multi: update models.ChannelAuthProof with v2 field

diff --git a/discovery/gossiper.go b/discovery/gossiper.go
index 9d0338c..2cbd4e8 100644
--- a/discovery/gossiper.go
+++ b/discovery/gossiper.go
@@ -2504,25 +2504,25 @@ func (d *AuthenticatedGossiper) updateChannel(ctx context.Context,
 			ExtraOpaqueData: info.ExtraOpaqueData,
 		}
 		chanAnn.NodeSig1, err = lnwire.NewSigFromECDSARawSignature(
-			info.AuthProof.NodeSig1Bytes,
+			info.AuthProof.NodeSig1(),
 		)
 		if err != nil {
 			return nil, nil, err
 		}
 		chanAnn.NodeSig2, err = lnwire.NewSigFromECDSARawSignature(
-			info.AuthProof.NodeSig2Bytes,
+			info.AuthProof.NodeSig2(),
 		)
 		if err != nil {
 			return nil, nil, err
 		}
 		chanAnn.BitcoinSig1, err = lnwire.NewSigFromECDSARawSignature(
-			info.AuthProof.BitcoinSig1Bytes,
+			info.AuthProof.BitcoinSig1(),
 		)
 		if err != nil {
 			return nil, nil, err
 		}
 		chanAnn.BitcoinSig2, err = lnwire.NewSigFromECDSARawSignature(
-			info.AuthProof.BitcoinSig2Bytes,
+			info.AuthProof.BitcoinSig2(),
 		)
 		if err != nil {
 			return nil, nil, err
@@ -2808,12 +2808,12 @@ func (d *AuthenticatedGossiper) handleChanAnnouncement(ctx context.Context,
 		// If the proof checks out, then we'll save the proof itself to
 		// the database so we can fetch it later when gossiping with
 		// other nodes.
-		proof = &models.ChannelAuthProof{
-			NodeSig1Bytes:    ann.NodeSig1.ToSignatureBytes(),
-			NodeSig2Bytes:    ann.NodeSig2.ToSignatureBytes(),
-			BitcoinSig1Bytes: ann.BitcoinSig1.ToSignatureBytes(),
-			BitcoinSig2Bytes: ann.BitcoinSig2.ToSignatureBytes(),
-		}
+		proof = models.NewV1ChannelAuthProof(
+			ann.NodeSig1.ToSignatureBytes(),
+			ann.NodeSig2.ToSignatureBytes(),
+			ann.BitcoinSig1.ToSignatureBytes(),
+			ann.BitcoinSig2.ToSignatureBytes(),
+		)
 	}
 
 	// With the proof validated (if necessary), we can now store it within
@@ -3758,21 +3758,25 @@ func (d *AuthenticatedGossiper) handleAnnSig(ctx context.Context,
 	// We now have both halves of the channel announcement proof, then
 	// we'll reconstruct the initial announcement so we can validate it
 	// shortly below.
-	var dbProof models.ChannelAuthProof
+	var dbProof *models.ChannelAuthProof
 	if isFirstNode {
-		dbProof.NodeSig1Bytes = ann.NodeSignature.ToSignatureBytes()
-		dbProof.NodeSig2Bytes = oppProof.NodeSignature.ToSignatureBytes()
-		dbProof.BitcoinSig1Bytes = ann.BitcoinSignature.ToSignatureBytes()
-		dbProof.BitcoinSig2Bytes = oppProof.BitcoinSignature.ToSignatureBytes()
+		dbProof = models.NewV1ChannelAuthProof(
+			ann.NodeSignature.ToSignatureBytes(),
+			oppProof.NodeSignature.ToSignatureBytes(),
+			ann.BitcoinSignature.ToSignatureBytes(),
+			oppProof.BitcoinSignature.ToSignatureBytes(),
+		)
 	} else {
-		dbProof.NodeSig1Bytes = oppProof.NodeSignature.ToSignatureBytes()
-		dbProof.NodeSig2Bytes = ann.NodeSignature.ToSignatureBytes()
-		dbProof.BitcoinSig1Bytes = oppProof.BitcoinSignature.ToSignatureBytes()
-		dbProof.BitcoinSig2Bytes = ann.BitcoinSignature.ToSignatureBytes()
+		dbProof = models.NewV1ChannelAuthProof(
+			oppProof.NodeSignature.ToSignatureBytes(),
+			ann.NodeSignature.ToSignatureBytes(),
+			oppProof.BitcoinSignature.ToSignatureBytes(),
+			ann.BitcoinSignature.ToSignatureBytes(),
+		)
 	}
 
