lnd.xprv/lnwire/single_funding_response.go

159 lines
5.1 KiB
Go
Raw Normal View History

package lnwire
import (
"io"
"github.com/roasbeef/btcd/btcec"
"github.com/roasbeef/btcutil"
)
// SingleFundingResponse is the message Bob sends to Alice after she initiates
// the single funder channel workflow via a SingleFundingRequest message. Once
// Alice receives Bob's response, then she has all the items necessary to
// construct the funding transaction, and both commitment transactions.
type SingleFundingResponse struct {
// PendingChannelID serves to uniquely identify the future channel
// created by the initiated single funder workflow.
PendingChannelID [32]byte
// ChannelDerivationPoint is an secp256k1 point which will be used to
// derive the public key the responder will use for the half of the
// 2-of-2 multi-sig. Using the channel derivation point (CDP), and the
// responder's identity public key (A), the channel public key is
// computed as: C = A + CDP. In order to be valid all CDP's MUST have
// an odd y-coordinate.
ChannelDerivationPoint *btcec.PublicKey
// CommitmentKey is key the responder to the funding workflow wishes to
// use within their versino of the commitment transaction for any
// delayed (CSV) or immediate outputs to them.
CommitmentKey *btcec.PublicKey
// RevocationKey is the initial key to be used for the revocation
// clause within the self-output of the responder's commitment
// transaction. Once an initial new state is created, the responder
// will send a preimage which will allow the initiator to sweep the
// responder's funds if the violate the contract.
RevocationKey *btcec.PublicKey
// CsvDelay is the number of blocks to use for the relative time lock
// in the pay-to-self output of both commitment transactions.
CsvDelay uint32
// DeliveryPkScript defines the public key script that the initiator
// would like to use to receive their balance in the case of a
// cooperative close. Only the following script templates are
// supported: P2PKH, P2WKH, P2SH, and P2WSH.
DeliveryPkScript PkScript
// DustLimit is the threshold below which no HTLC output should be
// generated for remote commitment transaction; ie. HTLCs below
// this amount are not enforceable onchain for their point of view.
DustLimit btcutil.Amount
// ConfirmationDepth is the number of confirmations that the initiator
// of a funding workflow is requesting be required before the channel
// is considered fully open.
ConfirmationDepth uint32
}
// NewSingleFundingResponse creates, and returns a new empty
// SingleFundingResponse.
func NewSingleFundingResponse(chanID [32]byte, rk, ck, cdp *btcec.PublicKey,
delay uint32, deliveryScript PkScript,
dustLimit btcutil.Amount, confDepth uint32) *SingleFundingResponse {
return &SingleFundingResponse{
PendingChannelID: chanID,
ChannelDerivationPoint: cdp,
CommitmentKey: ck,
RevocationKey: rk,
CsvDelay: delay,
DeliveryPkScript: deliveryScript,
DustLimit: dustLimit,
ConfirmationDepth: confDepth,
}
}
// A compile time check to ensure SingleFundingResponse implements the
// lnwire.Message interface.
var _ Message = (*SingleFundingResponse)(nil)
// Decode deserializes the serialized SingleFundingResponse stored in the passed
// io.Reader into the target SingleFundingResponse using the deserialization
// rules defined by the passed protocol version.
//
// This is part of the lnwire.Message interface.
func (c *SingleFundingResponse) Decode(r io.Reader, pver uint32) error {
return readElements(r,
c.PendingChannelID[:],
&c.ChannelDerivationPoint,
&c.CommitmentKey,
&c.RevocationKey,
&c.CsvDelay,
&c.DeliveryPkScript,
&c.DustLimit,
&c.ConfirmationDepth)
}
// Encode serializes the target SingleFundingResponse 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 (c *SingleFundingResponse) Encode(w io.Writer, pver uint32) error {
return writeElements(w,
c.PendingChannelID[:],
c.ChannelDerivationPoint,
c.CommitmentKey,
c.RevocationKey,
c.CsvDelay,
c.DeliveryPkScript,
c.DustLimit,
c.ConfirmationDepth)
}
// MsgType returns the uint32 code which uniquely identifies this message as a
// SingleFundingResponse on the wire.
//
// This is part of the lnwire.Message interface.
func (c *SingleFundingResponse) MsgType() MessageType {
return MsgSingleFundingResponse
}
// MaxPayloadLength returns the maximum allowed payload length for a
// SingleFundingResponse. This is calculated by summing the max length of all
// the fields within a SingleFundingResponse. To enforce a maximum
// DeliveryPkScript size, the size of a P2PKH public key script is used.
//
// This is part of the lnwire.Message interface.
func (c *SingleFundingResponse) MaxPayloadLength(uint32) uint32 {
var length uint32
// PendingChannelID - 32 bytes
length += 32
// ChannelDerivationPoint - 33 bytes
length += 33
// CommitmentKey - 33 bytes
length += 33
// RevocationKey - 33 bytes
length += 33
// CsvDelay - 4 bytes
length += 4
// DeliveryPkScript - 25 bytes
length += 25
// DustLimit - 8 bytes
length += 8
// ConfirmationDepth - 4 bytes
length += 4
return length
}