taprpc+mutli: move marshal functions from priceoraclerpc and universerpc

docs/examples/basic-price-oracle/main.go

@@ -11,6 +11,7 @@ import (
 	"net"
 	"time"
 
+	"github.com/lightninglabs/taproot-assets/rpcutils"
 	oraclerpc "github.com/lightninglabs/taproot-assets/taprpc/priceoraclerpc"
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/credentials/insecure"
@@ -105,7 +106,7 @@ func (p *RpcPriceOracleServer) QueryRateTick(_ context.Context,
 
 	// Ensure that the payment asset is BTC. We only support BTC as the
 	// payment asset in this example.
-	if !oraclerpc.IsAssetBtc(req.PaymentAsset) {
+	if !rpcutils.IsAssetBtc(req.PaymentAsset) {
 		return &oraclerpc.QueryRateTickResponse{
 			Result: &oraclerpc.QueryRateTickResponse_Error{
 				Error: &oraclerpc.QueryRateTickErrResponse{

itest/universe_test.go

@@ -17,6 +17,7 @@ import (
 	"github.com/lightninglabs/taproot-assets/fn"
 	"github.com/lightninglabs/taproot-assets/internal/test"
 	"github.com/lightninglabs/taproot-assets/mssmt"
+	"github.com/lightninglabs/taproot-assets/rpcutils"
 	"github.com/lightninglabs/taproot-assets/taprpc"
 	"github.com/lightninglabs/taproot-assets/taprpc/mintrpc"
 	unirpc "github.com/lightninglabs/taproot-assets/taprpc/universerpc"
@@ -709,7 +710,7 @@ func testFederationSyncConfig(t *harnessTest) {
 		AssetID:   assetID1,
 		ProofType: universe.ProofTypeIssuance,
 	}
-	uniIdRpc1 := unirpc.MarshalUniverseID(assetIDBytes1, nil)
+	uniIdRpc1 := rpcutils.MarshalUniverseID(assetIDBytes1, nil)
 	uniIdRpc1.ProofType = unirpc.ProofType_PROOF_TYPE_ISSUANCE
 
 	// Generate universe ID #2.
@@ -720,7 +721,7 @@ func testFederationSyncConfig(t *harnessTest) {
 		GroupKey:  groupKey2,
 		ProofType: universe.ProofTypeTransfer,
 	}
-	uniIdRpc2 := unirpc.MarshalUniverseID(nil, groupKeyBytes2)
+	uniIdRpc2 := rpcutils.MarshalUniverseID(nil, groupKeyBytes2)
 	uniIdRpc2.ProofType = unirpc.ProofType_PROOF_TYPE_TRANSFER
 
 	// Set both the global and a universe specific federation sync configs.

proof/courier.go

@@ -1074,7 +1074,7 @@ func (c *UniverseRpcCourier) DeliverProof(ctx context.Context,
 
 		// Construct universe key.
 		outPoint := transitionProof.OutPoint()
-		assetKey := unirpc.MarshalAssetKey(
+		assetKey := rpcutils.MarshalAssetKey(
 			outPoint, proofAsset.ScriptKey.PubKey,
 		)
 		assetID := proofAsset.ID()
@@ -1088,7 +1088,7 @@ func (c *UniverseRpcCourier) DeliverProof(ctx context.Context,
 			groupPubKeyBytes = groupPubKey.SerializeCompressed()
 		}
 
-		universeID := unirpc.MarshalUniverseID(
+		universeID := rpcutils.MarshalUniverseID(
 			assetID[:], groupPubKeyBytes,
 		)
 		universeKey := unirpc.UniverseKey{
@@ -1150,10 +1150,10 @@ func (c *UniverseRpcCourier) ReceiveProof(ctx context.Context,
 		}
 
 		universeKey := unirpc.UniverseKey{
-			Id: unirpc.MarshalUniverseID(
+			Id: rpcutils.MarshalUniverseID(
 				loc.AssetID[:], groupKeyBytes,
 			),
-			LeafKey: unirpc.MarshalAssetKey(
+			LeafKey: rpcutils.MarshalAssetKey(
 				*loc.OutPoint, &loc.ScriptKey,
 			),
 		}

rpcserver.go

@@ -6160,7 +6160,7 @@ func MarshalAssetFedSyncCfg(
 	if uniID.GroupKey != nil {
 		groupKeyBytes = uniID.GroupKey.SerializeCompressed()
 	}
-	uniIdRPC := unirpc.MarshalUniverseID(assetIDBytes, groupKeyBytes)
+	uniIdRPC := rpcutils.MarshalUniverseID(assetIDBytes, groupKeyBytes)
 
