token: don't store the CID in the token, symmetric API for sealed

token/delegation/delegation.go

@@ -15,7 +15,6 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/ipfs/go-cid"
 	"github.com/libp2p/go-libp2p/core/crypto"
 
 	"github.com/ucan-wg/go-ucan/did"
@@ -44,8 +43,6 @@ type Token struct {
 	notBefore *time.Time
 	// The timestamp at which the Invocation becomes invalid
 	expiration *time.Time
-	// The CID of the Token when enclosed in an Envelope and encoded to DAG-CBOR
-	cid cid.Cid
 }
 
 // New creates a validated Token from the provided parameters and options.
@@ -67,7 +64,6 @@ func New(privKey crypto.PrivKey, aud did.DID, cmd command.Command, pol policy.Po
 		policy:   pol,
 		meta:     meta.NewMeta(),
 		nonce:    nil,
-		cid:      cid.Undef,
 	}
 
 	for _, opt := range opts {
@@ -156,13 +152,6 @@ func (t *Token) Expiration() *time.Time {
 	return t.expiration
 }
 
-// CID returns the content identifier of the Token model when enclosed
-// in an Envelope and encoded to DAG-CBOR.
-// Returns cid.Undef if the token has not been serialized or deserialized yet.
-func (t *Token) CID() cid.Cid {
-	return t.cid
-}
-
 func (t *Token) validate() error {
 	var errs error
 

token/delegation/examples_test.go

@@ -223,10 +223,10 @@ func ExampleToken_FromSealed() {
 	cborBytes := exampleCBORData()
 	fmt.Println("DAG-CBOR (base64) in:", base64.StdEncoding.EncodeToString(cborBytes))
 
-	tkn, err := delegation.FromSealed(cborBytes)
+	tkn, c, err := delegation.FromSealed(cborBytes)
 	printThenPanicOnErr(err)
 
-	fmt.Println("CID (base58BTC):", envelope.CIDToBase58BTC(tkn.CID()))
+	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())

token/delegation/ipld.go

@@ -47,39 +47,35 @@ func (t *Token) ToSealedWriter(w io.Writer, privKey crypto.PrivKey) (cid.Cid, er
 // 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, error) {
+func FromSealed(data []byte) (*Token, cid.Cid, error) {
 	tkn, err := FromDagCbor(data)
 	if err != nil {
-		return nil, err
+		return nil, cid.Undef, err
 	}
 
 	id, err := envelope.CIDFromBytes(data)
 	if err != nil {
-		return nil, err
+		return nil, cid.Undef, err
 	}
 
-	tkn.cid = id
-
-	return tkn, nil
+	return tkn, id, nil
 }
 
 // FromSealedReader is the same as Unseal but accepts an io.Reader.
-func FromSealedReader(r io.Reader) (*Token, error) {
+func FromSealedReader(r io.Reader) (*Token, cid.Cid, error) {
 	cidReader := envelope.NewCIDReader(r)
 
 	tkn, err := FromDagCborReader(cidReader)
 	if err != nil {
-		return nil, err
+		return nil, cid.Undef, err
 	}
 
 	id, err := cidReader.CID()
 	if err != nil {
-		return nil, err
+		return nil, cid.Undef, err
 	}
 
-	tkn.cid = id
-
-	return tkn, nil
+	return tkn, id, nil
 }
 
 // Encode marshals a Token to the format specified by the provided

token/delegation/schema_test.go

@@ -39,9 +39,9 @@ func TestSchemaRoundTrip(t *testing.T) {
 		fmt.Println("cborBytes length", len(cborBytes))
 		fmt.Println("cbor", string(cborBytes))
 
-		p2, err := delegation.FromSealed(cborBytes)
+		p2, c2, err := delegation.FromSealed(cborBytes)
 		require.NoError(t, err)
-		assert.Equal(t, id, p2.CID())
+		assert.Equal(t, id, c2)
 		fmt.Println("read Cbor", p2)
 
 		readJson, err := p2.ToDagJson(privKey)
@@ -70,10 +70,9 @@ func TestSchemaRoundTrip(t *testing.T) {
 		assert.Equal(t, newCID, envelope.CIDToBase58BTC(id))
 
 		// buf = bytes.NewBuffer(cborBytes.Bytes())
-		p2, err := delegation.FromSealedReader(cborBytes)
+		p2, c2, err := delegation.FromSealedReader(cborBytes)
 		require.NoError(t, err)
-		t.Log(len(p2.CID().Bytes()), p2.CID().Bytes())
-		assert.Equal(t, envelope.CIDToBase58BTC(id), envelope.CIDToBase58BTC(p2.CID()))
+		assert.Equal(t, envelope.CIDToBase58BTC(id), envelope.CIDToBase58BTC(c2))
 
 		readJson := &bytes.Buffer{}
 		require.NoError(t, p2.ToDagJsonWriter(readJson, privKey))
@@ -96,7 +95,7 @@ func BenchmarkRoundTrip(b *testing.B) {
 	b.Run("via buffers", func(b *testing.B) {
 		p1, _ := delegation.FromDagJson(delegationJson)
 		cborBytes, _, _ := p1.ToSealed(privKey)
-		p2, _ := delegation.FromSealed(cborBytes)
+		p2, _, _ := delegation.FromSealed(cborBytes)
 
 		b.ResetTimer()
 
@@ -117,7 +116,7 @@ func BenchmarkRoundTrip(b *testing.B) {
 		b.Run("Unseal", func(b *testing.B) {
 			b.ReportAllocs()
 			for i := 0; i < b.N; i++ {
-				_, _ = delegation.FromSealed(cborBytes)
+				_, _, _ = delegation.FromSealed(cborBytes)
 			}
 		})
 
@@ -134,7 +133,7 @@ func BenchmarkRoundTrip(b *testing.B) {
 		cborBuf := &bytes.Buffer{}
 		_, _ = p1.ToSealedWriter(cborBuf, privKey)
 		cborBytes := cborBuf.Bytes()
-		p2, _ := delegation.FromSealedReader(bytes.NewReader(cborBytes))
+		p2, _, _ := delegation.FromSealedReader(bytes.NewReader(cborBytes))
 
 		b.ResetTimer()
 
@@ -161,7 +160,7 @@ func BenchmarkRoundTrip(b *testing.B) {
 			reader := bytes.NewReader(cborBytes)
 			for i := 0; i < b.N; i++ {
 				_, _ = reader.Seek(0, 0)
-				_, _ = delegation.FromSealedReader(reader)
+				_, _, _ = delegation.FromSealedReader(reader)
 			}
 		})