Merge branch 'v1' into v1-policy-subset-selection

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)

pkg/policy/match.go

@@ -11,14 +11,32 @@ import (
 	"github.com/ucan-wg/go-ucan/pkg/policy/selector"
 )
 
+func (p Policy) Filter(sel selector.Selector) Policy {
+	return p.FilterWithMatcher(sel, selector.SegmentEquals)
+}
+
+// FilterWithMatcher extracts a subset of the policy related to the specified selector,
+// by matching each segment using the given selector.SegmentMatcher.
+func (p Policy) FilterWithMatcher(sel selector.Selector, matcher selector.SegmentMatcher) Policy {
+	var filtered Policy
+	for _, stmt := range p {
+		if stmt.Selector().Matches(sel, matcher) {
+			filtered = append(filtered, stmt)
+		}
+	}
+
+	return filtered
+}
+
 // Match determines if the IPLD node matches the policy document.
-func Match(policy Policy, node ipld.Node) bool {
-	for _, stmt := range policy {
+func (p Policy) Match(node datamodel.Node) bool {
+	for _, stmt := range p {
 		ok := matchStatement(stmt, node)
 		if !ok {
 			return false
 		}
 	}
+
 	return true
 }
 

pkg/policy/match_test.go

@@ -1,7 +1,9 @@
 package policy
 
 import (
+	"encoding/json"
 	"fmt"
+	"reflect"
 	"testing"
 
 	"github.com/ipfs/go-cid"
@@ -9,6 +11,7 @@ import (
 	"github.com/ipld/go-ipld-prime/codec/dagjson"
 	cidlink "github.com/ipld/go-ipld-prime/linking/cid"
 	"github.com/ipld/go-ipld-prime/node/basicnode"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
 	"github.com/ucan-wg/go-ucan/pkg/policy/literal"
@@ -24,15 +27,15 @@ func TestMatch(t *testing.T) {
 			nd := nb.Build()
 
 			pol := Policy{Equal(selector.MustParse("."), literal.String("test"))}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 
 			pol = Policy{Equal(selector.MustParse("."), literal.String("test2"))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 
 			pol = Policy{Equal(selector.MustParse("."), literal.Int(138))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 		})
 
@@ -43,15 +46,15 @@ func TestMatch(t *testing.T) {
 			nd := nb.Build()
 
 			pol := Policy{Equal(selector.MustParse("."), literal.Int(138))}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 
 			pol = Policy{Equal(selector.MustParse("."), literal.Int(1138))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 
 			pol = Policy{Equal(selector.MustParse("."), literal.String("138"))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 		})
 
@@ -62,15 +65,15 @@ func TestMatch(t *testing.T) {
 			nd := nb.Build()
 
 			pol := Policy{Equal(selector.MustParse("."), literal.Float(1.138))}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 
 			pol = Policy{Equal(selector.MustParse("."), literal.Float(11.38))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 
 			pol = Policy{Equal(selector.MustParse("."), literal.String("138"))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 		})
 
@@ -84,15 +87,15 @@ func TestMatch(t *testing.T) {
 			nd := nb.Build()
 
 			pol := Policy{Equal(selector.MustParse("."), literal.Link(l0))}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 
 			pol = Policy{Equal(selector.MustParse("."), literal.Link(l1))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 
 			pol = Policy{Equal(selector.MustParse("."), literal.String("bafybeif4owy5gno5lwnixqm52rwqfodklf76hsetxdhffuxnplvijskzqq"))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 		})
 
@@ -106,19 +109,19 @@ func TestMatch(t *testing.T) {
 			nd := nb.Build()
 
 			pol := Policy{Equal(selector.MustParse(".foo"), literal.String("bar"))}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 
 			pol = Policy{Equal(selector.MustParse(".[\"foo\"]"), literal.String("bar"))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.True(t, ok)
 
 			pol = Policy{Equal(selector.MustParse(".foo"), literal.String("baz"))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 
 			pol = Policy{Equal(selector.MustParse(".foobar"), literal.String("bar"))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 		})
 
