def test_preimage_testdata(self):
seed = bip39.seed(
'alcohol woman abuse must during monitor noble actual mixed trade anger aisle',
'')
coin = coins.by_name(self.tx.coin_name)
bip143 = Bitcoin(self.tx, None, coin)
bip143.hash143_add_input(self.inp1)
bip143.hash143_add_input(self.inp2)
for txo in [self.out1, self.out2]:
txo_bin = TxOutputBinType()
txo_bin.amount = txo.amount
script_pubkey = output_derive_script(txo.address, coin)
bip143.hash143_add_output(txo_bin, script_pubkey)
keychain = Keychain(seed, [[coin.curve_name, []]])
node = keychain.derive(self.inp2.address_n)
# test data public key hash
# only for input 2 - input 1 is not segwit
result = bip143.hash143_preimage_hash(self.inp2, [node.public_key()],
1)
self.assertEqual(
hexlify(result),
b'2fa3f1351618b2532228d7182d3221d95c21fd3d496e7e22e9ded873cf022a8b'
)
def test_bip143_outputs(self):
seed = bip39.seed('alcohol woman abuse must during monitor noble actual mixed trade anger aisle', '')
coin = coins.by_name(self.tx.coin_name)
bip143 = Bitcoin(self.tx, None, coin)
for txo in [self.out1, self.out2]:
txo_bin = TxOutputBinType()
txo_bin.amount = txo.amount
script_pubkey = output_derive_script(txo, coin)
bip143.hash143_add_output(txo_bin, script_pubkey)
outputs_hash = get_tx_hash(bip143.h_outputs, double=coin.sign_hash_double)
self.assertEqual(hexlify(outputs_hash), b'de984f44532e2173ca0d64314fcefe6d30da6f8cf27bafa706da61df8a226c83')
def test_outputs(self):
seed = bip39.seed('alcohol woman abuse must during monitor noble actual mixed trade anger aisle', '')
coin = coins.by_name(self.tx.coin_name)
bip143 = Bitcoin(self.tx, None, coin)
for txo in [self.out1, self.out2]:
txo_bin = TxOutputBinType()
txo_bin.amount = txo.amount
script_pubkey = output_derive_script(txo, coin)
bip143.hash143_add_output(txo_bin, script_pubkey)
outputs_hash = get_tx_hash(bip143.h_outputs, double=coin.sign_hash_double)
self.assertEqual(hexlify(outputs_hash), b'863ef3e1a92afbfdb97f31ad0fc7683ee943e9abcf2501590ff8f6551f47e5e5')
def test_bip143_preimage_testdata(self):
seed = bip39.seed('alcohol woman abuse must during monitor noble actual mixed trade anger aisle', '')
coin = coins.by_name(self.tx.coin_name)
bip143 = Bitcoin(self.tx, None, coin)
bip143.hash143_add_input(self.inp1)
for txo in [self.out1, self.out2]:
txo_bin = TxOutputBinType()
txo_bin.amount = txo.amount
script_pubkey = output_derive_script(txo, coin)
bip143.hash143_add_output(txo_bin, script_pubkey)
# test data public key hash
result = bip143.hash143_preimage_hash(self.inp1, unhexlify('79091972186c449eb1ded22b78e40d009bdf0089'))
self.assertEqual(hexlify(result), b'64f3b0f4dd2bb3aa1ce8566d220cc74dda9df97d8490cc81d89d735c92e59fb6')
def test_bip143_preimage_testdata(self):
seed = bip39.seed('alcohol woman abuse must during monitor noble actual mixed trade anger aisle', '')
coin = coins.by_name(self.tx.coin_name)
bip143 = Bitcoin(self.tx, None, coin)
bip143.hash143_add_input(self.inp1)
for txo in [self.out1, self.out2]:
txo_bin = TxOutputBinType()
txo_bin.amount = txo.amount
script_pubkey = output_derive_script(txo.address, coin)
bip143.hash143_add_output(txo_bin, script_pubkey)
keychain = Keychain(seed, [[coin.curve_name, []]])
node = keychain.derive(self.inp1.address_n)
# test data public key hash
result = bip143.hash143_preimage_hash(self.inp1, [node.public_key()], 1)
