paseto/v4: embed the Peer inside the PublicMode

This provides simple operation when working with Pack and Unpack.

3 files changed, 31 insertions, 38 deletions

diff --git a/lib/paseto/v4/public_mode.go b/lib/paseto/v4/public_mode.go
index 10e19cd6..551f1a5e 100644
--- a/lib/paseto/v4/public_mode.go
+++ b/lib/paseto/v4/public_mode.go
@@ -33,19 +33,24 @@ var (
 type PublicMode struct {
 	peers map[string]paseto.Peer
 
-	PrivateKey ed25519.PrivateKey
-	PublicKey  ed25519.PublicKey
+	paseto.Peer
 
 	sync.Mutex
 }
 
 // NewPublicMode returns new instance of public mode from ed25519 seeds.
-func NewPublicMode(seed [ed25519.SeedSize]byte) (pmode *PublicMode) {
+// The id parameter is required when processing [paseto.Message] with
+// [PublicMode.Pack] and [PublicMode.Unpack], but optional when processing
+// payload with [PublicMode.Sign] and [PublicMode.Verify].
+func NewPublicMode(id string, seed [ed25519.SeedSize]byte) (pmode *PublicMode) {
 	pmode = &PublicMode{
 		peers: make(map[string]paseto.Peer),
+		Peer: paseto.Peer{
+			ID:      id,
+			Private: ed25519.NewKeyFromSeed(seed[:]),
+		},
 	}
-	pmode.PrivateKey = ed25519.NewKeyFromSeed(seed[:])
-	pmode.PublicKey = pmode.PrivateKey.Public().(ed25519.PublicKey)
+	pmode.Public = pmode.Private.Public().(ed25519.PublicKey)
 	return pmode
 }
 
@@ -66,7 +71,7 @@ func (pmode *PublicMode) AddPeer(peer paseto.Peer) (err error) {
 	return nil
 }
 
-// GetPeer returns the Peer and true if ID found in list of peers.
+// GetPeer returns the Peer and true if ID found in list of known peers.
 func (pmode *PublicMode) GetPeer(id string) (peer paseto.Peer, ok bool) {
 	pmode.Lock()
 	peer, ok = pmode.peers[id]
@@ -122,7 +127,7 @@ func (pmode *PublicMode) Sign(payload, footer, implicit []byte) (
 	}
 
 	// Step 4: Sign pae.
-	sig := ed25519.Sign(pmode.PrivateKey, pae)
+	sig := ed25519.Sign(pmode.Peer.Private, pae)
 
 	// Step 5: Pack all into token,
 	var buf bytes.Buffer
@@ -197,7 +202,7 @@ func (pmode *PublicMode) Verify(token string, implicit []byte) (
 	}
 
 	// Step 6: Verify the signature.
-	if !ed25519.Verify(pmode.PublicKey, msg.PAE, msg.Sig) {
+	if !ed25519.Verify(pmode.Peer.Public, msg.PAE, msg.Sig) {
 		return nil, nil, fmt.Errorf(`%s: %w`, logp, ErrSignature)
 	}
 
diff --git a/lib/paseto/v4/public_mode_example_test.go b/lib/paseto/v4/public_mode_example_test.go
index 49f98ce0..1d24ce69 100644
--- a/lib/paseto/v4/public_mode_example_test.go
+++ b/lib/paseto/v4/public_mode_example_test.go
@@ -19,7 +19,7 @@ func ExamplePublicMode_Sign() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	pmode := pasetov4.NewPublicMode([32]byte(seed))
+	pmode := pasetov4.NewPublicMode(`testsign`, [32]byte(seed))
 
 	payload := []byte(`{"data":"signed message!"}`)
 	footer := []byte(`{"peer_id":1000}`)
@@ -46,7 +46,7 @@ func ExamplePublicMode_Verify() {
 	if err != nil {
 		log.Fatal(err)
 	}
-	pmode := pasetov4.NewPublicMode([32]byte(seed))
+	pmode := pasetov4.NewPublicMode(`testverify`, [32]byte(seed))
 
 	token := `v4.public.eyJkYXRhIjoic2lnbmVkIG1lc3NhZ2UhIn0kqxCoccpjcXj3jNt6Q8cafIIF2JpapJrFNWi0mBJKS-Q3IU4dXZx-_Qx3P7LtSPnHyu6deqdeg72jb6hTCz4E.eyJwZWVyX2lkIjoxMDAwfQ`
 