 	chanAnn, e1Ann, e2Ann, err := netann.CreateChanAnnouncement(
-		&dbProof, chanInfo, e1, e2,
+		dbProof, chanInfo, e1, e2,
 	)
 	if err != nil {
 		log.Error(err)
@@ -3798,7 +3802,7 @@ func (d *AuthenticatedGossiper) handleAnnSig(ctx context.Context,
 	// attest to the bitcoin keys by validating the signatures of
 	// announcement. If proof is valid then we'll populate the channel edge
 	// with it, so we can announce it on peer connect.
-	err = d.cfg.Graph.AddProof(ann.ShortChannelID, &dbProof)
+	err = d.cfg.Graph.AddProof(ann.ShortChannelID, dbProof)
 	if err != nil {
 		err := fmt.Errorf("unable add proof to the channel chanID=%v:"+
 			" %v", ann.ChannelID, err)
diff --git a/graph/builder_test.go b/graph/builder_test.go
index b6fe886..f2648a0 100644
--- a/graph/builder_test.go
+++ b/graph/builder_test.go
@@ -279,12 +279,12 @@ func TestWakeUpOnStaleBranch(t *testing.T) {
 		ChannelID:     chanID1,
 		NodeKey1Bytes: node1.PubKeyBytes,
 		NodeKey2Bytes: node2.PubKeyBytes,
-		AuthProof: &models.ChannelAuthProof{
-			NodeSig1Bytes:    testSig.Serialize(),
-			NodeSig2Bytes:    testSig.Serialize(),
-			BitcoinSig1Bytes: testSig.Serialize(),
-			BitcoinSig2Bytes: testSig.Serialize(),
-		},
+		AuthProof: models.NewV1ChannelAuthProof(
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+		),
 		Features:      lnwire.EmptyFeatureVector(),
 		FundingScript: fn.Some(fundingScript1),
 	}
@@ -300,12 +300,12 @@ func TestWakeUpOnStaleBranch(t *testing.T) {
 		ChannelID:     chanID2,
 		NodeKey1Bytes: node1.PubKeyBytes,
 		NodeKey2Bytes: node2.PubKeyBytes,
-		AuthProof: &models.ChannelAuthProof{
-			NodeSig1Bytes:    testSig.Serialize(),
-			NodeSig2Bytes:    testSig.Serialize(),
-			BitcoinSig1Bytes: testSig.Serialize(),
-			BitcoinSig2Bytes: testSig.Serialize(),
-		},
+		AuthProof: models.NewV1ChannelAuthProof(
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+		),
 		Features:      lnwire.EmptyFeatureVector(),
 		FundingScript: fn.Some(fundingScript2),
 	}
@@ -493,12 +493,12 @@ func TestDisconnectedBlocks(t *testing.T) {
 		NodeKey2Bytes:    node2.PubKeyBytes,
 		BitcoinKey1Bytes: node1.PubKeyBytes,
 		BitcoinKey2Bytes: node2.PubKeyBytes,
-		AuthProof: &models.ChannelAuthProof{
-			NodeSig1Bytes:    testSig.Serialize(),
-			NodeSig2Bytes:    testSig.Serialize(),
-			BitcoinSig1Bytes: testSig.Serialize(),
-			BitcoinSig2Bytes: testSig.Serialize(),
-		},
+		AuthProof: models.NewV1ChannelAuthProof(
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+		),
 		Features:      lnwire.EmptyFeatureVector(),
 		FundingScript: fn.Some([]byte{}),
 	}
@@ -516,12 +516,12 @@ func TestDisconnectedBlocks(t *testing.T) {
 		NodeKey2Bytes:    node2.PubKeyBytes,
 		BitcoinKey1Bytes: node1.PubKeyBytes,
 		BitcoinKey2Bytes: node2.PubKeyBytes,
-		AuthProof: &models.ChannelAuthProof{
-			NodeSig1Bytes:    testSig.Serialize(),
-			NodeSig2Bytes:    testSig.Serialize(),
-			BitcoinSig1Bytes: testSig.Serialize(),
-			BitcoinSig2Bytes: testSig.Serialize(),
-		},
+		AuthProof: models.NewV1ChannelAuthProof(
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+		),
 		Features:      lnwire.EmptyFeatureVector(),
 		FundingScript: fn.Some([]byte{}),
 	}
@@ -649,12 +649,12 @@ func TestChansClosedOfflinePruneGraph(t *testing.T) {
 		ChannelID:     chanID1.ToUint64(),
 		NodeKey1Bytes: node1.PubKeyBytes,
 		NodeKey2Bytes: node2.PubKeyBytes,
-		AuthProof: &models.ChannelAuthProof{
-			NodeSig1Bytes:    testSig.Serialize(),
-			NodeSig2Bytes:    testSig.Serialize(),
-			BitcoinSig1Bytes: testSig.Serialize(),
-			BitcoinSig2Bytes: testSig.Serialize(),
-		},
+		AuthProof: models.NewV1ChannelAuthProof(
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+		),
 		ChannelPoint:  *chanUTXO,
 		Capacity:      chanValue,
 		Features:      lnwire.EmptyFeatureVector(),
diff --git a/graph/db/graph_test.go b/graph/db/graph_test.go
index 7c4255b..fcae25e 100644
--- a/graph/db/graph_test.go
+++ b/graph/db/graph_test.go
@@ -566,12 +566,12 @@ func TestEdgeInsertionDeletion(t *testing.T) {
 		Version:   lnwire.GossipVersion1,
 		ChannelID: chanID,
 		ChainHash: *chaincfg.MainNetParams.GenesisHash,
-		AuthProof: &models.ChannelAuthProof{
-			NodeSig1Bytes:    testSig.Serialize(),
-			NodeSig2Bytes:    testSig.Serialize(),
-			BitcoinSig1Bytes: testSig.Serialize(),
-			BitcoinSig2Bytes: testSig.Serialize(),
-		},
+		AuthProof: models.NewV1ChannelAuthProof(
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+		),
 		Features:     lnwire.EmptyFeatureVector(),
 		ChannelPoint: outpoint,
 		Capacity:     9000,
@@ -642,12 +642,12 @@ func createEdge(height, txIndex uint32, txPosition uint16, outPointIndex uint32,
 		Version:   lnwire.GossipVersion1,
 		ChannelID: shortChanID.ToUint64(),
 		ChainHash: *chaincfg.MainNetParams.GenesisHash,
-		AuthProof: &models.ChannelAuthProof{
-			NodeSig1Bytes:    testSig.Serialize(),
-			NodeSig2Bytes:    testSig.Serialize(),
-			BitcoinSig1Bytes: testSig.Serialize(),
-			BitcoinSig2Bytes: testSig.Serialize(),
-		},
+		AuthProof: models.NewV1ChannelAuthProof(
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+		),
 		ChannelPoint:    outpoint,
 		Capacity:        9000,
 		ExtraOpaqueData: make([]byte, 0),
@@ -821,17 +821,20 @@ func assertEdgeInfoEqual(t *testing.T, e1 *models.ChannelEdgeInfo,
 	}
 
