def _simpleDES (key, data):
assert len (key) in [8, 16, 24]
assert len (data) in [8, 16, 24]
assert not len (data) % len (key)
cipher = M2Crypto.EVP.Cipher (alg='des_ecb', op=0, iv=8*'00',
key=_unhexlify(key),
salt=None,
padding = 0)
return cipher.update (_unhexlify(data))
def _search_string_to_bytes_list(searchstr, sflag=0, radix=16):
"""
# TODO: Document
This yields so in the future i can support wildcards
"""
# TODO: Implement radix?
if isinstance(searchstr, str):
searchstr = searchstr.encode('utf8')
searchstr = searchstr.lstrip()
match = b''
for c in [b'"', b"'"]:
if searchstr.startswith(c):
searchstr = searchstr[1:]
match = c
break
# Decode a search string representing a string (ex: '"Hello\nworld!"')
if match:
i = searchstr.rfind(match)
if i not in (-1, 0) and searchstr[i - 1] != '\\':
searchstr = searchstr[:i]
# TODO: Actual string parsing
yield searchstr
# Decode a search string representing hex bytes
else:
for b in _whitespaces:
searchstr = searchstr.replace(b, b'')
yield _unhexlify(searchstr)
def generateResponse (nonce, key=16*'00', ourNonce = None, debug=False):
"""
Given a nonce picked by the verifier computes the response of the prover.
nonce -- the nonce as given by the verifier.
our_nonce -- the nonce of the prover (in case he choses one).
debug -- output the intermediate steps.
"""
nt = _decipher(nonce, key)
nt2 = nt[1:]+nt[:1]
nr = ourNonce or os.urandom(8)
d1 = _decipher (nr, key)
buff = int (_hexlify (d1), 16) ^ int (_hexlify (nt2), 16)
buff = buff & 0xffffffffffffff00 >> 8 | buff & 0x00000000000000ff << 56
d2 = _decipher (_unhexlify(hex (buff)[2:-1]), key)
if debug:
print 'nt =', _hexlify (nt)
print 'nt2 =', _hexlify (nt2)
print 'D1 =', _hexlify (d1)
print 'Buff =', hex(buff)[2:-1]
print 'D2 =', _hexlify(d2)
print 'D1 || D2 =', _hexlify (d1) + _hexlify (d2)
return (d1 + d2, nr)
def row2feature(row, id_field, geometry_field):
feature = {'type': 'Feature', 'properties': _copy(row)}
geometry = feature['properties'].pop(geometry_field)
feature['geometry'] = _loadshape(_unhexlify(geometry))
feature['id'] = feature['properties'].pop(id_field)
return feature
def row2feature(row, id_field, geometry_field):
feature = {'type': 'Feature', 'properties': _copy(row)}
geometry = feature['properties'].pop(geometry_field)
feature['geometry'] = _loadshape(_unhexlify(geometry))
feature['id'] = feature['properties'].pop(id_field)
return feature
def decipherSendMode (data, key):
assert not len(data) % len(key)
iv = 8*'00'
res = []
while len(data):
iv = _hexlify(_simpleDES(crc.mergeList(key), xorit(iv, data[0:8])))
res.append(iv)
data = data[8:]
return _unhexlify (''.join(res))
def row2feature(row, id_field, geometry_field):
""" Convert a database row dict to a feature dict.
"""
feature = {'type': 'Feature', 'properties': _copy(row)}
geometry = feature['properties'].pop(geometry_field)
feature['geometry'] = _loadshape(_unhexlify(geometry))
feature['id'] = feature['properties'].pop(id_field)
return feature
def row2feature(row, id_field, geometry_field):
""" Convert a database row dict to a feature dict.
"""
feature = {'type': 'Feature', 'properties': _copy(row)}
geometry = feature['properties'].pop(geometry_field)
feature['geometry'] = _loadshape(_unhexlify(geometry))
feature['id'] = feature['properties'].pop(id_field)
return feature
def verifyResponse (resp, nr, key = 16*'00'):
"""
Verifies the resonse given by the verifier for mutual authentication.
resp -- the response as given by the verifier.
nonce -- the nonce as chosen by the prover.
"""
_resp = _unhexlify (resp)
nr2 = nr[1:]+nr[:1]
return _decipher (_resp, key) == nr2
def _decipher (data, key = 16*'00', iv=8*'00', pad=None):
_key = _unhexlify (key)
_iv = _unhexlify (iv)
pbuf = cStringIO.StringIO ()
cbuf = cStringIO.StringIO (data)
if pad is None:
_pad = 0
else:
_pad = 1
des_box = M2Crypto.EVP.Cipher (alg='des_ede_cbc',
op=0, key=_key,
iv=_iv,
padding = _pad)
plaintext = _cipher_filter(des_box, cbuf, pbuf)
pbuf.close ()
cbuf.close ()
des_box = None
return plaintext
def _to_bytes(value, length, dummy, _unhexlify=_unhexlify):
"""An implementation of int.to_bytes for python 2.x."""
fmt = '%%0%dx' % (2 * length,)
return _unhexlify(fmt % value)
def _to_bytes(value, length, endianess, unhexlify=_unhexlify):
fmt = '%%0%ix' % (2 * length)
return _unhexlify(fmt % value)
def _to_bytes(value, dummy0, dummy1, _unhexlify=_unhexlify):
"""An implementation of int.to_bytes for python 2.x."""
return _unhexlify('%040x' % value)
def _to_bytes(value, dummy0, dummy1, _unhexlify=_unhexlify):
"""An implementation of int.to_bytes for python 2.x."""
return _unhexlify('%040x' % value)
isDes -- for the special case of TDES where k1 = k2 (DES).
"""
if isDES:
sessionKey = ourNonce[:4] + nonce[:4]
assert len(sessionKey) is 8
return sessionKey
else:
sessionKey = ourNonce[:4] + nonce[:4] + ourNonce[4:] + nonce[4:]
assert len(sessionKey) is 16
return sessionKey
def isDES (key):
"""
Returns True if a given 3DES key is used to actually do DES.
"""
h = len (key) / 2
return key[:h] == key[h:]
if __name__ == '__main__':
nonce = 0x6e7577944adffc0c
_nonce = _unhexlify (hex (nonce)[2:])
ourNonce = 0x1122334455667788
_ourNonce = _unhexlify (hex (ourNonce)[2:])
response, nr = generateResponse (_nonce, ourNonce = _ourNonce, debug=True)
print 'Response = ', _hexlify (response)
print 'Nonce = ', _hexlify (nr)
print 'Verification ok?', verifyResponse ('AD6CC16025CCFB7B', nr)
print 'Session key = ', _hexlify (deriveSessionKey (_nonce, ourNonce = _ourNonce, isDES=True))
def _to_bytes(value, length, endianess, unhexlify=_unhexlify):
fmt = '%%0%ix' % (2 * length)
return _unhexlify(fmt % value)