def test_decrypt(self):
des = DES(b"PASSWORD")
expected = b"abcdefgh"
actual = des.decrypt(b"\x15\x14\x4f\x75\x8c\x83\xd0\x34")
assert actual == expected
def test_encrypt_block(self):
with pytest.raises(ValueError) as exc:
DES.key56_to_key64(b"\x00")
assert str(exc.value) == \
"DES 7-byte key is not 7 bytes in length, actual: 1"
def test_encrypt_large_bytes_fail_no_padding(self):
with pytest.raises(ValueError) as exc:
des = DES(b"PASSWORD")
des.encrypt(b"abcdefghijklmnopqrstuvwxyz", pad=False)
assert str(exc.value) == "DES encryption must be a multiple of 8 bytes"
def _calc_resp(password_hash, server_challenge):
"""
Generate the LM response given a 16-byte password hash and the
challenge from the CHALLENGE_MESSAGE
:param password_hash: A 16-byte password hash
:param server_challenge: A random 8-byte response generated by the
server in the CHALLENGE_MESSAGE
:return res: A 24-byte buffer to contain the LM response upon return
"""
# padding with zeros to make the hash 21 bytes long
password_hash += b'\x00' * (21 - len(password_hash))
res = b''
dobj = DES(DES.key56_to_key64(password_hash[0:7]))
res = res + dobj.encrypt(server_challenge[0:8])
dobj = DES(DES.key56_to_key64(password_hash[7:14]))
res = res + dobj.encrypt(server_challenge[0:8])
dobj = DES(DES.key56_to_key64(password_hash[14:21]))
res = res + dobj.encrypt(server_challenge[0:8])
return res