221 lines
9.4 KiB
Python
221 lines
9.4 KiB
Python
#!/usr/bin/env python
|
|
# vim:ts=4:sw=4:softtabstop=4:smarttab:expandtab
|
|
import sys
|
|
|
|
ECB = 0
|
|
CBC = 1
|
|
class Des(object):
|
|
__pc1 = [56, 48, 40, 32, 24, 16, 8, 0, 57, 49, 41, 33, 25, 17,
|
|
9, 1, 58, 50, 42, 34, 26, 18, 10, 2, 59, 51, 43, 35,
|
|
62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21,
|
|
13, 5, 60, 52, 44, 36, 28, 20, 12, 4, 27, 19, 11, 3]
|
|
__left_rotations = [1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 1]
|
|
__pc2 = [13, 16, 10, 23, 0, 4,2, 27, 14, 5, 20, 9,
|
|
22, 18, 11, 3, 25, 7, 15, 6, 26, 19, 12, 1,
|
|
40, 51, 30, 36, 46, 54, 29, 39, 50, 44, 32, 47,
|
|
43, 48, 38, 55, 33, 52, 45, 41, 49, 35, 28, 31]
|
|
__ip = [57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3,
|
|
61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7,
|
|
56, 48, 40, 32, 24, 16, 8, 0, 58, 50, 42, 34, 26, 18, 10, 2,
|
|
60, 52, 44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6]
|
|
__expansion_table = [31, 0, 1, 2, 3, 4, 3, 4, 5, 6, 7, 8,
|
|
7, 8, 9, 10, 11, 12,11, 12, 13, 14, 15, 16,
|
|
15, 16, 17, 18, 19, 20,19, 20, 21, 22, 23, 24,
|
|
23, 24, 25, 26, 27, 28,27, 28, 29, 30, 31, 0]
|
|
__sbox = [[14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
|
|
0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
|
|
4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
|
|
15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13],
|
|
[15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
|
|
3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
|
|
0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
|
|
13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9],
|
|
[10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
|
|
13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
|
|
13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
|
|
1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12],
|
|
[7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
|
|
13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
|
|
10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
|
|
3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14],
|
|
[2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
|
|
14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
|
|
4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
|
|
11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3],
|
|
[12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
|
|
10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
|
|
9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
|
|
4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13],
|
|
[4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
|
|
13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
|
|
1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
|
|
6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12],
|
|
[13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
|
|
1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
|
|
7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
|
|
2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11],]
|
|
__p = [15, 6, 19, 20, 28, 11,27, 16, 0, 14, 22, 25,
|
|
4, 17, 30, 9, 1, 7,23,13, 31, 26, 2, 8,18, 12, 29, 5, 21, 10,3, 24]
|
|
__fp = [39, 7, 47, 15, 55, 23, 63, 31,38, 6, 46, 14, 54, 22, 62, 30,
|
|
37, 5, 45, 13, 53, 21, 61, 29,36, 4, 44, 12, 52, 20, 60, 28,
|
|
35, 3, 43, 11, 51, 19, 59, 27,34, 2, 42, 10, 50, 18, 58, 26,
|
|
33, 1, 41, 9, 49, 17, 57, 25,32, 0, 40, 8, 48, 16, 56, 24]
|
|
# Type of crypting being done
|
|
ENCRYPT = 0x00
|
|
DECRYPT = 0x01
|
|
def __init__(self, key, mode=ECB, IV=None):
|
|
if len(key) != 8:
|
|
raise ValueError("Invalid DES key size. Key must be exactly 8 bytes long.")
|
|
self.block_size = 8
|
|
self.key_size = 8
|
|
self.__padding = ''
|
|
self.setMode(mode)
|
|
if IV:
|
|
self.setIV(IV)
|
|
self.L = []
|
|
self.R = []
|
|
self.Kn = [ [0] * 48 ] * 16 # 16 48-bit keys (K1 - K16)
|
|
self.final = []
|
|
self.setKey(key)
|
|
def getKey(self):
|
|
return self.__key
|
|
def setKey(self, key):
|
|
self.__key = key
|
|
self.__create_sub_keys()
|
|
def getMode(self):
|
|
return self.__mode
|
|
