package lnwire import ( "io" "github.com/btcsuite/btcd/btcec" ) // RevokeAndAck is sent by either side once a CommitSig message has been // received, and validated. This message serves to revoke the prior commitment // transaction, which was the most up to date version until a CommitSig message // referencing the specified ChannelPoint was received. Additionally, this // message also piggyback's the next revocation hash that Alice should use when // constructing the Bob's version of the next commitment transaction (which // would be done before sending a CommitSig message). This piggybacking allows // Alice to send the next CommitSig message modifying Bob's commitment // transaction without first asking for a revocation hash initially. type RevokeAndAck struct { // ChanID uniquely identifies to which currently active channel this // RevokeAndAck applies to. ChanID ChannelID // Revocation is the preimage to the revocation hash of the now prior // commitment transaction. Revocation [32]byte // NextRevocationKey is the next commitment point which should be used // for the next commitment transaction the remote peer creates for us. // This, in conjunction with revocation base point will be used to // create the proper revocation key used within the commitment // transaction. NextRevocationKey *btcec.PublicKey // ExtraData is the set of data that was appended to this message to // fill out the full maximum transport message size. These fields can // be used to specify optional data such as custom TLV fields. ExtraData ExtraOpaqueData } // NewRevokeAndAck creates a new RevokeAndAck message. func NewRevokeAndAck() *RevokeAndAck { return &RevokeAndAck{ ExtraData: make([]byte, 0), } } // A compile time check to ensure RevokeAndAck implements the lnwire.Message // interface. var _ Message = (*RevokeAndAck)(nil) // Decode deserializes a serialized RevokeAndAck message stored in the // passed io.Reader observing the specified protocol version. // // This is part of the lnwire.Message interface. func (c *RevokeAndAck) Decode(r io.Reader, pver uint32) error { return ReadElements(r, &c.ChanID, c.Revocation[:], &c.NextRevocationKey, &c.ExtraData, ) } // Encode serializes the target RevokeAndAck into the passed io.Writer // observing the protocol version specified. // // This is part of the lnwire.Message interface. func (c *RevokeAndAck) Encode(w io.Writer, pver uint32) error { return WriteElements(w, c.ChanID, c.Revocation[:], c.NextRevocationKey, c.ExtraData, ) } // MsgType returns the integer uniquely identifying this message type on the // wire. // // This is part of the lnwire.Message interface. func (c *RevokeAndAck) MsgType() MessageType { return MsgRevokeAndAck } // MaxPayloadLength returns the maximum allowed payload size for a RevokeAndAck // complete message observing the specified protocol version. // // This is part of the lnwire.Message interface. func (c *RevokeAndAck) MaxPayloadLength(uint32) uint32 { return MaxMsgBody } // TargetChanID returns the channel id of the link for which this message is // intended. // // NOTE: Part of peer.LinkUpdater interface. func (c *RevokeAndAck) TargetChanID() ChannelID { return c.ChanID }