@@ -131,11 +134,11 @@ func TestMatch(t *testing.T) {
 			nd := nb.Build()
 
 			pol := Policy{Equal(selector.MustParse(".[0]"), literal.String("foo"))}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 
 			pol = Policy{Equal(selector.MustParse(".[1]"), literal.String("foo"))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 		})
 	})
@@ -148,7 +151,7 @@ func TestMatch(t *testing.T) {
 			nd := nb.Build()
 
 			pol := Policy{GreaterThan(selector.MustParse("."), literal.Int(1))}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 		})
 
@@ -159,11 +162,11 @@ func TestMatch(t *testing.T) {
 			nd := nb.Build()
 
 			pol := Policy{GreaterThanOrEqual(selector.MustParse("."), literal.Int(1))}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 
 			pol = Policy{GreaterThanOrEqual(selector.MustParse("."), literal.Int(138))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.True(t, ok)
 		})
 
@@ -174,7 +177,7 @@ func TestMatch(t *testing.T) {
 			nd := nb.Build()
 
 			pol := Policy{GreaterThan(selector.MustParse("."), literal.Float(1))}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 		})
 
@@ -185,11 +188,11 @@ func TestMatch(t *testing.T) {
 			nd := nb.Build()
 
 			pol := Policy{GreaterThanOrEqual(selector.MustParse("."), literal.Float(1))}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 
 			pol = Policy{GreaterThanOrEqual(selector.MustParse("."), literal.Float(1.38))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.True(t, ok)
 		})
 
@@ -200,7 +203,7 @@ func TestMatch(t *testing.T) {
 			nd := nb.Build()
 
 			pol := Policy{LessThan(selector.MustParse("."), literal.Int(1138))}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 		})
 
@@ -211,11 +214,11 @@ func TestMatch(t *testing.T) {
 			nd := nb.Build()
 
 			pol := Policy{LessThanOrEqual(selector.MustParse("."), literal.Int(1138))}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 
 			pol = Policy{LessThanOrEqual(selector.MustParse("."), literal.Int(138))}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.True(t, ok)
 		})
 	})
@@ -227,11 +230,11 @@ func TestMatch(t *testing.T) {
 		nd := nb.Build()
 
 		pol := Policy{Not(Equal(selector.MustParse("."), literal.Bool(true)))}
-		ok := Match(pol, nd)
+		ok := pol.Match(nd)
 		require.True(t, ok)
 
 		pol = Policy{Not(Equal(selector.MustParse("."), literal.Bool(false)))}
-		ok = Match(pol, nd)
+		ok = pol.Match(nd)
 		require.False(t, ok)
 	})
 
@@ -247,7 +250,7 @@ func TestMatch(t *testing.T) {
 				LessThan(selector.MustParse("."), literal.Int(1138)),
 			),
 		}
-		ok := Match(pol, nd)
+		ok := pol.Match(nd)
 		require.True(t, ok)
 
 		pol = Policy{
@@ -256,11 +259,11 @@ func TestMatch(t *testing.T) {
 				Equal(selector.MustParse("."), literal.Int(1138)),
 			),
 		}
-		ok = Match(pol, nd)
+		ok = pol.Match(nd)
 		require.False(t, ok)
 
 		pol = Policy{And()}
-		ok = Match(pol, nd)
+		ok = pol.Match(nd)
 		require.True(t, ok)
 	})
 
@@ -276,7 +279,7 @@ func TestMatch(t *testing.T) {
 				LessThan(selector.MustParse("."), literal.Int(1138)),
 			),
 		}
-		ok := Match(pol, nd)
+		ok := pol.Match(nd)
 		require.True(t, ok)
 
 		pol = Policy{
@@ -285,11 +288,11 @@ func TestMatch(t *testing.T) {
 				Equal(selector.MustParse("."), literal.Int(1138)),
 			),
 		}
-		ok = Match(pol, nd)
+		ok = pol.Match(nd)
 		require.False(t, ok)
 
 		pol = Policy{Or()}
-		ok = Match(pol, nd)
+		ok = pol.Match(nd)
 		require.True(t, ok)
 	})
 
