Merge pull request #1423 from lightninglabs/taprpc-groupkey-support

Support group keys on `SendPayment` & `AddInvoice`

Author: GeorgeTsagk

asset/asset.go

@@ -348,6 +348,23 @@ func NewSpecifierFromGroupKey(groupPubKey btcec.PublicKey) Specifier {
 	}
 }
 
+// NewExlusiveSpecifier creates a specifier that may only include one of asset
+// ID or group key. If both are set then a specifier over the group key is
+// created.
+func NewExclusiveSpecifier(id *ID,
+	groupPubKey *btcec.PublicKey) (Specifier, error) {
+
+	switch {
+	case groupPubKey != nil:
+		return NewSpecifierFromGroupKey(*groupPubKey), nil
+
+	case id != nil:
+		return NewSpecifierFromId(*id), nil
+	}
+
+	return Specifier{}, fmt.Errorf("must set either asset ID or group key")
+}
+
 // String returns a human-readable description of the specifier.
 func (s *Specifier) String() string {
 	// An unset asset ID is represented as an empty string.

rfq/manager.go

@@ -4,12 +4,15 @@ import (
 	"context"
 	"encoding/hex"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"sync"
 	"time"
 
 	"github.com/btcsuite/btcd/btcec/v2"
+	"github.com/btcsuite/btcd/btcec/v2/schnorr"
 	"github.com/lightninglabs/lndclient"
+	"github.com/lightninglabs/taproot-assets/address"
 	"github.com/lightninglabs/taproot-assets/asset"
 	"github.com/lightninglabs/taproot-assets/fn"
 	"github.com/lightninglabs/taproot-assets/rfqmsg"
@@ -232,6 +235,7 @@ func (m *Manager) startSubsystems(ctx context.Context) error {
 		HtlcInterceptor:  m.cfg.HtlcInterceptor,
 		HtlcSubscriber:   m.cfg.HtlcSubscriber,
 		AcceptHtlcEvents: m.acceptHtlcEvents,
+		SpecifierChecker: m.AssetMatchesSpecifier,
 	})
 	if err != nil {
 		return fmt.Errorf("error initializing RFQ order handler: %w",
@@ -948,6 +952,10 @@ func (m *Manager) getAssetGroupKey(ctx context.Context,
 	// Perform the DB query.
 	group, err := m.cfg.GroupLookup.QueryAssetGroup(ctx, id)
 	if err != nil {
+		if errors.Is(err, address.ErrAssetGroupUnknown) {
+			return fn.None[btcec.PublicKey](), nil
+		}
+
 		return fn.None[btcec.PublicKey](), err
 	}
 
@@ -971,6 +979,18 @@ func (m *Manager) AssetMatchesSpecifier(ctx context.Context,
 
 	switch {
 	case specifier.HasGroupPubKey():
+		specifierGK := specifier.UnwrapGroupKeyToPtr()
+
+		// Let's directly check if the ID is equal to the X coordinate
+		// of the group key. This is used by the sender to indicate that
+		// any asset that belongs to this group may be used.
+		groupKeyX := schnorr.SerializePubKey(specifierGK)
+		if asset.ID(groupKeyX) == id {
+			return true, nil
+		}
+
+		// Now let's make an actual query to find this assetID's group,
+		// if it exists.
 		group, err := m.getAssetGroupKey(ctx, id)
 		if err != nil {
 			return false, err
@@ -980,8 +1000,6 @@ func (m *Manager) AssetMatchesSpecifier(ctx context.Context,
 			return false, nil
 		}
 
-		specifierGK := specifier.UnwrapGroupKeyToPtr()
-
 		return group.UnwrapToPtr().IsEqual(specifierGK), nil
 
 	case specifier.HasId():