 	require.True(t, bytes.Equal(
-		e1.AuthProof.NodeSig1Bytes, e2.AuthProof.NodeSig1Bytes,
+		e1.AuthProof.NodeSig1(),
+		e2.AuthProof.NodeSig1(),
 	))
 	require.True(t, bytes.Equal(
-		e1.AuthProof.NodeSig2Bytes, e2.AuthProof.NodeSig2Bytes,
+		e1.AuthProof.NodeSig2(),
+		e2.AuthProof.NodeSig2(),
 	))
 	require.True(t, bytes.Equal(
-		e1.AuthProof.BitcoinSig1Bytes,
-		e2.AuthProof.BitcoinSig1Bytes,
+		e1.AuthProof.BitcoinSig1(),
+		e2.AuthProof.BitcoinSig1(),
 	))
 	require.True(t, bytes.Equal(
-		e1.AuthProof.BitcoinSig2Bytes, e2.AuthProof.BitcoinSig2Bytes,
+		e1.AuthProof.BitcoinSig2(),
+		e2.AuthProof.BitcoinSig2(),
 	))
 
 	if e1.ChannelPoint != e2.ChannelPoint {
@@ -917,12 +920,12 @@ func createChannelEdge(node1, node2 *models.Node,
 		return edgeInfo, nil, nil
 	}
 
-	edgeInfo.AuthProof = &models.ChannelAuthProof{
-		NodeSig1Bytes:    testSig.Serialize(),
-		NodeSig2Bytes:    testSig.Serialize(),
-		BitcoinSig1Bytes: testSig.Serialize(),
-		BitcoinSig2Bytes: testSig.Serialize(),
-	}
+	edgeInfo.AuthProof = models.NewV1ChannelAuthProof(
+		testSig.Serialize(),
+		testSig.Serialize(),
+		testSig.Serialize(),
+		testSig.Serialize(),
+	)
 
 	edge1 := &models.ChannelEdgePolicy{
 		SigBytes:                  testSig.Serialize(),
@@ -1373,12 +1376,12 @@ func TestAddEdgeProof(t *testing.T) {
 	require.Equal(t, edge1, dbEdge)
 
 	// Now, add the edge proof.
-	proof := &models.ChannelAuthProof{
-		NodeSig1Bytes:    testSig.Serialize(),
-		NodeSig2Bytes:    testSig.Serialize(),
-		BitcoinSig1Bytes: testSig.Serialize(),
-		BitcoinSig2Bytes: testSig.Serialize(),
-	}
+	proof := models.NewV1ChannelAuthProof(
+		testSig.Serialize(),
+		testSig.Serialize(),
+		testSig.Serialize(),
+		testSig.Serialize(),
+	)
 