@@ -313,7 +316,7 @@ func TestMatch(t *testing.T) {
 					require.NoError(t, err)
 
 					pol := Policy{statement}
-					ok := Match(pol, nd)
+					ok := pol.Match(nd)
 					require.True(t, ok)
 				})
 			}(s)
@@ -337,7 +340,7 @@ func TestMatch(t *testing.T) {
 					require.NoError(t, err)
 
 					pol := Policy{statement}
-					ok := Match(pol, nd)
+					ok := pol.Match(nd)
 					require.False(t, ok)
 				})
 			}(s)
@@ -373,7 +376,7 @@ func TestMatch(t *testing.T) {
 					GreaterThan(selector.MustParse(".value"), literal.Int(2)),
 				),
 			}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 
 			pol = Policy{
@@ -382,7 +385,7 @@ func TestMatch(t *testing.T) {
 					GreaterThan(selector.MustParse(".value"), literal.Int(20)),
 				),
 			}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 		})
 
@@ -404,7 +407,7 @@ func TestMatch(t *testing.T) {
 					GreaterThan(selector.MustParse(".value"), literal.Int(60)),
 				),
 			}
-			ok := Match(pol, nd)
+			ok := pol.Match(nd)
 			require.True(t, ok)
 
 			pol = Policy{
@@ -413,7 +416,7 @@ func TestMatch(t *testing.T) {
 					GreaterThan(selector.MustParse(".value"), literal.Int(100)),
 				),
 			}
-			ok = Match(pol, nd)
+			ok = pol.Match(nd)
 			require.False(t, ok)
 		})
 	})
@@ -432,7 +435,7 @@ func TestPolicyExamples(t *testing.T) {
 
 		pol, err := FromDagJson(policy)
 		require.NoError(t, err)
-		return Match(pol, data)
+		return pol.Match(data)
 	}
 
 	t.Run("And", func(t *testing.T) {
@@ -536,6 +539,104 @@ func FuzzMatch(f *testing.F) {
 			t.Skip()
 		}
 
-		Match(policy, dataNode)
+		policy.Match(dataNode)
+	})
+}
+
+func TestPolicyFilter(t *testing.T) {
+	sel1 := selector.Selector{selector.NewFieldSegment("http")}
+	sel2 := selector.Selector{selector.NewFieldSegment("jsonrpc")}
+
+	stmt1 := Equal(sel1, basicnode.NewString("value1"))
+	stmt2 := Equal(sel2, basicnode.NewString("value2"))
+
+	p := Policy{stmt1, stmt2}
+
+	filtered := p.Filter(sel1)
+	assert.Len(t, filtered, 1)
+	assert.Equal(t, stmt1, filtered[0])
+
+	filtered = p.Filter(sel2)
+	assert.Len(t, filtered, 1)
+	assert.Equal(t, stmt2, filtered[0])
+
+	sel3 := selector.Selector{selector.NewFieldSegment("nonexistent")}
+	filtered = p.Filter(sel3)
+	assert.Len(t, filtered, 0)
+
+	stmt1 = Equal(
+		selector.Selector{selector.NewFieldSegment(".http.host")},
+		basicnode.NewString("mainnet.infura.io"),
+	)
+	stmt2, err := Like(
+		selector.Selector{selector.NewFieldSegment(".jsonrpc.method")},
+		"eth_*",
+	)
+	require.NoError(t, err)
+
+	p = Policy{stmt1, stmt2}
+	filtered = p.FilterWithMatcher(selector.Selector{selector.NewFieldSegment(".http")}, selector.SegmentStartsWith)
+	assert.Len(t, filtered, 1)
+	assert.Equal(t, stmt1, filtered[0])
+}
+
+func FuzzPolicyFilter(f *testing.F) {
+	f.Add([]byte(`{"selector": [{"field": "http"}], "value": "value1"}`))
+	f.Add([]byte(`{"selector": [{"field": "jsonrpc"}], "value": "value2"}`))
+
+	f.Fuzz(func(t *testing.T, data []byte) {
+		var input struct {
+			Selector []struct {
+				Field string `json:"field"` // because selector.segment is not public
+			} `json:"selector"`
+			Value string `json:"value"`
+		}
+		if err := json.Unmarshal(data, &input); err != nil {
+			t.Skip()
+		}
+
+		var sel selector.Selector
+		for _, seg := range input.Selector {
+			sel = append(sel, selector.NewFieldSegment(seg.Field))
+		}
+		stmt := Equal(sel, basicnode.NewString(input.Value))
+
+		// create a policy and filter it based on the fuzzy input selector
+		p := Policy{stmt}
+		filtered := p.Filter(sel)
+
+		// verify that the filtered policy contains the statement
+		if len(filtered) != 1 || !reflect.DeepEqual(filtered[0], stmt) {
+			t.Errorf("filtered policy does not contain the expected statement")
+		}
+	})
+}
+
+func BenchmarkPolicyFilter(b *testing.B) {
+	sel1 := selector.Selector{selector.NewFieldSegment("http")}
+	sel2 := selector.Selector{selector.NewFieldSegment("jsonrpc")}
+
+	stmt1 := Equal(sel1, basicnode.NewString("value1"))
+	stmt2 := Equal(sel2, basicnode.NewString("value2"))
+
+	p := Policy{stmt1, stmt2}
+
+	b.Run("Filter by sel1", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			p.Filter(sel1)
+		}
+	})
+
+	b.Run("Filter by sel2", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			p.Filter(sel2)
+		}
+	})
+
+	sel3 := selector.Selector{selector.NewFieldSegment("nonexistent")}
+	b.Run("Filter by sel3", func(b *testing.B) {
+		for i := 0; i < b.N; i++ {
+			p.Filter(sel3)
+		}
 	})
 }

