def _calc_initial(self):
Hpoint = self.setup._ecdsa_H
HGpoint = self.setup._ecdsa_HG
k = self.nonce
a = self.amount_mod
# We don't want to calculate (a * Hpoint) since the time to execute
# would reveal information about size / bitcount of a. So, we use
# the nonce as a blinding offset factor.
Ppoint = ((a - k) % order) * Hpoint + k * HGpoint
if Ppoint == ecdsa.ellipticcurve.INFINITY:
raise ResultAtInfinity
self.P_uncompressed = point_to_ser(Ppoint, comp=False)
self.P_compressed = point_to_ser(Ppoint, comp=True)
def sign_message(self, sequence, message, password):
sig = None
try:
message = message.encode('utf8')
inputPath = self.get_derivation() + "/%d/%d" % sequence
msg_hash = Hash(msg_magic(message))
inputHash = to_hexstr(msg_hash)
hasharray = []
hasharray.append({'hash': inputHash, 'keypath': inputPath})
hasharray = json.dumps(hasharray)
msg = b'{"sign":{"meta":"sign message", "data":%s}}' % hasharray.encode('utf8')
dbb_client = self.plugin.get_client(self)
if not dbb_client.is_paired():
raise Exception(_("Could not sign message."))
reply = dbb_client.hid_send_encrypt(msg)
self.handler.show_message(_("Signing message ...") + "\n\n" +
_("To continue, touch the Digital Bitbox's blinking light for 3 seconds.") + "\n\n" +
_("To cancel, briefly touch the blinking light or wait for the timeout."))
reply = dbb_client.hid_send_encrypt(msg) # Send twice, first returns an echo for smart verification (not implemented)
self.handler.finished()
if 'error' in reply:
raise Exception(reply['error']['message'])
if 'sign' not in reply:
raise Exception(_("Could not sign message."))
if 'recid' in reply['sign'][0]:
# firmware > v2.1.1
sig = bytes([27 + int(reply['sign'][0]['recid'], 16) + 4]) + binascii.unhexlify(reply['sign'][0]['sig'])
pk, compressed = pubkey_from_signature(sig, msg_hash)
pk = point_to_ser(pk.pubkey.point, compressed)
addr = public_key_to_p2pkh(pk)
if verify_message(addr, sig, message) is False:
raise Exception(_("Could not sign message"))
elif 'pubkey' in reply['sign'][0]:
# firmware <= v2.1.1
for i in range(4):
sig = bytes([27 + i + 4]) + binascii.unhexlify(reply['sign'][0]['sig'])
try:
addr = public_key_to_p2pkh(binascii.unhexlify(reply['sign'][0]['pubkey']))
if verify_message(addr, sig, message):
break
except Exception:
continue
else:
raise Exception(_("Could not sign message"))
except BaseException as e:
self.give_error(e)
return sig
def verify_signature(self, signature, message, verification_key):
"This method verifies signature of message"
try:
pk, compressed = pubkey_from_signature(signature,
Hash(msg_magic(message)))
pubkey = point_to_ser(pk.pubkey.point, compressed).hex()
return pubkey == verification_key
except Exception as e:
self.print_error("verify_signature:", repr(e))
return False
def decrypt(data, privkey):
""" Decrypt using the private key; returns (message, key) or raises
DecryptionFailed on failure. """
if len(data) < 33 + 16 + 16: # key, at least 1 block, and mac
raise DecryptionFailed
try:
nonce_pub = ser_to_point(data[:33])
except:
raise DecryptionFailed
sec = int.from_bytes(privkey, 'big')
key = hashlib.sha256(point_to_ser(sec * nonce_pub, comp=True)).digest()
return decrypt_with_symmkey(data, key), key
def encrypt(message, pubkey, pad_to_length=None):
"""
pad_to_length must be a multiple of 16, and equal to or larger than
len(message)+4. Default is to choose the smallest possible value.
If the `pubkey` is not a valid point, raises EncryptionFailed.
"""
try:
pubpoint = ser_to_point(pubkey)
except:
raise EncryptionFailed
nonce_sec = ecdsa.util.randrange(order)
nonce_pub = point_to_ser(nonce_sec * G, comp=True)
key = hashlib.sha256(point_to_ser(nonce_sec * pubpoint,
comp=True)).digest()
plaintext = len(message).to_bytes(4, 'big') + message
if pad_to_length is None:
plaintext += b'\0' * (-len(plaintext) % 16)
else:
if pad_to_length % 16 != 0:
raise ValueError(f'{pad_to_length} not multiple of 16')
need = pad_to_length - len(plaintext)
if need < 0:
raise ValueError(f'{pad_to_length} < {len(plaintext)}')
plaintext += b'\0' * need
iv = b'\0' * 16
if AES:
ciphertext = AES.new(key, AES.MODE_CBC, iv).encrypt(plaintext)
else:
aes_cbc = pyaes.AESModeOfOperationCBC(key, iv=iv)
aes = pyaes.Encrypter(aes_cbc, padding=pyaes.PADDING_NONE)
ciphertext = aes.feed(
plaintext) + aes.feed() # empty aes.feed() flushes buffer
mac = hmacdigest(key, ciphertext, 'sha256')[:16]
return nonce_pub + ciphertext + mac
def add_points(points_iterable):
""" Adds one or more serialized points together. This is fastest if the
points are already uncompressed. Returns uncompressed point.