self.assertEqual(hexlify(result), b'6e28aca7041720995d4acf59bbda64eef5d6f23723d23f2e994757546674bbd9')
def test_preimage_testdata(self):
seed = bip39.seed('alcohol woman abuse must during monitor noble actual mixed trade anger aisle', '')
coin = coins.by_name(self.tx.coin_name)
bip143 = Bitcoin(self.tx, None, coin)
bip143.hash143_add_input(self.inp1)
bip143.hash143_add_input(self.inp2)
for txo in [self.out1, self.out2]:
txo_bin = TxOutputBinType()
txo_bin.amount = txo.amount
script_pubkey = output_derive_script(txo, coin)
bip143.hash143_add_output(txo_bin, script_pubkey)
# test data public key hash
# only for input 2 - input 1 is not segwit
result = bip143.hash143_preimage_hash(self.inp2, unhexlify('1d0f172a0ecb48aee1be1f2687d2963ae33f71a1'))
self.assertEqual(hexlify(result), b'c37af31116d1b27caf68aae9e3ac82f1477929014d5b917657d0eb49478cb670')
def test_zip243(self):
coin = coins.by_name("Zcash")
for v in self.VECTORS:
tx = SignTx(
coin_name="Zcash",
inputs_count=len(v["inputs"]),
outputs_count=len(v["outputs"]),
version=v["version"],
lock_time=v["lock_time"],
expiry=v["expiry"],
overwintered=(v["version"] >= 3),
version_group_id=v["version_group_id"],
)
zip243 = Zip243()
for i in v["inputs"]:
txi = TxInputType()
txi.amount = i["amount"]
txi.prev_hash = unhexlify(i["prevout"][0])
txi.prev_index = i["prevout"][1]
txi.script_type = i["script_type"]
txi.sequence = i["sequence"]
zip243.add_prevouts(txi)
zip243.add_sequence(txi)
for o in v["outputs"]:
txo = TxOutputBinType()
txo.amount = o["amount"]
txo.script_pubkey = unhexlify(o["script_pubkey"])
zip243.add_output(txo)
self.assertEqual(hexlify(zip243.get_prevouts_hash()),
v["prevouts_hash"])
self.assertEqual(hexlify(zip243.get_sequence_hash()),
v["sequence_hash"])
self.assertEqual(hexlify(zip243.get_outputs_hash()),
v["outputs_hash"])
self.assertEqual(
hexlify(
zip243.preimage_hash(coin, tx, txi,
unhexlify(i["pubkeyhash"]),
v["hash_type"])),
v["preimage_hash"],
)
def test_zip143(self):
coin = coins.by_name("Zcash")
for v in self.VECTORS:
tx = SignTx(
coin_name="Zcash",
inputs_count=len(v["inputs"]),
outputs_count=len(v["outputs"]),
version=v["version"],
lock_time=v["lock_time"],
expiry=v["expiry"],
version_group_id=v["version_group_id"],
)
zip143 = Overwintered(tx, None, coin)
for i in v["inputs"]:
txi = TxInputType()
txi.amount = i["amount"]
txi.prev_hash = unhexlify(i["prevout"][0])
txi.prev_index = i["prevout"][1]
txi.script_type = i["script_type"]
txi.sequence = i["sequence"]
zip143.hash143_add_input(txi)
for o in v["outputs"]:
txo = TxOutputBinType()
txo.amount = o["amount"]
txo.script_pubkey = unhexlify(o["script_pubkey"])
zip143.hash143_add_output(txo, txo.script_pubkey)
self.assertEqual(hexlify(get_tx_hash(zip143.h_prevouts)),
v["prevouts_hash"])
self.assertEqual(hexlify(get_tx_hash(zip143.h_sequence)),
v["sequence_hash"])
self.assertEqual(hexlify(get_tx_hash(zip143.h_outputs)),
v["outputs_hash"])
self.assertEqual(
hexlify(
zip143.hash143_preimage_hash(txi,
unhexlify(i["pubkeyhash"]))),
v["preimage_hash"],
)
async def check_tx_fee(tx: SignTx, keychain: seed.Keychain):
coin = coins.by_name(tx.coin_name)