 	// First, add the proof to the rest of the channel edge info and try
 	// to call AddChannelEdge again - this should fail due to the channel
@@ -1781,12 +1784,12 @@ func fillTestGraph(t testing.TB, graph *ChannelGraph, numNodes,
 				Version:   lnwire.GossipVersion1,
 				ChannelID: chanID,
 				ChainHash: *chaincfg.MainNetParams.GenesisHash,
-				AuthProof: &models.ChannelAuthProof{
-					NodeSig1Bytes:    testSig.Serialize(),
-					NodeSig2Bytes:    testSig.Serialize(),
-					BitcoinSig1Bytes: testSig.Serialize(),
-					BitcoinSig2Bytes: testSig.Serialize(),
-				},
+				AuthProof: models.NewV1ChannelAuthProof(
+					testSig.Serialize(),
+					testSig.Serialize(),
+					testSig.Serialize(),
+					testSig.Serialize(),
+				),
 				Features:     lnwire.EmptyFeatureVector(),
 				ChannelPoint: op,
 				Capacity:     1000,
@@ -1964,12 +1967,12 @@ func TestGraphPruning(t *testing.T) {
 			Version:   lnwire.GossipVersion1,
 			ChannelID: chanID,
 			ChainHash: *chaincfg.MainNetParams.GenesisHash,
-			AuthProof: &models.ChannelAuthProof{
-				NodeSig1Bytes:    testSig.Serialize(),
-				NodeSig2Bytes:    testSig.Serialize(),
-				BitcoinSig1Bytes: testSig.Serialize(),
-				BitcoinSig2Bytes: testSig.Serialize(),
-			},
+			AuthProof: models.NewV1ChannelAuthProof(
+				testSig.Serialize(),
+				testSig.Serialize(),
+				testSig.Serialize(),
+				testSig.Serialize(),
+			),
 			Features:     lnwire.EmptyFeatureVector(),
 			ChannelPoint: op,
 			Capacity:     1000,
diff --git a/graph/db/kv_store.go b/graph/db/kv_store.go
index 7407278..b137c62 100644
--- a/graph/db/kv_store.go
+++ b/graph/db/kv_store.go
@@ -1398,6 +1398,12 @@ func (c *KVStore) HasChannelEdge(
 func (c *KVStore) AddEdgeProof(chanID lnwire.ShortChannelID,
 	proof *models.ChannelAuthProof) error {
 
+	// We only support v1 channel proofs in the KVStore.
+	if proof.Version != lnwire.GossipVersion1 {
+		return fmt.Errorf("only v1 channel proofs supported, got v%d",
+			proof.Version)
+	}
+
 	// Construct the channel's primary key which is the 8-byte channel ID.
 	var chanKey [8]byte
 	binary.BigEndian.PutUint64(chanKey[:], chanID.ToUint64())
@@ -4738,10 +4744,10 @@ func putChanEdgeInfo(edgeIndex kvdb.RwBucket,
 	authProof := edgeInfo.AuthProof
 	var nodeSig1, nodeSig2, bitcoinSig1, bitcoinSig2 []byte
 	if authProof != nil {
-		nodeSig1 = authProof.NodeSig1Bytes
-		nodeSig2 = authProof.NodeSig2Bytes
-		bitcoinSig1 = authProof.BitcoinSig1Bytes
-		bitcoinSig2 = authProof.BitcoinSig2Bytes
+		nodeSig1 = authProof.NodeSig1()
+		nodeSig2 = authProof.NodeSig2()
+		bitcoinSig1 = authProof.BitcoinSig1()
+		bitcoinSig2 = authProof.BitcoinSig2()
 	}
 
 	if err := wire.WriteVarBytes(&b, 0, nodeSig1); err != nil {
@@ -4899,24 +4905,42 @@ func deserializeChanEdgeInfo(r io.Reader) (*models.ChannelEdgeInfo, error) {
 		return nil, err
 	}
 
-	proof := &models.ChannelAuthProof{}
+	proof := &models.ChannelAuthProof{
+		// KV store always uses v1.
+		Version: lnwire.GossipVersion1,
+	}
 
-	proof.NodeSig1Bytes, err = wire.ReadVarBytes(r, 0, 80, "sigs")
+	nodeSig1, err := wire.ReadVarBytes(r, 0, 80, "sigs")
 	if err != nil {
 		return nil, err
 	}
-	proof.NodeSig2Bytes, err = wire.ReadVarBytes(r, 0, 80, "sigs")
+	if len(nodeSig1) > 0 {
+		proof.NodeSig1Bytes = fn.Some(nodeSig1)
+	}
+
+	nodeSig2, err := wire.ReadVarBytes(r, 0, 80, "sigs")
 	if err != nil {
 		return nil, err
 	}
-	proof.BitcoinSig1Bytes, err = wire.ReadVarBytes(r, 0, 80, "sigs")
+	if len(nodeSig2) > 0 {
+		proof.NodeSig2Bytes = fn.Some(nodeSig2)
+	}
+
+	bitcoinSig1, err := wire.ReadVarBytes(r, 0, 80, "sigs")
 	if err != nil {
 		return nil, err
 	}
-	proof.BitcoinSig2Bytes, err = wire.ReadVarBytes(r, 0, 80, "sigs")
+	if len(bitcoinSig1) > 0 {
+		proof.BitcoinSig1Bytes = fn.Some(bitcoinSig1)
+	}
+
+	bitcoinSig2, err := wire.ReadVarBytes(r, 0, 80, "sigs")
 	if err != nil {
 		return nil, err
 	}
+	if len(bitcoinSig2) > 0 {
+		proof.BitcoinSig2Bytes = fn.Some(bitcoinSig2)
+	}
 
