (ctn Reader) GetInvocation() (*invocation.Token, error) {
-	for _, t := range ctn {
-		if inv, ok := t.(*invocation.Token); ok {
-			return inv, nil
-		}
-	}
-	return nil, ErrNotFound
-}
-
-func FromCar(r io.Reader) (Reader, error) {
-	_, it, err := readCar(r)
-	if err != nil {
-		return nil, err
-	}
-
-	ctn := make(Reader)
-
-	for block, err := range it {
-		if err != nil {
-			return nil, err
-		}
-
-		err = ctn.addToken(block.data)
-		if err != nil {
-			return nil, err
-		}
-	}
-
-	return ctn, nil
-}
-
-func FromCarBase64(r io.Reader) (Reader, error) {
-	return FromCar(base64.NewDecoder(base64.StdEncoding, r))
-}
-
-func FromCbor(r io.Reader) (Reader, error) {
-	n, err := ipld.DecodeStreaming(r, dagcbor.Decode)
-	if err != nil {
-		return nil, err
-	}
-	if n.Kind() != datamodel.Kind_List {
-		return nil, fmt.Errorf("not a list")
-	}
-
-	ctn := make(Reader, n.Length())
-
-	it := n.ListIterator()
-	for !it.Done() {
-		_, val, err := it.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
-}
-
-func FromCborBase64(r io.Reader) (Reader, error) {
-	return FromCbor(base64.NewDecoder(base64.StdEncoding, r))
-}
-
-func (ctn Reader) addToken(data []byte) error {
-	tkn, c, err := token.FromSealed(data)
-	if err != nil {
-		return err
-	}
-	ctn[c] = tkn
-	return nil
-}

pkg/container/serial_test.go

@@ -1,184 +0,0 @@
-package container
-
-import (
-	"bytes"
-	"crypto/rand"
-	"fmt"
-	"io"
-	"strings"
-	"testing"
-	"time"
-
-	"github.com/ipfs/go-cid"
-	"github.com/libp2p/go-libp2p/core/crypto"
-	"github.com/stretchr/testify/require"
-
-	"github.com/ucan-wg/go-ucan/did"
-	"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
-		writer func(ctn Writer, w io.Writer) error
-		reader func(io.Reader) (Reader, error)
-	}{
-		{"car", Writer.ToCar, FromCar},
-		{"carBase64", Writer.ToCarBase64, FromCarBase64},
-		{"cbor", Writer.ToCbor, FromCbor},
-		{"cborBase64", Writer.ToCborBase64, FromCborBase64},
-	} {
-		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(c, data)
-				tokens[c] = dlg
-				dataSize += len(data)
-			}
-
-			buf := bytes.NewBuffer(nil)
-
-			err := tc.writer(writer, buf)
-			require.NoError(t, err)
-
-			t.Logf("data size %d", dataSize)
-			t.Logf("container overhead: %d%%, %d bytes", int(float32(buf.Len()-dataSize)/float32(dataSize)*100.0), buf.Len()-dataSize)
-
-			reader, err := tc.reader(bytes.NewReader(buf.Bytes()))
-			require.NoError(t, err)
-
-			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)
-	}{
-		{"car", Writer.ToCar, FromCar},
-		{"carBase64", Writer.ToCarBase64, FromCarBase64},
-		{"cbor", Writer.ToCbor, FromCbor},
-		{"cborBase64", Writer.ToCborBase64, FromCborBase64},
-	} {
-		writer := NewWriter()
-
-		for i := 0; i < 10; i++ {
-			_, c, data := randToken()
-			writer.AddSealed(c, 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 randBytes(n int) []byte {
-	b := make([]byte, n)
-	_, _ = rand.Read(b)
-	return b
-}
-
-func randDID() (crypto.PrivKey, did.DID) {
-	privKey, _, err := crypto.GenerateEd25519Key(rand.Reader)
-	if err != nil {
-		panic(err)
-	}
-	d, err := did.FromPrivKey(privKey)
-	if err != nil {
-		panic(err)
-	}
-	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)),
-		delegation.WithSubject(iss),
-	}
-	for i := 0; i < 3; i++ {
-		opts = append(opts, delegation.WithMeta(randomString(8), randomString(10)))
-	}
-
-	t, err := delegation.New(priv, aud, cmd, pol, opts...)
-	if err != nil {
-		panic(err)
-	}
-	b, c, err := t.ToSealed(priv)
-	if err != nil {
-		panic(err)
-	}
-	return t, c, b
-}

pkg/container/writer.go

@@ -1,61 +0,0 @@
-package container
-
-import (
-	"encoding/base64"
-	"io"
-
-	"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"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-)
-
-// TODO: should we have a multibase to wrap the cbor? but there is no reader/write in go-multibase :-(
-
-// Writer is a token container writer. It provides a convenient way to aggregate and serialize tokens together.
-type Writer map[cid.Cid][]byte
-
-func NewWriter() Writer {
-	return make(Writer)
-}
-
-// AddSealed includes a "sealed" token (serialized with a ToSealed* function) in the container.
-func (ctn Writer) AddSealed(cid cid.Cid, data []byte) {
-	ctn[cid] = data
-}
-
-func (ctn Writer) ToCar(w io.Writer) error {
-	return writeCar(w, nil, func(yield func(carBlock, error) bool) {
-		for c, bytes := range ctn {
-			if !yield(carBlock{c: c, data: bytes}, nil) {
-				return
-			}
-		}
-	})
-}
-
-func (ctn Writer) ToCarBase64(w io.Writer) error {
-	w2 := base64.NewEncoder(base64.StdEncoding, w)
-	defer w2.Close()
-	return ctn.ToCar(w2)
-}
-
-func (ctn Writer) ToCbor(w io.Writer) error {
-	node, err := qp.BuildList(basicnode.Prototype.Any, int64(len(ctn)), func(la datamodel.ListAssembler) {
-		for _, bytes := range ctn {
-			qp.ListEntry(la, qp.Bytes(bytes))
-		}
-	})
-	if err != nil {
-		return err
-	}
-	return ipld.EncodeStreaming(w, node, dagcbor.Encode)
-}
-
-func (ctn Writer) ToCborBase64(w io.Writer) error {
-	w2 := base64.NewEncoder(base64.StdEncoding, w)
-	defer w2.Close()
-	return ctn.ToCbor(w2)
-}

pkg/meta/meta.go

@@ -1,173 +0,0 @@
-package meta
-
-import (
-	"errors"
-	"fmt"
-	"reflect"
-	"strings"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-	"github.com/ipld/go-ipld-prime/printer"
-)
-
-var ErrUnsupported = errors.New("failure adding unsupported type to meta")
-
-var ErrNotFound = errors.New("key-value not found in meta")
-
-// 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 {
-	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()
-}
-
-// 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()
-}
-
-// GetNode retrieves a value as a raw IPLD node.
-// Returns ErrNotFound if the given key is missing.
-// Returns datamodel.ErrWrongKind if the value has the wrong type.
-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 the value are: bool, string, int, int32, int64, []byte,
-// and ipld.Node.
-func (m *Meta) Add(key string, val any) error {
-	switch val := val.(type) {
-	case bool:
-		m.Values[key] = basicnode.NewBool(val)
-	case string:
-		m.Values[key] = basicnode.NewString(val)
-	case int:
-		m.Values[key] = basicnode.NewInt(int64(val))
-	case int32:
-		m.Values[key] = basicnode.NewInt(int64(val))
-	case int64:
-		m.Values[key] = basicnode.NewInt(val)
-	case float32:
-		m.Values[key] = basicnode.NewFloat(float64(val))
-	case float64:
-		m.Values[key] = basicnode.NewFloat(val)
-	case []byte:
-		m.Values[key] = basicnode.NewBytes(val)
-	case datamodel.Node:
-		m.Values[key] = val
-	default:
-		return fmt.Errorf("%w: %s", ErrUnsupported, fqtn(val))
-	}
-	m.Keys = append(m.Keys, key)
-	return nil
-}
-
-// 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 {
-	buf := strings.Builder{}
-	buf.WriteString("{")
-
-	var i int
-	for key, node := range m.Values {
-		if i > 0 {
-			buf.WriteString(", ")
-		}
-		i++
-		buf.WriteString(key)
-		buf.WriteString(":")
-		buf.WriteString(printer.Sprint(node))
-	}
-
-	buf.WriteString("}")
-	return buf.String()
-}
-
-func fqtn(val any) string {
-	var name string
-
-	t := reflect.TypeOf(val)
-	for t.Kind() == reflect.Pointer {
-		name += "*"
-		t = t.Elem()
-	}
-
-	return name + t.PkgPath() + "." + t.Name()
-}

pkg/meta/meta_test.go

@@ -1,23 +0,0 @@
-package meta_test
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/require"
-	"github.com/ucan-wg/go-ucan/pkg/meta"
-	"gotest.tools/v3/assert"
-)
-
-func TestMeta_Add(t *testing.T) {
-	t.Parallel()
-
-	type Unsupported struct{}
-
-	t.Run("error if not primative or Node", func(t *testing.T) {
-		t.Parallel()
-
-		err := (&meta.Meta{}).Add("invalid", &Unsupported{})
-		require.ErrorIs(t, err, meta.ErrUnsupported)
-		assert.ErrorContains(t, err, "*github.com/ucan-wg/go-ucan/pkg/meta_test.Unsupported")
-	})
-}

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/match.go

@@ -1,293 +0,0 @@
-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"
-)
-
-// Match determines if the IPLD node satisfies the policy.
-func (p Policy) Match(node datamodel.Node) bool {
-	for _, stmt := range p {
-		ok := matchStatement(stmt, node)
-		if !ok {
-			return false
-		}
-	}
-	return true
-}
-
-// Filter performs a recursive filtering of the Statement, and prunes what doesn't match the given path
-func (p Policy) Filter(path ...string) Policy {
-	var filtered Policy
-
-	for _, stmt := range p {
-		newChild, remain := filter(stmt, path)
-		if newChild != nil && len(remain) == 0 {
-			filtered = append(filtered, newChild)
-		}
-	}
-
-	return filtered
-}
-
-func matchStatement(statement Statement, node ipld.Node) bool {
-	switch statement.Kind() {
-	case KindEqual:
-		if s, ok := statement.(equality); ok {
-			one, _, err := s.selector.Select(node)
-			if err != nil {
-				return false
-			}
-			if one != nil {
-				return datamodel.DeepEqual(s.value, one)
-			}
-
-			return false
-		}
-	case KindGreaterThan:
-		if s, ok := statement.(equality); ok {
-			one, _, err := s.selector.Select(node)
-			if err != nil || one == nil {
-				return false
-			}
-			return isOrdered(s.value, one, gt)
-		}
-	case KindGreaterThanOrEqual:
-		if s, ok := statement.(equality); ok {
-			one, _, err := s.selector.Select(node)
-			if err != nil || one == nil {
-				return false
-			}
-			return isOrdered(s.value, one, gte)
-		}
-	case KindLessThan:
-		if s, ok := statement.(equality); ok {
-			one, _, err := s.selector.Select(node)
-			if err != nil || one == nil {
-				return false
-			}
-			return isOrdered(s.value, one, lt)
-		}
-	case KindLessThanOrEqual:
-		if s, ok := statement.(equality); ok {
-			one, _, err := s.selector.Select(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 := s.selector.Select(node)
-			if err != nil || one == nil {
-				return false
-			}
-			v, err := one.AsString()
-			if err != nil {
-				return false
-			}
-			return s.pattern.Match(v)
-		}
-	case KindAll:
-		if s, ok := statement.(quantifier); ok {
-			one, many, err := s.selector.Select(node)
-			if err != nil {
-				return false
-			}
-
-			if one != nil {
-				it := one.ListIterator()
-				if it != nil {
-					for !it.Done() {
-						_, v, err := it.Next()
-						if err != nil {
-							return false
-						}
-						ok := matchStatement(s.statement, v)
-						if !ok {
-							return false
-						}
-					}
-				} else {
-					ok := matchStatement(s.statement, one)
-					if !ok {
-						return false
-					}
-				}
-			}
-
-			if len(many) > 0 {
-				for _, n := range many {
-					ok := matchStatement(s.statement, n)
-					if !ok {
-						return false
-					}
-				}
-			}
-
-			return true
-		}
-	case KindAny:
-		if s, ok := statement.(quantifier); ok {
-			one, many, err := s.selector.Select(node)
-			if err != nil {
-				return false
-			}
-
-			if one != nil {
-				it := one.ListIterator()
-				if it != nil {
-					for !it.Done() {
-						_, v, err := it.Next()
-						if err != nil {
-							return false
-						}
-						ok := matchStatement(s.statement, v)
-						if ok {
-							return true
-						}
-					}
-				} else {
-					ok := matchStatement(s.statement, one)
-					if ok {
-						return true
-					}
-				}
-			}
-
-			if len(many) > 0 {
-				for _, n := range many {
-					ok := matchStatement(s.statement, n)
-					if ok {
-						return true
-					}
-				}
-			}
-
-			return false
-		}
-	}
-	panic(fmt.Errorf("unimplemented statement kind: %s", statement.Kind()))
-}
-
-// filter performs a recursive filtering of the Statement, and prunes what doesn't match the given path
-func filter(stmt Statement, path []string) (Statement, []string) {
-	// For each kind, we do some of the following if it applies:
-	// - test the path against the selector, consuming segments
-	// - for terminal statements (equality, wildcard), require all the segments to have been consumed
-	// - recursively filter child (negation, quantifier) or children (connective) statements with the remaining path
-	switch stmt.(type) {
-	case equality:
-		match, remain := stmt.(equality).selector.MatchPath(path...)
-		if match && len(remain) == 0 {
-			return stmt, remain
-		}
-		return nil, nil
-	case negation:
-		newChild, remain := filter(stmt.(negation).statement, path)
-		if newChild != nil && len(remain) == 0 {
-			return negation{
-				statement: newChild,
-			}, nil
-		}
-		return nil, nil
-	case connective:
-		var newChildren []Statement
-		for _, child := range stmt.(connective).statements {
-			newChild, remain := filter(child, path)
-			if newChild != nil && len(remain) == 0 {
-				newChildren = append(newChildren, newChild)
-			}
-		}
-		if len(newChildren) == 0 {
-			return nil, nil
-		}
-		return connective{
-			kind:       stmt.(connective).kind,
-			statements: newChildren,
-		}, nil
-	case wildcard:
-		match, remain := stmt.(wildcard).selector.MatchPath(path...)
-		if match && len(remain) == 0 {
-			return stmt, remain
-		}
-		return nil, nil
-	case quantifier:
-		match, remain := stmt.(quantifier).selector.MatchPath(path...)
-		if match && len(remain) == 0 {
-			return stmt, remain
-		}
-		if !match {
-			return nil, nil
-		}
-		newChild, remain := filter(stmt.(quantifier).statement, remain)
-		if newChild != nil && len(remain) == 0 {
-			return quantifier{
-				kind:      stmt.(quantifier).kind,
-				selector:  stmt.(quantifier).selector,
-				statement: newChild,
-			}, nil
-		}
-		return nil, nil
-	default:
-		panic(fmt.Errorf("unimplemented statement kind: %s", stmt.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 }

pkg/policy/policy.go

@@ -1,246 +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
-	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 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.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

