mirror of
https://github.com/lightningnetwork/lnd.git
synced 2024-11-19 18:10:34 +01:00
7dfe4018ce
This commit was previously split into the following parts to ease review: - 2d746f68: replace imports - 4008f0fd: use ecdsa.Signature - 849e33d1: remove btcec.S256() - b8f6ebbd: use v2 library correctly - fa80bca9: bump go modules
89 lines
2.7 KiB
Go
89 lines
2.7 KiB
Go
package keychain
|
|
|
|
import (
|
|
"crypto/sha256"
|
|
|
|
"github.com/btcsuite/btcd/btcec/v2"
|
|
)
|
|
|
|
// NewPubKeyECDH wraps the given key of the key ring so it adheres to the
|
|
// SingleKeyECDH interface.
|
|
func NewPubKeyECDH(keyDesc KeyDescriptor, ecdh ECDHRing) *PubKeyECDH {
|
|
return &PubKeyECDH{
|
|
keyDesc: keyDesc,
|
|
ecdh: ecdh,
|
|
}
|
|
}
|
|
|
|
// PubKeyECDH is an implementation of the SingleKeyECDH interface. It wraps an
|
|
// ECDH key ring so it can perform ECDH shared key generation against a single
|
|
// abstracted away private key.
|
|
type PubKeyECDH struct {
|
|
keyDesc KeyDescriptor
|
|
ecdh ECDHRing
|
|
}
|
|
|
|
// PubKey returns the public key of the private key that is abstracted away by
|
|
// the interface.
|
|
//
|
|
// NOTE: This is part of the SingleKeyECDH interface.
|
|
func (p *PubKeyECDH) PubKey() *btcec.PublicKey {
|
|
return p.keyDesc.PubKey
|
|
}
|
|
|
|
// ECDH performs a scalar multiplication (ECDH-like operation) between the
|
|
// abstracted private key and a remote public key. The output returned will be
|
|
// the sha256 of the resulting shared point serialized in compressed format. If
|
|
// k is our private key, and P is the public key, we perform the following
|
|
// operation:
|
|
//
|
|
// sx := k*P
|
|
// s := sha256(sx.SerializeCompressed())
|
|
//
|
|
// NOTE: This is part of the SingleKeyECDH interface.
|
|
func (p *PubKeyECDH) ECDH(pubKey *btcec.PublicKey) ([32]byte, error) {
|
|
return p.ecdh.ECDH(p.keyDesc, pubKey)
|
|
}
|
|
|
|
// PrivKeyECDH is an implementation of the SingleKeyECDH in which we do have the
|
|
// full private key. This can be used to wrap a temporary key to conform to the
|
|
// SingleKeyECDH interface.
|
|
type PrivKeyECDH struct {
|
|
// PrivKey is the private key that is used for the ECDH operation.
|
|
PrivKey *btcec.PrivateKey
|
|
}
|
|
|
|
// PubKey returns the public key of the private key that is abstracted away by
|
|
// the interface.
|
|
//
|
|
// NOTE: This is part of the SingleKeyECDH interface.
|
|
func (p *PrivKeyECDH) PubKey() *btcec.PublicKey {
|
|
return p.PrivKey.PubKey()
|
|
}
|
|
|
|
// ECDH performs a scalar multiplication (ECDH-like operation) between the
|
|
// abstracted private key and a remote public key. The output returned will be
|
|
// the sha256 of the resulting shared point serialized in compressed format. If
|
|
// k is our private key, and P is the public key, we perform the following
|
|
// operation:
|
|
//
|
|
// sx := k*P
|
|
// s := sha256(sx.SerializeCompressed())
|
|
//
|
|
// NOTE: This is part of the SingleKeyECDH interface.
|
|
func (p *PrivKeyECDH) ECDH(pub *btcec.PublicKey) ([32]byte, error) {
|
|
var (
|
|
pubJacobian btcec.JacobianPoint
|
|
s btcec.JacobianPoint
|
|
)
|
|
pub.AsJacobian(&pubJacobian)
|
|
|
|
btcec.ScalarMultNonConst(&p.PrivKey.Key, &pubJacobian, &s)
|
|
s.ToAffine()
|
|
sPubKey := btcec.NewPublicKey(&s.X, &s.Y)
|
|
return sha256.Sum256(sPubKey.SerializeCompressed()), nil
|
|
}
|
|
|
|
var _ SingleKeyECDH = (*PubKeyECDH)(nil)
|
|
var _ SingleKeyECDH = (*PrivKeyECDH)(nil)
|