rfq/marshal.go

@@ -0,0 +1,173 @@
+package rfq
+
+import (
+	"fmt"
+
+	"github.com/lightninglabs/taproot-assets/fn"
+	"github.com/lightninglabs/taproot-assets/rfqmath"
+	"github.com/lightninglabs/taproot-assets/rfqmsg"
+	"github.com/lightninglabs/taproot-assets/taprpc/rfqrpc"
+)
+
+// MarshalAcceptedSellQuoteEvent marshals a peer accepted sell quote event to
+// its RPC representation.
+func MarshalAcceptedSellQuoteEvent(
+	event *PeerAcceptedSellQuoteEvent) *rfqrpc.PeerAcceptedSellQuote {
+
+	return MarshalAcceptedSellQuote(event.SellAccept)
+}
+
+// MarshalAcceptedSellQuote marshals a peer accepted sell quote to its RPC
+// representation.
+func MarshalAcceptedSellQuote(
+	accept rfqmsg.SellAccept) *rfqrpc.PeerAcceptedSellQuote {
+
+	rpcAssetRate := &rfqrpc.FixedPoint{
+		Coefficient: accept.AssetRate.Rate.Coefficient.String(),
+		Scale:       uint32(accept.AssetRate.Rate.Scale),
+	}
+
+	// Calculate the equivalent asset units for the given total BTC amount
+	// based on the asset-to-BTC conversion rate.
+	numAssetUnits := rfqmath.MilliSatoshiToUnits(
+		accept.Request.PaymentMaxAmt, accept.AssetRate.Rate,
+	)
+
+	minTransportableMSat := rfqmath.MinTransportableMSat(
+		rfqmath.DefaultOnChainHtlcMSat, accept.AssetRate.Rate,
+	)
+
+	return &rfqrpc.PeerAcceptedSellQuote{
+		Peer:                 accept.Peer.String(),
+		Id:                   accept.ID[:],
+		Scid:                 uint64(accept.ShortChannelId()),
+		BidAssetRate:         rpcAssetRate,
+		Expiry:               uint64(accept.AssetRate.Expiry.Unix()),
+		AssetAmount:          numAssetUnits.ScaleTo(0).ToUint64(),
+		MinTransportableMsat: uint64(minTransportableMSat),
+	}
+}
+
+// MarshalAcceptedBuyQuoteEvent marshals a peer accepted buy quote event to
+// its rpc representation.
+func MarshalAcceptedBuyQuoteEvent(
+	event *PeerAcceptedBuyQuoteEvent) (*rfqrpc.PeerAcceptedBuyQuote,
+	error) {
+
+	// We now calculate the minimum amount of asset units that can be
+	// transported within a single HTLC for this asset at the given rate.
+	// This corresponds to the 354 satoshi minimum non-dust HTLC value.
+	minTransportableUnits := rfqmath.MinTransportableUnits(
+		rfqmath.DefaultOnChainHtlcMSat, event.AssetRate.Rate,
+	).ScaleTo(0).ToUint64()
+
+	return &rfqrpc.PeerAcceptedBuyQuote{
+		Peer:           event.Peer.String(),
+		Id:             event.ID[:],
+		Scid:           uint64(event.ShortChannelId()),
+		AssetMaxAmount: event.Request.AssetMaxAmt,
+		AskAssetRate: &rfqrpc.FixedPoint{
+			Coefficient: event.AssetRate.Rate.Coefficient.String(),
+			Scale:       uint32(event.AssetRate.Rate.Scale),
+		},
+		Expiry:                uint64(event.AssetRate.Expiry.Unix()),
+		MinTransportableUnits: minTransportableUnits,
+	}, nil
+}
+
+// MarshalInvalidQuoteRespEvent marshals an invalid quote response event to
+// its rpc representation.
+func MarshalInvalidQuoteRespEvent(
+	event *InvalidQuoteRespEvent) *rfqrpc.InvalidQuoteResponse {
+
+	peer := event.QuoteResponse.MsgPeer()
+	id := event.QuoteResponse.MsgID()
+
+	return &rfqrpc.InvalidQuoteResponse{
+		Status: rfqrpc.QuoteRespStatus(event.Status),
+		Peer:   peer.String(),
+		Id:     id[:],
+	}
+}
+
+// MarshalIncomingRejectQuoteEvent marshals an incoming reject quote event to
+// its RPC representation.
+func MarshalIncomingRejectQuoteEvent(
+	event *IncomingRejectQuoteEvent) *rfqrpc.RejectedQuoteResponse {
+
+	return &rfqrpc.RejectedQuoteResponse{
+		Peer:         event.Peer.String(),
+		Id:           event.ID.Val[:],
+		ErrorMessage: event.Err.Val.Msg,
+		ErrorCode:    uint32(event.Err.Val.Code),
+	}
+}
+
+// NewAddAssetBuyOrderResponse creates a new AddAssetBuyOrderResponse from
+// the given RFQ event.
+func NewAddAssetBuyOrderResponse(
+	event fn.Event) (*rfqrpc.AddAssetBuyOrderResponse, error) {
+
+	resp := &rfqrpc.AddAssetBuyOrderResponse{}
+
+	switch e := event.(type) {
+	case *PeerAcceptedBuyQuoteEvent:
+		acceptedQuote, err := MarshalAcceptedBuyQuoteEvent(e)
+		if err != nil {
+			return nil, err
+		}
+
+		resp.Response = &rfqrpc.AddAssetBuyOrderResponse_AcceptedQuote{
+			AcceptedQuote: acceptedQuote,
+		}
+		return resp, nil
+
+	case *InvalidQuoteRespEvent:
+		resp.Response = &rfqrpc.AddAssetBuyOrderResponse_InvalidQuote{
+			InvalidQuote: MarshalInvalidQuoteRespEvent(e),
+		}
+		return resp, nil
+
+	case *IncomingRejectQuoteEvent:
+		resp.Response = &rfqrpc.AddAssetBuyOrderResponse_RejectedQuote{
+			RejectedQuote: MarshalIncomingRejectQuoteEvent(e),
+		}
+		return resp, nil
+
+	default:
+		return nil, fmt.Errorf("unknown AddAssetBuyOrder event "+
+			"type: %T", e)
+	}
+}
+
+// NewAddAssetSellOrderResponse creates a new AddAssetSellOrderResponse from
+// the given RFQ event.
+func NewAddAssetSellOrderResponse(
+	event fn.Event) (*rfqrpc.AddAssetSellOrderResponse, error) {
+
+	resp := &rfqrpc.AddAssetSellOrderResponse{}
+
+	switch e := event.(type) {
+	case *PeerAcceptedSellQuoteEvent:
+		resp.Response = &rfqrpc.AddAssetSellOrderResponse_AcceptedQuote{
+			AcceptedQuote: MarshalAcceptedSellQuoteEvent(e),
+		}
+		return resp, nil
+
+	case *InvalidQuoteRespEvent:
+		resp.Response = &rfqrpc.AddAssetSellOrderResponse_InvalidQuote{
+			InvalidQuote: MarshalInvalidQuoteRespEvent(e),
+		}
+		return resp, nil
+
+	case *IncomingRejectQuoteEvent:
+		resp.Response = &rfqrpc.AddAssetSellOrderResponse_RejectedQuote{
+			RejectedQuote: MarshalIncomingRejectQuoteEvent(e),
+		}
+		return resp, nil
+
+	default:
+		return nil, fmt.Errorf("unknown AddAssetSellOrder event "+
+			"type: %T", e)
+	}
+}

