From 33e3f0cd052bab0f57803a0a8aefaec69edf6613 Mon Sep 17 00:00:00 2001
From: Henrique Dias <hacdias@gmail.com>
Date: Wed, 10 May 2023 13:40:19 +0200
Subject: [PATCH] feat(ipns): helper ValidateWithPeerID and UnmarshalIpnsEntry
 (#294)

---
 gateway/handler_ipns_record.go |  6 ++----
 ipns/ipns.go                   | 21 +++++++++++++++++++
 ipns/validate_test.go          | 38 ++++++++++++++++++++++++++++++++--
 3 files changed, 59 insertions(+), 6 deletions(-)

diff --git a/gateway/handler_ipns_record.go b/gateway/handler_ipns_record.go
index 9d4f93e06..73d9dabd5 100644
--- a/gateway/handler_ipns_record.go
+++ b/gateway/handler_ipns_record.go
@@ -10,9 +10,8 @@ import (
 	"time"
 
 	"github.com/cespare/xxhash/v2"
-	"github.com/gogo/protobuf/proto"
 	ipath "github.com/ipfs/boxo/coreiface/path"
-	ipns_pb "github.com/ipfs/boxo/ipns/pb"
+	"github.com/ipfs/boxo/ipns"
 	"github.com/ipfs/go-cid"
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/trace"
@@ -50,8 +49,7 @@ func (i *handler) serveIpnsRecord(ctx context.Context, w http.ResponseWriter, r
 		return false
 	}
 
-	var record ipns_pb.IpnsEntry
-	err = proto.Unmarshal(rawRecord, &record)
+	record, err := ipns.UnmarshalIpnsEntry(rawRecord)
 	if err != nil {
 		webError(w, err, http.StatusInternalServerError)
 		return false
diff --git a/ipns/ipns.go b/ipns/ipns.go
index 87ddadb03..db92b39ff 100644
--- a/ipns/ipns.go
+++ b/ipns/ipns.go
@@ -130,6 +130,16 @@ func createCborDataForIpnsEntry(e *pb.IpnsEntry) ([]byte, error) {
 	return buf.Bytes(), nil
 }
 
+// ValidateWithPeerID validates the given IPNS entry against the given peer ID.
+func ValidateWithPeerID(pid peer.ID, entry *pb.IpnsEntry) error {
+	pk, err := ExtractPublicKey(pid, entry)
+	if err != nil {
+		return err
+	}
+
+	return Validate(pk, entry)
+}
+
 // Validates validates the given IPNS entry against the given public key.
 func Validate(pk ic.PubKey, entry *pb.IpnsEntry) error {
 	// Make sure max size is respected
@@ -287,6 +297,17 @@ func EmbedPublicKey(pk ic.PubKey, entry *pb.IpnsEntry) error {
 	return nil
 }
 
+// UnmarshalIpnsEntry unmarshalls an IPNS entry from a slice of bytes.
+func UnmarshalIpnsEntry(data []byte) (*pb.IpnsEntry, error) {
+	var entry pb.IpnsEntry
+	err := proto.Unmarshal(data, &entry)
+	if err != nil {
+		return nil, err
+	}
+
+	return &entry, nil
+}
+
 // ExtractPublicKey extracts a public key matching `pid` from the IPNS record,
 // if possible.
 //
diff --git a/ipns/validate_test.go b/ipns/validate_test.go
index e75d0aee7..1b24ec492 100644
--- a/ipns/validate_test.go
+++ b/ipns/validate_test.go
@@ -19,6 +19,7 @@ import (
 	pstore "github.com/libp2p/go-libp2p/core/peerstore"
 	"github.com/libp2p/go-libp2p/p2p/host/peerstore/pstoremem"
 	"github.com/multiformats/go-multicodec"
+	"github.com/stretchr/testify/assert"
 )
 
 func testValidatorCase(t *testing.T, priv crypto.PrivKey, kbook pstore.KeyBook, key string, val []byte, eol time.Time, exp error) {
@@ -143,8 +144,6 @@ func TestEmbeddedPubKeyValidate(t *testing.T) {
 }
 
 func TestPeerIDPubKeyValidate(t *testing.T) {
-	t.Skip("disabled until libp2p/go-libp2p-crypto#51 is fixed")
-
 	goodeol := time.Now().Add(time.Hour)
 	kbook, err := pstoremem.NewPeerstore()
 	if err != nil {
@@ -413,3 +412,38 @@ func genKeys(t *testing.T) (crypto.PrivKey, peer.ID, string) {
 
 	return priv, pid, ipnsKey
 }
+
+func TestValidateWithPeerID(t *testing.T) {
+	path := []byte("/ipfs/bafkreifjjcie6lypi6ny7amxnfftagclbuxndqonfipmb64f2km2devei4")
+	eol := time.Now().Add(time.Hour)
+
+	rnd := rand.New(rand.NewSource(42))
+
+	sk, pk, err := crypto.GenerateEd25519Key(rnd)
+	assert.NoError(t, err)
+
+	pid, err := peer.IDFromPublicKey(pk)
+	assert.NoError(t, err)
+
+	entry, err := Create(sk, path, 1, eol, 0)
+	assert.NoError(t, err)
+
+	t.Run("valid peer ID", func(t *testing.T) {
+		t.Parallel()
+		err = ValidateWithPeerID(pid, entry)
+		assert.NoError(t, err)
+	})
+
+	t.Run("invalid peer ID", func(t *testing.T) {
+		t.Parallel()
+
+		_, pk2, err := crypto.GenerateEd25519Key(rnd)
+		assert.NoError(t, err)
+
+		pid2, err := peer.IDFromPublicKey(pk2)
+		assert.NoError(t, err)
+
+		err = ValidateWithPeerID(pid2, entry)
+		assert.ErrorIs(t, err, ErrSignature)
+	})
+}