class Md4_u(Utility):
"""utility class for L{MD4<Md4>} cryptographic hash"""
constants = [hsqrt(i) for i in [0, 2, 3]]
shifts = [[3, 7, 11, 19], [3, 5, 9, 13], [3, 9, 11, 15]]
r = [
[
i,
((i * 4) + (i / 4)) %
16, # 0, 4, 8, 12, 1, 5, 9, 13, 2, 6, 10, 14, 3, 7, 11, 15
[0, 8, 4, 12, 2, 10, 6, 14, 1, 9, 5, 13, 3, 11, 7, 15][i]
] for i in range(16)
]
@staticmethod
def f(b, c, d):
return (b & c) | ((~b) & d)
@staticmethod
def g(b, c, d):
return (b & c) | (b & d) | (c & d)
@staticmethod
def h(b, c, d):
return (b ^ c ^ d)
hex = "0123456789ABCDEF"
IVhex = hex + hex[::-1]
IVs = dwords(struct.unpack("<4L", hex2bin(IVhex)))
def decrypt(self, ciphertext, key):
#L = ciphertext[:self.middle]
#R = ciphertext[self.middle:]
#L, R = dwords([0x41ea3a0a, 0x94baa940])
L, R = dwords([0xdee9d4d8, 0xf7131ed9]) # for xtea
for F, extra in self.round_parameters(backward=True):
L, R = self.out_f(R, F(L, key, *extra)), L
return L, R
class Sha224_u(Utility):
"""utility class for sha-224"""
pickled = get_variables("sha224", ["IVs"])
if pickled is None:
# lowest 32 bits of sha384 IVs
IVs = dwords(Sha384_u.IVs)
save_variables("sha224", {"IVs": IVs})
else:
IVs = pickled["IVs"]
class Md5_u(Utility):
"""utility class for MD5 cryptographic hash"""
g_coefficients = [[1, 0], [5, 1], [3, 5], [7, 0]]
K = dwords([abs(sin(index + 1)) * (2**32) for index in range(16 * 4)])
shifts = [[7, 12, 17, 22], [5, 9, 14, 20], [4, 11, 16, 23],
[6, 10, 15, 21]]
@staticmethod
def g(b, c, d):
return (b & d) | (c & (~d))
@staticmethod
def i(b, c, d):
return c ^ (b | (~d))
"""
def F(self, R, key, *extra):
delta, shift = extra
return (((R << 4) ^ (R >> 5)) + R) ^ (delta + key[(delta >> shift) & 3])
def round_parameters(self, backward):
if not backward:
delta = 0
for _ in xrange(self.cycles):
yield self.F, [delta, 0]
delta += Tea_u.constant
yield self.F, [delta, 11]
else:
delta = self.cycles * Tea_u.constant
for _ in xrange(self.cycles):
yield self.F, [delta, 11]
delta -= Tea_u.constant
yield self.F, [delta, 0]
if __name__ == "__main__":
print [str(i) for i in Tea(64).crypt("\x00" * 8, dwords([0, 0, 0, 0]))]
print [str(i) for i in Tea(64).decrypt("\x41\xea\x3a\x0a\x94\xba\xa9\x40", dwords([0, 0, 0, 0]))]
print
#assert tea().crypt("\x00" * 8, Dwords([0, 0, 0, 0])) == Dwords([0x41ea3a0a, 0x94baa940])
#assert tea().decrypt("\x41\xea\x3a\x0a\x94\xba\xa9\x40", Dwords([0, 0, 0, 0])) == [0, 0]
print [str(i) for i in Xtea(64).crypt("\x00" * 8, dwords([0, 0, 0, 0]))]
#XTEA ['\xdee9d4d8', '\xf7131ed9']
print [str(i) for i in Xtea(64).decrypt("\xDE\xE9\xD4\xD8\xF7\x13\x1E\xD9" , dwords([0, 0, 0, 0]))]
