def encrypt_message(pubkey, message, display_only, bip32, coin, address_n):
if len(address_n) > 0:
priv_node = bip32.get_private_node(address_n)
priv_key = tools.EcKey(priv_node.private_key)
signing = True
else:
signing = False
if signing:
if display_only:
payload = chr(0x80 + 1)
else:
payload = chr(1)
address, signature = sign_message(bip32, coin, address_n, message)
address_bin = tools.bc_address_decode(address)[:21]
payload += tools.ser_length(len(message)) + message + address_bin + signature
else:
if display_only:
payload = chr(0x80)
else:
payload = chr(0)
payload += tools.ser_length(len(message)) + message
nonce = tools.get_local_entropy()
nonce_key = tools.EcKey(nonce)
nonce_pub = binascii.unhexlify(nonce_key.get_public_key(True))
dest_pub = tools.public_key_to_point(pubkey)
shared_secret_point = dest_pub * nonce_key.privkey.secret_multiplier
shared_secret = tools.point_to_public_key(shared_secret_point, True)
keying_bytes = PBKDF2(shared_secret, "Bitcoin Secure Message" + nonce_pub, iterations=2048, macmodule=hmac, digestmodule=sha256).read(80)
aes_key = keying_bytes[:32]
hmac_key = keying_bytes[32:64]
aes_iv = keying_bytes[64:]
encrypter = pyaes.Encrypter(pyaes.AESModeOfOperationCFB(key=aes_key, iv=aes_iv, segment_size=16))
payload = encrypter.feed(payload) + encrypter.feed()
msg_hmac = hmac.HMAC(key=hmac_key, msg=payload, digestmod=sha256).digest()[:8]
return (nonce_pub, payload, msg_hmac)
def serialize_input(self, inp):
if self.have_inputs >= self.inputs_len:
raise Exception("Already have all inputs")
r = ''
if self.have_inputs == 0:
r += self._serialize_header()
r += ser_uint256(int(binascii.hexlify(inp.prev_hash), 16))
r += struct.pack("<I", inp.prev_index)
r += tools.ser_length(len(inp.script_sig))
r += inp.script_sig
r += struct.pack("<I", inp.sequence)
self.have_inputs += 1
self.size += len(r)
return r
def serialize_output(self, output):
if self.have_inputs < self.inputs_len:
raise Exception("Need all inputs first")
if self.have_outputs >= self.outputs_len:
raise Exception("Already have all outputs")
r = ''
if self.have_outputs == 0:
# First output, let's serialize tx middle
r += self._serialize_middle()
r += struct.pack("<q", output.amount)
r += tools.ser_length(len(output.script_pubkey))
r += output.script_pubkey
self.have_outputs += 1
if self.have_outputs == self.outputs_len:
r += self._serialize_footer()
self.size += len(r)
return r
def message_magic(message):
magic = chr(24) + "Bitcoin Signed Message:\n" + tools.ser_length(len(message)) + message
return magic
def _serialize_middle(self):
return tools.ser_length(self.outputs_len)
def _serialize_header(self):
r = struct.pack("<i", self.version)
r += tools.ser_length(self.inputs_len)
return r