 	if !proof.IsEmpty() {
 		edgeInfo.AuthProof = proof
diff --git a/graph/db/models/channel_auth_proof.go b/graph/db/models/channel_auth_proof.go
index daf120b..1e1fb03 100644
--- a/graph/db/models/channel_auth_proof.go
+++ b/graph/db/models/channel_auth_proof.go
@@ -1,35 +1,119 @@
 package models
 
+import (
+	"github.com/lightningnetwork/lnd/fn/v2"
+	"github.com/lightningnetwork/lnd/lnwire"
+)
+
 // ChannelAuthProof is the authentication proof (the signature portion) for a
-// channel. Using the four signatures contained in the struct, and some
+// channel.
+//
+// For v1 channels:
+// Using the four node and bitcoin signatures contained in the struct, and some
 // auxiliary knowledge (the funding script, node identities, and outpoint) nodes
 // on the network are able to validate the authenticity and existence of a
 // channel. Each of these signatures signs the following digest: chanID ||
 // nodeID1 || nodeID2 || bitcoinKey1|| bitcoinKey2 || 2-byte-feature-len ||
 // features.
+//
+// For v2 channels:
+// The single schnorr signature signs the tlv fields of the v2 channel
+// announcement message which are in the signed range.
 type ChannelAuthProof struct {
+	// Version is the version of the channel announcement.
+	Version lnwire.GossipVersion
+
 	// NodeSig1Bytes are the raw bytes of the first node signature encoded
 	// in DER format.
-	NodeSig1Bytes []byte
+	//
+	// NOTE: v1 channel announcements only.
+	NodeSig1Bytes fn.Option[[]byte]
 
 	// NodeSig2Bytes are the raw bytes of the second node signature
 	// encoded in DER format.
-	NodeSig2Bytes []byte
+	//
+	// NOTE: v1 channel announcements only.
+	NodeSig2Bytes fn.Option[[]byte]
 
 	// BitcoinSig1Bytes are the raw bytes of the first bitcoin signature
 	// encoded in DER format.
-	BitcoinSig1Bytes []byte
+	//
+	// NOTE: v1 channel announcements only.
+	BitcoinSig1Bytes fn.Option[[]byte]
 
 	// BitcoinSig2Bytes are the raw bytes of the second bitcoin signature
 	// encoded in DER format.
-	BitcoinSig2Bytes []byte
+	//
+	// NOTE: v1 channel announcements only.
+	BitcoinSig2Bytes fn.Option[[]byte]
+
+	// Signature is the raw bytes of the single schnorr signature for v2
+	// channel announcements.
+	//
+	// NOTE: v2 channel announcements only.
+	Signature fn.Option[[]byte]
 }
 
