package discovery import ( "github.com/btcsuite/btcd/btcec" "github.com/go-errors/errors" "github.com/lightningnetwork/lnd/channeldb" "github.com/lightningnetwork/lnd/lnwallet" "github.com/lightningnetwork/lnd/lnwire" ) // CreateChanAnnouncement is a helper function which creates all channel // announcements given the necessary channel related database items. This // function is used to transform out database structs into the corresponding wire // structs for announcing new channels to other peers, or simply syncing up a // peer's initial routing table upon connect. func CreateChanAnnouncement(chanProof *channeldb.ChannelAuthProof, chanInfo *channeldb.ChannelEdgeInfo, e1, e2 *channeldb.ChannelEdgePolicy) (*lnwire.ChannelAnnouncement, *lnwire.ChannelUpdate, *lnwire.ChannelUpdate, error) { // First, using the parameters of the channel, along with the channel // authentication chanProof, we'll create re-create the original // authenticated channel announcement. chanID := lnwire.NewShortChanIDFromInt(chanInfo.ChannelID) chanAnn := &lnwire.ChannelAnnouncement{ ShortChannelID: chanID, NodeID1: chanInfo.NodeKey1Bytes, NodeID2: chanInfo.NodeKey2Bytes, ChainHash: chanInfo.ChainHash, BitcoinKey1: chanInfo.BitcoinKey1Bytes, BitcoinKey2: chanInfo.BitcoinKey2Bytes, Features: lnwire.NewRawFeatureVector(), } var err error chanAnn.BitcoinSig1, err = lnwire.NewSigFromRawSignature( chanProof.BitcoinSig1Bytes, ) if err != nil { return nil, nil, nil, err } chanAnn.BitcoinSig2, err = lnwire.NewSigFromRawSignature( chanProof.BitcoinSig2Bytes, ) if err != nil { return nil, nil, nil, err } chanAnn.NodeSig1, err = lnwire.NewSigFromRawSignature( chanProof.NodeSig1Bytes, ) if err != nil { return nil, nil, nil, err } chanAnn.NodeSig2, err = lnwire.NewSigFromRawSignature( chanProof.NodeSig2Bytes, ) if err != nil { return nil, nil, nil, err } // We'll unconditionally queue the channel's existence chanProof as it // will need to be processed before either of the channel update // networkMsgs. // Since it's up to a node's policy as to whether they advertise the // edge in a direction, we don't create an advertisement if the edge is // nil. var edge1Ann, edge2Ann *lnwire.ChannelUpdate if e1 != nil { edge1Ann = &lnwire.ChannelUpdate{ ChainHash: chanInfo.ChainHash, ShortChannelID: chanID, Timestamp: uint32(e1.LastUpdate.Unix()), Flags: e1.Flags, TimeLockDelta: e1.TimeLockDelta, HtlcMinimumMsat: e1.MinHTLC, BaseFee: uint32(e1.FeeBaseMSat), FeeRate: uint32(e1.FeeProportionalMillionths), } edge1Ann.Signature, err = lnwire.NewSigFromRawSignature(e1.SigBytes) if err != nil { return nil, nil, nil, err } } if e2 != nil { edge2Ann = &lnwire.ChannelUpdate{ ChainHash: chanInfo.ChainHash, ShortChannelID: chanID, Timestamp: uint32(e2.LastUpdate.Unix()), Flags: e2.Flags, TimeLockDelta: e2.TimeLockDelta, HtlcMinimumMsat: e2.MinHTLC, BaseFee: uint32(e2.FeeBaseMSat), FeeRate: uint32(e2.FeeProportionalMillionths), } edge2Ann.Signature, err = lnwire.NewSigFromRawSignature(e2.SigBytes) if err != nil { return nil, nil, nil, err } } return chanAnn, edge1Ann, edge2Ann, nil } // copyPubKey performs a copy of the target public key, setting a fresh curve // parameter during the process. func copyPubKey(pub *btcec.PublicKey) *btcec.PublicKey { return &btcec.PublicKey{ Curve: btcec.S256(), X: pub.X, Y: pub.Y, } } // SignAnnouncement is a helper function which is used to sign any outgoing // channel node node announcement messages. func SignAnnouncement(signer lnwallet.MessageSigner, pubKey *btcec.PublicKey, msg lnwire.Message) (*btcec.Signature, error) { var ( data []byte err error ) switch m := msg.(type) { case *lnwire.ChannelAnnouncement: data, err = m.DataToSign() case *lnwire.ChannelUpdate: data, err = m.DataToSign() case *lnwire.NodeAnnouncement: data, err = m.DataToSign() default: return nil, errors.New("can't sign message " + "of this format") } if err != nil { return nil, errors.Errorf("unable to get data to sign: %v", err) } return signer.SignMessage(pubKey, data) }