Note: intermediate sums are allowed to be the point at infinity, but not the
final result.
"""
plist = []
if seclib:
ctx = seclib.ctx
for pser in points_iterable:
P_buf = create_string_buffer(64)
_b = bytes(pser)
res = seclib.secp256k1_ec_pubkey_parse(ctx, P_buf, _b,
c_size_t(len(_b)))
if not res:
raise ValueError(
'point could not be parsed by the secp256k1 library')
plist.append(P_buf)
if not plist:
raise ValueError('empty list')
num = len(plist)
result_buf = create_string_buffer(64)
publist = (c_void_p * num)(*(cast(x, c_void_p) for x in plist))
res = seclib.secp256k1_ec_pubkey_combine(ctx, result_buf, publist, num)
if res != 1:
raise ResultAtInfinity
serpoint = create_string_buffer(65)
sersize = c_size_t(65)
res = seclib.secp256k1_ec_pubkey_serialize(
ctx, serpoint, byref(sersize), result_buf,
secp256k1.SECP256K1_EC_UNCOMPRESSED)
assert res == 1
assert sersize.value == 65
return serpoint.raw
else:
for pser in points_iterable:
plist.append(ser_to_point(pser))
if not plist:
raise ValueError('empty list')
Psum = sum(plist[1:], plist[0])
if Psum == ecdsa.ellipticcurve.INFINITY:
raise ResultAtInfinity
return point_to_ser(Psum, comp=False)
def sign_transaction(self, tx, password, *, use_cache=False):
if tx.is_complete():
return
try:
p2pkhTransaction = True
derivations = self.get_tx_derivations(tx)
inputhasharray = []
hasharray = []
pubkeyarray = []
# Build hasharray from inputs
for i, txin in enumerate(tx.inputs()):
if txin['type'] == 'coinbase':
self.give_error("Coinbase not supported") # should never happen
if txin['type'] != 'p2pkh':
p2pkhTransaction = False
for x_pubkey in txin['x_pubkeys']:
if x_pubkey in derivations:
index = derivations.get(x_pubkey)
inputPath = "%s/%d/%d" % (self.get_derivation(), index[0], index[1])
inputHash = Hash(binascii.unhexlify(tx.serialize_preimage(i)))
hasharray_i = {'hash': to_hexstr(inputHash), 'keypath': inputPath}
hasharray.append(hasharray_i)
inputhasharray.append(inputHash)
break
else:
self.give_error("No matching x_key for sign_transaction") # should never happen
# Build pubkeyarray from outputs
for _type, address, amount in tx.outputs():
info = tx.output_info.get(address)
if info is not None:
index, xpubs, m, script_type = info
changePath = self.get_derivation() + "/%d/%d" % index
changePubkey = self.derive_pubkey(index[0], index[1])
pubkeyarray_i = {'pubkey': changePubkey, 'keypath': changePath}
pubkeyarray.append(pubkeyarray_i)
# Special serialization of the unsigned transaction for
# the mobile verification app.
# At the moment, verification only works for p2pkh transactions.
if p2pkhTransaction:
class CustomTXSerialization(Transaction):
@classmethod
def input_script(self, txin, estimate_size=False, sign_schnorr=False):
if txin['type'] == 'p2pkh':
return Transaction.get_preimage_script(txin)
if txin['type'] == 'p2sh':
# Multisig verification has partial support, but is disabled. This is the
# expected serialization though, so we leave it here until we activate it.
return '00' + push_script(Transaction.get_preimage_script(txin))
raise Exception("unsupported type %s" % txin['type'])
tx_dbb_serialized = CustomTXSerialization(tx.serialize()).serialize()
else:
# We only need this for the signing echo / verification.
tx_dbb_serialized = None
# Build sign command
dbb_signatures = []
steps = math.ceil(1.0 * len(hasharray) / self.maxInputs)
for step in range(int(steps)):
hashes = hasharray[step * self.maxInputs : (step + 1) * self.maxInputs]
msg = {
"sign": {
"data": hashes,
"checkpub": pubkeyarray,
},
}
if tx_dbb_serialized is not None:
msg["sign"]["meta"] = to_hexstr(Hash(tx_dbb_serialized))
msg = json.dumps(msg).encode('ascii')
dbb_client = self.plugin.get_client(self)
if not dbb_client.is_paired():
raise Exception("Could not sign transaction.")
reply = dbb_client.hid_send_encrypt(msg)
if 'error' in reply:
raise Exception(reply['error']['message'])
if 'echo' not in reply:
raise Exception("Could not sign transaction.")
if self.plugin.is_mobile_paired() and tx_dbb_serialized is not None:
reply['tx'] = tx_dbb_serialized
self.plugin.comserver_post_notification(reply)
if steps > 1:
self.handler.show_message(_("Signing large transaction. Please be patient ...") + "\n\n" +
_("To continue, touch the Digital Bitbox's blinking light for 3 seconds.") + " " +
_("(Touch {} of {})").format((step + 1), steps) + "\n\n" +
_("To cancel, briefly touch the blinking light or wait for the timeout.") + "\n\n")
else:
self.handler.show_message(_("Signing transaction...") + "\n\n" +
_("To continue, touch the Digital Bitbox's blinking light for 3 seconds.") + "\n\n" +
_("To cancel, briefly touch the blinking light or wait for the timeout."))