@@ -1,60 +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 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/selector/selector.go

@@ -1,492 +0,0 @@
-package selector
-
-import (
-	"fmt"
-	"strings"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-	"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
-
-// Select perform the selection described by the selector on the input IPLD DAG.
-// If no error, Select returns either one ipld.Node or a []ipld.Node.
-func (s Selector) Select(subject ipld.Node) (ipld.Node, []ipld.Node, error) {
-	return resolve(s, subject, nil)
-}
-
-// MatchPath tells if the selector operates on the given (string only) path segments.
-// It returns the segments that didn't get consumed by the matching.
-func (s Selector) MatchPath(pathSegment ...string) (bool, []string) {
-	return matchPath(s, pathSegment)
-}
-
-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    []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
-}
-
-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
-		}
-
-		// 1st level: handle the different segment types (iterator, field, slice, index)
-		// 2nd level: handle different node kinds (list, map, string, bytes)
-		switch {
-		case seg.Iterator():
-			if cur == nil || cur.Kind() == datamodel.Kind_Null {
-				if seg.Optional() {
-					// build empty list
-					nb := basicnode.Prototype.List.NewBuilder()
-					assembler, err := nb.BeginList(0)
-					if err != nil {
-						return nil, nil, err
-					}
-
-					if err = assembler.Finish(); err != nil {
-						return nil, nil, err
-					}
-
-					return nb.Build(), nil, nil
-				} else {
-					return nil, nil, newResolutionError(fmt.Sprintf("can not iterate over kind: %s", kindString(cur)), at)
-				}
-			} else {
-				var many []ipld.Node
-				switch cur.Kind() {
-				case datamodel.Kind_List:
-					it := cur.ListIterator()
-					for !it.Done() {
-						_, v, err := it.Next()
-						if err != nil {
-							return nil, nil, err
-						}
-
-						// check if there are more iterator segments
-						if len(sel) > i+1 && sel[i+1].Iterator() {
-							if v.Kind() == datamodel.Kind_List {
-								// recursively resolve the remaining selector segments
-								var o ipld.Node
-								var m []ipld.Node
-								o, m, err = resolve(sel[i+1:], v, at)
-								if err != nil {
-									// if the segment is optional and an error occurs, skip the current iteration.
-									if seg.Optional() {
-										continue
-									} else {
-										return nil, nil, err
-									}
-								}
-								if m != nil {
-									many = append(many, m...)
-								} else if o != nil {
-									many = append(many, o)
-								}
-							} else {
-								// if the current value is not a list and the next segment is optional, skip the current iteration
-								if sel[i+1].Optional() {
-									continue
-								} else {
-									return nil, nil, newResolutionError(fmt.Sprintf("can not iterate over kind: %s", kindString(v)), at)
-								}
-							}
-						} else {
-							// if there are no more iterator segments, append the current value to the result
-							many = append(many, v)
-						}
-					}
-				case datamodel.Kind_Map:
-					it := cur.MapIterator()
-					for !it.Done() {
-						_, v, err := it.Next()
-						if err != nil {
-							return nil, nil, err
-						}
-
-						if len(sel) > i+1 && sel[i+1].Iterator() {
-							if v.Kind() == datamodel.Kind_List {
-								var o ipld.Node
-								var m []ipld.Node
-								o, m, err = resolve(sel[i+1:], v, at)
-								if err != nil {
-									if seg.Optional() {
-										continue
-									} else {
-										return nil, nil, err
-									}
-								}
-								if m != nil {
-									many = append(many, m...)
-								} else if o != nil {
-									many = append(many, o)
-								}
-							} else {
-								if sel[i+1].Optional() {
-									continue
-								} else {
-									return nil, nil, newResolutionError(fmt.Sprintf("can not iterate over kind: %s", kindString(v)), at)
-								}
-							}
-						} else {
-							many = append(many, v)
-						}
-					}
-				default:
-					return nil, nil, newResolutionError(fmt.Sprintf("can not iterate over kind: %s", kindString(cur)), at)
-				}
-
-				return nil, many, nil
-			}
-
-		case seg.Field() != "":
-			at = append(at, seg.Field())
-			if cur == nil {
-				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 {
-				switch cur.Kind() {
-				case 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
-						}
-					} else {
-						cur = n
-					}
-				case datamodel.Kind_List:
-					var many []ipld.Node
-					it := cur.ListIterator()
-					for !it.Done() {
-						_, v, err := it.Next()
-						if err != nil {
-							return nil, nil, err
-						}
-						if v.Kind() == datamodel.Kind_Map {
-							n, err := v.LookupByString(seg.Field())
-							if err == nil {
-								many = append(many, n)
-							}
-						}
-					}
-					if len(many) > 0 {
-						cur = nil
-						return nil, many, nil
-					} else if seg.Optional() {
-						cur = nil
-					} else {
-						return nil, nil, newResolutionError(fmt.Sprintf("no elements in list have field named: %s", seg.Field()), at)
-					}
-				default:
-					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)
-					}
-				}
-			}
-
-		case seg.Slice() != nil:
-			if cur == nil {
-				if seg.Optional() {
-					cur = nil
-				} else {
-					return nil, nil, newResolutionError(fmt.Sprintf("can not slice on kind: %s", kindString(cur)), at)
-				}
-			} else {
-				slice := seg.Slice()
-				var start, end, length int64
-				switch cur.Kind() {
-				case datamodel.Kind_List:
-					length = cur.Length()
-					start, end = resolveSliceIndices(slice, length)
-				case datamodel.Kind_Bytes:
-					b, _ := cur.AsBytes()
-					length = int64(len(b))
-					start, end = resolveSliceIndices(slice, length)
-				case datamodel.Kind_String:
-					str, _ := cur.AsString()
-					length = int64(len(str))
-					start, end = resolveSliceIndices(slice, length)
-				default:
-					return nil, nil, newResolutionError(fmt.Sprintf("can not slice on kind: %s", kindString(cur)), at)
-				}
-
-				if start < 0 || end < start || end > length {
-					if seg.Optional() {
-						cur = nil
-					} else {
-						return nil, nil, newResolutionError(fmt.Sprintf("slice out of bounds: [%d:%d]", start, end), at)
-					}
-				} else {
-					switch cur.Kind() {
-					case datamodel.Kind_List:
-						if end > cur.Length() {
-							end = cur.Length()
-						}
-						nb := basicnode.Prototype.List.NewBuilder()
-						assembler, _ := nb.BeginList(int64(end - start))
-						for i := start; i < end; i++ {
-							item, _ := cur.LookupByIndex(int64(i))
-							assembler.AssembleValue().AssignNode(item)
-						}
-						assembler.Finish()
-						cur = nb.Build()
-					case datamodel.Kind_Bytes:
-						b, _ := cur.AsBytes()
-						l := int64(len(b))
-						if end > l {
-							end = l
-						}
-						cur = basicnode.NewBytes(b[start:end])
-					case datamodel.Kind_String:
-						str, _ := cur.AsString()
-						l := int64(len(str))
-						if end > l {
-							end = l
-						}
-						cur = basicnode.NewString(str[start:end])
-					}
-				}
-			}
-
-		default: // Index()
-			at = append(at, fmt.Sprintf("%d", seg.Index()))
-			if cur == nil {
-				if seg.Optional() {
-					cur = nil
-				} else {
-					return nil, nil, newResolutionError(fmt.Sprintf("can not access index: %d on kind: %s", seg.Index(), kindString(cur)), at)
-				}
-			} else {
-				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()) {
-						if seg.Optional() {
-							cur = nil
-						} else {
-							return nil, nil, newResolutionError(fmt.Sprintf("index out of bounds: %d", seg.Index()), at)
-						}
-					} else {
-						cur, _ = cur.LookupByIndex(int64(idx))
-					}
-				case datamodel.Kind_String:
-					str, _ := cur.AsString()
-					if idx < 0 {
-						idx = len(str) + idx
-					}
-					if idx < 0 || idx >= len(str) {
-						if seg.Optional() {
-							cur = nil
-						} else {
-							return nil, nil, newResolutionError(fmt.Sprintf("index out of bounds: %d", seg.Index()), at)
-						}
-					} else {
-						cur = basicnode.NewString(string(str[idx]))
-					}
-				case datamodel.Kind_Bytes:
-					b, _ := cur.AsBytes()
-					if idx < 0 {
-						idx = len(b) + idx
-					}
-					if idx < 0 || idx >= len(b) {
-						if seg.Optional() {
-							cur = nil
-						} else {
-							return nil, nil, newResolutionError(fmt.Sprintf("index out of bounds: %d", seg.Index()), at)
-						}
-					} else {
-						cur = basicnode.NewInt(int64(b[idx]))
-					}
-				default:
-					return nil, nil, newResolutionError(fmt.Sprintf("can not access index: %d on kind: %s", seg.Index(), kindString(cur)), at)
-				}
-			}
-		}
-	}
-
-	return cur, nil, nil
-}
-
-func matchPath(sel Selector, path []string) (bool, []string) {
-	for _, seg := range sel {
-		if len(path) == 0 {
-			return true, path
-		}
-		switch {
-		case seg.Identity():
-			continue
-
-		case seg.Iterator():
-			// we have reached a [] iterator, it should have matched earlier
-			return false, nil
-
-		case seg.Field() != "":
-			// if exact match on the segment, we continue
-			if path[0] == seg.Field() {
-				path = path[1:]
-				continue
-			}
-			return false, nil
-
-		case seg.Slice() != nil:
-			// we have reached a [<int>:<int>] slicing, it should have matched earlier
-			return false, nil
-
-		default: // Index()
-			// we have reached a [<int>] indexing, it should have matched earlier
-			return false, nil
-		}
-	}
-	return true, path
-}
-
-// 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 end index for slicing.
-func resolveSliceIndices(slice []int, length int64) (int64, int64) {
-	start, end := int64(0), length
-	if len(slice) > 0 {
-		start = int64(slice[0])
-		if start < 0 {
-			start = length + start
-			if start < 0 {
-				start = 0
-			}
-		}
-	}
-	if len(slice) > 1 {
-		end = int64(slice[1])
-		if end <= 0 {
-			end = length + end
-			if end < start {
-				end = start
-			}
-		}
-	}
-
-	return start, end
-}
-
-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}
-}

token/delegation/delegation.go

@@ -1,244 +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 (
-	"crypto/rand"
-	"errors"
-	"fmt"
-	"time"
-
-	"github.com/libp2p/go-libp2p/core/crypto"
-
-	"github.com/ucan-wg/go-ucan/did"
-	"github.com/ucan-wg/go-ucan/pkg/command"
-	"github.com/ucan-wg/go-ucan/pkg/meta"
-	"github.com/ucan-wg/go-ucan/pkg/policy"
-)
-
-// 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 Token from the provided parameters and options.
-//
-// When creating a delegated token, the Issuer's (iss) DID is assembed
-// using the public key associated with the private key sent as the first
-// parameter.
-func New(privKey crypto.PrivKey, aud did.DID, cmd command.Command, pol policy.Policy, opts ...Option) (*Token, error) {
-	iss, err := did.FromPrivKey(privKey)
-	if err != nil {
-		return nil, err
-	}
-
-	tkn := &Token{
-		issuer:   iss,
-		audience: aud,
-		subject:  did.Undef,
-		command:  cmd,
-		policy:   pol,
-		meta:     meta.NewMeta(),
-		nonce:    nil,
-	}
-
-	for _, opt := range opts {
-		if err := opt(tkn); err != nil {
-			return nil, err
-		}
-	}
-
-	if len(tkn.nonce) == 0 {
-		tkn.nonce, err = generateNonce()
-		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.
-//
-// When creating a root token, both the Issuer's (iss) and Subject's
-// (sub) DIDs are assembled from the public key associated with the
-// private key passed as the first argument.
-func Root(privKey crypto.PrivKey, aud did.DID, cmd command.Command, pol policy.Policy, opts ...Option) (*Token, error) {
-	sub, err := did.FromPrivKey(privKey)
-	if err != nil {
-		return nil, err
-	}
-
-	opts = append(opts, WithSubject(sub))
-
-	return New(privKey, aud, cmd, pol, 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.Meta {
-	return t.meta
-}
-
-// 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
-}
-
-func (t *Token) validate() error {
-	var errs error
-
-	requiredDID := func(id did.DID, fieldname string) {
-		if !id.Defined() {
-			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)
-	}
-
-	tkn.audience, err = did.Parse(m.Aud)
-	if err != nil {
-		return nil, fmt.Errorf("parse audience: %w", err)
-	}
-
-	if m.Sub != nil {
-		tkn.subject, err = did.Parse(*m.Sub)
-		if err != nil {
-			return nil, fmt.Errorf("parse subject: %w", err)
-		}
-	} else {
-		tkn.subject = did.Undef
-	}
-
-	tkn.command, err = command.Parse(m.Cmd)
-	if err != nil {
-		return nil, fmt.Errorf("parse command: %w", err)
-	}
-
-	tkn.policy, err = policy.FromIPLD(m.Pol)
-	if 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 m.Nbf != nil {
-		t := time.Unix(*m.Nbf, 0)
-		tkn.notBefore = &t
-	}
-
-	if m.Exp != nil {
-		t := time.Unix(*m.Exp, 0)
-		tkn.expiration = &t
-	}
-
-	if err := tkn.validate(); err != nil {
-		return nil, err
-	}
-
-	return &tkn, nil
-}
-
-// generateNonce creates a 12-byte random nonce.
-// TODO: some crypto scheme require more, is that our case?
-func generateNonce() ([]byte, error) {
-	res := make([]byte, 12)
-	_, err := rand.Read(res)
-	if err != nil {
-		return nil, err
-	}
-	return res, 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 {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/examples_test.go

