def verify_tx_signature(self, signature, transaction, verification_key):
"It verifies the transaction signatures"
txin = list(
filter(lambda x: verification_key in x['pubkeys'],
transaction.inputs()))
if txin:
tx_num = transaction.inputs().index(txin[0])
pre_hash = Hash(bfh(transaction.serialize_preimage(tx_num)))
order = generator_secp256k1.order()
r, s = ecdsa.util.sigdecode_der(bfh(signature.decode()[:-2]),
order)
sig_string = ecdsa.util.sigencode_string(r, s, order)
compressed = len(verification_key) <= 66
for recid in range(0, 4):
try:
pubk = MyVerifyingKey.from_signature(sig_string,
recid,
pre_hash,
curve=SECP256k1)
pubkey = bh2u(point_to_ser(pubk.pubkey.point, compressed))
if verification_key == pubkey:
return True
except:
continue
else:
return False
def verify_tx_signature(self, signature, transaction, verification_key,
utxo):
'''Verify the signature for a specific utxo ("prevout_hash:n") given a
transaction and verification key.'''
txin = list(
filter(
lambda x:
(verification_key in x['pubkeys'] and utxo == "{}:{}".format(
x['tx_hash'], x['tx_pos'])), transaction.inputs()))
if txin:
tx_num = transaction.inputs().index(txin[0])
pre_hash = Hash(bfh(transaction.serialize_preimage(tx_num)))
order = generator_secp256k1.order()
r, s = ecdsa.util.sigdecode_der(bfh(signature.decode()[:-2]),
order)
sig_string = ecdsa.util.sigencode_string(r, s, order)
compressed = len(verification_key) <= 66
for recid in range(0, 4):
try:
pubk = MyVerifyingKey.from_signature(sig_string,
recid,
pre_hash,
curve=SECP256k1)
pubkey = bh2u(point_to_ser(pubk.pubkey.point, compressed))
if verification_key == pubkey:
return True
except:
continue
else:
return False
def verify_tx_signature(signature, transaction, verification_key, utxo):
'''Verify the signature for a specific utxo ("prevout_hash:n") given a
transaction and verification key. Ensures that the signature is valid
AND canonically encoded, so it will be accepted by network.
'''
tx_num = None
for n, x in enumerate(transaction.inputs()):
if (verification_key in x['pubkeys']
and utxo == "{}:{}".format(x['tx_hash'], x['tx_pos'])):
tx_num = n
break
else:
# verification_key / utxo combo not found in tx inputs, bail
return False
# calculate sighash digest (implicitly this is for sighash 0x41)
pre_hash = Hash(bfh(transaction.serialize_preimage(tx_num)))
order = generator_secp256k1.order()
try:
sigbytes = bfh(signature.decode())
except ValueError:
# not properly hex encoded or UnicodeDecodeError (garbage data)
return False
if not sigbytes or sigbytes[-1] != 0x41:
return False
DERsig = sigbytes[:
-1] # lop off the sighash byte for the DER check below
try:
# ensure DER encoding is canonical, and extract r,s if OK
r, s = CoinUtils.IsValidDERSignatureEncoding_With_Extract(DERsig)
except AssertionError:
return False
if (s << 1) > order:
# high S values are rejected by BCH network
return False
try:
pubkey_point = ser_to_point(bfh(verification_key))
except:
# ser_to_point will fail if pubkey is off-curve, infinity, or garbage.
return False
vk = MyVerifyingKey.from_public_point(pubkey_point, curve=SECP256k1)
try:
return vk.verify_digest(DERsig,
pre_hash,
sigdecode=ecdsa.util.sigdecode_der)
except:
# verify_digest returns True on success, otherwise raises
return False
def get_transaction_signature(self, tx, sk, vk):
txin = list(filter(lambda x: vk in x['pubkeys'], tx.inputs()))
if txin:
tx_num = tx.inputs().index(txin[0])
pre_hash = Hash(bfh(tx.serialize_preimage(tx_num)))
private_key = MySigningKey.from_secret_exponent(sk.secret, curve = SECP256k1)
public_key = private_key.get_verifying_key()
sig = private_key.sign_digest_deterministic(pre_hash, hashfunc=hashlib.sha256, sigencode = ecdsa.util.sigencode_der)
assert public_key.verify_digest(sig, pre_hash, sigdecode = ecdsa.util.sigdecode_der)
result = bh2u(sig) + int_to_hex(tx.nHashType() & 255, 1)
return result.encode('utf-8')
return b''
def get_transaction_signature(transaction, inputs, secret_keys):
"get transaction signature"
signatures = {}
for txin in transaction.inputs():
pubkey = txin['pubkeys'][0]
if pubkey in inputs:
tx_num = transaction.inputs().index(txin)
pre_hash = Hash(bfh(transaction.serialize_preimage(tx_num)))
private_key = MySigningKey.from_secret_exponent(secret_keys[pubkey].secret, curve=SECP256k1)
public_key = private_key.get_verifying_key()
sig = private_key.sign_digest_deterministic(pre_hash,
hashfunc=hashlib.sha256,
sigencode=ecdsa.util.sigencode_der)
assert public_key.verify_digest(sig, pre_hash, sigdecode=ecdsa.util.sigdecode_der)
signatures[txin['tx_hash'] + ":" + str(txin['tx_pos'])] = (bh2u(sig) + int_to_hex(transaction.nHashType() & 255, 1)).encode('utf-8')
return signatures
def show_qr(self):
from electroncash.bitcoin import base_encode, bfh
text = bfh(str(self.tx))
text = base_encode(text, base=43)
self.app.qr_dialog(_("Raw Transaction"), text)
