def sign_message(self, message, keypath):
to_hash = b""
to_hash += self.message_magic
to_hash += ser_compact_size(len(message))
to_hash += message
hashed_message = hash256(to_hash)
to_send = '{"sign":{"data":[{"hash":"'
to_send += binascii.hexlify(hashed_message)
to_send += '","keypath":"'
to_send += keypath
to_send += '"}]}}'
reply = send_encrypt(to_send, self.password, self.device)
print(reply)
if 'error' in reply:
return
print(
"Touch the device for 3 seconds to sign. Touch briefly to cancel")
reply = send_encrypt(to_send, self.password, self.device)
print(reply)
if 'error' in reply:
return
sig = binascii.unhexlify(reply['sign'][0]['sig'])
r = sig[0:32]
s = sig[32:64]
recid = binascii.unhexlify(reply['sign'][0]['recid'])
compact_sig = ser_sig_compact(r, s, recid)
print(binascii.hexlify(compact_sig))
return json.dumps({"signature": base64.b64encode(compact_sig)})
def make_txn_sighash(self, replace_idx, replacement, sighash_type):
# calculate the hash value for one input of current transaction
# - blank all script inputs
# - except one single tx in, which is provided
# - serialize that without witness data
# - append SIGHASH_ALL=1 value (LE32)
# - sha256 over that
fd = self.fd
old_pos = fd.tell()
rv = tcc.sha256()
# version number
rv.update(pack('<i', self.txn_version)) # nVersion
# inputs
rv.update(ser_compact_size(self.num_inputs))
for in_idx, txi in self.input_iter():
if in_idx == replace_idx:
assert not self.inputs[in_idx].witness_utxo
assert not self.inputs[in_idx].is_segwit
assert replacement.scriptSig
rv.update(replacement.serialize())
else:
txi.scriptSig = b''
rv.update(txi.serialize())
# outputs
rv.update(ser_compact_size(self.num_outputs))
for out_idx, txo in self.output_iter():
rv.update(txo.serialize())
# locktime
rv.update(pack('<I', self.lock_time))
assert sighash_type == SIGHASH_ALL, "only SIGHASH_ALL supported"
# SIGHASH_ALL==1 value
rv.update(b'\x01\x00\x00\x00')
fd.seek(old_pos)
# double SHA256
return tcc.sha256(rv.digest()).digest()
def write(self, out_fd, ktype, val, key=b''):
# serialize helper: write w/ size and key byte
out_fd.write(ser_compact_size(1 + len(key)))
out_fd.write(bytes([ktype]) + key)
if isinstance(val, tuple):
(pos, ll) = val
out_fd.write(ser_compact_size(ll))
self.fd.seek(pos)
while ll:
t = self.fd.read(min(64, ll))
out_fd.write(t)
ll -= len(t)
elif isinstance(val, list):
# for subpaths lists (LE32 ints)
assert ktype in (PSBT_IN_BIP32_DERIVATION,
PSBT_OUT_BIP32_DERIVATION)
out_fd.write(ser_compact_size(len(val) * 4))
for i in val:
out_fd.write(pack('<I', i))
else:
out_fd.write(ser_compact_size(len(val)))
out_fd.write(val)
def hash_message(cls, msg=None, msg_len=0):
# Perform sha256 for message-signing purposes (only)
# - or get setup for that, if msg == None
s = tcc.sha256()
s.update(cls.msg_signing_prefix())
msg_len = msg_len or len(msg)
s.update(ser_compact_size(msg_len))
if msg is None:
return s
s.update(msg)
return tcc.sha256(s.digest()).digest()
def serialize(self, out_fd, upgrade_txn=False):
# Ouput into a file.
wr = lambda *a: self.write(out_fd, *a)
out_fd.write(b'psbt\xff')
if upgrade_txn and self.is_complete():
# write out the ready-to-transmit txn
# - means we are also a combiner in this case
# - hard tho, due to variable length data.
# - XXX probably a bad idea, so disabled for now
out_fd.write(
b'\x01\x00') # keylength=1, key=b'', PSBT_GLOBAL_UNSIGNED_TX
with SizerFile() as fd:
self.finalize(fd)
txn_len = fd.tell()
out_fd.write(ser_compact_size(txn_len))
self.finalize(out_fd)
else:
# provide original txn (unchanged)
wr(PSBT_GLOBAL_UNSIGNED_TX, self.txn)
for k in self.unknown:
wr(k[0], self.unknown[k], k[1:])
# sep between globals in inputs
out_fd.write(b'\0')
for idx, inp in enumerate(self.inputs):
inp.serialize(out_fd, idx)
out_fd.write(b'\0')
for idx, outp in enumerate(self.outputs):
if outp:
outp.serialize(out_fd, idx)
out_fd.write(b'\0')
def finalize(self, fd):
# Stream out the finalized transaction, with signatures applied
# - assumption is it's complete already.
fd.write(pack('<i', self.txn_version)) # nVersion
# does this txn require witness data to be included?
# - yes, if the original txn had some
# - yes, if we did a segwit signature on any input
needs_witness = self.had_witness or any(i.is_segwit
for i in self.inputs if i)
if needs_witness:
# zero marker, and flags=0x01
fd.write(b'\x00\x01')
# inputs
fd.write(ser_compact_size(self.num_inputs))
for in_idx, txi in self.input_iter():
inp = self.inputs[in_idx]
if inp.is_segwit:
if inp.is_p2sh:
# multisig (p2sh) segwit still requires the script here.
txi.scriptSig = inp.scriptSig
else:
# major win for segwit (p2pkh): no redeem script bloat anymore
txi.scriptSig = b''
# NOTE: Actual signature will be in witness data area
elif inp.added_sig:
# insert the new signature(s)
pubkey, der_sig = inp.added_sig
s = b''
if not inp.is_multisig:
s += ser_push_data(der_sig)
s += ser_push_data(pubkey)
else:
assert False, 'p2sh combining not supported'
txi.scriptSig = s
fd.write(txi.serialize())
# outputs
fd.write(ser_compact_size(self.num_outputs))
for out_idx, txo in self.output_iter():
fd.write(txo.serialize())
if needs_witness:
# witness values
# - preserve any given ones, add ours
for in_idx, wit in self.input_witness_iter():
inp = self.inputs[in_idx]
if inp.is_segwit and inp.added_sig:
# put in new sig: wit is a CTxInWitness
assert not wit.scriptWitness.stack, 'replacing non-empty?'
pubkey, der_sig = inp.added_sig
if not inp.is_multisig:
assert pubkey[0] in {
0x02, 0x03
} and len(pubkey) == 33, "bad v0 pubkey"
wit.scriptWitness.stack = [der_sig, pubkey]
else:
assert False, 'p2sh combining not supported'
fd.write(wit.serialize())
# locktime
fd.write(pack('<I', self.lock_time))
