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Diffstat (limited to 'django/srpproject/srp/aes.py')
| -rw-r--r-- | django/srpproject/srp/aes.py | 655 |
1 files changed, 0 insertions, 655 deletions
diff --git a/django/srpproject/srp/aes.py b/django/srpproject/srp/aes.py deleted file mode 100644 index 4c27d41..0000000 --- a/django/srpproject/srp/aes.py +++ /dev/null @@ -1,655 +0,0 @@ -#!/usr/bin/python -# -# aes.py: implements AES - Advanced Encryption Standard -# from the SlowAES project, http://code.google.com/p/slowaes/ -# -# Copyright (c) 2008 Josh Davis ( http://www.josh-davis.org ), -# Alex Martelli ( http://www.aleax.it ) -# -# Ported from C code written by Laurent Haan ( http://www.progressive-coding.com ) -# -# Licensed under the Apache License, Version 2.0 -# http://www.apache.org/licenses/ -# -import os -import sys -import math - -def append_PKCS7_padding(s): - """return s padded to a multiple of 16-bytes by PKCS7 padding""" - numpads = 16 - (len(s)%16) - return s + numpads*chr(numpads) - -def strip_PKCS7_padding(s): - """return s stripped of PKCS7 padding""" - if len(s)%16 or not s: - raise ValueError("String of len %d can't be PCKS7-padded" % len(s)) - numpads = ord(s[-1]) - if numpads > 16: - raise ValueError("String ending with %r can't be PCKS7-padded" % s[-1]) - return s[:-numpads] - -class AES(object): - # valid key sizes - keySize = dict(SIZE_128=16, SIZE_192=24, SIZE_256=32) - - # Rijndael S-box - sbox = [0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, - 0x2b, 0xfe, 0xd7, 0xab, 0x76, 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, - 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, 0xb7, - 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, - 0x71, 0xd8, 0x31, 0x15, 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, - 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, 0x09, 0x83, - 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, - 0xe3, 0x2f, 0x84, 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, - 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, 0xd0, 0xef, 0xaa, - 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, - 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, - 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, 0xcd, 0x0c, 0x13, 0xec, - 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, - 0x73, 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, - 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, 0xe0, 0x32, 0x3a, 0x0a, 0x49, - 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, - 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, - 0xea, 0x65, 0x7a, 0xae, 0x08, 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, - 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, 0x70, - 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, - 0x86, 0xc1, 0x1d, 0x9e, 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, - 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, 0x8c, 0xa1, - 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, - 0x54, 0xbb, 0x16] - - # Rijndael Inverted S-box - rsbox = [0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, - 0x9e, 0x81, 0xf3, 0xd7, 0xfb , 0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, - 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb , 0x54, - 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, - 0x42, 0xfa, 0xc3, 0x4e , 0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, - 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25 , 0x72, 0xf8, - 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, - 0x65, 0xb6, 0x92 , 0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, - 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84 , 0x90, 0xd8, 0xab, - 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, - 0x45, 0x06 , 0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, - 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b , 0x3a, 0x91, 0x11, 0x41, - 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, - 0x73 , 0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, - 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e , 0x47, 0xf1, 0x1a, 0x71, 0x1d, - 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b , - 0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, - 0xfe, 0x78, 0xcd, 0x5a, 0xf4 , 0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, - 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f , 0x60, - 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, - 0x93, 0xc9, 0x9c, 0xef , 0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, - 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61 , 0x17, 0x2b, - 