def test_der_size() -> None:
sig8 = 1, 1
sig72 = ec.n - 1, ec.n - 1
sig71 = 2**255 - 1, ec.n - 1
sig70 = 2**255 - 1, 2**255 - 1
sig70b = 2**255 - 1, 2**248 - 1
sig69 = 2**255 - 1, 2**247 - 1
sig68 = 2**247 - 1, 2**247 - 1
sigs = [sig8, sig72, sig71, sig70, sig70b, sig69, sig68]
lenghts = [8, 72, 71, 70, 70, 69, 68] # not including script.SIGHASHES
for lenght, sig in zip(lenghts, sigs):
for sighash in script.SIGHASHES:
der_sig = _serialize(*sig, sighash)
r, s, sighash2 = _deserialize(der_sig)
assert sig == (r, s)
assert sighash == sighash2
assert len(der_sig) == lenght + 1
# with the last one only...
assert (r, s, sighash) == _deserialize((r, s, sighash))
def test_der_size():
sig8 = 1, 1
sig72 = ec.n - 1, ec.n - 1
sig71 = 2**255 - 1, ec.n - 1
sig70 = 2**255 - 1, 2**255 - 1
sig70b = 2**255 - 1, 2**248 - 1
sig69 = 2**255 - 1, 2**247 - 1
sig68 = 2**247 - 1, 2**247 - 1
sigs = [sig8, sig72, sig71, sig70, sig70b, sig69, sig68]
lenghts = [8, 72, 71, 70, 70, 69, 68]
for lenght, sig in zip(lenghts, sigs):
for sighash in SIGHASHES + [None]:
der_sig = _serialize(*sig, sighash)
r, s, sighash2 = _deserialize(der_sig)
assert sig == (r, s)
assert sighash == sighash2
assert len(der_sig) == lenght + 0 if sighash is None else 1
# with the last one only...
assert (r, s, sighash) == _deserialize((r, s, sighash))
def test_der_serialize() -> None:
sig = 2**247 - 1, 2**247 - 1
err_msg = "invalid sighash: 0x"
with pytest.raises(ValueError, match=err_msg):
_serialize(*sig, 0x85)
for sighash in script.SIGHASHES:
err_msg = "scalar r not in 1..n-1: "
for r in (0, ec.n):
bad_sig = r, sig[1]
with pytest.raises(ValueError, match=err_msg):
_serialize(*bad_sig, sighash)
for s in (0, ec.n):
bad_sig = sig[0], s
err_msg = "scalar s not in 1..n-1: "
with pytest.raises(ValueError, match=err_msg):
_serialize(*bad_sig, sighash)
def test_der(self):
sighash_all = b"\x01"
sig9 = 1, 1
sig73 = ec.n - 1, ec.n - 1
sig72 = 2**255 - 1, ec.n - 1
sig71 = 2**255 - 1, 2**255 - 1
sig71b = 2**255 - 1, 2**248 - 1
sig70 = 2**255 - 1, 2**247 - 1
sig69 = 2**247 - 1, 2**247 - 1
sigs = [sig9, sig73, sig72, sig71, sig71b, sig70, sig69]
lenghts = [9, 73, 72, 71, 71, 70, 69]
for lenght, sig in zip(lenghts, sigs):
dersig = _serialize(*sig, sighash_all)
r, s, sighash = _deserialize(dersig)
self.assertEqual(sig, (r, s))
self.assertEqual(sighash_all, sighash)
self.assertEqual(len(dersig), lenght)
# without sighash
r, s, no_sighash = _deserialize(dersig[:-1])
self.assertEqual(sig, (r, s))
self.assertIsNone(no_sighash)
# with the last one
self.assertEqual((r, s, sighash), _deserialize((r, s, sighash)))
# Invalid sighash (b'\x00')
badsig = dersig[:-1] + b"\x00"
self.assertRaises(ValueError, _deserialize, badsig)
# _deserialize(badsig)
# DER signature size should be in [8, 73]
dersig2 = dersig + b"\x00" * 70
self.assertRaises(ValueError, _deserialize, dersig2)
# DER signature must be of type 0x30 (compound)
dersig2 = b"\x00" + dersig[1:]
self.assertRaises(ValueError, _deserialize, dersig2)
# Declared signature size does not match with size
dersig2 = dersig[:1] + b"\x00" + dersig[2:]
self.assertRaises(ValueError, _deserialize, dersig2)
Rsize = dersig[3]
# Zero-size integers are not allowed for r
dersig2 = dersig[:3] + b"\x00" + dersig[4:]
self.assertRaises(ValueError, _deserialize, dersig2)
# Length of the s scalar must be inside the signature
dersig2 = dersig[:3] + b"\x80" + dersig[4:]
self.assertRaises(ValueError, _deserialize, dersig2)
# Zero-size integers are not allowed for s
dersig2 = dersig[:Rsize + 5] + b"\x00" + dersig[Rsize + 6:]
self.assertRaises(ValueError, _deserialize, dersig2)