pkg/policy/policy.go

@@ -26,6 +26,7 @@ type Policy []Statement
 
 type Statement interface {
 	Kind() string
+	Selector() selector.Selector
 }
 
 type equality struct {
@@ -38,6 +39,10 @@ func (e equality) Kind() string {
 	return e.kind
 }
 
+func (e equality) Selector() selector.Selector {
+	return e.selector
+}
+
 func Equal(selector selector.Selector, value ipld.Node) Statement {
 	return equality{kind: KindEqual, selector: selector, value: value}
 }
@@ -66,6 +71,10 @@ func (n negation) Kind() string {
 	return KindNot
 }
 
+func (n negation) Selector() selector.Selector {
+	return n.statement.Selector()
+}
+
 func Not(stmt Statement) Statement {
 	return negation{statement: stmt}
 }
@@ -79,6 +88,15 @@ func (c connective) Kind() string {
 	return c.kind
 }
 
+func (c connective) Selector() selector.Selector {
+	// assuming the first statement's selector is representative
+	if len(c.statements) > 0 {
+		return c.statements[0].Selector()
+	}
+
+	return selector.Selector{}
+}
+
 func And(stmts ...Statement) Statement {
 	return connective{kind: KindAnd, statements: stmts}
 }
@@ -96,6 +114,10 @@ func (n wildcard) Kind() string {
 	return KindLike
 }
 
+func (n wildcard) Selector() selector.Selector {
+	return n.selector
+}
+
 func Like(selector selector.Selector, pattern string) (Statement, error) {
 	g, err := parseGlob(pattern)
 	if err != nil {
@@ -115,6 +137,10 @@ func (n quantifier) Kind() string {
 	return n.kind
 }
 
+func (n quantifier) Selector() selector.Selector {
+	return n.selector
+}
+
 func All(selector selector.Selector, statement Statement) Statement {
 	return quantifier{kind: KindAll, selector: selector, statement: statement}
 }

pkg/policy/selector/selector.go

@@ -23,6 +23,21 @@ func (s Selector) String() string {
 	return res.String()
 }
 
+// Matches checks if the selector matches another selector.
+func (s Selector) Matches(other Selector, matcher SegmentMatcher) bool {
+	if len(s) != len(other) {
+		return false
+	}
+
+	for i, seg := range s {
+		if !matcher(seg, other[i]) {
+			return false
+		}
+	}
+
+	return true
+}
+
 var Identity = segment{".", true, false, false, nil, "", 0}
 