def setMode(self, mode):
|
|
self.__mode = mode
|
|
def getIV(self):
|
|
return self.__iv
|
|
def setIV(self, IV):
|
|
if not IV or len(IV) != self.block_size:
|
|
raise ValueError("Invalid Initial Value (IV), must be a multiple of " + str(self.block_size) + " bytes")
|
|
self.__iv = IV
|
|
def getPadding(self):
|
|
return self.__padding
|
|
def __String_to_BitList(self, data):
|
|
l = len(data) * 8
|
|
result = [0] * l
|
|
pos = 0
|
|
for c in data:
|
|
i = 7
|
|
ch = ord(c)
|
|
while i >= 0:
|
|
if ch & (1 << i) != 0:
|
|
result[pos] = 1
|
|
else:
|
|
result[pos] = 0
|
|
pos += 1
|
|
i -= 1
|
|
return result
|
|
def __BitList_to_String(self, data):
|
|
result = ''
|
|
pos = 0
|
|
c = 0
|
|
while pos < len(data):
|
|
c += data[pos] << (7 - (pos % 8))
|
|
if (pos % 8) == 7:
|
|
result += chr(c)
|
|
c = 0
|
|
pos += 1
|
|
return result
|
|
def __permutate(self, table, block):
|
|
return [block[x] for x in table]
|
|
def __create_sub_keys(self):
|
|
key = self.__permutate(Des.__pc1, self.__String_to_BitList(self.getKey()))
|
|
i = 0
|
|
self.L = key[:28]
|
|
self.R = key[28:]
|
|
while i < 16:
|
|
j = 0
|
|
while j < Des.__left_rotations[i]:
|
|
self.L.append(self.L[0])
|
|
del self.L[0]
|
|
self.R.append(self.R[0])
|
|
del self.R[0]
|
|
j += 1
|
|
self.Kn[i] = self.__permutate(Des.__pc2, self.L + self.R)
|
|
i += 1
|
|
def __des_crypt(self, block, crypt_type):
|
|
block = self.__permutate(Des.__ip, block)
|
|
self.L = block[:32]
|
|
self.R = block[32:]
|
|
if crypt_type == Des.ENCRYPT:
|
|
iteration = 0
|
|
iteration_adjustment = 1
|
|
else:
|
|
iteration = 15
|
|
iteration_adjustment = -1
|
|
i = 0
|
|
while i < 16:
|
|
tempR = self.R[:]
|
|
self.R = self.__permutate(Des.__expansion_table, self.R)
|
|
self.R = [x ^ y for x,y in zip(self.R, self.Kn[iteration])]
|
|
B = [self.R[:6], self.R[6:12], self.R[12:18], self.R[18:24], self.R[24:30], self.R[30:36], self.R[36:42], self.R[42:]]
|
|
j = 0
|
|
Bn = [0] * 32
|
|
pos = 0
|
|
while j < 8:
|
|
m = (B[j][0] << 1) + B[j][5]
|
|
n = (B[j][1] << 3) + (B[j][2] << 2) + (B[j][3] << 1) + B[j][4]
|
|
v = Des.__sbox[j][(m << 4) + n]
|
|
Bn[pos] = (v & 8) >> 3
|
|
Bn[pos + 1] = (v & 4) >> 2
|
|
Bn[pos + 2] = (v & 2) >> 1
|
|
Bn[pos + 3] = v & 1
|
|
pos += 4
|
|
j += 1
|
|
self.R = self.__permutate(Des.__p, Bn)
|
|
self.R = [x ^ y for x, y in zip(self.R, self.L)]
|
|
self.L = tempR
|
|
i += 1
|
|
iteration += iteration_adjustment
|
|
self.final = self.__permutate(Des.__fp, self.R + self.L)
|
|
return self.final
|
|
def crypt(self, data, crypt_type):
|
|
if not data:
|
|
return ''
|
|
if len(data) % self.block_size != 0:
|
|
if crypt_type == Des.DECRYPT: # Decryption must work on 8 byte blocks
|
|
raise ValueError("Invalid data length, data must be a multiple of " + str(self.block_size) + " bytes\n.")
|
|
if not self.getPadding():
|
|
raise ValueError("Invalid data length, data must be a multiple of " + str(self.block_size) + " bytes\n. Try setting the optional padding character")
|
|
else:
|
|
data += (self.block_size - (len(data) % self.block_size)) * self.getPadding()
|
|
if self.getMode() == CBC:
|
|
if self.getIV():
|
|
iv = self.__String_to_BitList(self.getIV())
|
|
else:
|
|
raise ValueError("For CBC mode, you must supply the Initial Value (IV) for ciphering")
|
|
i = 0
|
|
dict = {}
|
|
result = []
|
|
while i < len(data):
|
|
block = self.__String_to_BitList(data[i:i+8])
|
|
if self.getMode() == CBC:
|
|
if crypt_type == Des.ENCRYPT:
|
|
block = [x ^ y for x, y in zip(block, iv)]
|
|
processed_block = self.__des_crypt(block, crypt_type)
|
|
if crypt_type == Des.DECRYPT:
|
|
processed_block = [x ^ y for x, y in zip(processed_block, iv)]
|
|
iv = block
|
|
else:
|
|
iv = processed_block
|
|
else:
|
|
processed_block = self.__des_crypt(block, crypt_type)
|
|
result.append(self.__BitList_to_String(processed_block))
|
|
i += 8
|
|
if crypt_type == Des.DECRYPT and self.getPadding():
|
|
s = result[-1]
|
|
while s[-1] == self.getPadding():
|
|
s = s[:-1]
|
|
result[-1] = s
|
|
return ''.join(result)
|
|
def encrypt(self, data, pad=''):
|
|
self.__padding = pad
|
|
return self.crypt(data, Des.ENCRYPT)
|
|
def decrypt(self, data, pad=''):
|
|
self.__padding = pad
|
|
return self.crypt(data, Des.DECRYPT)
|