Merge pull request #1402 from lightninglabs/group-key-refactor

[wallet 1/3]: refactor in preparation for group key channel funding

Author: ffranr

fn/memory.go

@@ -1,5 +1,13 @@
 package fn
 
+import "errors"
+
+var (
+	// ErrNilPointerDeference is returned when a nil pointer is
+	// dereferenced.
+	ErrNilPointerDeference = errors.New("nil pointer dereference")
+)
+
 // Ptr returns the pointer of the given value. This is useful in instances
 // where a function returns the value, but a pointer is wanted. Without this,
 // then an intermediate variable is needed.
@@ -32,7 +40,31 @@ func ToArray[T ByteArray](v []byte) T {
 // CopySlice returns a copy of the given slice. Does a shallow copy of the
 // slice itself, not the underlying elements.
 func CopySlice[T any](slice []T) []T {
+	if slice == nil {
+		return nil
+	}
+
 	newSlice := make([]T, len(slice))
 	copy(newSlice, slice)
 	return newSlice
 }
+
+// Deref safely dereferences a pointer. If the pointer is nil, it returns the
+// zero value of type T and an error.
+func Deref[T any](ptr *T) (T, error) {
+	if ptr == nil {
+		var zero T
+		return zero, ErrNilPointerDeference
+	}
+
+	return *ptr, nil
+}
+
+// DerefPanic dereferences a pointer. If the pointer is nil, it panics.
+func DerefPanic[T any](ptr *T) T {
+	if ptr == nil {
+		panic(ErrNilPointerDeference)
+	}
+
+	return *ptr
+}

key_ring.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 
-	"github.com/davecgh/go-spew/spew"
 	"github.com/lightninglabs/lndclient"
 	"github.com/lightninglabs/taproot-assets/asset"
 	"github.com/lightninglabs/taproot-assets/tapgarden"
@@ -60,23 +59,6 @@ func (l *LndRpcKeyRing) DeriveNextTaprootAssetKey(
 	return *keyDesc, nil
 }
 
-// DeriveKey attempts to derive an arbitrary key specified by the passed
-// KeyLocator. This may be used in several recovery scenarios, or when manually
-// rotating something like our current default node key.
-func (l *LndRpcKeyRing) DeriveKey(ctx context.Context,
-	keyLoc keychain.KeyLocator) (keychain.KeyDescriptor, error) {
-
-	tapdLog.Debugf("Deriving new key, key_loc=%v", spew.Sdump(keyLoc))
-
-	keyDesc, err := l.lnd.WalletKit.DeriveKey(ctx, &keyLoc)
-	if err != nil {
-		return keychain.KeyDescriptor{}, fmt.Errorf("unable to "+
-			"derive key ring: %w", err)
-	}
-
-	return *keyDesc, nil
-}
-
 // IsLocalKey returns true if the key is under the control of the wallet
 // and can be derived by it.
 func (l *LndRpcKeyRing) IsLocalKey(ctx context.Context,

proof/archive.go

@@ -133,9 +133,8 @@ type AnnotatedProof struct {
 	*AssetSnapshot
 }
 
-// Archiver is the main storage backend the ProofArchiver uses to store and
-// query for proof files.
-type Archiver interface {
+// Exporter is used to fetch proofs by their unique identifier.
+type Exporter interface {
 	// FetchProof fetches a proof for an asset uniquely identified by the
 	// passed ProofIdentifier.
 	//
@@ -144,6 +143,12 @@ type Archiver interface {
 	// locator then ErrMultipleProofs should be returned to indicate more
 	// specific fields need to be set in the Locator (e.g. the OutPoint).
 	FetchProof(ctx context.Context, id Locator) (Blob, error)
+}
+
+// Archiver is the main storage backend the ProofArchiver uses to store and
+// query for proof files.
+type Archiver interface {
+	Exporter
 
 	// FetchIssuanceProof fetches the issuance proof for an asset, given the
 	// anchor point of the issuance (NOT the genesis point for the asset).