# h_first is used to make sure the inputs and outputs streamed in Phase 1
# are the same as in Phase 2. it is thus not required to fully hash the
# tx, as the SignTx info is streamed only once
h_first = utils.HashWriter(sha256()) # not a real tx hash
if coin.decred:
hash143 = decred.DecredPrefixHasher(
tx) # pseudo BIP-0143 prefix hashing
tx_ser = TxRequestSerializedType()
elif tx.overwintered:
if tx.version == 3:
hash143 = zcash.Zip143() # ZIP-0143 transaction hashing
elif tx.version == 4:
hash143 = zcash.Zip243() # ZIP-0243 transaction hashing
else:
raise SigningError(
FailureType.DataError,
"Unsupported version for overwintered transaction",
)
else:
hash143 = segwit_bip143.Bip143() # BIP-0143 transaction hashing
multifp = multisig.MultisigFingerprint(
) # control checksum of multisig inputs
weight = tx_weight.TxWeightCalculator(tx.inputs_count, tx.outputs_count)
total_in = 0 # sum of input amounts
segwit_in = 0 # sum of segwit input amounts
total_out = 0 # sum of output amounts
change_out = 0 # change output amount
wallet_path = [] # common prefix of input paths
segwit = {} # dict of booleans stating if input is segwit
# output structures
txo_bin = TxOutputBinType()
tx_req = TxRequest()
tx_req.details = TxRequestDetailsType()
for i in range(tx.inputs_count):
progress.advance()
# STAGE_REQUEST_1_INPUT
txi = await helpers.request_tx_input(tx_req, i)
wallet_path = input_extract_wallet_path(txi, wallet_path)
writers.write_tx_input_check(h_first, txi)
weight.add_input(txi)
hash143.add_prevouts(
txi) # all inputs are included (non-segwit as well)
hash143.add_sequence(txi)
if not addresses.validate_full_path(txi.address_n, coin,
txi.script_type):
await helpers.confirm_foreign_address(txi.address_n)
if txi.multisig:
multifp.add(txi.multisig)
if txi.script_type in (
InputScriptType.SPENDWITNESS,
InputScriptType.SPENDP2SHWITNESS,
):
if not coin.segwit:
raise SigningError(FailureType.DataError,
"Segwit not enabled on this coin")
if not txi.amount:
raise SigningError(FailureType.DataError,
"Segwit input without amount")
segwit[i] = True
segwit_in += txi.amount
total_in += txi.amount
elif txi.script_type in (
InputScriptType.SPENDADDRESS,
InputScriptType.SPENDMULTISIG,
):
if coin.force_bip143 or tx.overwintered:
if not txi.amount:
raise SigningError(FailureType.DataError,
"Expected input with amount")
segwit[i] = False
segwit_in += txi.amount
total_in += txi.amount
else:
segwit[i] = False
total_in += await get_prevtx_output_value(
coin, tx_req, txi.prev_hash, txi.prev_index)
else:
raise SigningError(FailureType.DataError,
"Wrong input script type")
if coin.decred:
w_txi = writers.empty_bytearray(8 if i == 0 else 0 + 9 +
len(txi.prev_hash))
if i == 0: # serializing first input => prepend headers
writers.write_bytes(w_txi, get_tx_header(coin, tx))
writers.write_tx_input_decred(w_txi, txi)
tx_ser.serialized_tx = w_txi
tx_req.serialized = tx_ser
if coin.decred:
hash143.add_output_count(tx)
for o in range(tx.outputs_count):
# STAGE_REQUEST_3_OUTPUT
txo = await helpers.request_tx_output(tx_req, o)
txo_bin.amount = txo.amount
txo_bin.script_pubkey = output_derive_script(txo, coin, keychain)
weight.add_output(txo_bin.script_pubkey)
if change_out == 0 and output_is_change(txo, wallet_path, segwit_in,
multifp):
# output is change and does not need confirmation
change_out = txo.amount
elif not await helpers.confirm_output(txo, coin):