rfq/order.go

@@ -7,6 +7,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/btcsuite/btcd/btcec/v2/schnorr"
 	"github.com/davecgh/go-spew/spew"
 	"github.com/lightninglabs/lndclient"
 	"github.com/lightninglabs/taproot-assets/asset"
@@ -58,7 +59,8 @@ type SerialisedScid = rfqmsg.SerialisedScid
 type Policy interface {
 	// CheckHtlcCompliance returns an error if the given HTLC intercept
 	// descriptor does not satisfy the subject policy.
-	CheckHtlcCompliance(htlc lndclient.InterceptedHtlc) error
+	CheckHtlcCompliance(ctx context.Context, htlc lndclient.InterceptedHtlc,
+		specifierChecker rfqmsg.SpecifierChecker) error
 
 	// Expiry returns the policy's expiry time as a unix timestamp.
 	Expiry() uint64
@@ -145,8 +147,8 @@ func NewAssetSalePolicy(quote rfqmsg.BuyAccept) *AssetSalePolicy {
 // included as a hop hint within the invoice. The SCID is the only piece of
 // information used to determine the policy applicable to the HTLC. As a result,
 // HTLC custom records are not expected to be present.
-func (c *AssetSalePolicy) CheckHtlcCompliance(
-	htlc lndclient.InterceptedHtlc) error {
+func (c *AssetSalePolicy) CheckHtlcCompliance(_ context.Context,
+	htlc lndclient.InterceptedHtlc, _ rfqmsg.SpecifierChecker) error {
 
 	// Since we will be reading CurrentAmountMsat value we acquire a read
 	// lock.
@@ -248,11 +250,23 @@ func (c *AssetSalePolicy) GenerateInterceptorResponse(
 
 	outgoingAmt := rfqmath.DefaultOnChainHtlcMSat
 
-	// Unpack asset ID.
-	assetID, err := c.AssetSpecifier.UnwrapIdOrErr()
-	if err != nil {
-		return nil, fmt.Errorf("asset sale policy has no asset ID: %w",
-			err)
+	var assetID asset.ID
+
+	// We have performed checks for the asset IDs inside the HTLC against
+	// the specifier's group key in a previous step. Here we just need to
+	// provide a dummy value as the asset ID. The real asset IDs will be
+	// carefully picked in a later step in the process. What really matters
+	// now is the total amount.
+	switch {
+	case c.AssetSpecifier.HasGroupPubKey():
+		groupKey := c.AssetSpecifier.UnwrapGroupKeyToPtr()
+		groupKeyX := schnorr.SerializePubKey(groupKey)
+
+		assetID = asset.ID(groupKeyX)
+
+	case c.AssetSpecifier.HasId():
+		specifierID := *c.AssetSpecifier.UnwrapIdToPtr()
+		copy(assetID[:], specifierID[:])
 	}
 