 var (
@@ -41,6 +56,48 @@ type segment struct {
 	index    int
 }
 
+// NewFieldSegment creates a new segment for a field.
+func NewFieldSegment(field string) segment {
+	return segment{
+		str:   fmt.Sprintf(".%s", field),
+		field: field,
+	}
+}
+
+// NewIndexSegment creates a new segment for an index.
+func NewIndexSegment(index int) segment {
+	return segment{
+		str:   fmt.Sprintf("[%d]", index),
+		index: index,
+	}
+}
+
+// NewSliceSegment creates a new segment for a slice.
+func NewSliceSegment(slice []int) segment {
+	return segment{
+		str:   fmt.Sprintf("[%d:%d]", slice[0], slice[1]),
+		slice: slice,
+	}
+}
+
+// NewIteratorSegment creates a new segment for an iterator.
+func NewIteratorSegment() segment {
+	return segment{
+		str:      "*",
+		iterator: true,
+	}
+}
+
+type SegmentMatcher func(s1, s2 segment) bool
+
+var SegmentEquals SegmentMatcher = func(s1, s2 segment) bool {
+	return s1.str == s2.str
+}
+
+var SegmentStartsWith SegmentMatcher = func(s1, s2 segment) bool {
+	return strings.HasPrefix(s1.str, s2.str)
+}
+
 // String returns the segment's string representation.
 func (s segment) String() string {
 	return s.str

tokens/delegation/delegation.go

@@ -49,10 +49,6 @@ type Token struct {
 }
 
 // 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 {
@@ -90,12 +86,6 @@ func New(privKey crypto.PrivKey, aud did.DID, cmd command.Command, pol policy.Po
 	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 {