-// IsEmpty check is the authentication proof is empty Proof is empty if at
-// least one of the signatures are equal to nil.
+// IsEmpty check is the authentication proof is empty Proof is empty.
 func (c *ChannelAuthProof) IsEmpty() bool {
-	return len(c.NodeSig1Bytes) == 0 ||
-		len(c.NodeSig2Bytes) == 0 ||
-		len(c.BitcoinSig1Bytes) == 0 ||
-		len(c.BitcoinSig2Bytes) == 0
+	// For v1 channel announcements, we either have all four signatures or
+	// none.
+	if c.Version == lnwire.GossipVersion1 {
+		return c.NodeSig1Bytes.IsNone()
+	}
+
+	// For v2 channel announcements, we only have a single signature.
+	return c.Signature.IsNone()
+}
+
+// NewV1ChannelAuthProof creates a new ChannelAuthProof for a v1 channel
+// announcement.
+func NewV1ChannelAuthProof(nodeSig1, nodeSig2, bitcoinSig1,
+	bitcoinSig2 []byte) *ChannelAuthProof {
+
+	return &ChannelAuthProof{
+		Version:          lnwire.GossipVersion1,
+		NodeSig1Bytes:    fn.Some(nodeSig1),
+		NodeSig2Bytes:    fn.Some(nodeSig2),
+		BitcoinSig1Bytes: fn.Some(bitcoinSig1),
+		BitcoinSig2Bytes: fn.Some(bitcoinSig2),
+	}
+}
+
+// NewV2ChannelAuthProof creates a new ChannelAuthProof for a v2 channel
+// announcement.
+func NewV2ChannelAuthProof(signature []byte) *ChannelAuthProof {
+	return &ChannelAuthProof{
+		Version:   lnwire.GossipVersion2,
+		Signature: fn.Some(signature),
+	}
+}
+
+// NodeSig1 returns the first node signature bytes, or an empty slice if not
+// present.
+func (c *ChannelAuthProof) NodeSig1() []byte {
+	return c.NodeSig1Bytes.UnwrapOr([]byte{})
+}
+
+// NodeSig2 returns the second node signature bytes, or an empty slice if not
+// present.
+func (c *ChannelAuthProof) NodeSig2() []byte {
+	return c.NodeSig2Bytes.UnwrapOr([]byte{})
+}
+
+// BitcoinSig1 returns the first bitcoin signature bytes, or an empty slice if
+// not present.
+func (c *ChannelAuthProof) BitcoinSig1() []byte {
+	return c.BitcoinSig1Bytes.UnwrapOr([]byte{})
+}
+
+// BitcoinSig2 returns the second bitcoin signature bytes, or an empty slice if
+// not present.
+func (c *ChannelAuthProof) BitcoinSig2() []byte {
+	return c.BitcoinSig2Bytes.UnwrapOr([]byte{})
+}
+
+// Sig returns the v2 signature bytes, or an empty slice if not present.
+func (c *ChannelAuthProof) Sig() []byte {
+	return c.Signature.UnwrapOr([]byte{})
 }
diff --git a/graph/db/sql_store.go b/graph/db/sql_store.go
index aeeeb37..2535826 100644
--- a/graph/db/sql_store.go
+++ b/graph/db/sql_store.go
@@ -2966,6 +2966,12 @@ func (s *SQLStore) DisconnectBlockAtHeight(height uint32) (
 func (s *SQLStore) AddEdgeProof(scid lnwire.ShortChannelID,
 	proof *models.ChannelAuthProof) error {
 
+	// For now, we only support v1 channel proofs.
+	if proof.Version != lnwire.GossipVersion1 {
+		return fmt.Errorf("only v1 channel proofs supported, got v%d",
+			proof.Version)
+	}
+
 	var (
 		ctx       = context.TODO()
 		scidBytes = channelIDToBytes(scid.ToUint64())
@@ -2975,10 +2981,10 @@ func (s *SQLStore) AddEdgeProof(scid lnwire.ShortChannelID,
 		res, err := db.AddV1ChannelProof(
 			ctx, sqlc.AddV1ChannelProofParams{
 				Scid:              scidBytes,
-				Node1Signature:    proof.NodeSig1Bytes,
-				Node2Signature:    proof.NodeSig2Bytes,
-				Bitcoin1Signature: proof.BitcoinSig1Bytes,
-				Bitcoin2Signature: proof.BitcoinSig2Bytes,
+				Node1Signature:    proof.NodeSig1(),
+				Node2Signature:    proof.NodeSig2(),
+				Bitcoin1Signature: proof.BitcoinSig1(),
+				Bitcoin2Signature: proof.BitcoinSig2(),
 			},
 		)
 		if err != nil {
@@ -4284,10 +4290,10 @@ func insertChannel(ctx context.Context, db SQLQueries,
 	if edge.AuthProof != nil {
 		proof := edge.AuthProof
 
-		createParams.Node1Signature = proof.NodeSig1Bytes
-		createParams.Node2Signature = proof.NodeSig2Bytes
-		createParams.Bitcoin1Signature = proof.BitcoinSig1Bytes
-		createParams.Bitcoin2Signature = proof.BitcoinSig2Bytes
+		createParams.Node1Signature = proof.NodeSig1()
+		createParams.Node2Signature = proof.NodeSig2()
+		createParams.Bitcoin1Signature = proof.BitcoinSig1()
+		createParams.Bitcoin2Signature = proof.BitcoinSig2()
 	}
 
 	// Insert the new channel record.
@@ -4483,12 +4489,16 @@ func buildEdgeInfoWithBatchData(chain chainhash.Hash,
 	// safely check if one signature is present to determine if we have the
 	// rest of the signatures for the auth proof.
 	if len(dbChan.Bitcoin1Signature) > 0 {
-		channel.AuthProof = &models.ChannelAuthProof{
-			NodeSig1Bytes:    dbChan.Node1Signature,
-			NodeSig2Bytes:    dbChan.Node2Signature,
-			BitcoinSig1Bytes: dbChan.Bitcoin1Signature,
-			BitcoinSig2Bytes: dbChan.Bitcoin2Signature,
+		// For v1 channels, we have four signatures.
+		if dbChan.Version == int16(lnwire.GossipVersion1) {
+			channel.AuthProof = models.NewV1ChannelAuthProof(
+				dbChan.Node1Signature,
+				dbChan.Node2Signature,
+				dbChan.Bitcoin1Signature,
+				dbChan.Bitcoin2Signature,
+			)
 		}
+		// TODO(elle): Add v2 support when needed.
 	}
 