@@ -63,31 +63,24 @@ func ExamplePublicMode_Verify() {
 }
 
 func ExamplePublicMode_Pack() {
-	createPeer := func(id, secret string) (
-		peer paseto.Peer, pmode *pasetov4.PublicMode,
-	) {
+	createPeerMode := func(id, secret string) (pmode *pasetov4.PublicMode) {
 		seed, err := hex.DecodeString(secret)
 		if err != nil {
 			log.Fatal(err)
 		}
-		pmode = pasetov4.NewPublicMode([32]byte(seed))
-		peer = paseto.Peer{
-			ID:      id,
-			Private: pmode.PrivateKey,
-			Public:  pmode.PublicKey,
-		}
-		return peer, pmode
+		pmode = pasetov4.NewPublicMode(id, [32]byte(seed))
+		return pmode
 	}
-	sender, senderpm := createPeer(
+	senderpm := createPeerMode(
 		`john@example.com`,
 		`b4cbfb43df4ce210727d953e4a713307fa19bb7d9f85041438d9e11b942a3774`,
 	)
-	receiver, _ := createPeer(
+	receivpm := createPeerMode(
 		`jane@example.org`,
 		`2222222222222222222222222222222222222222222222222222222222222222`,
 	)
 
-	sendMsg := paseto.NewMessage(sender, receiver, `hello`)
+	sendMsg := paseto.NewMessage(senderpm.Peer, receivpm.Peer, `hello`)
 	sendMsg.Payload.Data = map[string]string{
 		`email`: `hello@example.com`,
 	}
@@ -114,38 +107,33 @@ func ExamplePublicMode_Pack() {
 }
 
 func ExamplePublicMode_Unpack() {
-	createPeer := func(id, secret string) (
-		peer paseto.Peer, pmode *pasetov4.PublicMode,
+	createPeerMode := func(id, secret string) (
+		pmode *pasetov4.PublicMode,
 	) {
 		seed, err := hex.DecodeString(secret)
 		if err != nil {
 			log.Fatal(err)
 		}
-		pmode = pasetov4.NewPublicMode([32]byte(seed))
-		peer = paseto.Peer{
-			ID:      id,
-			Private: pmode.PrivateKey,
-			Public:  pmode.PublicKey,
-		}
-		return peer, pmode
+		pmode = pasetov4.NewPublicMode(id, [32]byte(seed))
+		return pmode
 	}
-	sender, _ := createPeer(
+	senderpm := createPeerMode(
 		`john@example.com`,
 		`b4cbfb43df4ce210727d953e4a713307fa19bb7d9f85041438d9e11b942a3774`,
 	)
-	_, recvpm := createPeer(
+	receivpm := createPeerMode(
 		`jane@example.org`,
 		`2222222222222222222222222222222222222222222222222222222222222222`,
 	)
 
 	// Add the sender to list of receiver's peer.
-	recvpm.AddPeer(sender)
+	receivpm.AddPeer(senderpm.Peer)
 
 	// This is the token send by sender.
 	token := `v4.public.eyJkYXRhIjp7ImVtYWlsIjoiaGVsbG9AZXhhbXBsZS5jb20ifSwiaXNzIjoiam9obkBleGFtcGxlLmNvbSIsInN1YiI6ImhlbGxvIiwiYXVkIjoiamFuZUBleGFtcGxlLm9yZyIsImV4cCI6MTc3NDg1OTg4OSwibmJmIjoxNzc0ODU5ODI5LCJpYXQiOjE3NzQ4NTk4Mjl9eGHMkOlYiVchKl1GqQwSMyTC8eWCpXhNJHGHq_MEJNqlKur-kPpHqY-hWHoh4I1RaBq68MN_TNveqwPIbk9iBQ.eyJkYXRhIjp7InF1b3RlIjoiTGl2ZSB0byBlYXQifSwicGVlcl9pZCI6ImpvaG5AZXhhbXBsZS5jb20ifQ`
 
 	recvMsg := paseto.Message{}
-	err := recvpm.Unpack(token, nil, &recvMsg)
+	err := receivpm.Unpack(token, nil, &recvMsg)
 	if err != nil {
 		log.Fatal(err)
 	}
diff --git a/lib/paseto/v4/public_mode_test.go b/lib/paseto/v4/public_mode_test.go
index 1231d86b..658facb8 100644
--- a/lib/paseto/v4/public_mode_test.go
+++ b/lib/paseto/v4/public_mode_test.go
@@ -59,7 +59,7 @@ func TestPublicMode_Sign(t *testing.T) {
 			}()
 
 			tc.init()
-			pmode := NewPublicMode([32]byte(tc.seed))
+			pmode := NewPublicMode(`testsign`, [32]byte(tc.seed))
 			gotToken, err := pmode.Sign([]byte(tc.Payload), []byte(tc.Footer),
 				[]byte(tc.Implicit))
 			if err != nil {
@@ -96,7 +96,7 @@ func TestPublicMode_Verify(t *testing.T) {
 			}()
 
 			tc.init()
-			pmode := NewPublicMode([32]byte(tc.seed))
+			pmode := NewPublicMode(`testverify`, [32]byte(tc.seed))
 			gotMsg, gotFooter, err := pmode.Verify(tc.Token, []byte(tc.Implicit))
 			if err != nil {
 				if tc.ExpectFail {