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, - 0x21, 0x0c, 0x7d] - - def getSBoxValue(self,num): - """Retrieves a given S-Box Value""" - return self.sbox[num] - - def getSBoxInvert(self,num): - """Retrieves a given Inverted S-Box Value""" - return self.rsbox[num] - - def rotate(self, word): - """ Rijndael's key schedule rotate operation. - - Rotate a word eight bits to the left: eg, rotate(1d2c3a4f) == 2c3a4f1d - Word is an char list of size 4 (32 bits overall). - """ - return word[1:] + word[:1] - - # Rijndael Rcon - Rcon = [0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, - 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, - 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, - 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, - 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, - 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, - 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, - 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, - 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, - 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, - 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, - 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, - 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, - 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, - 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, - 0xd8, 0xab, 0x4d, 0x9a, 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, - 0x6a, 0xd4, 0xb3, 0x7d, 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, - 0xd3, 0xbd, 0x61, 0xc2, 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, - 0x83, 0x1d, 0x3a, 0x74, 0xe8, 0xcb, 0x8d, 0x01, 0x02, 0x04, 0x08, - 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36, 0x6c, 0xd8, 0xab, 0x4d, 0x9a, - 0x2f, 0x5e, 0xbc, 0x63, 0xc6, 0x97, 0x35, 0x6a, 0xd4, 0xb3, 0x7d, - 0xfa, 0xef, 0xc5, 0x91, 0x39, 0x72, 0xe4, 0xd3, 0xbd, 0x61, 0xc2, - 0x9f, 0x25, 0x4a, 0x94, 0x33, 0x66, 0xcc, 0x83, 0x1d, 0x3a, 0x74, - 0xe8, 0xcb ] - - def getRconValue(self, num): - """Retrieves a given Rcon Value""" - return self.Rcon[num] - - def core(self, word, iteration): - """Key schedule core.""" - # rotate the 32-bit word 8 bits to the left - word = self.rotate(word) - # apply S-Box substitution on all 4 parts of the 32-bit word - for i in range(4): - word[i] = self.getSBoxValue(word[i]) - # XOR the output of the rcon operation with i to the first part - # (leftmost) only - word[0] = word[0] ^ self.getRconValue(iteration) - return word - - def expandKey(self, key, size, expandedKeySize): - """Rijndael's key expansion. - - Expands an 128,192,256 key into an 176,208,240 bytes key - - expandedKey is a char list of large enough size, - key is the non-expanded key. - """ - # current expanded keySize, in bytes - currentSize = 0 - rconIteration = 1 - expandedKey = [0] * expandedKeySize - - # set the 16, 24, 32 bytes of the expanded key to the input key - for j in range(size): - expandedKey[j] = key[j] - currentSize += size - - while currentSize < expandedKeySize: - # assign the previous 4 bytes to the temporary value t - t = expandedKey[currentSize-4:currentSize] - - # every 16,24,32 bytes we apply the core schedule to t - # and increment rconIteration afterwards - if currentSize % size == 0: - t = self.core(t, rconIteration) - rconIteration += 1 - # For 256-bit keys, we add an extra sbox to the calculation - if size == self.keySize["SIZE_256"] and ((currentSize % size) == 16): - for l in range(4): t[l] = self.getSBoxValue(t[l]) - - # We XOR t with the four-byte block 16,24,32 bytes before the new - # expanded key. This becomes the next four bytes in the expanded - # key. - for m in range(4): - expandedKey[currentSize] = expandedKey[currentSize - size] ^ \ - t[m] - currentSize += 1 - - return expandedKey - - def addRoundKey(self, state, roundKey): - """Adds (XORs) the round key to the state.""" - for i in range(16): - state[i] ^= roundKey[i] - return state - - def createRoundKey(self, expandedKey, roundKeyPointer): - """Create a round key. - Creates a round key from the given expanded key and the - position within the expanded key. - """ - roundKey = [0] * 16 - for i in range(4): - for j in range(4): - roundKey[j*4+i] = expandedKey[roundKeyPointer + i*4 + j] - return roundKey - - def galois_multiplication(self, a, b): - """Galois multiplication of 8 bit characters a and b.""" - p = 0 - for counter in range(8): - if b & 1: p ^= a - hi_bit_set = a & 0x80 - a <<= 1 - # keep a 8 bit - a &= 0xFF - if hi_bit_set: - a ^= 0x1b - b >>= 1 - return p - - # - # substitute all the values from the state with