 	return channel, nil
diff --git a/graph/notifications_test.go b/graph/notifications_test.go
index e220a0b..fab5b4c 100644
--- a/graph/notifications_test.go
+++ b/graph/notifications_test.go
@@ -68,12 +68,12 @@ var (
 	_           = testSScalar.SetByteSlice(testSBytes)
 	testSig     = ecdsa.NewSignature(testRScalar, testSScalar)
 
-	testAuthProof = models.ChannelAuthProof{
-		NodeSig1Bytes:    testSig.Serialize(),
-		NodeSig2Bytes:    testSig.Serialize(),
-		BitcoinSig1Bytes: testSig.Serialize(),
-		BitcoinSig2Bytes: testSig.Serialize(),
-	}
+	testAuthProof = *models.NewV1ChannelAuthProof(
+		testSig.Serialize(),
+		testSig.Serialize(),
+		testSig.Serialize(),
+		testSig.Serialize(),
+	)
 )
 
 func createTestNode(t *testing.T) *models.Node {
@@ -452,12 +452,12 @@ func TestEdgeUpdateNotification(t *testing.T) {
 		ChannelID:     chanID.ToUint64(),
 		NodeKey1Bytes: node1.PubKeyBytes,
 		NodeKey2Bytes: node2.PubKeyBytes,
-		AuthProof: &models.ChannelAuthProof{
-			NodeSig1Bytes:    testSig.Serialize(),
-			NodeSig2Bytes:    testSig.Serialize(),
-			BitcoinSig1Bytes: testSig.Serialize(),
-			BitcoinSig2Bytes: testSig.Serialize(),
-		},
+		AuthProof: models.NewV1ChannelAuthProof(
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+		),
 		Features:      lnwire.EmptyFeatureVector(),
 		ChannelPoint:  *chanPoint,
 		Capacity:      chanValue,
@@ -648,12 +648,12 @@ func TestNodeUpdateNotification(t *testing.T) {
 		NodeKey1Bytes: node1.PubKeyBytes,
 		NodeKey2Bytes: node2.PubKeyBytes,
 		Features:      lnwire.EmptyFeatureVector(),
-		AuthProof: &models.ChannelAuthProof{
-			NodeSig1Bytes:    testSig.Serialize(),
-			NodeSig2Bytes:    testSig.Serialize(),
-			BitcoinSig1Bytes: testSig.Serialize(),
-			BitcoinSig2Bytes: testSig.Serialize(),
-		},
+		AuthProof: models.NewV1ChannelAuthProof(
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+		),
 		FundingScript: fn.Some(script),
 	}
 	copy(edge.BitcoinKey1Bytes[:], bitcoinKey1.SerializeCompressed())
@@ -834,12 +834,12 @@ func TestNotificationCancellation(t *testing.T) {
 		ChannelID:     chanID.ToUint64(),
 		NodeKey1Bytes: node1.PubKeyBytes,
 		NodeKey2Bytes: node2.PubKeyBytes,
-		AuthProof: &models.ChannelAuthProof{
-			NodeSig1Bytes:    testSig.Serialize(),
-			NodeSig2Bytes:    testSig.Serialize(),
-			BitcoinSig1Bytes: testSig.Serialize(),
-			BitcoinSig2Bytes: testSig.Serialize(),
-		},
+		AuthProof: models.NewV1ChannelAuthProof(
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+		),
 		Features:      lnwire.EmptyFeatureVector(),
 		ChannelPoint:  *chanPoint,
 		Capacity:      chanValue,
@@ -911,12 +911,12 @@ func TestChannelCloseNotification(t *testing.T) {
 		ChannelID:     chanID.ToUint64(),
 		NodeKey1Bytes: node1.PubKeyBytes,
 		NodeKey2Bytes: node2.PubKeyBytes,
-		AuthProof: &models.ChannelAuthProof{
-			NodeSig1Bytes:    testSig.Serialize(),
-			NodeSig2Bytes:    testSig.Serialize(),
-			BitcoinSig1Bytes: testSig.Serialize(),
-			BitcoinSig2Bytes: testSig.Serialize(),
-		},
+		AuthProof: models.NewV1ChannelAuthProof(
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+			testSig.Serialize(),
+		),
 		Features:      lnwire.EmptyFeatureVector(),
 		ChannelPoint:  *chanUtxo,
 		Capacity:      chanValue,
diff --git a/netann/channel_announcement.go b/netann/channel_announcement.go
index 9bb21c4..fee3c5a 100644
--- a/netann/channel_announcement.go
+++ b/netann/channel_announcement.go
@@ -56,25 +56,25 @@ func CreateChanAnnouncement(chanProof *models.ChannelAuthProof,
 