tokens/delegation/examples_test.go

@@ -1,313 +0,0 @@
-package delegation_test
-
-import (
-	"bytes"
-	"encoding/base64"
-	"encoding/hex"
-	"encoding/json"
-	"fmt"
-
-	"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/tokens/delegation"
-	"github.com/ucan-wg/go-ucan/tokens/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() {
-	issuerPrivKey := examplePrivKey(issuerPrivKeyCfg)
-	audienceDID := exampleDID(AudienceDID)
-	command := exampleCommand(subJectCmd)
-	policy := examplePolicy(subjectPol)
-	subjectDID := exampleDID(subjectDID)
-
-	// Don't do this in your code - a nonce should be a cryptographically
-	// strong random slice of bytes to ensure the integrity of your private
-	// key.  For this example, a fixed nonce is required to obtain the fixed
-	// printed output (below).  If unsure of what value to supply for the
-	// nonce, don't pass the WithNonce option and one will be generated
-	// when the token is created.
-	nonce := []byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b}
-
-	tkn, err := delegation.New(
-		issuerPrivKey,
-		audienceDID,
-		command,
-		policy,
-		delegation.WithSubject(subjectDID),
-		delegation.WithNonce(nonce),
-	)
-	printThenPanicOnErr(err)
-	data, id, err := tkn.ToSealed(issuerPrivKey)
-	printThenPanicOnErr(err)
-
-	printCIDAndSealed(id, data)
-
-	//Output:
-	//CID (base58BTC): zdpuAw26pFuvZa2Z9YAtpZZnWN6VmnRFr7Z8LVY5c7RVWoxGY
-	//DAG-CBOR (base64) out: 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
-	//Converted to DAG-JSON out:
-	//[
-	//	{
-	//		"/": {
-	//			"bytes": "mnAkgfjAx4SA5pzJmtaHRJtTGNpF1y6oqb4yhGoM2H2EUGbBYT4rVDjMKBgCjhdGHjipm00L8iR5SsQh3sIEBQ"
-	//		}
-	//	},
-	//	{
-	//		"h": {
-	//			"/": {
-	//				"bytes": "NO0BcQ"
-	//			}
-	//		},
-	//		"ucan/dlg@1.0.0-rc.1": {
-	//			"aud": "did:key:z6Mkq5YmbJcTrPExNDi26imrTCpKhepjBFBSHqrBDN2ArPkv",
-	//			"cmd": "/foo/bar",
-	//			"exp": null,
-	//			"iss": "did:key:z6Mkpzn2n3ZGT2VaqMGSQC3tzmzV4TS9S71iFsDXE1WnoNH2",
-	//			"meta": {},
-	//			"nonce": {
-	//				"/": {
-	//					"bytes": "AAECAwQFBgcICQoL"
-	//				}
-	//			},
-	//			"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() {
-	issuerPrivKey := examplePrivKey(issuerPrivKeyCfg)
-	audienceDID := exampleDID(AudienceDID)
-	command := exampleCommand(subJectCmd)
-	policy := examplePolicy(subjectPol)
-
-	// Don't do this in your code - a nonce should be a cryptographically
-	// strong random slice of bytes to ensure the integrity of your private
-	// key.  For this example, a fixed nonce is required to obtain the fixed
-	// printed output (below).  If unsure of what value to supply for the
-	// nonce, don't pass the WithNonce option and one will be generated
-	// when the token is created.
-	nonce := []byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b}
-
-	tkn, err := delegation.Root(
-		issuerPrivKey,
-		audienceDID,
-		command,
-		policy,
-		delegation.WithNonce(nonce),
-	)
-	printThenPanicOnErr(err)
-	data, id, err := tkn.ToSealed(issuerPrivKey)
-	printThenPanicOnErr(err)
-
-	printCIDAndSealed(id, data)
-
-	//Output:
-	//CID (base58BTC): zdpuAnbsR3e6DK8hBk5WA7KwbHYN6CKY4a3Bv1GNehvFYShQ8
-	//DAG-CBOR (base64) out: 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
-	//Converted to DAG-JSON out:
-	//[
-	//	{
-	//		"/": {
-	//			"bytes": "67ASBczF/wlIP0ESENn+4ZNQKukjcTNz+fo7K2tYa6OUm0rWICDJJkDWm7lJeQt+KvSA+Y4ctHTQbAr3Lr7mDg"
-	//		}
-	//	},
-	//	{
-	//		"h": {
-	//			"/": {
-	//				"bytes": "NO0BcQ"
-	//			}
-	//		},
-	//		"ucan/dlg@1.0.0-rc.1": {
-	//			"aud": "did:key:z6Mkq5YmbJcTrPExNDi26imrTCpKhepjBFBSHqrBDN2ArPkv",
-	//			"cmd": "/foo/bar",
-	//			"exp": null,
-	//			"iss": "did:key:z6Mkpzn2n3ZGT2VaqMGSQC3tzmzV4TS9S71iFsDXE1WnoNH2",
-	//			"meta": {},
-	//			"nonce": {
-	//				"/": {
-	//					"bytes": "AAECAwQFBgcICQoL"
-	//				}
-	//			},
