lnd/lnwire/single_funding_complete.go

145 lines
4.4 KiB
Go

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
// SingleFundingComplete 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 SingleFundingComplete. 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
}