@@ -1,331 +0,0 @@
-package delegation_test
-
-import (
-	"bytes"
-	"crypto/rand"
-	"encoding/base64"
-	"encoding/hex"
-	"encoding/json"
-	"fmt"
-	"time"
-
-	"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/codec/dagjson"
-	"github.com/libp2p/go-libp2p/core/crypto"
-
-	"github.com/ucan-wg/go-ucan/did"
-	"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"
-	"github.com/ucan-wg/go-ucan/token/internal/envelope"
-)
-
-// The following example shows how to create a delegation.Token with
-// distinct DIDs for issuer (iss), audience (aud) and subject (sub).
-func ExampleNew() {
-	issPriv, issPub, err := crypto.GenerateEd25519Key(rand.Reader)
-	printThenPanicOnErr(err)
-
-	issDid, err := did.FromPubKey(issPub)
-	printThenPanicOnErr(err)
-	fmt.Println("issDid:", issDid)
-
-	audDid := did.MustParse(AudienceDID)
-	subDid := did.MustParse(subjectDID)
-
-	// The command defines the shape of the arguments that will be evaluated against the policy
-	cmd := command.MustParse("/foo/bar")
-
-	// The policy defines what is allowed to do.
-	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")),
-		)),
-	)
-
-	tkn, err := delegation.New(issPriv, audDid, cmd, pol,
-		delegation.WithSubject(subDid),
-		delegation.WithExpirationIn(time.Hour),
-		delegation.WithNotBeforeIn(time.Minute),
-		delegation.WithMeta("foo", "bar"),
-		delegation.WithMeta("baz", 123),
-	)
-	printThenPanicOnErr(err)
-
-	// "Seal", meaning encode and wrap into a signed envelope.
-	data, id, err := tkn.ToSealed(issPriv)
-	printThenPanicOnErr(err)
-
-	printCIDAndSealed(id, data)
-
-	// Example output:
-	//
-	// issDid: did:key:z6MkhVFznPeR572rTK51UjoTNpnF8cxuWfPm9oBMPr7y8ABe
-	//
-	// CID (base58BTC): zdpuAv6g2eJSc4RJwEpmooGLVK4wJ4CZpnM92tPVYt5jtMoLW
-	//
-	// DAG-CBOR (base64) out: glhA5rvl8uKmDVGvAVSt4m/0MGiXl9dZwljJJ9m2qHCoIB617l26UvMxyH5uvN9hM7ozfVATiq4mLhoGgm9IGnEEAqJhaEQ07QFxc3VjYW4vZGxnQDEuMC4wLXJjLjGpY2F1ZHg4ZGlkOmtleTp6Nk1rcTVZbWJKY1RyUEV4TkRpMjZpbXJUQ3BLaGVwakJGQlNIcXJCRE4yQXJQa3ZjY21kaC9mb28vYmFyY2V4cBpnDWzqY2lzc3g4ZGlkOmtleTp6Nk1raFZGem5QZVI1NzJyVEs1MVVqb1ROcG5GOGN4dVdmUG05b0JNUHI3eThBQmVjbmJmGmcNXxZjcG9sg4NiPT1nLnN0YXR1c2VkcmFmdINjYWxsaS5yZXZpZXdlcoNkbGlrZWYuZW1haWxtKkBleGFtcGxlLmNvbYNjYW55ZS50YWdzgmJvcoKDYj09YS5kbmV3c4NiPT1hLmVwcmVzc2NzdWJ4OGRpZDprZXk6ejZNa3RBMXVCZENwcTR1SkJxRTlqak1pTHl4WkJnOWE2eGdQUEtKak1xc3M2WmMyZG1ldGGiY2Jhehh7Y2Zvb2NiYXJlbm9uY2VMu0HMgJ5Y+M84I/66
-	//
-	// Converted to DAG-JSON out:
-	// [
-	//	{
-	//		"/": {
-	//			"bytes": "5rvl8uKmDVGvAVSt4m/0MGiXl9dZwljJJ9m2qHCoIB617l26UvMxyH5uvN9hM7ozfVATiq4mLhoGgm9IGnEEAg"
-	//		}
-	//	},
-	//	{
-	//		"h": {
-	//			"/": {
-	//				"bytes": "NO0BcQ"
-	//			}
-	//		},
-	//		"ucan/dlg@1.0.0-rc.1": {
-	//			"aud": "did:key:z6Mkq5YmbJcTrPExNDi26imrTCpKhepjBFBSHqrBDN2ArPkv",
-	//			"cmd": "/foo/bar",
-	//			"exp": 1728933098,
-	//			"iss": "did:key:z6MkhVFznPeR572rTK51UjoTNpnF8cxuWfPm9oBMPr7y8ABe",
-	//			"meta": {
-	//				"baz": 123,
-	//				"foo": "bar"
-	//			},
-	//			"nbf": 1728929558,
-	//			"nonce": {
-	//				"/": {
-	//					"bytes": "u0HMgJ5Y+M84I/66"
-	//				}
-	//			},
-	//			"pol": [
-	//				[
-	//					"==",
-	//					".status",
-	//					"draft"
-	//				],
-	//				[
-	//					"all",
-	//					".reviewer",
-	//					[
-	//						"like",
-	//						".email",
-	//						"*@example.com"
-	//					]
-	//				],
-	//				[
-	//					"any",
-	//					".tags",
-	//					[
-	//						"or",
-	//						[
-	//							[
-	//								"==",
-	//								".",
-	//								"news"
-	//							],
-	//							[
-	//								"==",
-	//								".",
-	//								"press"
-	//							]
-	//						]
-	//					]
-	//				]
-	//			],
-	//			"sub": "did:key:z6MktA1uBdCpq4uJBqE9jjMiLyxZBg9a6xgPPKJjMqss6Zc2"
-	//		}
-	//	}
-	// ]
-}
-
-// The following example shows how to create a UCAN root delegation.Token
-// - a delegation.Token with the subject (sub) set to the value of issuer
-// (iss).
-func ExampleRoot() {
-	issPriv, issPub, err := crypto.GenerateEd25519Key(rand.Reader)
-	printThenPanicOnErr(err)
-
-	issDid, err := did.FromPubKey(issPub)
-	printThenPanicOnErr(err)
-	fmt.Println("issDid:", issDid)
-
-	audDid := did.MustParse(AudienceDID)
-
-	// The command defines the shape of the arguments that will be evaluated against the policy
-	cmd := command.MustParse("/foo/bar")
-
-	// The policy defines what is allowed to do.
-	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")),
-		)),
-	)
-
-	tkn, err := delegation.Root(issPriv, audDid, cmd, pol,
-		delegation.WithExpirationIn(time.Hour),
-		delegation.WithNotBeforeIn(time.Minute),
-		delegation.WithMeta("foo", "bar"),
-		delegation.WithMeta("baz", 123),
-	)
-	printThenPanicOnErr(err)
-
-	// "Seal", meaning encode and wrap into a signed envelope.
-	data, id, err := tkn.ToSealed(issPriv)
-	printThenPanicOnErr(err)
-
-	printCIDAndSealed(id, data)
-
-	// Example output:
-	//
-	// issDid: did:key:z6MknWJqz17Y4AfsXSJUFKomuBR4GTkViM7kJYutzTMkCyFF
-	//
-	// CID (base58BTC): zdpuAwLojgfvFCbjz2FsKrvN1khDQ9mFGT6b6pxjMfz73Roed
-	//
-	// DAG-CBOR (base64) out: 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
-	//
-	// Converted to DAG-JSON out:
-	// [
-	//	{
-	//		"/": {
-	//			"bytes": "6dBhbhhGE36CW22OxjOEIAqdDmBqCNsAhCRljnBdXd7YrVOUG+bnXGCIwd4dTGgpEdmY06PFIl7IXKXCh/ESBg"
-	//		}
-	//	},
-	//	{
-	//		"h": {
-	//			"/": {
-	//				"bytes": "NO0BcQ"
-	//			}
-	//		},
-	//		"ucan/dlg@1.0.0-rc.1": {
-	//			"aud": "did:key:z6Mkq5YmbJcTrPExNDi26imrTCpKhepjBFBSHqrBDN2ArPkv",
-	//			"cmd": "/foo/bar",
-	//			"exp": 1728933168,
-	//			"iss": "did:key:z6MknWJqz17Y4AfsXSJUFKomuBR4GTkViM7kJYutzTMkCyFF",
-	//			"meta": {
-	//				"baz": 123,
-	//				"foo": "bar"
-	//			},
-	//			"nbf": 1728929628,
-	//			"nonce": {
-	//				"/": {
-	//					"bytes": "JOsjYi1Pq3OIB0La"
-	//				}
-	//			},
-	//			"pol": [
-	//				[
-	//					"==",
-	//					".status",
-	//					"draft"
-	//				],
-	//				[
-	//					"all",
-	//					".reviewer",
-	//					[
-	//						"like",
-	//						".email",
-	//						"*@example.com"
-	//					]
-	//				],
-	//				[
-	//					"any",
-	//					".tags",
-	//					[
-	//						"or",
-	//						[
-	//							[
-	//								"==",
-	//								".",
-	//								"news"
-	//							],
-	//							[
-	//								"==",
-	//								".",
-	//								"press"
-	//							]
-	//						]
-	//					]
-	//				]
-	//			],
-	//			"sub": "did:key:z6MknWJqz17Y4AfsXSJUFKomuBR4GTkViM7kJYutzTMkCyFF"
-	//		}
-	//	}
-	// ]
-}
-
-// The following example demonstrates how to get a delegation.Token from
-// a DAG-CBOR []byte.
-func ExampleToken_FromSealed() {
-	const cborBase64 = "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"
-
-	cborBytes, err := base64.StdEncoding.DecodeString(cborBase64)
-	printThenPanicOnErr(err)
-
-	tkn, c, err := delegation.FromSealed(cborBytes)
-	printThenPanicOnErr(err)
-
-	fmt.Println("CID (base58BTC):", envelope.CIDToBase58BTC(c))
-	fmt.Println("Issuer (iss):", tkn.Issuer().String())
-	fmt.Println("Audience (aud):", tkn.Audience().String())
-	fmt.Println("Subject (sub):", tkn.Subject().String())
-	fmt.Println("Command (cmd):", tkn.Command().String())
-	fmt.Println("Policy (pol):", tkn.Policy().String())
-	fmt.Println("Nonce (nonce):", hex.EncodeToString(tkn.Nonce()))
-	fmt.Println("Meta (meta):", tkn.Meta().String())
-	fmt.Println("NotBefore (nbf):", tkn.NotBefore())
-	fmt.Println("Expiration (exp):", tkn.Expiration())
-
-	// Output:
-	// CID (base58BTC): zdpuAw26pFuvZa2Z9YAtpZZnWN6VmnRFr7Z8LVY5c7RVWoxGY
-	// Issuer (iss): did:key:z6Mkpzn2n3ZGT2VaqMGSQC3tzmzV4TS9S71iFsDXE1WnoNH2
-	// Audience (aud): did:key:z6Mkq5YmbJcTrPExNDi26imrTCpKhepjBFBSHqrBDN2ArPkv
-	// Subject (sub): did:key:z6MktA1uBdCpq4uJBqE9jjMiLyxZBg9a6xgPPKJjMqss6Zc2
-	// Command (cmd): /foo/bar
-	// Policy (pol): [
-	//   ["==", ".status", "draft"],
-	//   ["all", ".reviewer",
-	//     ["like", ".email", "*@example.com"]],
-	//   ["any", ".tags",
-	//     ["or", [
-	//       ["==", ".", "news"],
-	//       ["==", ".", "press"]]]
-	//     ]
-	// ]
-	// Nonce (nonce): 000102030405060708090a0b
-	// Meta (meta): {}
-	// NotBefore (nbf): <nil>
-	// Expiration (exp): <nil>
-}
-
-func printCIDAndSealed(id cid.Cid, data []byte) {
-	fmt.Println("CID (base58BTC):", envelope.CIDToBase58BTC(id))
-	fmt.Println("DAG-CBOR (base64) out:", base64.StdEncoding.EncodeToString(data))
-	fmt.Println("Converted to DAG-JSON out:")
-
-	node, err := ipld.Decode(data, dagcbor.Decode)
-	printThenPanicOnErr(err)
-
-	rawJSON, err := ipld.Encode(node, dagjson.Encode)
-	printThenPanicOnErr(err)
-
-	prettyJSON := &bytes.Buffer{}
-	err = json.Indent(prettyJSON, rawJSON, "", "\t")
-	printThenPanicOnErr(err)
-
-	fmt.Println(prettyJSON.String())
-}
-
-func printThenPanicOnErr(err error) {
-	if err != nil {
-		panic(err)
-	}
-}

