// SignPayment returns a signed transaction on the current payment channel.
func (c *Channel) SignPayment(amount *big.Int) (Cheque, error) {
sig, err := crypto.Sign(sha3(c.Id[:], c.from[:], c.to[:], c.nonce.Bytes(), amount.Bytes()), c.key)
if err != nil {
return Cheque{}, err
}
return Cheque{Sig: sig, From: c.from, To: c.to, Nonce: c.nonce, Amount: amount}, nil
}
func (tx *Transaction) SignECDSA(prv *ecdsa.PrivateKey) (*Transaction, error) {
h := tx.SigHash()
sig, err := crypto.Sign(h[:], prv)
if err != nil {
return nil, err
}
return tx.WithSignature(sig)
}
func (am *Manager) Sign(a Account, toSign []byte) (signature []byte, err error) {
am.mutex.RLock()
defer am.mutex.RUnlock()
unlockedKey, found := am.unlocked[a.Address]
if !found {
return nil, ErrLocked
}
signature, err = crypto.Sign(toSign, unlockedKey.PrivateKey)
return signature, err
}
func encodePacket(priv *ecdsa.PrivateKey, ptype byte, req interface{}) ([]byte, error) {
b := new(bytes.Buffer)
b.Write(headSpace)
b.WriteByte(ptype)
if err := rlp.Encode(b, req); err != nil {
glog.V(logger.Error).Infoln("error encoding packet:", err)
return nil, err
}
packet := b.Bytes()
sig, err := crypto.Sign(crypto.Sha3(packet[headSize:]), priv)
if err != nil {
glog.V(logger.Error).Infoln("could not sign packet:", err)
return nil, err
}
copy(packet[macSize:], sig)
// add the hash to the front. Note: this doesn't protect the
// packet in any way. Our public key will be part of this hash in
// The future.
copy(packet, crypto.Sha3(packet[macSize:]))
return packet, nil
}
// authMsg creates an encrypted initiator handshake message.
func (h *encHandshake) authMsg(prv *ecdsa.PrivateKey, token []byte) ([]byte, error) {
var tokenFlag byte
if token == nil {
// no session token found means we need to generate shared secret.
// ecies shared secret is used as initial session token for new peers
// generate shared key from prv and remote pubkey
var err error
if token, err = h.ecdhShared(prv); err != nil {
return nil, err
}
} else {
// for known peers, we use stored token from the previous session
tokenFlag = 0x01
}
// sign known message:
// ecdh-shared-secret^nonce for new peers
// token^nonce for old peers
signed := xor(token, h.initNonce)
signature, err := crypto.Sign(signed, h.randomPrivKey.ExportECDSA())
if err != nil {
return nil, err
}
// encode auth message
// signature || sha3(ecdhe-random-pubk) || pubk || nonce || token-flag
msg := make([]byte, authMsgLen)
n := copy(msg, signature)
n += copy(msg[n:], crypto.Sha3(exportPubkey(&h.randomPrivKey.PublicKey)))
n += copy(msg[n:], crypto.FromECDSAPub(&prv.PublicKey)[1:])
n += copy(msg[n:], h.initNonce)
msg[n] = tokenFlag
// encrypt auth message using remote-pubk
return ecies.Encrypt(rand.Reader, h.remotePub, msg, nil, nil)
}
// sign calculates and sets the cryptographic signature for the message , also
// setting the sign flag.
func (self *Message) sign(key *ecdsa.PrivateKey) (err error) {
self.Flags |= signatureFlag
self.Signature, err = crypto.Sign(self.hash(), key)
return
}