lnd.xprv/lnwire/revoke_and_ack.go
Olaoluwa Osuntokun 2263a6a1b7
lnwire: modify RevokeAndAck to remove NextRevocationHash
This commit modifies the RevokeAndAck message in order to bring it more
in line with the current draft of the specification. The prior version
was based on a version that used a revocation hash for HTLC’s and a
revocation key for commitment outputs. The current commitment design
uses revocation keys uniformly throughout.
2017-07-30 17:47:33 -07:00

84 lines
2.7 KiB
Go

package lnwire
import (
"io"
"github.com/roasbeef/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 without revocation base point will be used to
// create the proper revocation key used within the commitment
// transaction.
NextRevocationKey *btcec.PublicKey
}
// NewRevokeAndAck creates a new RevokeAndAck message.
func NewRevokeAndAck() *RevokeAndAck {
return &RevokeAndAck{}
}
// 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,
)
}
// 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,
)
}
// 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 {
// 32 + 32 + 33
return 97
}