rpcserver.go

@@ -2235,8 +2235,7 @@ func (r *rpcServer) FundVirtualPsbt(ctx context.Context,
 	// Extract the passive assets that are needed for the fully RPC driven
 	// flow.
 	passivePackets, err := r.cfg.AssetWallet.CreatePassiveAssets(
-		ctx, []*tappsbt.VPacket{fundedVPkt.VPacket},
-		fundedVPkt.InputCommitments,
+		ctx, fundedVPkt.VPackets, fundedVPkt.InputCommitments,
 	)
 	if err != nil {
 		return nil, fmt.Errorf("error creating passive assets: %w", err)
@@ -2257,7 +2256,12 @@ func (r *rpcServer) FundVirtualPsbt(ctx context.Context,
 		}
 	}
 
-	response.FundedPsbt, err = serialize(fundedVPkt.VPacket)
+	// TODO(guggero): Remove this once we support multiple packets.
+	if len(fundedVPkt.VPackets) > 1 {
+		return nil, fmt.Errorf("only one packet supported")
+	}
+
+	response.FundedPsbt, err = serialize(fundedVPkt.VPackets[0])
 	if err != nil {
 		return nil, fmt.Errorf("error serializing packet: %w", err)
 	}
@@ -3387,11 +3391,13 @@ func (r *rpcServer) BurnAsset(ctx context.Context,
 		// We found the asset group, so we can use the group key to
 		// burn the asset.
 		groupKey = &assetGroup.GroupPubKey
+
 	case errors.Is(err, address.ErrAssetGroupUnknown):
 		// We don't know the asset group, so we'll try to burn the
 		// asset using the asset ID only.
 		rpcsLog.Debug("Asset group key not found, asset may not be " +
 			"part of a group")
+
 	case err != nil:
 		return nil, fmt.Errorf("error querying asset group: %w", err)
 	}
@@ -3419,16 +3425,22 @@ func (r *rpcServer) BurnAsset(ctx context.Context,
 		return nil, fmt.Errorf("error funding burn: %w", err)
 	}
 
+	// We don't support burning by group key yet, so we only expect a single
+	// vPacket (which implies a single asset ID is involved).
+	if len(fundResp.VPackets) > 1 {
+		return nil, fmt.Errorf("only one packet supported")
+	}
+
 	// Now we can sign the packet and send it to the chain.
-	_, err = r.cfg.AssetWallet.SignVirtualPacket(fundResp.VPacket)
+	vPkt := fundResp.VPackets[0]
+	_, err = r.cfg.AssetWallet.SignVirtualPacket(vPkt)
 	if err != nil {
 		return nil, fmt.Errorf("error signing packet: %w", err)
 	}
 
 	resp, err := r.cfg.ChainPorter.RequestShipment(
 		tapfreighter.NewPreSignedParcel(
-			[]*tappsbt.VPacket{fundResp.VPacket},
-			fundResp.InputCommitments, in.Note,
+			fundResp.VPackets, fundResp.InputCommitments, in.Note,
 		),
 	)
 	if err != nil {
@@ -3443,7 +3455,7 @@ func (r *rpcServer) BurnAsset(ctx context.Context,
 
 	var burnProof *taprpc.DecodedProof
 	for idx := range resp.Outputs {
-		vOut := fundResp.VPacket.Outputs[idx]
+		vOut := vPkt.Outputs[idx]
 		tOut := resp.Outputs[idx]
 		if vOut.Asset.IsBurn() {
 			p, err := proof.Decode(tOut.ProofSuffix)
@@ -6427,54 +6439,71 @@ func MarshalAssetFedSyncCfg(
 }
 
 // unmarshalAssetSpecifier unmarshals an asset specifier from the RPC form.
-func unmarshalAssetSpecifier(req *rfqrpc.AssetSpecifier) (*asset.ID,
+func unmarshalAssetSpecifier(s *rfqrpc.AssetSpecifier) (*asset.ID,
 	*btcec.PublicKey, error) {
 