 	// Marshal proof type.
 	proofTypeRpc, err := MarshalUniProofType(uniID.ProofType)

rpcutils/marshal.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"crypto/sha256"
+	"encoding/hex"
 	"fmt"
 
 	"github.com/btcsuite/btcd/blockchain"
@@ -17,7 +18,9 @@ import (
 	"github.com/lightninglabs/taproot-assets/fn"
 	"github.com/lightninglabs/taproot-assets/rfq"
 	"github.com/lightninglabs/taproot-assets/taprpc"
+	"github.com/lightninglabs/taproot-assets/taprpc/priceoraclerpc"
 	"github.com/lightninglabs/taproot-assets/taprpc/rfqrpc"
+	"github.com/lightninglabs/taproot-assets/taprpc/universerpc"
 	"github.com/lightningnetwork/lnd/keychain"
 )
 
@@ -689,3 +692,84 @@ func NewAddAssetSellOrderResponse(
 			"type: %T", e)
 	}
 }
+
+// IsAssetBtc is a helper function that returns true if the given asset
+// specifier represents BTC, and false otherwise.
+func IsAssetBtc(assetSpecifier *priceoraclerpc.AssetSpecifier) bool {
+	// An unset asset specifier does not represent BTC.
+	if assetSpecifier == nil {
+		return false
+	}
+
+	// Verify that the asset specifier has a valid asset ID (either bytes or
+	// string). The asset ID must be all zeros for the asset specifier to
+	// represent BTC.
+	assetIdBytes := assetSpecifier.GetAssetId()
+	assetIdStr := assetSpecifier.GetAssetIdStr()
+
+	if len(assetIdBytes) != 32 && assetIdStr == "" {
+		return false
+	}
+
+	var assetId [32]byte
+	copy(assetId[:], assetIdBytes)
+
+	var zeroAssetId [32]byte
+	zeroAssetHexStr := hex.EncodeToString(zeroAssetId[:])
+
+	isAssetIdZero := bytes.Equal(assetId[:], zeroAssetId[:]) ||
+		assetIdStr == zeroAssetHexStr
+
+	// Ensure that the asset specifier does not have any group key related
+	// fields set. When specifying BTC, the group key fields must be unset.
+	groupKeySet := assetSpecifier.GetGroupKey() != nil ||
+		assetSpecifier.GetGroupKeyStr() != ""
+
+	return isAssetIdZero && !groupKeySet
+}
+
+// MarshalOutpoint marshals a wire.OutPoint into an RPC ready Outpoint.
+func MarshalOutpoint(outPoint wire.OutPoint) *universerpc.Outpoint {
+	return &universerpc.Outpoint{
+		HashStr: outPoint.Hash.String(),
+		Index:   int32(outPoint.Index),
+	}
+}
+
+// MarshalAssetKey returns an RPC ready AssetKey.
+func MarshalAssetKey(outPoint wire.OutPoint,
+	scriptKeyPubKey *btcec.PublicKey) *universerpc.AssetKey {
+
+	scriptKeyBytes := scriptKeyPubKey.SerializeCompressed()
+
+	return &universerpc.AssetKey{
+		Outpoint: &universerpc.AssetKey_Op{
+			Op: MarshalOutpoint(outPoint),
+		},
+		ScriptKey: &universerpc.AssetKey_ScriptKeyBytes{
+			ScriptKeyBytes: scriptKeyBytes,
+		},
+	}
+}
+
+// MarshalUniverseID returns an RPC ready universe ID.
+func MarshalUniverseID(assetIDBytes []byte,
+	groupKeyBytes []byte) *universerpc.ID {
+
+	// We will marshal either a group key ID or an asset ID. If group key
+	// bytes are given, we marshal a group key ID, otherwise we marshal an
+	// asset ID.
+	if groupKeyBytes != nil {
+		return &universerpc.ID{
+			Id: &universerpc.ID_GroupKey{
+				GroupKey: groupKeyBytes,
+			},
+		}
+	}
+
+	return &universerpc.ID{
+		Id: &universerpc.ID_AssetId{
+			AssetId: assetIDBytes,
+		},
+	}
+}

taprpc/priceoraclerpc/marshal_test.go → rpcutils/marshal_test.go

@@ -1,17 +1,18 @@
-package priceoraclerpc
+package rpcutils
 
 import (
 	"encoding/hex"
 	"testing"
 