 	var err error
 	chanAnn.BitcoinSig1, err = lnwire.NewSigFromECDSARawSignature(
-		chanProof.BitcoinSig1Bytes,
+		chanProof.BitcoinSig1(),
 	)
 	if err != nil {
 		return nil, nil, nil, err
 	}
 	chanAnn.BitcoinSig2, err = lnwire.NewSigFromECDSARawSignature(
-		chanProof.BitcoinSig2Bytes,
+		chanProof.BitcoinSig2(),
 	)
 	if err != nil {
 		return nil, nil, nil, err
 	}
 	chanAnn.NodeSig1, err = lnwire.NewSigFromECDSARawSignature(
-		chanProof.NodeSig1Bytes,
+		chanProof.NodeSig1(),
 	)
 	if err != nil {
 		return nil, nil, nil, err
 	}
 	chanAnn.NodeSig2, err = lnwire.NewSigFromECDSARawSignature(
-		chanProof.NodeSig2Bytes,
+		chanProof.NodeSig2(),
 	)
 	if err != nil {
 		return nil, nil, nil, err
diff --git a/netann/channel_announcement_test.go b/netann/channel_announcement_test.go
index 49f61a5..02d1d56 100644
--- a/netann/channel_announcement_test.go
+++ b/netann/channel_announcement_test.go
@@ -40,12 +40,12 @@ func TestCreateChanAnnouncement(t *testing.T) {
 		ExtraOpaqueData: []byte{0x1},
 	}
 
-	chanProof := &models.ChannelAuthProof{
-		NodeSig1Bytes:    expChanAnn.NodeSig1.ToSignatureBytes(),
-		NodeSig2Bytes:    expChanAnn.NodeSig2.ToSignatureBytes(),
-		BitcoinSig1Bytes: expChanAnn.BitcoinSig1.ToSignatureBytes(),
-		BitcoinSig2Bytes: expChanAnn.BitcoinSig2.ToSignatureBytes(),
-	}
+	chanProof := models.NewV1ChannelAuthProof(
+		expChanAnn.NodeSig1.ToSignatureBytes(),
+		expChanAnn.NodeSig2.ToSignatureBytes(),
+		expChanAnn.BitcoinSig1.ToSignatureBytes(),
+		expChanAnn.BitcoinSig2.ToSignatureBytes(),
+	)
 	chanInfo := &models.ChannelEdgeInfo{
 		Version:          lnwire.GossipVersion1,
 		ChainHash:        expChanAnn.ChainHash,
diff --git a/routing/pathfind_test.go b/routing/pathfind_test.go
index b7256e3..bbb31fd 100644
--- a/routing/pathfind_test.go
+++ b/routing/pathfind_test.go
@@ -99,12 +99,12 @@ var (
 	_             = testSScalar.SetByteSlice(testSBytes)
 	testSig       = ecdsa.NewSignature(testRScalar, testSScalar)
 
-	testAuthProof = models.ChannelAuthProof{
-		NodeSig1Bytes:    testSig.Serialize(),
-		NodeSig2Bytes:    testSig.Serialize(),
-		BitcoinSig1Bytes: testSig.Serialize(),
-		BitcoinSig2Bytes: testSig.Serialize(),
-	}
+	testAuthProof = *models.NewV1ChannelAuthProof(
+		testSig.Serialize(),
+		testSig.Serialize(),
+		testSig.Serialize(),
+		testSig.Serialize(),
+	)
 )
 
 // noProbabilitySource is used in testing to return the same probability 1 for
diff --git a/rpcserver.go b/rpcserver.go
index 06e0155..0c49639 100644
--- a/rpcserver.go
+++ b/rpcserver.go
@@ -6980,10 +6980,10 @@ func marshalDBEdge(edgeInfo *models.ChannelEdgeInfo,
 	// channel announcement.
 	if includeAuthProof && edgeInfo.AuthProof != nil {
 		edge.AuthProof = &lnrpc.ChannelAuthProof{
-			NodeSig1:    edgeInfo.AuthProof.NodeSig1Bytes,
-			BitcoinSig1: edgeInfo.AuthProof.BitcoinSig1Bytes,
-			NodeSig2:    edgeInfo.AuthProof.NodeSig2Bytes,
-			BitcoinSig2: edgeInfo.AuthProof.BitcoinSig2Bytes,
+			NodeSig1:    edgeInfo.AuthProof.NodeSig1(),
+			BitcoinSig1: edgeInfo.AuthProof.BitcoinSig1(),
+			NodeSig2:    edgeInfo.AuthProof.NodeSig2(),
+			BitcoinSig2: edgeInfo.AuthProof.BitcoinSig2(),
 		}
 	}