Merge pull request #26 from ucan-wg/feat/calculate-cid

feat(cid): calculate the CID for decoded and newly created Tokeners

delegation/delegation.go

@@ -1,11 +1,21 @@
+// 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/ipfs/go-cid"
 	"github.com/libp2p/go-libp2p/core/crypto"
 
 	"github.com/ucan-wg/go-ucan/capability/command"
@@ -14,6 +24,7 @@ import (
 	"github.com/ucan-wg/go-ucan/pkg/meta"
 )
 
+// Token is an immutable type that holds the fields of a UCAN delegation.
 type Token struct {
 	// Issuer DID (sender)
 	issuer did.DID
@@ -33,6 +44,8 @@ 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.
@@ -50,6 +63,7 @@ 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 {
@@ -132,6 +146,13 @@ 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
 
@@ -151,6 +172,8 @@ func (t *Token) validate() error {
 	return errs
 }
 
+// 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
@@ -168,6 +191,7 @@ func WithExpiration(exp time.Time) Option {
 }
 
 // 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.
@@ -277,6 +301,7 @@ func tokenFromModel(m tokenPayloadModel) (*Token, error) {
 }
 
 // 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)

delegation/delegation_test.go

@@ -1,7 +1,6 @@
 package delegation_test
 
 import (
-	"crypto/rand"
 	"testing"
 	"time"
 
@@ -64,6 +63,9 @@ const (
 	]
 ]
 `
+
+	newCID  = "zdpuAn9JgGPvnt2WCmTaKktZdbuvcVGTg9bUT5kQaufwUtZ6e"
+	rootCID = "zdpuAkgGmUp5JrXvehGuuw9JA8DLQKDaxtK3R8brDQQVC2i5X"
 )
 
 func TestConstructors(t *testing.T) {
@@ -86,7 +88,7 @@ func TestConstructors(t *testing.T) {
 	require.NoError(t, err)
 
 	t.Run("New", func(t *testing.T) {
-		dlg, err := delegation.New(privKey, aud, cmd, pol,
+		tkn, err := delegation.New(privKey, aud, cmd, pol,
 			delegation.WithNonce([]byte(nonce)),
 			delegation.WithSubject(sub),
 			delegation.WithExpiration(exp),
@@ -95,7 +97,7 @@ func TestConstructors(t *testing.T) {
 		)
 		require.NoError(t, err)
 
-		data, err := dlg.ToDagJson(privKey)
+		data, err := tkn.ToDagJson(privKey)
 		require.NoError(t, err)
 
 		t.Log(string(data))
@@ -106,15 +108,15 @@ func TestConstructors(t *testing.T) {
 	t.Run("Root", func(t *testing.T) {
 		t.Parallel()
 
-		dlg, err := delegation.Root(privKey, aud, cmd, pol,
+		tkn, err := delegation.Root(privKey, aud, cmd, pol,
 			delegation.WithNonce([]byte(nonce)),
 			delegation.WithExpiration(exp),
 			delegation.WithMeta("foo", "fooo"),
 			delegation.WithMeta("bar", "barr"),
 		)
 		require.NoError(t, err)
 
-		data, err := dlg.ToDagJson(privKey)
+		data, err := tkn.ToDagJson(privKey)
 		require.NoError(t, err)
 
 		t.Log(string(data))
@@ -123,9 +125,7 @@ func TestConstructors(t *testing.T) {
 	})
 }
 
-func privKey(t *testing.T, privKeyCfg string) crypto.PrivKey {
-	t.Helper()
-
+func privKey(t require.TestingT, privKeyCfg string) crypto.PrivKey {
 	privKeyMar, err := crypto.ConfigDecodeKey(privKeyCfg)
 	require.NoError(t, err)
 
@@ -134,23 +134,3 @@ func privKey(t *testing.T, privKeyCfg string) crypto.PrivKey {
 
 	return privKey
 }
-
-func TestKey(t *testing.T) {
-	// TODO: why is this broken?
-	t.Skip("TODO: why is this broken?")
-
-	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()
-}