 	// Compute the outgoing asset amount given the msat outgoing amount and
@@ -341,8 +355,9 @@ func NewAssetPurchasePolicy(quote rfqmsg.SellAccept) *AssetPurchasePolicy {
 
 // CheckHtlcCompliance returns an error if the given HTLC intercept descriptor
 // does not satisfy the subject policy.
-func (c *AssetPurchasePolicy) CheckHtlcCompliance(
-	htlc lndclient.InterceptedHtlc) error {
+func (c *AssetPurchasePolicy) CheckHtlcCompliance(ctx context.Context,
+	htlc lndclient.InterceptedHtlc,
+	specifierChecker rfqmsg.SpecifierChecker) error {
 
 	// Since we will be reading CurrentAmountMsat value we acquire a read
 	// lock.
@@ -368,7 +383,9 @@ func (c *AssetPurchasePolicy) CheckHtlcCompliance(
 	}
 
 	// Sum the asset balance in the HTLC record.
-	assetAmt, err := htlcRecord.SumAssetBalance(c.AssetSpecifier)
+	assetAmt, err := htlcRecord.SumAssetBalance(
+		ctx, c.AssetSpecifier, specifierChecker,
+	)
 	if err != nil {
 		return fmt.Errorf("error summing asset balance: %w", err)
 	}
@@ -523,15 +540,19 @@ func NewAssetForwardPolicy(incoming, outgoing Policy) (*AssetForwardPolicy,
 
 // CheckHtlcCompliance returns an error if the given HTLC intercept descriptor
 // does not satisfy the subject policy.
-func (a *AssetForwardPolicy) CheckHtlcCompliance(
-	htlc lndclient.InterceptedHtlc) error {
+func (a *AssetForwardPolicy) CheckHtlcCompliance(ctx context.Context,
+	htlc lndclient.InterceptedHtlc, sChk rfqmsg.SpecifierChecker) error {
 
-	if err := a.incomingPolicy.CheckHtlcCompliance(htlc); err != nil {
+	if err := a.incomingPolicy.CheckHtlcCompliance(
+		ctx, htlc, sChk,
+	); err != nil {
 		return fmt.Errorf("error checking forward policy, inbound "+
 			"HTLC does not comply with policy: %w", err)
 	}
 
-	if err := a.outgoingPolicy.CheckHtlcCompliance(htlc); err != nil {
+	if err := a.outgoingPolicy.CheckHtlcCompliance(
+		ctx, htlc, sChk,
+	); err != nil {
 		return fmt.Errorf("error checking forward policy, outbound "+
 			"HTLC does not comply with policy: %w", err)
 	}
@@ -642,6 +663,10 @@ type OrderHandlerCfg struct {
 	// HtlcSubscriber is a subscriber that is used to retrieve live HTLC
 	// event updates.
 	HtlcSubscriber HtlcSubscriber
+
+	// SpecifierChecker is an interface that contains methods for
+	// checking certain properties related to asset specifiers.
+	SpecifierChecker rfqmsg.SpecifierChecker
 }
 
 // OrderHandler orchestrates management of accepted quote bundles. It monitors
@@ -684,7 +709,7 @@ func NewOrderHandler(cfg OrderHandlerCfg) (*OrderHandler, error) {
 //
 // NOTE: This function must be thread safe. It is used by an external
 // interceptor service.
-func (h *OrderHandler) handleIncomingHtlc(_ context.Context,
+func (h *OrderHandler) handleIncomingHtlc(ctx context.Context,
 	htlc lndclient.InterceptedHtlc) (*lndclient.InterceptedHtlcResponse,
 	error) {
 
@@ -716,7 +741,7 @@ func (h *OrderHandler) handleIncomingHtlc(_ context.Context,
 	// At this point, we know that a policy exists and has not expired
 	// whilst sitting in the local cache. We can now check that the HTLC
 	// complies with the policy.
-	err = policy.CheckHtlcCompliance(htlc)
+	err = policy.CheckHtlcCompliance(ctx, htlc, h.cfg.SpecifierChecker)
 	if err != nil {
 		log.Warnf("HTLC does not comply with policy: %v "+
 			"(HTLC=%v, policy=%v)", err, htlc, policy)