token/delegation/ipld.go

@@ -1,233 +0,0 @@
-package delegation
-
-import (
-	"io"
-
-	"github.com/ipfs/go-cid"
-	"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/libp2p/go-libp2p/core/crypto"
-
-	"github.com/ucan-wg/go-ucan/did"
-	"github.com/ucan-wg/go-ucan/token/internal/envelope"
-)
-
-// ToSealed wraps the delegation token in an envelope, generates the
-// signature, encodes the result to DAG-CBOR and calculates the CID of
-// the resulting binary data.
-func (t *Token) ToSealed(privKey crypto.PrivKey) ([]byte, cid.Cid, error) {
-	data, err := t.ToDagCbor(privKey)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	id, err := envelope.CIDFromBytes(data)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	return data, id, nil
-}
-
-// ToSealedWriter is the same as ToSealed but accepts an io.Writer.
-func (t *Token) ToSealedWriter(w io.Writer, privKey crypto.PrivKey) (cid.Cid, error) {
-	cidWriter := envelope.NewCIDWriter(w)
-
-	if err := t.ToDagCborWriter(cidWriter, privKey); err != nil {
-		return cid.Undef, err
-	}
-
-	return cidWriter.CID()
-}
-
-// FromSealed decodes the provided binary data from the DAG-CBOR format,
-// verifies that the envelope's signature is correct based on the public
-// key taken from the issuer (iss) field and calculates the CID of the
-// incoming data.
-func FromSealed(data []byte) (*Token, cid.Cid, error) {
-	tkn, err := FromDagCbor(data)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	id, err := envelope.CIDFromBytes(data)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	return tkn, id, nil
-}
-
-// FromSealedReader is the same as Unseal but accepts an io.Reader.
-func FromSealedReader(r io.Reader) (*Token, cid.Cid, error) {
-	cidReader := envelope.NewCIDReader(r)
-
-	tkn, err := FromDagCborReader(cidReader)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	id, err := cidReader.CID()
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	return tkn, id, nil
-}
-
-// Encode marshals a Token to the format specified by the provided
-// codec.Encoder.
-func (t *Token) Encode(privKey crypto.PrivKey, encFn codec.Encoder) ([]byte, error) {
-	node, err := t.toIPLD(privKey)
-	if err != nil {
-		return nil, err
-	}
-
-	return ipld.Encode(node, encFn)
-}
-
-// EncodeWriter is the same as Encode, but accepts an io.Writer.
-func (t *Token) EncodeWriter(w io.Writer, privKey crypto.PrivKey, encFn codec.Encoder) error {
-	node, err := t.toIPLD(privKey)
-	if err != nil {
-		return err
-	}
-
-	return ipld.EncodeStreaming(w, node, encFn)
-}
-
-// ToDagCbor marshals the Token to the DAG-CBOR format.
-func (t *Token) ToDagCbor(privKey crypto.PrivKey) ([]byte, error) {
-	return t.Encode(privKey, dagcbor.Encode)
-}
-
-// ToDagCborWriter is the same as ToDagCbor, but it accepts an io.Writer.
-func (t *Token) ToDagCborWriter(w io.Writer, privKey crypto.PrivKey) error {
-	return t.EncodeWriter(w, privKey, dagcbor.Encode)
-}
-
-// ToDagJson marshals the Token to the DAG-JSON format.
-func (t *Token) ToDagJson(privKey crypto.PrivKey) ([]byte, error) {
-	return t.Encode(privKey, dagjson.Encode)
-}
-
-// ToDagJsonWriter is the same as ToDagJson, but it accepts an io.Writer.
-func (t *Token) ToDagJsonWriter(w io.Writer, privKey crypto.PrivKey) error {
-	return t.EncodeWriter(w, privKey, dagjson.Encode)
-}
-
-// Decode unmarshals the input data using the format specified by the
-// provided codec.Decoder into a Token.
-//
-// An error is returned if the conversion fails, or if the resulting
-// Token is invalid.
-func Decode(b []byte, decFn codec.Decoder) (*Token, 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) (*Token, error) {
-	node, err := ipld.DecodeStreaming(r, decFn)
-	if err != nil {
-		return nil, err
-	}
-	return FromIPLD(node)
-}
-
-// FromDagCbor unmarshals the input data into a Token.
-//
-// An error is returned if the conversion fails, or if the resulting
-// Token is invalid.
-func FromDagCbor(data []byte) (*Token, error) {
-	pay, err := envelope.FromDagCbor[*tokenPayloadModel](data)
-	if err != nil {
-		return nil, err
-	}
-
-	tkn, err := tokenFromModel(*pay)
-	if err != nil {
-		return nil, err
-	}
-
-	return tkn, err
-}
-
-// FromDagCborReader is the same as FromDagCbor, but accept an io.Reader.
-func FromDagCborReader(r io.Reader) (*Token, error) {
-	return DecodeReader(r, dagcbor.Decode)
-}
-
-// FromDagJson unmarshals the input data into a Token.
-//
-// An error is returned if the conversion fails, or if the resulting
-// Token is invalid.
-func FromDagJson(data []byte) (*Token, error) {
-	return Decode(data, dagjson.Decode)
-}
-
-// FromDagJsonReader is the same as FromDagJson, but accept an io.Reader.
-func FromDagJsonReader(r io.Reader) (*Token, error) {
-	return DecodeReader(r, dagjson.Decode)
-}
-
-// FromIPLD decode the given IPLD representation into a Token.
-func FromIPLD(node datamodel.Node) (*Token, error) {
-	pay, err := envelope.FromIPLD[*tokenPayloadModel](node)
-	if err != nil {
-		return nil, err
-	}
-
-	tkn, err := tokenFromModel(*pay)
-	if err != nil {
-		return nil, err
-	}
-
-	return tkn, err
-}
-
-func (t *Token) toIPLD(privKey crypto.PrivKey) (datamodel.Node, error) {
-	var sub *string
-
-	if t.subject != did.Undef {
-		s := t.subject.String()
-		sub = &s
-	}
-
-	pol, err := t.policy.ToIPLD()
-	if err != nil {
-		return nil, err
-	}
-
-	var nbf *int64
-	if t.notBefore != nil {
-		u := t.notBefore.Unix()
-		nbf = &u
-	}
-
-	var exp *int64
-	if t.expiration != nil {
-		u := t.expiration.Unix()
-		exp = &u
-	}
-
-	model := &tokenPayloadModel{
-		Iss:   t.issuer.String(),
-		Aud:   t.audience.String(),
-		Sub:   sub,
-		Cmd:   t.command.String(),
-		Pol:   pol,
-		Nonce: t.nonce,
-		Meta:  *t.meta,
-		Nbf:   nbf,
-		Exp:   exp,
-	}
-
-	return envelope.ToIPLD(privKey, model)
-}

token/delegation/options.go

@@ -1,91 +0,0 @@
-package delegation
-
-import (
-	"fmt"
-	"time"
-
-	"github.com/ucan-wg/go-ucan/did"
-)
-
-// Option is a type that allows optional fields to be set during the
-// creation of a Token.
-type Option func(*Token) error
-
-// WithExpiration set's the Token's optional "expiration" field to the
-// value of the provided time.Time.
-func WithExpiration(exp time.Time) Option {
-	return func(t *Token) error {
-		if exp.Before(time.Now()) {
-			return fmt.Errorf("a Token's expiration should be set to a time in the future: %s", exp.String())
-		}
-
-		t.expiration = &exp
-		return nil
-	}
-}
-
-// WithExpirationIn set's the Token's optional "expiration" field to Now() plus the given duration.
-func WithExpirationIn(exp time.Duration) Option {
-	return func(t *Token) error {
-		expTime := time.Now().Add(exp)
-		t.expiration = &expTime
-		return nil
-	}
-}
-
-// WithMeta adds a key/value pair in the "meta" field.
-//
-// WithMeta can be used multiple times in the same call.
-// Accepted types for the value are: bool, string, int, int32, int64, []byte,
-// and ipld.Node.
-func WithMeta(key string, val any) Option {
-	return func(t *Token) error {
-		return t.meta.Add(key, val)
-	}
-}
-
-// WithNotBefore set's the Token's optional "notBefore" field to the value
-// of the provided time.Time.
-func WithNotBefore(nbf time.Time) Option {
-	return func(t *Token) error {
-		if nbf.Before(time.Now()) {
-			return fmt.Errorf("a Token's \"not before\" field should be set to a time in the future: %s", nbf.String())
-		}
-
-		t.notBefore = &nbf
-		return nil
-	}
-}
-
-// WithNotBeforeIn set's the Token's optional "notBefore" field to the value
-// of the provided time.Time.
-func WithNotBeforeIn(nbf time.Duration) Option {
-	return func(t *Token) error {
-		nbfTime := time.Now().Add(nbf)
-		t.notBefore = &nbfTime
-		return nil
-	}
-}
-
-// WithSubject sets the Tokens's optional "subject" field to the value of
-// provided did.DID.
-//
-// This Option should only be used with the New constructor - since
-// Subject is a required parameter when creating a Token via the Root
-// constructor, any value provided via this Option will be silently
-// overwritten.
-func WithSubject(sub did.DID) Option {
-	return func(t *Token) error {
-		t.subject = sub
-		return nil
-	}
-}
-
-// WithNonce sets the Token's nonce with the given value.
-// If this option is not used, a random 12-byte nonce is generated for this required field.
-func WithNonce(nonce []byte) Option {
-	return func(t *Token) error {
-		t.nonce = nonce
-		return nil
-	}
-}

token/delegation/schema.go

@@ -1,85 +0,0 @@
-package delegation
-
-import (
-	_ "embed"
-	"fmt"
-	"sync"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/datamodel"
-	"github.com/ipld/go-ipld-prime/node/bindnode"
-	"github.com/ipld/go-ipld-prime/schema"
-
-	"github.com/ucan-wg/go-ucan/pkg/meta"
-	"github.com/ucan-wg/go-ucan/token/internal/envelope"
-)
-
-// [Tag] is the string used as a key within the SigPayload that identifies
-// that the TokenPayload is a delegation.
-//
-// [Tag]: https://github.com/ucan-wg/delegation/tree/v1_ipld#type-tag
-const Tag = "ucan/dlg@1.0.0-rc.1"
-
-// TODO: update the above Tag URL once the delegation specification is merged.
-
-//go:embed delegation.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("failed to load IPLD schema: %s", err))
-	}
-	return ts
-}
-
-func payloadType() schema.Type {
-	return mustLoadSchema().TypeByName("Payload")
-}
-
-var _ envelope.Tokener = (*tokenPayloadModel)(nil)
-
-type tokenPayloadModel struct {
-	// Issuer DID (sender)
-	Iss string
-	// Audience DID (receiver)
-	Aud string
-	// Principal that the chain is about (the Subject)
-	// optional: can be nil
-	Sub *string
-
-	// The Command to eventually invoke
-	Cmd string
-
-	// The delegation policy
-	Pol datamodel.Node
-
-	// A unique, random nonce
-	Nonce []byte
-
-	// Arbitrary Metadata
-	Meta meta.Meta
-
-	// "Not before" UTC Unix Timestamp in seconds (valid from), 53-bits integer
-	// optional: can be nil
-	Nbf *int64
-	// The timestamp at which the Invocation becomes invalid
-	// optional: can be nil
-	Exp *int64
-}
-
-func (e *tokenPayloadModel) Prototype() schema.TypedPrototype {
-	return bindnode.Prototype((*tokenPayloadModel)(nil), payloadType())
-}
-
-func (*tokenPayloadModel) Tag() string {
-	return Tag
-}