raise SigningError(FailureType.ActionCancelled, "Output cancelled")
if coin.decred:
if txo.decred_script_version is not None and txo.decred_script_version != 0:
raise SigningError(
FailureType.ActionCancelled,
"Cannot send to output with script version != 0",
)
txo_bin.decred_script_version = txo.decred_script_version
w_txo_bin = writers.empty_bytearray(4 + 8 + 2 + 4 +
len(txo_bin.script_pubkey))
if o == 0: # serializing first output => prepend outputs count
writers.write_varint(w_txo_bin, tx.outputs_count)
writers.write_tx_output(w_txo_bin, txo_bin)
tx_ser.serialized_tx = w_txo_bin
tx_req.serialized = tx_ser
hash143.set_last_output_bytes(w_txo_bin)
writers.write_tx_output(h_first, txo_bin)
hash143.add_output(txo_bin)
total_out += txo_bin.amount
fee = total_in - total_out
if fee < 0:
raise SigningError(FailureType.NotEnoughFunds, "Not enough funds")
# fee > (coin.maxfee per byte * tx size)
if fee > (coin.maxfee_kb / 1000) * (weight.get_total() / 4):
if not await helpers.confirm_feeoverthreshold(fee, coin):
raise SigningError(FailureType.ActionCancelled,
"Signing cancelled")
if not await helpers.confirm_total(total_in - change_out, fee, coin):
raise SigningError(FailureType.ActionCancelled, "Total cancelled")
if coin.decred:
hash143.add_locktime_expiry(tx)
return h_first, hash143, segwit, total_in, wallet_path
async def sign_tx(tx: SignTx, keychain: seed.Keychain):
tx = helpers.sanitize_sign_tx(tx)
progress.init(tx.inputs_count, tx.outputs_count)
# Phase 1
h_first, hash143, segwit, authorized_in, wallet_path = await check_tx_fee(
tx, keychain)
# Phase 2
# - sign inputs
# - check that nothing changed
coin = coins.by_name(tx.coin_name)
tx_ser = TxRequestSerializedType()
txo_bin = TxOutputBinType()
tx_req = TxRequest()
tx_req.details = TxRequestDetailsType()
tx_req.serialized = None
if coin.decred:
prefix_hash = hash143.prefix_hash()
for i_sign in range(tx.inputs_count):
progress.advance()
txi_sign = None
key_sign = None
key_sign_pub = None
if segwit[i_sign]:
# STAGE_REQUEST_SEGWIT_INPUT
txi_sign = await helpers.request_tx_input(tx_req, i_sign)
if not input_is_segwit(txi_sign):
raise SigningError(FailureType.ProcessError,
"Transaction has changed during signing")
input_check_wallet_path(txi_sign, wallet_path)
key_sign = keychain.derive(txi_sign.address_n, coin.curve_name)
key_sign_pub = key_sign.public_key()
txi_sign.script_sig = input_derive_script(coin, txi_sign,
key_sign_pub)
w_txi = writers.empty_bytearray(7 + len(txi_sign.prev_hash) + 4 +
len(txi_sign.script_sig) + 4)
if i_sign == 0: # serializing first input => prepend headers
writers.write_bytes(w_txi, get_tx_header(coin, tx, True))
writers.write_tx_input(w_txi, txi_sign)
tx_ser.serialized_tx = w_txi
tx_req.serialized = tx_ser
elif coin.force_bip143 or tx.overwintered:
# STAGE_REQUEST_SEGWIT_INPUT
txi_sign = await helpers.request_tx_input(tx_req, i_sign)
input_check_wallet_path(txi_sign, wallet_path)
is_bip143 = (txi_sign.script_type == InputScriptType.SPENDADDRESS
or txi_sign.script_type
== InputScriptType.SPENDMULTISIG)
if not is_bip143 or txi_sign.amount > authorized_in:
raise SigningError(FailureType.ProcessError,
"Transaction has changed during signing")
authorized_in -= txi_sign.amount
key_sign = keychain.derive(txi_sign.address_n, coin.curve_name)
key_sign_pub = key_sign.public_key()