# Signature size does not match with scalars
dersig2 = dersig[:Rsize + 5] + b"\x4f" + dersig[Rsize + 6:]
self.assertRaises(ValueError, _deserialize, dersig2)
# r scalar must be an integer
dersig2 = dersig[:2] + b"\x00" + dersig[3:]
self.assertRaises(ValueError, _deserialize, dersig2)
# Negative numbers are not allowed for r
dersig2 = dersig[:4] + b"\x80" + dersig[5:]
self.assertRaises(ValueError, _deserialize, dersig2)
# Invalid null bytes at the start of r
dersig2 = dersig[:4] + b"\x00\x00" + dersig[6:]
self.assertRaises(ValueError, _deserialize, dersig2)
# deserialize(dersig2)
# s scalar must be an integer
dersig2 = dersig[:Rsize + 4] + b"\x00" + dersig[Rsize + 5:]
self.assertRaises(ValueError, _deserialize, dersig2)
# Negative numbers are not allowed for s
dersig2 = dersig[:Rsize + 6] + b"\x80" + dersig[Rsize + 7:]
self.assertRaises(ValueError, _deserialize, dersig2)
# Invalid null bytes at the start of s
dersig2 = dersig[:Rsize + 6] + b"\x00\x00" + dersig[Rsize + 8:]
self.assertRaises(ValueError, _deserialize, dersig2)
# sighash size > 1
self.assertRaises(ValueError, _serialize, *sig, sighash_all + b"\x01")
# negative signature scalar
sig2 = -1, sig[1]
self.assertRaises(ValueError, _serialize, *sig2, sighash_all)
# Invalid sighash type b'\x00'
self.assertRaises(ValueError, _deserialize, dersig[:-1] + b"\x00")
def test_der_deserialize() -> None:
err_msg = "non-hexadecimal number found "
with pytest.raises(ValueError, match=err_msg):
_deserialize("not a sig")
sig = 2**255 - 1, 2**247 - 1
for sighash in script.SIGHASHES:
der_sig = _serialize(*sig, sighash)
r_size = der_sig[3]
bad_der_sig = b"\x00" * 74
err_msg = "invalid DER size: "
with pytest.raises(ValueError, match=err_msg):
_deserialize(bad_der_sig)
bad_der_sig = b"\x31" + der_sig[1:]
err_msg = "DER type must be 0x30 "
with pytest.raises(ValueError, match=err_msg):
_deserialize(bad_der_sig)
bad_der_sig = der_sig[:1] + b"\x41" + der_sig[2:]
err_msg = "Declared size incompatible with actual size: "
with pytest.raises(ValueError, match=err_msg):
_deserialize(bad_der_sig)
bad_der_sig = der_sig + b"\x01"
err_msg = "Declared size incompatible with actual size: "
with pytest.raises(ValueError, match=err_msg):
_deserialize(bad_der_sig)
bad_der_sig = der_sig[:-1] + b"\x00"
err_msg = "invalid sighash: 0x"
with pytest.raises(ValueError, match=err_msg):
_deserialize(bad_der_sig)
# r and s scalars
for offset in (4, 6 + r_size):
bad_der_sig = der_sig[:offset - 2] + b"\x00" + der_sig[offset - 1:]
err_msg = "scalar must be an integer"
with pytest.raises(ValueError, match=err_msg):
_deserialize(bad_der_sig)
bad_der_sig = der_sig[:offset - 1] + b"\x00" + der_sig[offset:]
err_msg = "scalar has size zero"
with pytest.raises(ValueError, match=err_msg):
_deserialize(bad_der_sig)
bad_der_sig = der_sig[:offset - 1] + b"\x80" + der_sig[offset:]
err_msg = "Size of scalar is too large: "
with pytest.raises(ValueError, match=err_msg):
_deserialize(bad_der_sig)
bad_der_sig = der_sig[:offset] + b"\x80" + der_sig[offset + 1:]
err_msg = "Negative number not allowed for scalar"
with pytest.raises(ValueError, match=err_msg):
_deserialize(bad_der_sig)
bad_der_sig = der_sig[:offset] + b"\x00\x7f" + der_sig[offset + 2:]
err_msg = "invalid null bytes at the start of scalar"
with pytest.raises(ValueError, match=err_msg):
_deserialize(bad_der_sig)
data_size = der_sig[1]
malleated_size = (data_size + 1).to_bytes(1, byteorder="big")
bad_der_sig = der_sig[:1] + malleated_size + der_sig[2:] + b"\x01"
err_msg = "Too big DER size for "
with pytest.raises(ValueError, match=err_msg):
_deserialize(bad_der_sig)