token/delegation/schema_test.go

@@ -1,176 +0,0 @@
-package delegation_test
-
-import (
-	"bytes"
-	_ "embed"
-	"fmt"
-	"testing"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"gotest.tools/v3/golden"
-
-	"github.com/ucan-wg/go-ucan/token/delegation"
-	"github.com/ucan-wg/go-ucan/token/internal/envelope"
-)
-
-//go:embed delegation.ipldsch
-var schemaBytes []byte
-
-func TestSchemaRoundTrip(t *testing.T) {
-	t.Parallel()
-
-	delegationJson := golden.Get(t, "new.dagjson")
-	privKey := privKey(t, issuerPrivKeyCfg)
-
-	t.Run("via buffers", func(t *testing.T) {
-		t.Parallel()
-
-		// format:    dagJson   -->   PayloadModel   -->   dagCbor   -->   PayloadModel   -->   dagJson
-		// function:      DecodeDagJson()           Seal()        Unseal()          EncodeDagJson()
-
-		p1, err := delegation.FromDagJson(delegationJson)
-		require.NoError(t, err)
-
-		cborBytes, id, err := p1.ToSealed(privKey)
-		require.NoError(t, err)
-		assert.Equal(t, newCID, envelope.CIDToBase58BTC(id))
-		fmt.Println("cborBytes length", len(cborBytes))
-		fmt.Println("cbor", string(cborBytes))
-
-		p2, c2, err := delegation.FromSealed(cborBytes)
-		require.NoError(t, err)
-		assert.Equal(t, id, c2)
-		fmt.Println("read Cbor", p2)
-
-		readJson, err := p2.ToDagJson(privKey)
-		require.NoError(t, err)
-		fmt.Println("readJson length", len(readJson))
-		fmt.Println("json: ", string(readJson))
-
-		assert.JSONEq(t, string(delegationJson), string(readJson))
-	})
-
-	t.Run("via streaming", func(t *testing.T) {
-		t.Parallel()
-
-		buf := bytes.NewBuffer(delegationJson)
-
-		// format:    dagJson   -->   PayloadModel   -->   dagCbor   -->   PayloadModel   -->   dagJson
-		// function:      DecodeDagJson()           Seal()         Unseal()         EncodeDagJson()
-
-		p1, err := delegation.FromDagJsonReader(buf)
-		require.NoError(t, err)
-
-		cborBytes := &bytes.Buffer{}
-		id, err := p1.ToSealedWriter(cborBytes, privKey)
-		t.Log(len(id.Bytes()), id.Bytes())
-		require.NoError(t, err)
-		assert.Equal(t, newCID, envelope.CIDToBase58BTC(id))
-
-		// buf = bytes.NewBuffer(cborBytes.Bytes())
-		p2, c2, err := delegation.FromSealedReader(cborBytes)
-		require.NoError(t, err)
-		assert.Equal(t, envelope.CIDToBase58BTC(id), envelope.CIDToBase58BTC(c2))
-
-		readJson := &bytes.Buffer{}
-		require.NoError(t, p2.ToDagJsonWriter(readJson, privKey))
-
-		assert.JSONEq(t, string(delegationJson), readJson.String())
-	})
-}
-
-func BenchmarkSchemaLoad(b *testing.B) {
-	b.ReportAllocs()
-	for i := 0; i < b.N; i++ {
-		_, _ = ipld.LoadSchemaBytes(schemaBytes)
-	}
-}
-
-func BenchmarkRoundTrip(b *testing.B) {
-	delegationJson := golden.Get(b, "new.dagjson")
-	privKey := privKey(b, issuerPrivKeyCfg)
-
-	b.Run("via buffers", func(b *testing.B) {
-		p1, _ := delegation.FromDagJson(delegationJson)
-		cborBytes, _, _ := p1.ToSealed(privKey)
-		p2, _, _ := delegation.FromSealed(cborBytes)
-
-		b.ResetTimer()
-
-		b.Run("FromDagJson", func(b *testing.B) {
-			b.ReportAllocs()
-			for i := 0; i < b.N; i++ {
-				_, _ = delegation.FromDagJson(delegationJson)
-			}
-		})
-
-		b.Run("Seal", func(b *testing.B) {
-			b.ReportAllocs()
-			for i := 0; i < b.N; i++ {
-				_, _, _ = p1.ToSealed(privKey)
-			}
-		})
-
-		b.Run("Unseal", func(b *testing.B) {
-			b.ReportAllocs()
-			for i := 0; i < b.N; i++ {
-				_, _, _ = delegation.FromSealed(cborBytes)
-			}
-		})
-
-		b.Run("ToDagJson", func(b *testing.B) {
-			b.ReportAllocs()
-			for i := 0; i < b.N; i++ {
-				_, _ = p2.ToDagJson(privKey)
-			}
-		})
-	})
-
-	b.Run("via streaming", func(b *testing.B) {
-		p1, _ := delegation.FromDagJsonReader(bytes.NewReader(delegationJson))
-		cborBuf := &bytes.Buffer{}
-		_, _ = p1.ToSealedWriter(cborBuf, privKey)
-		cborBytes := cborBuf.Bytes()
-		p2, _, _ := delegation.FromSealedReader(bytes.NewReader(cborBytes))
-
-		b.ResetTimer()
-
-		b.Run("FromDagJsonReader", func(b *testing.B) {
-			b.ReportAllocs()
-			reader := bytes.NewReader(delegationJson)
-			for i := 0; i < b.N; i++ {
-				_, _ = reader.Seek(0, 0)
-				_, _ = delegation.FromDagJsonReader(reader)
-			}
-		})
-
-		b.Run("SealWriter", func(b *testing.B) {
-			b.ReportAllocs()
-			buf := &bytes.Buffer{}
-			for i := 0; i < b.N; i++ {
-				buf.Reset()
-				_, _ = p1.ToSealedWriter(buf, privKey)
-			}
-		})
-
-		b.Run("UnsealReader", func(b *testing.B) {
-			b.ReportAllocs()
-			reader := bytes.NewReader(cborBytes)
-			for i := 0; i < b.N; i++ {
-				_, _ = reader.Seek(0, 0)
-				_, _, _ = delegation.FromSealedReader(reader)
-			}
-		})
-
-		b.Run("ToDagJsonReader", func(b *testing.B) {
-			b.ReportAllocs()
-			buf := &bytes.Buffer{}
-			for i := 0; i < b.N; i++ {
-				buf.Reset()
-				_ = p2.ToDagJsonWriter(buf, privKey)
-			}
-		})
-	})
-}

token/delegation/testdata/new.dagjson

@@ -1 +0,0 @@
-[{"/":{"bytes":"FM6otj0r/noJWiGAC5WV86xAazxrF173IihuHJgEt35CtSzjeaelrR3UwaSr8xbE9sLpo5xJhUbo0QLI273hDA"}},{"h":{"/":{"bytes":"NO0BcQ"}},"ucan/dlg@1.0.0-rc.1":{"aud":"did:key:z6Mkq5YmbJcTrPExNDi26imrTCpKhepjBFBSHqrBDN2ArPkv","cmd":"/foo/bar","exp":7258118400,"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"}}]

token/delegation/testdata/root.dagjson

@@ -1 +0,0 @@
-[{"/":{"bytes":"aYBq08tfm0zQZnPg/5tB9kM5mklRU9PPIkV7CK68jEgbd76JbCGuu75vfLyBu3WTqKzLSJ583pbwu668m/7MBQ"}},{"h":{"/":{"bytes":"NO0BcQ"}},"ucan/dlg@1.0.0-rc.1":{"aud":"did:key:z6Mkq5YmbJcTrPExNDi26imrTCpKhepjBFBSHqrBDN2ArPkv","cmd":"/foo/bar","exp":7258118400,"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"}}]

token/inspect.go

@@ -1,19 +0,0 @@
-package token
-
-import (
-	"github.com/ipld/go-ipld-prime/datamodel"
-
-	"github.com/ucan-wg/go-ucan/token/internal/envelope"
-)
-
-type Info = envelope.Info
-
-// Inspect inspects the given token IPLD representation and extract some envelope facts.
-func Inspect(node datamodel.Node) (Info, error) {
-	return envelope.Inspect(node)
-}
-
-// FindTag inspect the given token IPLD representation and extract the token tag.
-func FindTag(node datamodel.Node) (string, error) {
-	return envelope.FindTag(node)
-}

token/interface.go

@@ -1,41 +0,0 @@
-package token
-
-import (
-	"io"
-
-	"github.com/ipfs/go-cid"
-	"github.com/ipld/go-ipld-prime/codec"
-	"github.com/libp2p/go-libp2p/core/crypto"
-
-	"github.com/ucan-wg/go-ucan/did"
-	"github.com/ucan-wg/go-ucan/pkg/meta"
-)
-
-type Token interface {
-	Marshaller
-
-	// Issuer returns the did.DID representing the Token's issuer.
-	Issuer() did.DID
-	// Meta returns the Token's metadata.
-	Meta() *meta.Meta
-}
-
-type Marshaller interface {
-	// ToSealed wraps the token in an envelope, generates the signature, encodes
-	// the result to DAG-CBOR and calculates the CID of the resulting binary data.
-	ToSealed(privKey crypto.PrivKey) ([]byte, cid.Cid, error)
-	// ToSealedWriter is the same as ToSealed but accepts an io.Writer.
-	ToSealedWriter(w io.Writer, privKey crypto.PrivKey) (cid.Cid, error)
-	// Encode marshals a Token to the format specified by the provided codec.Encoder.
-	Encode(privKey crypto.PrivKey, encFn codec.Encoder) ([]byte, error)
-	// EncodeWriter is the same as Encode, but accepts an io.Writer.
-	EncodeWriter(w io.Writer, privKey crypto.PrivKey, encFn codec.Encoder) error
-	// ToDagCbor marshals the Token to the DAG-CBOR format.
-	ToDagCbor(privKey crypto.PrivKey) ([]byte, error)
-	// ToDagCborWriter is the same as ToDagCbor, but it accepts an io.Writer.
-	ToDagCborWriter(w io.Writer, privKey crypto.PrivKey) error
-	// ToDagJson marshals the Token to the DAG-JSON format.
-	ToDagJson(privKey crypto.PrivKey) ([]byte, error)
-	// ToDagJsonWriter is the same as ToDagJson, but it accepts an io.Writer.
-	ToDagJsonWriter(w io.Writer, privKey crypto.PrivKey) error
-}

token/internal/envelope/cid.go

@@ -1,124 +0,0 @@
-package envelope
-
-import (
-	"crypto/sha256"
-	"hash"
-	"io"
-
-	"github.com/ipfs/go-cid"
-	"github.com/multiformats/go-multibase"
-	"github.com/multiformats/go-multicodec"
-	"github.com/multiformats/go-multihash"
-)
-
-var b58BTCEnc = multibase.MustNewEncoder(multibase.Base58BTC)
-
-// CIDToBase56BTC is a utility method to convert a CIDv1 to the canonical
-// string representation used by UCAN.
-func CIDToBase58BTC(id cid.Cid) string {
-	return id.Encode(b58BTCEnc)
-}
-
-// CIDFromBytes returns the UCAN content identifier for an arbitrary slice
-// of bytes.
-func CIDFromBytes(b []byte) (cid.Cid, error) {
-	return cid.V1Builder{
-		Codec:    uint64(multicodec.DagCbor),
-		MhType:   multihash.SHA2_256,
-		MhLength: 0,
-	}.Sum(b)
-}
-
-var _ io.Reader = (*CIDReader)(nil)
-
-// CIDReader wraps an io.Reader and includes a hash.Hash that is
-// incrementally updated as data is read from the child io.Reader.
-type CIDReader struct {
-	hash hash.Hash
-	r    io.Reader
-	err  error
-}
-
-// NewCIDReader initializes a hash.Hash to calculate the CID's hash and
-// returns the wrapped io.Reader.
-func NewCIDReader(r io.Reader) *CIDReader {
-	h := sha256.New()
-	h.Reset()
-
-	return &CIDReader{
-		hash: h,
-		r:    r,
-	}
-}
-
-// CID returns the UCAN-formatted cid.Cid created from the hash calculated
-// as bytes were read from the inner io.Reader.
-func (r *CIDReader) CID() (cid.Cid, error) {
-	if r.err != nil {
-		return cid.Undef, r.err // TODO: Wrap to say it's an error during streaming?
-	}
-
-	return cidFromHash(r.hash)
-}
-
-// Read implements io.Reader.
-func (r *CIDReader) Read(p []byte) (n int, err error) {
-	n, err = r.r.Read(p)
-	if err != nil && err != io.EOF {
-		r.err = err
-
-		return
-	}
-
-	_, _ = r.hash.Write(p[:n])
-
-	return
-}
-
-var _ io.Writer = (*CIDWriter)(nil)
-
-// CIDWriter wraps an io.Writer and includes a hash.Hash that is
-// incrementally updated as data is written to the child io.Writer.
-type CIDWriter struct {
-	hash hash.Hash
-	w    io.Writer
-	err  error
-}
-
-// NewCIDWriter initializes a hash.Hash to calculate the CID's hash and
-// returns the wrapped io.Writer.
-func NewCIDWriter(w io.Writer) *CIDWriter {
-	h := sha256.New()
-	h.Reset()
-
-	return &CIDWriter{
-		hash: h,
-		w:    w,
-	}
-}
-
-// CID returns the UCAN-formatted cid.Cid created from the hash calculated
-// as bytes were written from the inner io.Reader.
-func (w *CIDWriter) CID() (cid.Cid, error) {
-	return cidFromHash(w.hash)
-}
-
-// Write implements io.Writer.
-func (w *CIDWriter) Write(p []byte) (n int, err error) {
-	if _, err = w.hash.Write(p); err != nil {
-		w.err = err
-
-		return
-	}
-
-	return w.w.Write(p)
-}
-
-func cidFromHash(hash hash.Hash) (cid.Cid, error) {
-	mh, err := multihash.Encode(hash.Sum(nil), multihash.SHA2_256)
-	if err != nil {
-		return cid.Undef, err
-	}
-
-	return cid.NewCidV1(uint64(multicodec.DagCbor), mh), nil
-}