# Send twice, first returns an echo for smart verification
reply = dbb_client.hid_send_encrypt(msg)
self.handler.finished()
if 'error' in reply:
if reply["error"].get('code') in (600, 601):
# aborted via LED short touch or timeout
raise UserCancelled()
raise Exception(reply['error']['message'])
if 'sign' not in reply:
raise Exception("Could not sign transaction.")
dbb_signatures.extend(reply['sign'])
# Fill signatures
if len(dbb_signatures) != len(tx.inputs()):
raise Exception("Incorrect number of transactions signed.") # Should never occur
for i, txin in enumerate(tx.inputs()):
num = txin['num_sig']
for pubkey in txin['pubkeys']:
signatures = list(filter(None, txin['signatures']))
if len(signatures) == num:
break # txin is complete
ii = txin['pubkeys'].index(pubkey)
signed = dbb_signatures[i]
if 'recid' in signed:
# firmware > v2.1.1
recid = int(signed['recid'], 16)
s = binascii.unhexlify(signed['sig'])
h = inputhasharray[i]
pk = MyVerifyingKey.from_signature(s, recid, h, curve = SECP256k1)
pk = to_hexstr(point_to_ser(pk.pubkey.point, True))
elif 'pubkey' in signed:
# firmware <= v2.1.1
pk = signed['pubkey']
if pk != pubkey:
continue
sig_r = int(signed['sig'][:64], 16)
sig_s = int(signed['sig'][64:], 16)
sig = sigencode_der(sig_r, sig_s, generator_secp256k1.order())
txin['signatures'][ii] = to_hexstr(sig) + '41'
tx._inputs[i] = txin
except UserCancelled:
raise
except BaseException as e:
self.give_error(e, True)
else:
print_error("Transaction is_complete", tx.is_complete())
tx.raw = tx.serialize()
def __init__(self, H):
assert isinstance(H, bytes)
if not seclib:
try:
Hpoint = ser_to_point(H)
except:
raise ValueError("H could not be parsed")
HGpoint = Hpoint + ecdsa.SECP256k1.generator
if HGpoint == ecdsa.ellipticcurve.INFINITY:
# this happens if H = -G
raise InsecureHPoint(-1)
self._ecdsa_H = Hpoint
self._ecdsa_HG = HGpoint
self.H = point_to_ser(Hpoint, comp=False)
self.HG = point_to_ser(HGpoint, comp=False)
else:
ctx = seclib.ctx
H_buf = create_string_buffer(64)
res = seclib.secp256k1_ec_pubkey_parse(ctx, H_buf, H,
c_size_t(len(H)))
if not res:
raise ValueError(
'H could not be parsed by the secp256k1 library')
self._seclib_H = H_buf.raw
G = point_to_ser(ecdsa.SECP256k1.generator, comp=False)
G_buf = create_string_buffer(64)
res = seclib.secp256k1_ec_pubkey_parse(ctx, G_buf, G,
c_size_t(len(G)))
assert res, "G point should always deserialize without issue"
HG_buf = create_string_buffer(64)
publist = (c_void_p * 2)(*(cast(x, c_void_p)
for x in (H_buf, G_buf)))
res = seclib.secp256k1_ec_pubkey_combine(ctx, HG_buf, publist, 2)
if res != 1:
# this happens if H = -G
raise InsecureHPoint(-1)
self._seclib_HG = HG_buf.raw
# now serialize H and HG as uncompressed bytes
serpoint = create_string_buffer(65)
sersize = c_size_t(65)
res = seclib.secp256k1_ec_pubkey_serialize(
ctx, serpoint, byref(sersize), H_buf,
secp256k1.SECP256K1_EC_UNCOMPRESSED)
assert res == 1
assert sersize.value == 65
self.H = serpoint.raw
res = seclib.secp256k1_ec_pubkey_serialize(
ctx, serpoint, byref(sersize), HG_buf,
secp256k1.SECP256K1_EC_UNCOMPRESSED)
assert res == 1
assert sersize.value == 65
self.HG = serpoint.raw
def restore_from_privkey(self, secret_string):
"restore key pair from private key expressed in a hex form"
self.private_key = string_to_number(bytes.fromhex(secret_string))
self.eck = EC_KEY(bytes.fromhex(secret_string))
self.public_key = point_to_ser(self.private_key*self.G, True)
def generate_key_pair(self):
""" generate encryption/decryption pair """
self.private_key = ecdsa.util.randrange( self._r )
self.eck = EC_KEY(number_to_string(self.private_key, self._r))
self.public_key = point_to_ser(self.private_key*self.G, True)
