func (msg *authMsgV4) sealPlain(h *encHandshake) ([]byte, error) {
buf := make([]byte, authMsgLen)
n := copy(buf, msg.Signature[:])
n += copy(buf[n:], crypto.Sha3(exportPubkey(&h.randomPrivKey.PublicKey)))
n += copy(buf[n:], msg.InitiatorPubkey[:])
n += copy(buf[n:], msg.Nonce[:])
buf[n] = 0 // token-flag
return ecies.Encrypt(rand.Reader, h.remotePub, buf, nil, nil)
}
func sealEIP8(msg interface{}, h *encHandshake) ([]byte, error) {
buf := new(bytes.Buffer)
if err := rlp.Encode(buf, msg); err != nil {
return nil, err
}
// pad with random amount of data. the amount needs to be at least 100 bytes to make
// the message distinguishable from pre-EIP-8 handshakes.
pad := padSpace[:mrand.Intn(len(padSpace)-100)+100]
buf.Write(pad)
prefix := make([]byte, 2)
binary.BigEndian.PutUint16(prefix, uint16(buf.Len()+eciesOverhead))
enc, err := ecies.Encrypt(rand.Reader, h.remotePub, buf.Bytes(), nil, prefix)
return append(prefix, enc...), err
}
func Encrypt(pub *ecdsa.PublicKey, message []byte) ([]byte, error) {
return ecies.Encrypt(rand.Reader, ecies.ImportECDSAPublic(pub), message, nil, nil)
}
func (msg *authRespV4) sealPlain(hs *encHandshake) ([]byte, error) {
buf := make([]byte, authRespLen)
n := copy(buf, msg.RandomPubkey[:])
n += copy(buf[n:], msg.Nonce[:])
return ecies.Encrypt(rand.Reader, hs.remotePub, buf, nil, nil)
}