token/internal/envelope/cid_test.go

@@ -1,86 +0,0 @@
-package envelope_test
-
-import (
-	"io"
-	"testing"
-
-	"github.com/ipfs/go-cid"
-	"github.com/multiformats/go-multicodec"
-	"github.com/multiformats/go-multihash"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"gotest.tools/v3/golden"
-
-	"github.com/ucan-wg/go-ucan/token/internal/envelope"
-)
-
-func TestCidFromBytes(t *testing.T) {
-	t.Parallel()
-
-	expData := golden.Get(t, "example.dagcbor")
-	expHash, err := multihash.Sum(expData, uint64(multicodec.Sha2_256), -1)
-	require.NoError(t, err)
-
-	data, err := envelope.ToDagCbor(examplePrivKey(t), newExample(t))
-	require.NoError(t, err)
-
-	id, err := envelope.CIDFromBytes(data)
-	require.NoError(t, err)
-	assert.Equal(t, exampleCID, envelope.CIDToBase58BTC(id))
-	assert.Equal(t, expHash, id.Hash())
-}
-
-func TestStreaming(t *testing.T) {
-	t.Parallel()
-
-	expData := []byte("this is a test")
-
-	expCID, err := cid.V1Builder{
-		Codec:    uint64(multicodec.DagCbor),
-		MhType:   multihash.SHA2_256,
-		MhLength: 0,
-	}.Sum(expData)
-	require.NoError(t, err)
-
-	t.Run("CIDReader()", func(t *testing.T) {
-		t.Parallel()
-
-		r, w := io.Pipe() //nolint:varnamelen
-		cidReader := envelope.NewCIDReader(r)
-
-		go func() {
-			_, err := w.Write(expData)
-			assert.NoError(t, err)
-			assert.NoError(t, w.Close())
-		}()
-
-		actData, err := io.ReadAll(cidReader)
-		require.NoError(t, err)
-		assert.Equal(t, expData, actData)
-
-		actCID, err := cidReader.CID()
-		require.NoError(t, err)
-		assert.Equal(t, expCID, actCID)
-	})
-
-	t.Run("CIDWriter", func(t *testing.T) {
-		t.Parallel()
-
-		r, w := io.Pipe() //nolint:varnamelen
-		cidWriter := envelope.NewCIDWriter(w)
-
-		go func() {
-			_, err := cidWriter.Write(expData)
-			assert.NoError(t, err)
-			assert.NoError(t, w.Close())
-		}()
-
-		actData, err := io.ReadAll(r)
-		require.NoError(t, err)
-		assert.Equal(t, expData, actData)
-
-		actCID, err := cidWriter.CID()
-		require.NoError(t, err)
-		assert.Equal(t, expCID, actCID)
-	})
-}

token/internal/envelope/example_test.go

@@ -1,138 +0,0 @@
-package envelope_test
-
-import (
-	_ "embed"
-	"encoding/base64"
-	"fmt"
-	"sync"
-	"testing"
-
-	"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"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-	"github.com/ipld/go-ipld-prime/node/bindnode"
-	"github.com/ipld/go-ipld-prime/schema"
-	"github.com/libp2p/go-libp2p/core/crypto"
-	"github.com/stretchr/testify/require"
-	"gotest.tools/v3/golden"
-
-	"github.com/ucan-wg/go-ucan/token/internal/envelope"
-)
-
-const (
-	exampleCID             = "zdpuAyw6R5HvKSPzztuzXNYFx3ZGoMHMuAsXL6u3xLGQriRXQ"
-	exampleDID             = "did:key:z6MkpuK2Amsu1RqcLGgmHHQHhvmeXCCBVsM4XFSg2cCyg4Nh"
-	exampleGreeting        = "world"
-	examplePrivKeyCfg      = "CAESQP9v2uqECTuIi45dyg3znQvsryvf2IXmOF/6aws6aCehm0FVrj0zHR5RZSDxWNjcpcJqsGym3sjCungX9Zt5oA4="
-	exampleSignatureStr    = "PZV6A2aI7n+MlyADqcqmWhkuyNrgUCDz+qSLSnI9bpasOwOhKUTx95m5Nu5CO/INa1LqzHGioD9+PVf6qdtTBg"
-	exampleTag             = "ucan/example@v1.0.0-rc.1"
-	exampleTypeName        = "Example"
-	exampleVarsigHeaderStr = "NO0BcQ"
-
-	invalidSignatureStr = "PZV6A2aI7n+MlyADqcqmWhkuyNrgUCDz+qSLSnI9bpasOwOhKUTx95m5Nu5CO/INa1LqzHGioD9+PVf6qdtTBK"
-
-	exampleDAGCBORFilename = "example.dagcbor"
-	exampleDAGJSONFilename = "example.dagjson"
-)
-
-//go:embed testdata/example.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("failed to load IPLD schema: %s", err))
-	}
-
-	return ts
-}
-
-func exampleType() schema.Type {
-	return mustLoadSchema().TypeByName(exampleTypeName)
-}
-
-var _ envelope.Tokener = (*Example)(nil)
-
-type Example struct {
-	Hello  string
-	Issuer string
-}
-
-func newExample(t *testing.T) *Example {
-	t.Helper()
-
-	return &Example{
-		Hello:  exampleGreeting,
-		Issuer: exampleDID,
-	}
-}
-
-func (e *Example) Prototype() schema.TypedPrototype {
-	return bindnode.Prototype(e, exampleType())
-}
-
-func (*Example) Tag() string {
-	return exampleTag
-}
-
-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 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 exampleSignature(t *testing.T) []byte {
-	t.Helper()
-
-	sig, err := base64.RawStdEncoding.DecodeString(exampleSignatureStr)
-	require.NoError(t, err)
-
-	return sig
-}
-
-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
-}

token/internal/envelope/ipld.go

@@ -1,393 +0,0 @@
-// Package envelope provides functions that convert between wire-format
-// encoding of a [UCAN] token's [Envelope] and the Go type representing
-// a verified [TokenPayload].
-//
-// Encoding functions in this package require a private key as a
-// parameter so the VarsigHeader can be set and so that a
-// cryptographic signature can be generated.
-//
-// Decoding functions in this package likewise perform the signature
-// verification using a public key extracted from the TokenPayload as
-// described by requirement two below.
-//
-// Types that wish to be marshaled and unmarshaled from the using
-// is package have two requirements.
-//
-//  1. The type must implement the Tokener interface.
-//
-//  2. The IPLD Representation of the type must include an "iss"
-//     field when the TokenPayload is extracted from the Envelope.
-//     This field must contain the string representation of a
-//     "did:key" so that a public key can be extracted from the
-//
-// [Envelope]:https://github.com/ucan-wg/spec#envelope
-// [TokenPayload]: https://github.com/ucan-wg/spec#envelope
-// [UCAN]: https://ucan.xyz
-package envelope
-
-import (
-	"errors"
-	"fmt"
-	"io"
-	"strings"
-
-	"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/ipld/go-ipld-prime/fluent/qp"
-	"github.com/ipld/go-ipld-prime/node/basicnode"
-	"github.com/ipld/go-ipld-prime/node/bindnode"
-	"github.com/ipld/go-ipld-prime/schema"
-	"github.com/libp2p/go-libp2p/core/crypto"
-
-	"github.com/ucan-wg/go-ucan/did"
-	"github.com/ucan-wg/go-ucan/token/internal/varsig"
-)
-
-const (
-	VarsigHeaderKey = "h"
-	UCANTagPrefix   = "ucan/"
-)
-
-// Tokener must be implemented by types that wish to be enclosed in a
-// UCAN Envelope (presumbably one of the UCAN token types).
-type Tokener interface {
-	// Prototype provides the schema representation for an IPLD type so
-	// that the incoming datamodel.Kinds can be mapped to the appropriate
-	// schema.Kinds.
-	Prototype() schema.TypedPrototype
-
-	// Tag returns the expected key denoting the name of the IPLD node
-	// that should be processed as the token payload while decoding
-	// incoming bytes.
-	Tag() string
-}
-
-// Decode unmarshals the input data using the format specified by the
-// provided codec.Decoder into a Tokener.
-//
-// An error is returned if the conversion fails, or if the resulting
-// Tokener is invalid.
-func Decode[T Tokener](b []byte, decFn codec.Decoder) (T, error) {
-	node, err := ipld.Decode(b, decFn)
-	if err != nil {
-		return *new(T), err
-	}
-
-	return FromIPLD[T](node)
-}
-
-// DecodeReader is the same as Decode, but accept an io.Reader.
-func DecodeReader[T Tokener](r io.Reader, decFn codec.Decoder) (T, error) {
-	node, err := ipld.DecodeStreaming(r, decFn)
-	if err != nil {
-		return *new(T), err
-	}
-
-	return FromIPLD[T](node)
-}
-
-// FromDagCbor unmarshals the input data into a Tokener.
-//
-// An error is returned if the conversion fails, or if the resulting
-// Tokener is invalid.
-func FromDagCbor[T Tokener](b []byte) (T, error) {
-	return Decode[T](b, dagcbor.Decode)
-}
-
-// FromDagCborReader is the same as FromDagCbor, but accept an io.Reader.
-func FromDagCborReader[T Tokener](r io.Reader) (T, error) {
-	return DecodeReader[T](r, dagcbor.Decode)
-}
-
-// FromDagJson unmarshals the input data into a Tokener.
-//
-// An error is returned if the conversion fails, or if the resulting
-// Tokener is invalid.
-func FromDagJson[T Tokener](b []byte) (T, error) {
-	return Decode[T](b, dagjson.Decode)
-}
-
-// FromDagJsonReader is the same as FromDagJson, but accept an io.Reader.
-func FromDagJsonReader[T Tokener](r io.Reader) (T, error) {
-	return DecodeReader[T](r, dagjson.Decode)
-}
-
-// FromIPLD unwraps a Tokener from the provided IPLD datamodel.Node.
-//
-// An error is returned if the conversion fails, or if the resulting
-// Tokener is invalid.
-func FromIPLD[T Tokener](node datamodel.Node) (T, error) {
-	zero := *new(T)
-
-	info, err := Inspect(node)
-	if err != nil {
-		return zero, err
-	}
-
-	if info.Tag != zero.Tag() {
-		return zero, errors.New("data doesn't match the expected type")
-	}
-
-	// This needs to be done before converting this node to its schema
-	// representation (afterwards, the field might be renamed os it's safer
-	// to use the wire name).
-	issuerNode, err := info.tokenPayloadNode.LookupByString("iss")
-	if err != nil {
-		return zero, err
-	}
-
-	// Replaces the datamodel.Node in tokenPayloadNode with a
-	// schema.TypedNode so that we can cast it to a *token.Token after
-	// unwrapping it.
-	nb := zero.Prototype().Representation().NewBuilder()
-
-	err = nb.AssignNode(info.tokenPayloadNode)
-	if err != nil {
-		return zero, err
-	}
-
-	tokenPayloadNode := nb.Build()
-
-	tokenPayload := bindnode.Unwrap(tokenPayloadNode)
-	if tokenPayload == nil {
-		return zero, errors.New("failed to Unwrap the TokenPayload")
-	}
-
-	tkn, ok := tokenPayload.(T)
-	if !ok {
-		return zero, errors.New("failed to assert the TokenPayload type as *token.Token")
-	}
-
-	// Check that the issuer's DID contains a public key with a type that
-	// matches the VarsigHeader and then verify the SigPayload.
-	issuer, err := issuerNode.AsString()
-	if err != nil {
-		return zero, err
-	}
-
-	issuerDID, err := did.Parse(issuer)
-	if err != nil {
-		return zero, err
-	}
-
-	issuerPubKey, err := issuerDID.PubKey()
-	if err != nil {
-		return zero, err
-	}
-
-	issuerVarsigHeader, err := varsig.Encode(issuerPubKey.Type())
-	if err != nil {
-		return zero, err
-	}
-
-	if string(info.VarsigHeader) != string(issuerVarsigHeader) {
-		return zero, errors.New("the VarsigHeader key type doesn't match the issuer's key type")
-	}
-
-	data, err := ipld.Encode(info.sigPayloadNode, dagcbor.Encode)
-	if err != nil {
-		return zero, err
-	}
-
-	ok, err = issuerPubKey.Verify(data, info.Signature)
-	if err != nil || !ok {
-		return zero, errors.New("failed to verify the token's signature")
-	}
-
-	return tkn, nil
-}
-
-// Encode marshals a Tokener to the format specified by the provided
-// codec.Encoder.
-func Encode(privKey crypto.PrivKey, token Tokener, encFn codec.Encoder) ([]byte, error) {
-	node, err := ToIPLD(privKey, token)
-	if err != nil {
-		return nil, err
-	}
-
-	return ipld.Encode(node, encFn)
-}
-
-// EncodeWriter is the same as Encode but outputs to an io.Writer instead
-// of encoding into a []byte.
-func EncodeWriter(w io.Writer, privKey crypto.PrivKey, token Tokener, encFn codec.Encoder) error {
-	node, err := ToIPLD(privKey, token)
-	if err != nil {
-		return err
-	}
-
-	return ipld.EncodeStreaming(w, node, encFn)
-}
-
-// ToDagCbor marshals the Tokener to the DAG-CBOR format.
-func ToDagCbor(privKey crypto.PrivKey, token Tokener) ([]byte, error) {
-	return Encode(privKey, token, dagcbor.Encode)
-}
-
-// ToDagCborWriter is the same as ToDagCbor but outputs to an io.Writer
-// instead of encoding into a []byte.
-func ToDagCborWriter(w io.Writer, privKey crypto.PrivKey, token Tokener) error {
-	return EncodeWriter(w, privKey, token, dagcbor.Encode)
-}
-
-// ToDagJson marshals the Tokener to the DAG-JSON format.
-func ToDagJson(privKey crypto.PrivKey, token Tokener) ([]byte, error) {
-	return Encode(privKey, token, dagjson.Encode)
-}
-
-// ToDagJsonWriter is the same as ToDagJson but outputs to an io.Writer
-// instead of encoding into a []byte.
-func ToDagJsonWriter(w io.Writer, privKey crypto.PrivKey, token Tokener) error {
-	return EncodeWriter(w, privKey, token, dagjson.Encode)
-}
-
-// ToIPLD wraps the Tokener in an IPLD datamodel.Node.
-func ToIPLD(privKey crypto.PrivKey, token Tokener) (datamodel.Node, error) {
-	tokenPayloadNode := bindnode.Wrap(token, token.Prototype().Type()).Representation()
-
-	varsigHeader, err := varsig.Encode(privKey.Type())
-	if err != nil {
-		return nil, err
-	}
-
-	sigPayloadNode, err := qp.BuildMap(basicnode.Prototype.Any, 2, func(ma datamodel.MapAssembler) {
-		qp.MapEntry(ma, VarsigHeaderKey, qp.Bytes(varsigHeader))
-		qp.MapEntry(ma, token.Tag(), qp.Node(tokenPayloadNode))
-	})
-
-	data, err := ipld.Encode(sigPayloadNode, dagcbor.Encode)
-	if err != nil {
-		return nil, err
-	}
-
-	signature, err := privKey.Sign(data)
-	if err != nil {
-		return nil, err
-	}
-
-	return qp.BuildList(basicnode.Prototype.Any, 2, func(la datamodel.ListAssembler) {
-		qp.ListEntry(la, qp.Bytes(signature))
-		qp.ListEntry(la, qp.Node(sigPayloadNode))
-	})
-}
-
-// FindTag inspects the given token IPLD representation and extract the token tag.
-func FindTag(node datamodel.Node) (string, error) {
-	sigPayloadNode, err := node.LookupByIndex(1)
-	if err != nil {
-		return "", err
-	}
-
-	if sigPayloadNode.Kind() != datamodel.Kind_Map {
-		return "", fmt.Errorf("unexpected type instead of map")
-	}
-
-	it := sigPayloadNode.MapIterator()
-	i := 0
-
-	for !it.Done() {
-		if i >= 2 {
-			return "", fmt.Errorf("expected two and only two fields in SigPayload")
-		}
-		i++
-
-		k, _, err := it.Next()
-		if err != nil {
-			return "", err
-		}
-
-		key, err := k.AsString()
-		if err != nil {
-			return "", err
-		}
-
-		if strings.HasPrefix(key, UCANTagPrefix) {
-			return key, nil
-		}
-	}
-	return "", fmt.Errorf("no token tag found")
-}
-
-type Info struct {
-	Tag              string
-	Signature        []byte
-	VarsigHeader     []byte
-	sigPayloadNode   datamodel.Node // private, we don't want to expose that
-	tokenPayloadNode datamodel.Node // private, we don't want to expose that
-}
-
-// Inspect inspects the given token IPLD representation and extract some envelope facts.
-func Inspect(node datamodel.Node) (Info, error) {
-	var res Info
-
-	signatureNode, err := node.LookupByIndex(0)
-	if err != nil {
-		return Info{}, err
-	}
-
-	res.Signature, err = signatureNode.AsBytes()
-	if err != nil {
-		return Info{}, err
-	}
-
-	res.sigPayloadNode, err = node.LookupByIndex(1)
-	if err != nil {
-		return Info{}, err
-	}
-
-	if res.sigPayloadNode.Kind() != datamodel.Kind_Map {
-		return Info{}, fmt.Errorf("unexpected type instead of map")
-	}
-
-	it := res.sigPayloadNode.MapIterator()
-	foundVarsigHeader := false
-	foundTokenPayload := false
-	i := 0
-
-	for !it.Done() {
-		if i >= 2 {
-			return Info{}, fmt.Errorf("expected two and only two fields in SigPayload")
-		}
-		i++
-
-		k, v, err := it.Next()
-		if err != nil {
-			return Info{}, err
-		}
-
-		key, err := k.AsString()
-		if err != nil {
-			return Info{}, err
-		}
-
-		switch {
-		case key == VarsigHeaderKey:
-			foundVarsigHeader = true
-			res.VarsigHeader, err = v.AsBytes()
-			if err != nil {
-				return Info{}, err
-			}
-		case strings.HasPrefix(key, UCANTagPrefix):
-			foundTokenPayload = true
-			res.Tag = key
-			res.tokenPayloadNode = v
-		default:
-			return Info{}, fmt.Errorf("unexpected key type %q", key)
-		}
-	}
-
-	if i != 2 {
-		return Info{}, fmt.Errorf("expected two and only two fields in SigPayload: %d", i)
-	}
-	if !foundVarsigHeader {
-		return Info{}, errors.New("failed to find VarsigHeader field")
-	}
-	if !foundTokenPayload {
-		return Info{}, errors.New("failed to find TokenPayload field")
-	}
-
-	return res, nil
-}