+	"github.com/lightninglabs/taproot-assets/taprpc/priceoraclerpc"
 	"github.com/stretchr/testify/require"
 )
 
 // isAssetBtcTC is a test case for the IsAssetBtc function.
 type isAssetBtcTC struct {
 	testName string
 
-	assetSpecifier *AssetSpecifier
+	assetSpecifier *priceoraclerpc.AssetSpecifier
 	expected       bool
 }
 
@@ -32,13 +33,13 @@ func TestIsAssetBtc(t *testing.T) {
 		},
 		{
 			testName:       "empty asset specifier",
-			assetSpecifier: &AssetSpecifier{},
+			assetSpecifier: &priceoraclerpc.AssetSpecifier{},
 			expected:       false,
 		},
 		{
 			testName: "asset specifier with zero asset ID bytes",
-			assetSpecifier: &AssetSpecifier{
-				Id: &AssetSpecifier_AssetId{
+			assetSpecifier: &priceoraclerpc.AssetSpecifier{
+				Id: &priceoraclerpc.AssetSpecifier_AssetId{
 					AssetId: zeroAssetId[:],
 				},
 			},
@@ -47,53 +48,53 @@ func TestIsAssetBtc(t *testing.T) {
 		{
 			testName: "asset specifier with incorrect length " +
 				"zero asset ID bytes",
-			assetSpecifier: &AssetSpecifier{
-				Id: &AssetSpecifier_AssetId{
+			assetSpecifier: &priceoraclerpc.AssetSpecifier{
+				Id: &priceoraclerpc.AssetSpecifier_AssetId{
 					AssetId: []byte{0, 0, 0},
 				},
 			},
 			expected: false,
 		},
 		{
 			testName: "asset specifier with empty asset ID bytes",
-			assetSpecifier: &AssetSpecifier{
-				Id: &AssetSpecifier_AssetId{
+			assetSpecifier: &priceoraclerpc.AssetSpecifier{
+				Id: &priceoraclerpc.AssetSpecifier_AssetId{
 					AssetId: []byte{},
 				},
 			},
 			expected: false,
 		},
 		{
 			testName: "asset specifier with zero asset ID string",
-			assetSpecifier: &AssetSpecifier{
-				Id: &AssetSpecifier_AssetIdStr{
+			assetSpecifier: &priceoraclerpc.AssetSpecifier{
+				Id: &priceoraclerpc.AssetSpecifier_AssetIdStr{
 					AssetIdStr: zeroAssetHexStr,
 				},
 			},
 			expected: true,
 		},
 		{
 			testName: "asset specifier with empty asset ID string",
-			assetSpecifier: &AssetSpecifier{
-				Id: &AssetSpecifier_AssetIdStr{
+			assetSpecifier: &priceoraclerpc.AssetSpecifier{
+				Id: &priceoraclerpc.AssetSpecifier_AssetIdStr{
 					AssetIdStr: "",
 				},
 			},
 			expected: false,
 		},
 		{
 			testName: "asset specifier with set group key bytes",
-			assetSpecifier: &AssetSpecifier{
-				Id: &AssetSpecifier_GroupKey{
+			assetSpecifier: &priceoraclerpc.AssetSpecifier{
+				Id: &priceoraclerpc.AssetSpecifier_GroupKey{
 					GroupKey: []byte{0, 0, 0},
 				},
 			},
 			expected: false,
 		},
 		{
 			testName: "asset specifier with set group key string",
-			assetSpecifier: &AssetSpecifier{
-				Id: &AssetSpecifier_GroupKeyStr{
+			assetSpecifier: &priceoraclerpc.AssetSpecifier{
+				Id: &priceoraclerpc.AssetSpecifier_GroupKeyStr{
 					GroupKeyStr: "test-group-key",
 				},
 			},