hash143_hash = hash143.preimage_hash(
coin,
tx,
txi_sign,
addresses.ecdsa_hash_pubkey(key_sign_pub, coin),
get_hash_type(coin),
)
# if multisig, check if signing with a key that is included in multisig
if txi_sign.multisig:
multisig.multisig_pubkey_index(txi_sign.multisig, key_sign_pub)
signature = ecdsa_sign(key_sign, hash143_hash)
tx_ser.signature_index = i_sign
tx_ser.signature = signature
# serialize input with correct signature
txi_sign.script_sig = input_derive_script(coin, txi_sign,
key_sign_pub, signature)
w_txi_sign = writers.empty_bytearray(5 + len(txi_sign.prev_hash) +
4 + len(txi_sign.script_sig) +
4)
if i_sign == 0: # serializing first input => prepend headers
writers.write_bytes(w_txi_sign, get_tx_header(coin, tx))
writers.write_tx_input(w_txi_sign, txi_sign)
tx_ser.serialized_tx = w_txi_sign
tx_req.serialized = tx_ser
elif coin.decred:
txi_sign = await helpers.request_tx_input(tx_req, i_sign)
input_check_wallet_path(txi_sign, wallet_path)
key_sign = keychain.derive(txi_sign.address_n, coin.curve_name)
key_sign_pub = key_sign.public_key()
if txi_sign.script_type == InputScriptType.SPENDMULTISIG:
prev_pkscript = scripts.output_script_multisig(
multisig.multisig_get_pubkeys(txi_sign.multisig),
txi_sign.multisig.m,
)
elif txi_sign.script_type == InputScriptType.SPENDADDRESS:
prev_pkscript = scripts.output_script_p2pkh(
addresses.ecdsa_hash_pubkey(key_sign_pub, coin))
else:
raise ValueError("Unknown input script type")
h_witness = utils.HashWriter(blake256())
writers.write_uint32(
h_witness,
tx.version | decred.DECRED_SERIALIZE_WITNESS_SIGNING)
writers.write_varint(h_witness, tx.inputs_count)
for ii in range(tx.inputs_count):
if ii == i_sign:
writers.write_varint(h_witness, len(prev_pkscript))
writers.write_bytes(h_witness, prev_pkscript)
else:
writers.write_varint(h_witness, 0)
witness_hash = writers.get_tx_hash(h_witness,
double=coin.sign_hash_double,
reverse=False)
h_sign = utils.HashWriter(blake256())
writers.write_uint32(h_sign, decred.DECRED_SIGHASHALL)
writers.write_bytes(h_sign, prefix_hash)
writers.write_bytes(h_sign, witness_hash)
sig_hash = writers.get_tx_hash(h_sign,
double=coin.sign_hash_double)
signature = ecdsa_sign(key_sign, sig_hash)
tx_ser.signature_index = i_sign
tx_ser.signature = signature
# serialize input with correct signature
txi_sign.script_sig = input_derive_script(coin, txi_sign,
key_sign_pub, signature)
w_txi_sign = writers.empty_bytearray(
8 + 4 +
len(hash143.get_last_output_bytes()) if i_sign == 0 else 0 +
16 + 4 + len(txi_sign.script_sig))
if i_sign == 0:
writers.write_bytes(w_txi_sign,
hash143.get_last_output_bytes())
writers.write_uint32(w_txi_sign, tx.lock_time)
writers.write_uint32(w_txi_sign, tx.expiry)
writers.write_varint(w_txi_sign, tx.inputs_count)
writers.write_tx_input_decred_witness(w_txi_sign, txi_sign)
tx_ser.serialized_tx = w_txi_sign
tx_req.serialized = tx_ser
else:
# hash of what we are signing with this input
h_sign = utils.HashWriter(sha256())
# same as h_first, checked before signing the digest
h_second = utils.HashWriter(sha256())
if tx.overwintered:
writers.write_uint32(
h_sign, tx.version
| zcash.OVERWINTERED) # nVersion | fOverwintered
writers.write_uint32(h_sign,
tx.version_group_id) # nVersionGroupId
else:
writers.write_uint32(h_sign, tx.version) # nVersion
