lnd.xprv/lnwire/commit_sig.go

116 lines
3.3 KiB
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package lnwire
import (
"fmt"
"io"
"github.com/roasbeef/btcd/btcec"
"github.com/roasbeef/btcd/wire"
)
// CommitSig is sent by either side to stage any pending HTLC's in the
// receiver's pending set into a new commitment state. Implicitly, the new
// commitment transaction constructed which has been signed by CommitSig
// includes all HTLC's in the remote node's pending set. A CommitSig message
// may be sent after a series of UpdateAddHTLC/UpdateFufillHTLC messages in
// order to batch add several HTLC's with a single signature covering all
// implicitly accepted HTLC's.
type CommitSig struct {
// ChannelPoint uniquely identifies to which currently active channel
// this CommitSig applies to.
ChannelPoint wire.OutPoint
// CommitSig is Alice's signature for Bob's new commitment transaction.
// Alice is able to send this signature without requesting any
// additional data due to the piggybacking of Bob's next revocation
// hash in his prior RevokeAndAck message, as well as the canonical
// ordering used for all inputs/outputs within commitment transactions.
CommitSig *btcec.Signature
// TODO(roasbeef): add HTLC sigs after state machine is updated to
// support that
}
// NewCommitSig creates a new empty CommitSig message.
func NewCommitSig() *CommitSig {
return &CommitSig{}
}
// A compile time check to ensure CommitSig implements the lnwire.Message
// interface.
var _ Message = (*CommitSig)(nil)
// Decode deserializes a serialized CommitSig message stored in the
// passed io.Reader observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *CommitSig) Decode(r io.Reader, pver uint32) error {
// ChannelPoint(8)
// RequesterCommitSig(73max+2)
err := readElements(r,
&c.ChannelPoint,
&c.CommitSig,
)
if err != nil {
return err
}
return nil
}
// Encode serializes the target CommitSig into the passed io.Writer
// observing the protocol version specified.
//
// This is part of the lnwire.Message interface.
func (c *CommitSig) Encode(w io.Writer, pver uint32) error {
err := writeElements(w,
c.ChannelPoint,
c.CommitSig,
)
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 *CommitSig) Command() uint32 {
return CmdCommitSig
}
// MaxPayloadLength returns the maximum allowed payload size for a
// CommitSig complete message observing the specified protocol version.
//
// This is part of the lnwire.Message interface.
func (c *CommitSig) MaxPayloadLength(uint32) uint32 {
// 36 + 73
return 109
}
// Validate performs any necessary sanity checks to ensure all fields present
// on the CommitSig are valid.
//
// This is part of the lnwire.Message interface.
func (c *CommitSig) Validate() error {
// We're good!
return nil
}
// String returns the string representation of the target CommitSig.
//
// This is part of the lnwire.Message interface.
func (c *CommitSig) String() string {
var serializedSig []byte
if c.CommitSig != nil {
serializedSig = c.CommitSig.Serialize()
}
return fmt.Sprintf("\n--- Begin CommitSig ---\n") +
fmt.Sprintf("ChannelPoint:\t%v\n", c.ChannelPoint) +
fmt.Sprintf("CommitSig:\t\t%x\n", serializedSig) +
fmt.Sprintf("--- End CommitSig ---\n")
}