+	if s == nil {
+		return nil, nil, fmt.Errorf("asset specifier must be specified")
+	}
+
+	return parseAssetSpecifier(
+		s.GetAssetId(), s.GetAssetIdStr(), s.GetGroupKey(),
+		s.GetGroupKeyStr(),
+	)
+}
+
+// parseAssetSpecifier parses an asset specifier from the RPC form.
+func parseAssetSpecifier(reqAssetID []byte, reqAssetIDStr string,
+	reqGroupKey []byte, reqGroupKeyStr string) (*asset.ID, *btcec.PublicKey,
+	error) {
+
 	// Attempt to decode the asset specifier from the RPC request. In cases
 	// where both the asset ID and asset group key are provided, we will
 	// give precedence to the asset ID due to its higher level of
 	// specificity.
 	var (
-		assetID *asset.ID
-
-		groupKeyBytes []byte
-		groupKey      *btcec.PublicKey
-
-		err error
+		assetID  *asset.ID
+		groupKey *btcec.PublicKey
+		err      error
 	)
 
 	switch {
 	// Parse the asset ID if it's set.
-	case len(req.GetAssetId()) > 0:
+	case len(reqAssetID) > 0:
+		if len(reqAssetID) != sha256.Size {
+			return nil, nil, fmt.Errorf("asset ID must be 32 bytes")
+		}
+
 		var assetIdBytes [32]byte
-		copy(assetIdBytes[:], req.GetAssetId())
+		copy(assetIdBytes[:], reqAssetID)
 		id := asset.ID(assetIdBytes)
 		assetID = &id
 
-	case len(req.GetAssetIdStr()) > 0:
-		assetIDBytes, err := hex.DecodeString(req.GetAssetIdStr())
+	case len(reqAssetIDStr) > 0:
+		assetIDBytes, err := hex.DecodeString(reqAssetIDStr)
 		if err != nil {
 			return nil, nil, fmt.Errorf("error decoding asset "+
 				"ID: %w", err)
 		}
 
+		if len(assetIDBytes) != sha256.Size {
+			return nil, nil, fmt.Errorf("asset ID must be 32 bytes")
+		}
+
 		var id asset.ID
 		copy(id[:], assetIDBytes)
 		assetID = &id
 
 	// Parse the group key if it's set.
-	case len(req.GetGroupKey()) > 0:
-		groupKeyBytes = req.GetGroupKey()
-		groupKey, err = btcec.ParsePubKey(groupKeyBytes)
+	case len(reqGroupKey) > 0:
+		groupKey, err = btcec.ParsePubKey(reqGroupKey)
 		if err != nil {
 			return nil, nil, fmt.Errorf("error parsing group "+
 				"key: %w", err)
 		}
 
-	case len(req.GetGroupKeyStr()) > 0:
-		groupKeyBytes, err := hex.DecodeString(
-			req.GetGroupKeyStr(),
-		)
+	case len(reqGroupKeyStr) > 0:
+		groupKeyBytes, err := hex.DecodeString(reqGroupKeyStr)
 		if err != nil {
 			return nil, nil, fmt.Errorf("error decoding group "+
 				"key: %w", err)
@@ -7055,8 +7084,21 @@ func (r *rpcServer) FundChannel(ctx context.Context,
 		return nil, fmt.Errorf("error parsing peer pubkey: %w", err)
 	}
 
-	if len(req.AssetId) != sha256.Size {
-		return nil, fmt.Errorf("asset ID must be 32 bytes")
+	assetID, groupKey, err := parseAssetSpecifier(
+		req.GetAssetId(), "", nil, "",
+	)
+	if err != nil {
+		return nil, fmt.Errorf("error parsing asset specifier: %w", err)
+	}
+
+	// For channel funding, we need to make sure that the group key is set
+	// if the asset is grouped.
+	assetSpecifier, err := r.specifierWithGroupKeyLookup(
+		ctx, assetID, groupKey,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("error creating asset specifier: %w",
+			err)
 	}
 
 	if req.AssetAmount == 0 {
@@ -7067,12 +7109,12 @@ func (r *rpcServer) FundChannel(ctx context.Context,
 	}
 