if tx.timestamp:
writers.write_uint32(h_sign, tx.timestamp)
writers.write_varint(h_sign, tx.inputs_count)
for i in range(tx.inputs_count):
# STAGE_REQUEST_4_INPUT
txi = await helpers.request_tx_input(tx_req, i)
input_check_wallet_path(txi, wallet_path)
writers.write_tx_input_check(h_second, txi)
if i == i_sign:
txi_sign = txi
key_sign = keychain.derive(txi.address_n, coin.curve_name)
key_sign_pub = key_sign.public_key()
# for the signing process the script_sig is equal
# to the previous tx's scriptPubKey (P2PKH) or a redeem script (P2SH)
if txi_sign.script_type == InputScriptType.SPENDMULTISIG:
txi_sign.script_sig = scripts.output_script_multisig(
multisig.multisig_get_pubkeys(txi_sign.multisig),
txi_sign.multisig.m,
)
elif txi_sign.script_type == InputScriptType.SPENDADDRESS:
txi_sign.script_sig = scripts.output_script_p2pkh(
addresses.ecdsa_hash_pubkey(key_sign_pub, coin))
if coin.bip115:
txi_sign.script_sig += scripts.script_replay_protection_bip115(
txi_sign.prev_block_hash_bip115,
txi_sign.prev_block_height_bip115,
)
else:
raise SigningError(FailureType.ProcessError,
"Unknown transaction type")
else:
txi.script_sig = bytes()
writers.write_tx_input(h_sign, txi)
writers.write_varint(h_sign, tx.outputs_count)
for o in range(tx.outputs_count):
# STAGE_REQUEST_4_OUTPUT
txo = await helpers.request_tx_output(tx_req, o)
txo_bin.amount = txo.amount
txo_bin.script_pubkey = output_derive_script(
txo, coin, keychain)
writers.write_tx_output(h_second, txo_bin)
writers.write_tx_output(h_sign, txo_bin)
writers.write_uint32(h_sign, tx.lock_time)
if tx.overwintered:
writers.write_uint32(h_sign, tx.expiry) # expiryHeight
writers.write_varint(h_sign, 0) # nJoinSplit
writers.write_uint32(h_sign, get_hash_type(coin))
# check the control digests
if writers.get_tx_hash(h_first,
False) != writers.get_tx_hash(h_second):
raise SigningError(FailureType.ProcessError,
"Transaction has changed during signing")
# if multisig, check if signing with a key that is included in multisig
if txi_sign.multisig:
multisig.multisig_pubkey_index(txi_sign.multisig, key_sign_pub)
# compute the signature from the tx digest
signature = ecdsa_sign(
key_sign,
writers.get_tx_hash(h_sign, double=coin.sign_hash_double))
tx_ser.signature_index = i_sign
tx_ser.signature = signature
# serialize input with correct signature
txi_sign.script_sig = input_derive_script(coin, txi_sign,
key_sign_pub, signature)
w_txi_sign = writers.empty_bytearray(5 + len(txi_sign.prev_hash) +
4 + len(txi_sign.script_sig) +
4)
if i_sign == 0: # serializing first input => prepend headers
writers.write_bytes(w_txi_sign, get_tx_header(coin, tx))
writers.write_tx_input(w_txi_sign, txi_sign)
tx_ser.serialized_tx = w_txi_sign
tx_req.serialized = tx_ser
if coin.decred:
return await helpers.request_tx_finish(tx_req)
for o in range(tx.outputs_count):
progress.advance()
# STAGE_REQUEST_5_OUTPUT
txo = await helpers.request_tx_output(tx_req, o)
txo_bin.amount = txo.amount
txo_bin.script_pubkey = output_derive_script(txo, coin, keychain)
# serialize output
w_txo_bin = writers.empty_bytearray(5 + 8 + 5 +
len(txo_bin.script_pubkey) + 4)
if o == 0: # serializing first output => prepend outputs count
writers.write_varint(w_txo_bin, tx.outputs_count)
writers.write_tx_output(w_txo_bin, txo_bin)
