lnd/lnwire/commit_revocation.go

115 lines
3.5 KiB
Go

package lnwire
import (
"fmt"
"io"
)
// CommitRevocation is sent by either side once a CommitSignature 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
// CommitSignature message referencing the specified ChannelID 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 CommitSignature message).
// This piggybacking allows Alice to send the next CommitSignature message
// modifying Bob's commitment transaction without first asking for a revocation
// hash initially.
type CommitRevocation struct {
// ChannelID uniquely identifies to which currently active channel this
// CommitRevocation applies to.
ChannelID uint64
// Revocation is the pre-image to the revocation hash of the now prior
// commitment transaction.
Revocation [20]byte
// NextRevocationHash is the next revocation hash to use to create the
// next commitment transaction which is to be created upon receipt of a
// CommitSignature message.
NextRevocationHash [20]byte
}
// NewCommitRevocation creates a new CommitRevocation message.
func NewCommitRevocation() *CommitRevocation {
return &CommitRevocation{}
}
// A compile time check to ensure CommitRevocation implements the lnwire.Message
// interface.
var _ Message = (*CommitRevocation)(nil)
// Decode deserializes a serialized CommitRevocation message stored in the
// passed io.Reader observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *CommitRevocation) Decode(r io.Reader, pver uint32) error {
// ChannelID (8)
// NextRevocationHash (20)
// Revocation (20)
err := readElements(r,
&c.ChannelID,
&c.NextRevocationHash,
&c.Revocation,
)
if err != nil {
return err
}
return nil
}
// Encode serializes the target CommitRevocation into the passed io.Writer
// observing the protocol version specified.
//
// This is part of the lnwire.Message interface.
func (c *CommitRevocation) Encode(w io.Writer, pver uint32) error {
err := writeElements(w,
c.ChannelID,
c.NextRevocationHash,
c.Revocation,
)
if err != nil {
return err
}
return nil
}
// Command returns the integer uniquely identifying this message type on the
// wire.
//
// This is part of the lnwire.Message interface.
func (c *CommitRevocation) Command() uint32 {
return CmdCommitRevocation
}
// MaxPayloadLength returns the maximum allowed payload size for a
// CommitRevocation complete message observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *CommitRevocation) MaxPayloadLength(uint32) uint32 {
// 8 + 20 + 20
return 48
}
// Validate performs any necessary sanity checks to ensure all fields present
// on the CommitRevocation are valid.
//
// This is part of the lnwire.Message interface.
func (c *CommitRevocation) Validate() error {
// We're good!
return nil
}
// String returns the string representation of the target CommitRevocation.
//
// This is part of the lnwire.Message interface.
func (c *CommitRevocation) String() string {
return fmt.Sprintf("\n--- Begin CommitRevocation ---\n") +
fmt.Sprintf("ChannelID:\t%d\n", c.ChannelID) +
fmt.Sprintf("NextRevocationHash:\t%x\n", c.NextRevocationHash) +
fmt.Sprintf("Revocation:\t%x\n", c.Revocation) +
fmt.Sprintf("--- End CommitRevocation ---\n")
}