 	fundReq := tapchannel.FundReq{
-		PeerPub:     *peerPub,
-		AssetAmount: req.AssetAmount,
-		FeeRate:     chainfee.SatPerVByte(req.FeeRateSatPerVbyte),
-		PushAmount:  btcutil.Amount(req.PushSat),
+		PeerPub:        *peerPub,
+		AssetSpecifier: assetSpecifier,
+		AssetAmount:    req.AssetAmount,
+		FeeRate:        chainfee.SatPerVByte(req.FeeRateSatPerVbyte),
+		PushAmount:     btcutil.Amount(req.PushSat),
 	}
-	copy(fundReq.AssetID[:], req.AssetId)
 
 	chanPoint, err := r.cfg.AuxFundingController.FundChannel(ctx, fundReq)
 	if err != nil {
@@ -7085,6 +7127,30 @@ func (r *rpcServer) FundChannel(ctx context.Context,
 	}, nil
 }
 
+// specifierWithGroupKeyLookup returns an asset specifier that has the group key
+// set if it's a grouped asset.
+func (r *rpcServer) specifierWithGroupKeyLookup(ctx context.Context,
+	assetID *asset.ID, groupKey *btcec.PublicKey) (asset.Specifier, error) {
+
+	var result asset.Specifier
+
+	if assetID != nil && groupKey == nil {
+		dbGroupKey, err := r.cfg.TapAddrBook.QueryAssetGroup(
+			ctx, *assetID,
+		)
+		switch {
+		case err == nil && dbGroupKey.GroupKey != nil:
+			groupKey = &dbGroupKey.GroupPubKey
+
+		case err != nil:
+			return result, fmt.Errorf("unable to query asset "+
+				"group: %w", err)
+		}
+	}
+
+	return asset.NewSpecifier(assetID, groupKey, nil, true)
+}
+
 // EncodeCustomRecords allows RPC users to encode Taproot Asset channel related
 // data into the TLV format that is used in the custom records of the lnd
 // payment or other channel related RPCs. This RPC is completely stateless and

tapcfg/server.go

@@ -556,22 +556,22 @@ func genServerConfig(cfg *Config, cfgLogger btclog.Logger,
 			ProofUpdates: proofArchive,
 			ErrChan:      mainErrChan,
 		}),
-		AssetCustodian: tapgarden.NewCustodian(
-			&tapgarden.CustodianConfig{
-				ChainParams:  &tapChainParams,
-				WalletAnchor: walletAnchor,
-				ChainBridge:  chainBridge,
-				GroupVerifier: tapgarden.GenGroupVerifier(
-					context.Background(), assetMintingStore,
-				),
-				AddrBook:               addrBook,
-				ProofArchive:           proofArchive,
-				ProofNotifier:          multiNotifier,
-				ErrChan:                mainErrChan,
-				ProofCourierDispatcher: proofCourierDispatcher,
-				ProofRetrievalDelay:    cfg.CustodianProofRetrievalDelay, ProofWatcher: reOrgWatcher,
-			},
-		),
+		// nolint: lll
+		AssetCustodian: tapgarden.NewCustodian(&tapgarden.CustodianConfig{
+			ChainParams:  &tapChainParams,
+			WalletAnchor: walletAnchor,
+			ChainBridge:  chainBridge,
+			GroupVerifier: tapgarden.GenGroupVerifier(
+				context.Background(), assetMintingStore,
+			),
+			AddrBook:               addrBook,
+			ProofArchive:           proofArchive,
+			ProofNotifier:          multiNotifier,
+			ErrChan:                mainErrChan,
+			ProofCourierDispatcher: proofCourierDispatcher,
+			ProofRetrievalDelay:    cfg.CustodianProofRetrievalDelay,
+			ProofWatcher:           reOrgWatcher,
+		}),
 		ChainBridge:              chainBridge,
 		AddrBook:                 addrBook,
 		AddrBookDisableSyncer:    cfg.AddrBook.DisableSyncer,