token/internal/envelope/ipld_test.go

@@ -1,209 +0,0 @@
-package envelope_test
-
-import (
-	"bytes"
-	"crypto/sha256"
-	"encoding/base64"
-	"os"
-	"testing"
-
-	"github.com/ipld/go-ipld-prime"
-	"github.com/ipld/go-ipld-prime/codec/dagcbor"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"gotest.tools/v3/golden"
-
-	"github.com/ucan-wg/go-ucan/token/internal/envelope"
-)
-
-func TestDecode(t *testing.T) {
-	t.Parallel()
-
-	t.Run("via FromDagCbor", func(t *testing.T) {
-		t.Parallel()
-
-		data := golden.Get(t, "example.dagcbor")
-
-		tkn, err := envelope.FromDagCbor[*Example](data)
-		require.NoError(t, err)
-		assert.Equal(t, exampleGreeting, tkn.Hello)
-		assert.Equal(t, exampleDID, tkn.Issuer)
-	})
-
-	t.Run("via FromDagJson", func(t *testing.T) {
-		t.Parallel()
-
-		data := golden.Get(t, "example.dagjson")
-
-		tkn, err := envelope.FromDagJson[*Example](data)
-		require.NoError(t, err)
-		assert.Equal(t, exampleGreeting, tkn.Hello)
-		assert.Equal(t, exampleDID, tkn.Issuer)
-	})
-}
-
-func TestEncode(t *testing.T) {
-	t.Parallel()
-
-	t.Run("via ToDagCbor", func(t *testing.T) {
-		t.Parallel()
-
-		data, err := envelope.ToDagCbor(examplePrivKey(t), newExample(t))
-		require.NoError(t, err)
-		golden.AssertBytes(t, data, exampleDAGCBORFilename)
-	})
-
-	t.Run("via ToDagJson", func(t *testing.T) {
-		t.Parallel()
-
-		data, err := envelope.ToDagJson(examplePrivKey(t), newExample(t))
-		require.NoError(t, err)
-		golden.Assert(t, string(data), exampleDAGJSONFilename)
-	})
-}
-
-func TestRoundtrip(t *testing.T) {
-	t.Parallel()
-
-	t.Run("via FromDagCbor/ToDagCbor", func(t *testing.T) {
-		t.Parallel()
-
-		dataIn := golden.Get(t, exampleDAGCBORFilename)
-
-		tkn, err := envelope.FromDagCbor[*Example](dataIn)
-		require.NoError(t, err)
-		assert.Equal(t, exampleGreeting, tkn.Hello)
-		assert.Equal(t, exampleDID, tkn.Issuer)
-
-		dataOut, err := envelope.ToDagCbor(examplePrivKey(t), newExample(t))
-		require.NoError(t, err)
-		assert.Equal(t, dataIn, dataOut)
-	})
-
-	t.Run("via FromDagCborReader/ToDagCborWriter", func(t *testing.T) {
-		t.Parallel()
-
-		data := golden.Get(t, exampleDAGCBORFilename)
-
-		tkn, err := envelope.FromDagCborReader[*Example](bytes.NewReader(data))
-		require.NoError(t, err)
-		assert.Equal(t, exampleGreeting, tkn.Hello)
-		assert.Equal(t, exampleDID, tkn.Issuer)
-
-		w := &bytes.Buffer{}
-		require.NoError(t, envelope.ToDagCborWriter(w, examplePrivKey(t), newExample(t)))
-		assert.Equal(t, data, w.Bytes())
-	})
-
-	t.Run("via FromDagJson/ToDagJson", func(t *testing.T) {
-		t.Parallel()
-
-		dataIn := golden.Get(t, exampleDAGJSONFilename)
-
-		tkn, err := envelope.FromDagJson[*Example](dataIn)
-		require.NoError(t, err)
-		assert.Equal(t, exampleGreeting, tkn.Hello)
-		assert.Equal(t, exampleDID, tkn.Issuer)
-
-		dataOut, err := envelope.ToDagJson(examplePrivKey(t), newExample(t))
-		require.NoError(t, err)
-		assert.Equal(t, dataIn, dataOut)
-	})
-
-	t.Run("via FromDagJsonReader/ToDagJsonrWriter", func(t *testing.T) {
-		t.Parallel()
-
-		data := golden.Get(t, exampleDAGJSONFilename)
-
-		tkn, err := envelope.FromDagJsonReader[*Example](bytes.NewReader(data))
-		require.NoError(t, err)
-		assert.Equal(t, exampleGreeting, tkn.Hello)
-		assert.Equal(t, exampleDID, tkn.Issuer)
-
-		w := &bytes.Buffer{}
-		require.NoError(t, envelope.ToDagJsonWriter(w, examplePrivKey(t), newExample(t)))
-		assert.Equal(t, data, w.Bytes())
-	})
-}
-
-func TestFromIPLD_with_invalid_signature(t *testing.T) {
-	t.Parallel()
-
-	node := invalidNodeFromGolden(t)
-	tkn, err := envelope.FromIPLD[*Example](node)
-	assert.Nil(t, tkn)
-	require.EqualError(t, err, "failed to verify the token's signature")
-}
-
-func TestHash(t *testing.T) {
-	t.Parallel()
-
-	msg := []byte("this is a test")
-
-	hash1 := sha256.Sum256(msg)
-
-	hasher := sha256.New()
-
-	for _, b := range msg {
-		hasher.Write([]byte{b})
-	}
-
-	hash2 := hasher.Sum(nil)
-	hash3 := hasher.Sum(nil)
-
-	require.Equal(t, hash1[:], hash2)
-	require.Equal(t, hash1[:], hash3)
-}
-
-func TestInspect(t *testing.T) {
-	t.Parallel()
-
-	data := golden.Get(t, "example.dagcbor")
-	node, err := ipld.Decode(data, dagcbor.Decode)
-	require.NoError(t, err)
-
-	expSig, err := base64.RawStdEncoding.DecodeString("fPqfwL3iFpbw9SvBiq0DIbUurv9o6c36R08tC/yslGrJcwV51ghzWahxdetpEf6T5LCszXX9I/K8khvnmAxjAg")
-	require.NoError(t, err)
-
-	info, err := envelope.Inspect(node)
-	require.NoError(t, err)
-	assert.Equal(t, expSig, info.Signature)
-	assert.Equal(t, "ucan/example@v1.0.0-rc.1", info.Tag)
-	assert.Equal(t, []byte{0x34, 0xed, 0x1, 0x71}, info.VarsigHeader)
-}
-
-func FuzzInspect(f *testing.F) {
-	data, err := os.ReadFile("testdata/example.dagcbor")
-	require.NoError(f, err)
-
-	f.Add(data)
-
-	f.Fuzz(func(t *testing.T, data []byte) {
-		node, err := ipld.Decode(data, dagcbor.Decode)
-		if err != nil {
-			t.Skip()
-		}
-		_, err = envelope.Inspect(node)
-		if err != nil {
-			t.Skip()
-		}
-	})
-}
-
-func FuzzFindTag(f *testing.F) {
-	data, err := os.ReadFile("testdata/example.dagcbor")
-	require.NoError(f, err)
-
-	f.Add(data)
-
-	f.Fuzz(func(t *testing.T, data []byte) {
-		node, err := ipld.Decode(data, dagcbor.Decode)
-		if err != nil {
-			t.Skip()
-		}
-		_, err = envelope.FindTag(node)
-		if err != nil {
-			t.Skip()
-		}
-	})
-}

token/internal/envelope/testdata/example.dagcbor

@@ -1 +0,0 @@
-‚X@|úŸÀ½â–ðõ+ÁŠ­!µ.®ÿhéÍúGO-ü¬”jÉsyÖsY¨quëiþ“ä°¬Íuý#ò¼’ç˜c¢ahD4í
qxucan/example@v1.0.0-rc.1¢cissx8did:key:z6MkpuK2Amsu1RqcLGgmHHQHhvmeXCCBVsM4XFSg2cCyg4Nhehelloeworld

token/internal/envelope/testdata/example.dagjson

@@ -1 +0,0 @@
-[{"/":{"bytes":"fPqfwL3iFpbw9SvBiq0DIbUurv9o6c36R08tC/yslGrJcwV51ghzWahxdetpEf6T5LCszXX9I/K8khvnmAxjAg"}},{"h":{"/":{"bytes":"NO0BcQ"}},"ucan/example@v1.0.0-rc.1":{"hello":"world","iss":"did:key:z6MkpuK2Amsu1RqcLGgmHHQHhvmeXCCBVsM4XFSg2cCyg4Nh"}}]

token/internal/envelope/testdata/example.ipldsch

@@ -1,6 +0,0 @@
-type DID string
-
-type Example struct {
-  hello String
-  issuer DID (rename "iss")
-}