-	//			"pol": [
-	//				[
-	//					"==",
-	//					".status",
-	//					"draft"
-	//				],
-	//				[
-	//					"all",
-	//					".reviewer",
-	//					[
-	//						"like",
-	//						".email",
-	//						"*@example.com"
-	//					]
-	//				],
-	//				[
-	//					"any",
-	//					".tags",
-	//					[
-	//						"or",
-	//						[
-	//							[
-	//								"==",
-	//								".",
-	//								"news"
-	//							],
-	//							[
-	//								"==",
-	//								".",
-	//								"press"
-	//							]
-	//						]
-	//					]
-	//				]
-	//			],
-	//			"sub": "did:key:z6Mkpzn2n3ZGT2VaqMGSQC3tzmzV4TS9S71iFsDXE1WnoNH2"
-	//		}
-	//	}
-	//]
-}
-
-// The following example demonstrates how to get a delegation.Token from
-// a DAG-CBOR []byte.
-func ExampleToken_FromSealed() {
-	cborBytes := exampleCBORData()
-	fmt.Println("DAG-CBOR (base64) in:", base64.StdEncoding.EncodeToString(cborBytes))
-
-	tkn, err := delegation.FromSealed(cborBytes)
-	printThenPanicOnErr(err)
-
-	fmt.Println("CID (base58BTC):", envelope.CIDToBase58BTC(tkn.CID()))
-	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): TODO")
-	fmt.Println("Nonce (nonce):", hex.EncodeToString(tkn.Nonce()))
-	fmt.Println("Meta (meta): TODO")
-	fmt.Println("NotBefore (nbf):", tkn.NotBefore())
-	fmt.Println("Expiration (exp):", tkn.Expiration())
-
-	//Output:
-	//DAG-CBOR (base64) in: glhAmnAkgfjAx4SA5pzJmtaHRJtTGNpF1y6oqb4yhGoM2H2EUGbBYT4rVDjMKBgCjhdGHjipm00L8iR5SsQh3sIEBaJhaEQ07QFxc3VjYW4vZGxnQDEuMC4wLXJjLjGoY2F1ZHg4ZGlkOmtleTp6Nk1rcTVZbWJKY1RyUEV4TkRpMjZpbXJUQ3BLaGVwakJGQlNIcXJCRE4yQXJQa3ZjY21kaC9mb28vYmFyY2V4cPZjaXNzeDhkaWQ6a2V5Ono2TWtwem4ybjNaR1QyVmFxTUdTUUMzdHptelY0VFM5UzcxaUZzRFhFMVdub05IMmNwb2yDg2I9PWcuc3RhdHVzZWRyYWZ0g2NhbGxpLnJldmlld2Vyg2RsaWtlZi5lbWFpbG0qQGV4YW1wbGUuY29tg2NhbnllLnRhZ3OCYm9ygoNiPT1hLmRuZXdzg2I9PWEuZXByZXNzY3N1Yng4ZGlkOmtleTp6Nk1rdEExdUJkQ3BxNHVKQnFFOWpqTWlMeXhaQmc5YTZ4Z1BQS0pqTXFzczZaYzJkbWV0YaBlbm9uY2VMAAECAwQFBgcICQoL
-	//CID (base58BTC): zdpuAw26pFuvZa2Z9YAtpZZnWN6VmnRFr7Z8LVY5c7RVWoxGY
-	//Issuer (iss): did:key:z6Mkpzn2n3ZGT2VaqMGSQC3tzmzV4TS9S71iFsDXE1WnoNH2
-	//Audience (aud): did:key:z6Mkq5YmbJcTrPExNDi26imrTCpKhepjBFBSHqrBDN2ArPkv
-	//Subject (sub): did:key:z6MktA1uBdCpq4uJBqE9jjMiLyxZBg9a6xgPPKJjMqss6Zc2
-	//Command (cmd): /foo/bar
-	//Policy (pol): TODO
-	//Nonce (nonce): 000102030405060708090a0b
-	//Meta (meta): TODO
-	//NotBefore (nbf): <nil>
-	//Expiration (exp): <nil>
-}
-
-func exampleCBORData() []byte {
-	data, err := base64.StdEncoding.DecodeString("glhAmnAkgfjAx4SA5pzJmtaHRJtTGNpF1y6oqb4yhGoM2H2EUGbBYT4rVDjMKBgCjhdGHjipm00L8iR5SsQh3sIEBaJhaEQ07QFxc3VjYW4vZGxnQDEuMC4wLXJjLjGoY2F1ZHg4ZGlkOmtleTp6Nk1rcTVZbWJKY1RyUEV4TkRpMjZpbXJUQ3BLaGVwakJGQlNIcXJCRE4yQXJQa3ZjY21kaC9mb28vYmFyY2V4cPZjaXNzeDhkaWQ6a2V5Ono2TWtwem4ybjNaR1QyVmFxTUdTUUMzdHptelY0VFM5UzcxaUZzRFhFMVdub05IMmNwb2yDg2I9PWcuc3RhdHVzZWRyYWZ0g2NhbGxpLnJldmlld2Vyg2RsaWtlZi5lbWFpbG0qQGV4YW1wbGUuY29tg2NhbnllLnRhZ3OCYm9ygoNiPT1hLmRuZXdzg2I9PWEuZXByZXNzY3N1Yng4ZGlkOmtleTp6Nk1rdEExdUJkQ3BxNHVKQnFFOWpqTWlMeXhaQmc5YTZ4Z1BQS0pqTXFzczZaYzJkbWV0YaBlbm9uY2VMAAECAwQFBgcICQoL")
-	printThenPanicOnErr(err)
-
-	return data
-}
-
-func exampleDID(didStr string) did.DID {
-	id, err := did.Parse(didStr)
-	printThenPanicOnErr(err)
-
-	return id
-}
-
-func exampleCommand(cmdStr string) command.Command {
-	cmd, err := command.Parse(cmdStr)
-	printThenPanicOnErr(err)
-
-	return cmd
-}
-
-func examplePolicy(policyJSON string) policy.Policy {
-	pol, err := policy.FromDagJson(policyJSON)
-	printThenPanicOnErr(err)
-
-	return pol
-}
-
-func examplePrivKey(privKeyCfg string) crypto.PrivKey {
-	privKeyMar, err := crypto.ConfigDecodeKey(privKeyCfg)
-	printThenPanicOnErr(err)
-
-	privKey, err := crypto.UnmarshalPrivateKey(privKeyMar)
-	printThenPanicOnErr(err)
-
-	return privKey
-}
-
-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)
-	}
-}