package lnwire import ( "bytes" "fmt" "io" "github.com/roasbeef/btcd/btcec" "github.com/roasbeef/btcd/wire" ) // SingleFundingComplete is the message Alice sends to Bob once she is able to // fully assemble the funding transaction, and both versions of the commitment // transaction. The purpose of this message is to present Bob with the items // required for him to generate a signature for Alice's version of the // commitment transaction. type SingleFundingComplete struct { // ChannelID serves to uniquely identify the future channel created by // the initiated single funder workflow. // TODO(roasbeef): change all to PendingChannelID, document schema ChannelID uint64 // FundingOutPoint is the outpoint (txid:index) of the funding // transaction. With this value, Bob will be able to generate a // signature for Alice's version of the commitment transaction. FundingOutPoint wire.OutPoint // CommitSignature is Alice's signature for Bob's version of the // commitment transaction. CommitSignature *btcec.Signature // RevocationKey is the initial key to be used for the revocation // clause within the self-output of the initiators's commitment // transaction. Once an initial new state is created, the initiator // will send a preimage which will allow the initiator to sweep the // initiator's funds if the violate the contract. RevocationKey *btcec.PublicKey // StateHintObsfucator is the set of bytes used by the initiator to // obsfucate the state number encoded within the sequence number for // the commitment transaction's only input. The initiator generates // this value by hashing the 0th' state derived from the revocation PRF // an additional time. StateHintObsfucator [6]byte } // NewSingleFundingComplete creates, and returns a new empty // SingleFundingResponse. func NewSingleFundingComplete(chanID uint64, fundingPoint wire.OutPoint, commitSig *btcec.Signature, revokeKey *btcec.PublicKey, obsfucator [6]byte) *SingleFundingComplete { return &SingleFundingComplete{ ChannelID: chanID, FundingOutPoint: fundingPoint, CommitSignature: commitSig, RevocationKey: revokeKey, StateHintObsfucator: obsfucator, } } // Decode deserializes the serialized SingleFundingComplete stored in the passed // io.Reader into the target SingleFundingComplete using the deserialization // rules defined by the passed protocol version. // // This is part of the lnwire.Message interface. func (s *SingleFundingComplete) Decode(r io.Reader, pver uint32) error { // ChannelID (8) // FundingOutPoint (36) // CommitmentSignature (73) // RevocationKey (33) err := readElements(r, &s.ChannelID, &s.FundingOutPoint, &s.CommitSignature, &s.RevocationKey, s.StateHintObsfucator[:]) if err != nil { return err } return nil } // Encode serializes the target SingleFundingComplete into the passed io.Writer // implementation. Serialization will observe the rules defined by the passed // protocol version. // // This is part of the lnwire.Message interface. func (s *SingleFundingComplete) Encode(w io.Writer, pver uint32) error { // ChannelID (8) // FundingOutPoint (36) // Commitment Signature (73) // RevocationKey (33) err := writeElements(w, s.ChannelID, s.FundingOutPoint, s.CommitSignature, s.RevocationKey, s.StateHintObsfucator[:]) if err != nil { return err } return nil } // Command returns the uint32 code which uniquely identifies this message as a // SingleFundingRequest on the wire. // // This is part of the lnwire.Message interface. func (s *SingleFundingComplete) Command() uint32 { return CmdSingleFundingComplete } // MaxPayloadLength returns the maximum allowed payload length for a // SingleFundingComplete. This is calculated by summing the max length of all // the fields within a SingleFundingResponse. Therefore, the final breakdown // is: 8 + 36 + 33 + 73 + 4 = 154 // // This is part of the lnwire.Message interface. func (s *SingleFundingComplete) MaxPayloadLength(uint32) uint32 { return 154 } // Validate examines each populated field within the SingleFundingComplete for // field sanity. // // This is part of the lnwire.Message interface. func (s *SingleFundingComplete) Validate() error { var zeroHash [32]byte if bytes.Equal(zeroHash[:], s.FundingOutPoint.Hash[:]) { return fmt.Errorf("funding outpoint hash must be non-zero") } if s.CommitSignature == nil { return fmt.Errorf("commitment signature must be non-nil") } // TODO(roasbeef): fin validation // We're good! return nil }