tx_ser.signature_index = None
tx_ser.signature = None
tx_ser.serialized_tx = w_txo_bin
tx_req.serialized = tx_ser
any_segwit = True in segwit.values()
for i in range(tx.inputs_count):
progress.advance()
if segwit[i]:
# STAGE_REQUEST_SEGWIT_WITNESS
txi = await helpers.request_tx_input(tx_req, i)
input_check_wallet_path(txi, wallet_path)
if not input_is_segwit(txi) or txi.amount > authorized_in:
raise SigningError(FailureType.ProcessError,
"Transaction has changed during signing")
authorized_in -= txi.amount
key_sign = keychain.derive(txi.address_n, coin.curve_name)
key_sign_pub = key_sign.public_key()
hash143_hash = hash143.preimage_hash(
coin,
tx,
txi,
addresses.ecdsa_hash_pubkey(key_sign_pub, coin),
get_hash_type(coin),
)
signature = ecdsa_sign(key_sign, hash143_hash)
if txi.multisig:
# find out place of our signature based on the pubkey
signature_index = multisig.multisig_pubkey_index(
txi.multisig, key_sign_pub)
witness = scripts.witness_p2wsh(txi.multisig, signature,
signature_index,
get_hash_type(coin))
else:
witness = scripts.witness_p2wpkh(signature, key_sign_pub,
get_hash_type(coin))
tx_ser.serialized_tx = witness
tx_ser.signature_index = i
tx_ser.signature = signature
elif any_segwit:
tx_ser.serialized_tx = bytearray(
1) # empty witness for non-segwit inputs
tx_ser.signature_index = None
tx_ser.signature = None
tx_req.serialized = tx_ser
writers.write_uint32(tx_ser.serialized_tx, tx.lock_time)
if tx.overwintered:
if tx.version == 3:
writers.write_uint32(tx_ser.serialized_tx,
tx.expiry) # expiryHeight
writers.write_varint(tx_ser.serialized_tx, 0) # nJoinSplit
elif tx.version == 4:
writers.write_uint32(tx_ser.serialized_tx,
tx.expiry) # expiryHeight
writers.write_uint64(tx_ser.serialized_tx, 0) # valueBalance
writers.write_varint(tx_ser.serialized_tx, 0) # nShieldedSpend
writers.write_varint(tx_ser.serialized_tx, 0) # nShieldedOutput
writers.write_varint(tx_ser.serialized_tx, 0) # nJoinSplit
else:
raise SigningError(
FailureType.DataError,
"Unsupported version for overwintered transaction",
)
await helpers.request_tx_finish(tx_req)
async def sign_tx(tx: SignTx, root):
tx = sanitize_sign_tx(tx)
coin = coins.by_name(tx.coin_name)
# Phase 1
# - check inputs, previous transactions, and outputs
# - ask for confirmations
# - check fee
total_in = 0 # sum of input amounts
total_out = 0 # sum of output amounts
change_out = 0 # change output amount
# h_first is used to make sure the inputs and outputs streamed in Phase 1
# are the same as in Phase 2. it is thus not required to fully hash the
# tx, as the SignTx info is streamed only once
h_first = HashWriter(sha256) # not a real tx hash
txo_bin = TxOutputBinType()
tx_req = TxRequest()
tx_req.details = TxRequestDetailsType()
for i in range(tx.inputs_count):
# STAGE_REQUEST_1_INPUT
txi = await request_tx_input(tx_req, i)
write_tx_input_check(h_first, txi)
total_in += await get_prevtx_output_value(
tx_req, txi.prev_hash, txi.prev_index)
for o in range(tx.outputs_count):
# STAGE_REQUEST_3_OUTPUT
txo = await request_tx_output(tx_req, o)
if output_is_change(txo):
if change_out != 0:
raise SigningError(FailureType.ProcessError,
'Only one change output is valid')
change_out = txo.amount
else:
if not await confirm_output(txo, coin):
raise SigningError(FailureType.ActionCancelled,
'Output cancelled')