token/invocation/invocation.go

@@ -1,124 +0,0 @@
-// Package invocation implements the UCAN [invocation] 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.
-//
-// [envelope]: https://github.com/ucan-wg/spec#envelope
-// [invocation]: https://github.com/ucan-wg/invocation
-package invocation
-
-import (
-	"crypto/rand"
-	"errors"
-	"fmt"
-	"time"
-
-	"github.com/ucan-wg/go-ucan/did"
-	"github.com/ucan-wg/go-ucan/pkg/command"
-	"github.com/ucan-wg/go-ucan/pkg/meta"
-)
-
-// Token is an immutable type that holds the fields of a UCAN invocation.
-type Token struct {
-	// Issuer DID (invoker)
-	issuer did.DID
-	// Audience DID (receiver/executor)
-	audience did.DID
-	// Subject DID (subject being invoked)
-	subject did.DID
-	// The Command to invoke
-	command command.Command
-	// TODO: args
-	// TODO: prf
-	// A unique, random nonce
-	nonce []byte
-	// Arbitrary Metadata
-	meta *meta.Meta
-	// The timestamp at which the Invocation becomes invalid
-	expiration *time.Time
-	// The timestamp at which the Invocation was created
-	invokedAt *time.Time
-	// TODO: cause
-}
-
-// 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
-}
-
-// 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.Meta {
-	return t.meta
-}
-
-// Expiration returns the time at which the Token expires.
-func (t *Token) Expiration() *time.Time {
-	return t.expiration
-}
-
-func (t *Token) validate() error {
-	var errs error
-
-	requiredDID := func(id did.DID, fieldname string) {
-		if !id.Defined() {
-			errs = errors.Join(errs, fmt.Errorf(`a valid did is required for %s: %s`, fieldname, id.String()))
-		}
-	}
-
-	requiredDID(t.issuer, "Issuer")
-
-	// TODO
-
-	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
-	)
-
-	// TODO
-
-	return &tkn, nil
-}
-
-// generateNonce creates a 12-byte random nonce.
-// TODO: some crypto scheme require more, is that our case?
-func generateNonce() ([]byte, error) {
-	res := make([]byte, 12)
-	_, err := rand.Read(res)
-	if err != nil {
-		return nil, err
-	}
-	return res, nil
-}

token/invocation/invocation.ipldsch

@@ -1,23 +0,0 @@
-type DID string
-
-# The Invocation Payload attaches sender, receiver, and provenance to the Task.
-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
-
-    # A unique, random nonce
-    nonce Bytes
-
-    # Arbitrary Metadata
-    meta {String : Any}
-
-    # The timestamp at which the Invocation becomes invalid
-    exp nullable Int
-}

token/invocation/ipld.go

@@ -1,222 +0,0 @@
-package invocation
-
-import (
-	"io"
-
-	"github.com/ipfs/go-cid"
-	"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/libp2p/go-libp2p/core/crypto"
-
-	"github.com/ucan-wg/go-ucan/did"
-	"github.com/ucan-wg/go-ucan/token/internal/envelope"
-)
-
-// ToSealed wraps the invocation token in an envelope, generates the
-// signature, encodes the result to DAG-CBOR and calculates the CID of
-// the resulting binary data.
-func (t *Token) ToSealed(privKey crypto.PrivKey) ([]byte, cid.Cid, error) {
-	data, err := t.ToDagCbor(privKey)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	id, err := envelope.CIDFromBytes(data)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	return data, id, nil
-}
-
-// ToSealedWriter is the same as ToSealed but accepts an io.Writer.
-func (t *Token) ToSealedWriter(w io.Writer, privKey crypto.PrivKey) (cid.Cid, error) {
-	cidWriter := envelope.NewCIDWriter(w)
-
-	if err := t.ToDagCborWriter(cidWriter, privKey); err != nil {
-		return cid.Undef, err
-	}
-
-	return cidWriter.CID()
-}
-
-// FromSealed decodes the provided binary data from the DAG-CBOR format,
-// verifies that the envelope's signature is correct based on the public
-// key taken from the issuer (iss) field and calculates the CID of the
-// incoming data.
-func FromSealed(data []byte) (*Token, cid.Cid, error) {
-	tkn, err := FromDagCbor(data)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	id, err := envelope.CIDFromBytes(data)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	return tkn, id, nil
-}
-
-// FromSealedReader is the same as Unseal but accepts an io.Reader.
-func FromSealedReader(r io.Reader) (*Token, cid.Cid, error) {
-	cidReader := envelope.NewCIDReader(r)
-
-	tkn, err := FromDagCborReader(cidReader)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	id, err := cidReader.CID()
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	return tkn, id, nil
-}
-
-// Encode marshals a Token to the format specified by the provided
-// codec.Encoder.
-func (t *Token) Encode(privKey crypto.PrivKey, encFn codec.Encoder) ([]byte, error) {
-	node, err := t.toIPLD(privKey)
-	if err != nil {
-		return nil, err
-	}
-
-	return ipld.Encode(node, encFn)
-}
-
-// EncodeWriter is the same as Encode, but accepts an io.Writer.
-func (t *Token) EncodeWriter(w io.Writer, privKey crypto.PrivKey, encFn codec.Encoder) error {
-	node, err := t.toIPLD(privKey)
-	if err != nil {
-		return err
-	}
-
-	return ipld.EncodeStreaming(w, node, encFn)
-}
-
-// ToDagCbor marshals the Token to the DAG-CBOR format.
-func (t *Token) ToDagCbor(privKey crypto.PrivKey) ([]byte, error) {
-	return t.Encode(privKey, dagcbor.Encode)
-}
-
-// ToDagCborWriter is the same as ToDagCbor, but it accepts an io.Writer.
-func (t *Token) ToDagCborWriter(w io.Writer, privKey crypto.PrivKey) error {
-	return t.EncodeWriter(w, privKey, dagcbor.Encode)
-}
-
-// ToDagJson marshals the Token to the DAG-JSON format.
-func (t *Token) ToDagJson(privKey crypto.PrivKey) ([]byte, error) {
-	return t.Encode(privKey, dagjson.Encode)
-}
-
-// ToDagJsonWriter is the same as ToDagJson, but it accepts an io.Writer.
-func (t *Token) ToDagJsonWriter(w io.Writer, privKey crypto.PrivKey) error {
-	return t.EncodeWriter(w, privKey, dagjson.Encode)
-}
-
-// Decode unmarshals the input data using the format specified by the
-// provided codec.Decoder into a Token.
-//
-// An error is returned if the conversion fails, or if the resulting
-// Token is invalid.
-func Decode(b []byte, decFn codec.Decoder) (*Token, 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) (*Token, error) {
-	node, err := ipld.DecodeStreaming(r, decFn)
-	if err != nil {
-		return nil, err
-	}
-	return FromIPLD(node)
-}
-
-// FromDagCbor unmarshals the input data into a Token.
-//
-// An error is returned if the conversion fails, or if the resulting
-// Token is invalid.
-func FromDagCbor(data []byte) (*Token, error) {
-	pay, err := envelope.FromDagCbor[*tokenPayloadModel](data)
-	if err != nil {
-		return nil, err
-	}
-
-	tkn, err := tokenFromModel(*pay)
-	if err != nil {
-		return nil, err
-	}
-
-	return tkn, err
-}
-
-// FromDagCborReader is the same as FromDagCbor, but accept an io.Reader.
-func FromDagCborReader(r io.Reader) (*Token, error) {
-	return DecodeReader(r, dagcbor.Decode)
-}
-
-// FromDagJson unmarshals the input data into a Token.
-//
-// An error is returned if the conversion fails, or if the resulting
-// Token is invalid.
-func FromDagJson(data []byte) (*Token, error) {
-	return Decode(data, dagjson.Decode)
-}
-
-// FromDagJsonReader is the same as FromDagJson, but accept an io.Reader.
-func FromDagJsonReader(r io.Reader) (*Token, error) {
-	return DecodeReader(r, dagjson.Decode)
-}
-
-// FromIPLD decode the given IPLD representation into a Token.
-func FromIPLD(node datamodel.Node) (*Token, error) {
-	pay, err := envelope.FromIPLD[*tokenPayloadModel](node)
-	if err != nil {
-		return nil, err
-	}
-
-	tkn, err := tokenFromModel(*pay)
-	if err != nil {
-		return nil, err
-	}
-
-	return tkn, err
-}
-
-func (t *Token) toIPLD(privKey crypto.PrivKey) (datamodel.Node, error) {
-	var sub *string
-
-	if t.subject != did.Undef {
-		s := t.subject.String()
-		sub = &s
-	}
-
-	// TODO
-
-	var exp *int64
-	if t.expiration != nil {
-		u := t.expiration.Unix()
-		exp = &u
-	}
-
-	model := &tokenPayloadModel{
-		Iss:   t.issuer.String(),
-		Aud:   t.audience.String(),
-		Sub:   sub,
-		Cmd:   t.command.String(),
-		Nonce: t.nonce,
-		Meta:  *t.meta,
-		Exp:   exp,
-	}
-
-	return envelope.ToIPLD(privKey, model)
-}

token/invocation/schema.go

@@ -1,77 +0,0 @@
-package invocation
-
-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"
-
-	"github.com/ucan-wg/go-ucan/pkg/meta"
-	"github.com/ucan-wg/go-ucan/token/internal/envelope"
-)
-
-// [Tag] is the string used as a key within the SigPayload that identifies
-// that the TokenPayload is an invocation.
-//
-// [Tag]: https://github.com/ucan-wg/invocation#type-tag
-const Tag = "ucan/inv@1.0.0-rc.1"
-
-//go:embed invocation.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("failed to load IPLD schema: %s", err))
-	}
-	return ts
-}
-
-func payloadType() schema.Type {
-	return mustLoadSchema().TypeByName("Payload")
-}
-
-var _ envelope.Tokener = (*tokenPayloadModel)(nil)
-
-// TODO
-type tokenPayloadModel struct {
-	// Issuer DID (sender)
-	Iss string
-	// Audience DID (receiver)
-	Aud string
-	// Principal that the chain is about (the Subject)
-	// optional: can be nil
-	Sub *string
-
-	// The Command to eventually invoke
-	Cmd string
-
-	// A unique, random nonce
-	Nonce []byte
-
-	// Arbitrary Metadata
-	Meta meta.Meta
-
-	// The timestamp at which the Invocation becomes invalid
-	// optional: can be nil
-	Exp *int64
-}
-
-func (e *tokenPayloadModel) Prototype() schema.TypedPrototype {
-	return bindnode.Prototype((*tokenPayloadModel)(nil), payloadType())
-}
-
-func (*tokenPayloadModel) Tag() string {
-	return Tag
-}

token/read.go

@@ -1,125 +0,0 @@
-package token
-
-import (
-	"fmt"
-	"io"
-
-	"github.com/ipfs/go-cid"
-	"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/token/delegation"
-	"github.com/ucan-wg/go-ucan/token/internal/envelope"
-	"github.com/ucan-wg/go-ucan/token/invocation"
-)
-
-// FromSealed decodes an arbitrary token type from the binary data,
-// verifies that the envelope's signature is correct based on the public
-// key taken from the issuer (iss) field and calculates the CID of the
-// incoming data.
-// Supported and returned types are:
-// - delegation.Token
-// - invocation.Token
-func FromSealed(data []byte) (Token, cid.Cid, error) {
-	tkn, err := FromDagCbor(data)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	id, err := envelope.CIDFromBytes(data)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	return tkn, id, nil
-}
-
-// FromSealedReader is the same as Unseal but accepts an io.Reader.
-func FromSealedReader(r io.Reader) (Token, cid.Cid, error) {
-	cidReader := envelope.NewCIDReader(r)
-
-	tkn, err := FromDagCborReader(cidReader)
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	id, err := cidReader.CID()
-	if err != nil {
-		return nil, cid.Undef, err
-	}
-
-	return tkn, id, nil
-}
-
-// Decode unmarshals the input data using the format specified by the
-// provided codec.Decoder into an arbitrary UCAN token.
-// An error is returned if the conversion fails, or if the resulting
-// Token is invalid.
-// Supported and returned types are:
-// - delegation.Token
-// - invocation.Token
-func Decode(b []byte, decFn codec.Decoder) (Token, 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) (Token, error) {
-	node, err := ipld.DecodeStreaming(r, decFn)
-	if err != nil {
-		return nil, err
-	}
-	return fromIPLD(node)
-}
-
-// FromDagCbor unmarshals an arbitrary DagCbor encoded UCAN token.
-// An error is returned if the conversion fails, or if the resulting
-// Token is invalid.
-// Supported and returned types are:
-// - delegation.Token
-// - invocation.Token
-func FromDagCbor(b []byte) (Token, error) {
-	return Decode(b, dagcbor.Decode)
-}
-
-// FromDagCborReader is the same as FromDagCbor, but accept an io.Reader.
-func FromDagCborReader(r io.Reader) (Token, error) {
-	return DecodeReader(r, dagcbor.Decode)
-}
-
-// FromDagCbor unmarshals an arbitrary DagJson encoded UCAN token.
-// An error is returned if the conversion fails, or if the resulting
-// Token is invalid.
-// Supported and returned types are:
-// - delegation.Token
-// - invocation.Token
-func FromDagJson(b []byte) (Token, error) {
-	return Decode(b, dagjson.Decode)
-}
-
-// FromDagJsonReader is the same as FromDagJson, but accept an io.Reader.
-func FromDagJsonReader(r io.Reader) (Token, error) {
-	return DecodeReader(r, dagjson.Decode)
-}
-
-func fromIPLD(node datamodel.Node) (Token, error) {
-	tag, err := envelope.FindTag(node)
-	if err != nil {
-		return nil, err
-	}
-
-	switch tag {
-	case delegation.Tag:
-		return delegation.FromIPLD(node)
-	case invocation.Tag:
-		return invocation.FromIPLD(node)
-	default:
-		return nil, fmt.Errorf(`unknown tag "%s"`, tag)
-	}
-}