txo_bin.amount = txo.amount
txo_bin.script_pubkey = output_derive_script(txo, coin, root)
write_tx_output(h_first, txo_bin)
total_out += txo_bin.amount
fee = total_in - total_out
if fee < 0:
raise SigningError(FailureType.NotEnoughFunds,
'Not enough funds')
if fee > coin.maxfee_kb * ((estimate_tx_size(tx.inputs_count, tx.outputs_count) + 999) // 1000):
if not await confirm_feeoverthreshold(fee, coin):
raise SigningError(FailureType.ActionCancelled,
'Signing cancelled')
if not await confirm_total(total_out - change_out, fee, coin):
raise SigningError(FailureType.ActionCancelled,
'Total cancelled')
# Phase 2
# - sign inputs
# - check that nothing changed
tx_ser = TxRequestSerializedType()
for i_sign in range(tx.inputs_count):
# hash of what we are signing with this input
h_sign = HashWriter(sha256)
# same as h_first, checked at the end of this iteration
h_second = HashWriter(sha256)
txi_sign = None
key_sign = None
key_sign_pub = None
write_uint32(h_sign, tx.version)
write_varint(h_sign, tx.inputs_count)
for i in range(tx.inputs_count):
# STAGE_REQUEST_4_INPUT
txi = await request_tx_input(tx_req, i)
write_tx_input_check(h_second, txi)
if i == i_sign:
txi_sign = txi
key_sign = node_derive(root, txi.address_n)
key_sign_pub = key_sign.public_key()
txi.script_sig = input_derive_script(txi, key_sign_pub)
else:
txi.script_sig = bytes()
write_tx_input(h_sign, txi)
write_varint(h_sign, tx.outputs_count)
for o in range(tx.outputs_count):
# STAGE_REQUEST_4_OUTPUT
txo = await request_tx_output(tx_req, o)
txo_bin.amount = txo.amount
txo_bin.script_pubkey = output_derive_script(txo, coin, root)
write_tx_output(h_second, txo_bin)
write_tx_output(h_sign, txo_bin)
write_uint32(h_sign, tx.lock_time)
write_uint32(h_sign, 0x00000001) # SIGHASH_ALL hash_type
# check the control digests
if get_tx_hash(h_first, False) != get_tx_hash(h_second, False):
raise SigningError(FailureType.ProcessError,
'Transaction has changed during signing')
# compute the signature from the tx digest
signature = ecdsa_sign(key_sign, get_tx_hash(h_sign, True))
tx_ser.signature_index = i_sign
tx_ser.signature = signature
# serialize input with correct signature
txi_sign.script_sig = input_derive_script(
txi_sign, key_sign_pub, signature)
w_txi_sign = bytearray_with_cap(
len(txi_sign.prev_hash) + 4 + 5 + len(txi_sign.script_sig) + 4)
if i_sign == 0: # serializing first input => prepend tx version and inputs count
write_uint32(w_txi_sign, tx.version)
write_varint(w_txi_sign, tx.inputs_count)
write_tx_input(w_txi_sign, txi_sign)
tx_ser.serialized_tx = w_txi_sign
tx_req.serialized = tx_ser
for o in range(tx.outputs_count):
# STAGE_REQUEST_5_OUTPUT
txo = await request_tx_output(tx_req, o)
txo_bin.amount = txo.amount
txo_bin.script_pubkey = output_derive_script(txo, coin, root)
# serialize output
w_txo_bin = bytearray_with_cap(
5 + 8 + 5 + len(txo_bin.script_pubkey) + 4)
if o == 0: # serializing first output => prepend outputs count
write_varint(w_txo_bin, tx.outputs_count)
write_tx_output(w_txo_bin, txo_bin)
if o == tx.outputs_count - 1: # serializing last output => append tx lock_time
write_uint32(w_txo_bin, tx.lock_time)
tx_ser.signature_index = None
tx_ser.signature = None
tx_ser.serialized_tx = w_txo_bin
tx_req.serialized = tx_ser
await request_tx_finish(tx_req)