the value in the SBox - # using the state value as index for the SBox - # - def subBytes(self, state, isInv): - if isInv: getter = self.getSBoxInvert - else: getter = self.getSBoxValue - for i in range(16): state[i] = getter(state[i]) - return state - - # iterate over the 4 rows and call shiftRow() with that row - def shiftRows(self, state, isInv): - for i in range(4): - state = self.shiftRow(state, i*4, i, isInv) - return state - - # each iteration shifts the row to the left by 1 - def shiftRow(self, state, statePointer, nbr, isInv): - for i in range(nbr): - if isInv: - state[statePointer:statePointer+4] = \ - state[statePointer+3:statePointer+4] + \ - state[statePointer:statePointer+3] - else: - state[statePointer:statePointer+4] = \ - state[statePointer+1:statePointer+4] + \ - state[statePointer:statePointer+1] - return state - - # galois multiplication of the 4x4 matrix - def mixColumns(self, state, isInv): - # iterate over the 4 columns - for i in range(4): - # construct one column by slicing over the 4 rows - column = state[i:i+16:4] - # apply the mixColumn on one column - column = self.mixColumn(column, isInv) - # put the values back into the state - state[i:i+16:4] = column - - return state - - # galois multiplication of 1 column of the 4x4 matrix - def mixColumn(self, column, isInv): - if isInv: mult = [14, 9, 13, 11] - else: mult = [2, 1, 1, 3] - cpy = list(column) - g = self.galois_multiplication - - column[0] = g(cpy[0], mult[0]) ^ g(cpy[3], mult[1]) ^ \ - g(cpy[2], mult[2]) ^ g(cpy[1], mult[3]) - column[1] = g(cpy[1], mult[0]) ^ g(cpy[0], mult[1]) ^ \ - g(cpy[3], mult[2]) ^ g(cpy[2], mult[3]) - column[2] = g(cpy[2], mult[0]) ^ g(cpy[1], mult[1]) ^ \ - g(cpy[0], mult[2]) ^ g(cpy[3], mult[3]) - column[3] = g(cpy[3], mult[0]) ^ g(cpy[2], mult[1]) ^ \ - g(cpy[1], mult[2]) ^ g(cpy[0], mult[3]) - return column - - # applies the 4 operations of the forward round in sequence - def aes_round(self, state, roundKey): - state = self.subBytes(state, False) - state = self.shiftRows(state, False) - state = self.mixColumns(state, False) - state = self.addRoundKey(state, roundKey) - return state - - # applies the 4 operations of the inverse round in sequence - def aes_invRound(self, state, roundKey): - state = self.shiftRows(state, True) - state = self.subBytes(state, True) - state = self.addRoundKey(state, roundKey) - state = self.mixColumns(state, True) - return state - - # Perform the initial operations, the standard round, and the final - # operations of the forward aes, creating a round key for each round - def aes_main(self, state, expandedKey, nbrRounds): - state = self.addRoundKey(state, self.createRoundKey(expandedKey, 0)) - i = 1 - while i < nbrRounds: - state = self.aes_round(state, - self.createRoundKey(expandedKey, 16*i)) - i += 1 - state = self.subBytes(state, False) - state = self.shiftRows(state, False) - state = self.addRoundKey(state, - self.createRoundKey(expandedKey, 16*nbrRounds)) - return state - - # Perform the initial operations, the standard round, and the final - # operations of the inverse aes, creating a round key for each round - def aes_invMain(self, state, expandedKey, nbrRounds): - state = self.addRoundKey(state, - self.createRoundKey(expandedKey, 16*nbrRounds)) - i = nbrRounds - 1 - while i > 0: - state = self.aes_invRound(state, - self.createRoundKey(expandedKey, 16*i)) - i -= 1 - state = self.shiftRows(state, True) - state = self.subBytes(state, True) - state = self.addRoundKey(state, self.createRoundKey(expandedKey, 0)) - return state - - # encrypts a 128 bit input block against the given key of size specified - def encrypt(self, iput, key, size): - output = [0] * 16 - # the number of rounds - nbrRounds = 0 - # the 128 bit block to encode - block = [0] * 16 - # set the number of rounds - if size == self.keySize["SIZE_128"]: nbrRounds = 10 - elif size == self.keySize["SIZE_192"]: nbrRounds = 12 - elif size == self.keySize["SIZE_256"]: nbrRounds = 14 - else: return None - - # the expanded keySize - expandedKeySize = 16*(nbrRounds+1) - - # Set the block values, for the block: - # a0,0 a0,1 a0,2 a0,3 - # a1,0 a1,1 a1,2 a1,3 - # a2,0 a2,1 a2,2 a2,3 - # a3,0 a3,1 a3,2 a3,3 - # the mapping order is a0,0 a1,0 a2,0 a3,0 a0,1 a1,1 ... a2,3 a3,3 - # - # iterate over the columns - for i in range(4): - # iterate over the rows - for j in range(4): - block[(i+(j*4))] = iput[(i*4)+j] - - # expand the key into an 176, 208, 240 bytes key - # the expanded key - expandedKey = self.expandKey(key, size, expandedKeySize) - - # encrypt the block using the expandedKey - block = self.aes_main(block, expandedKey, nbrRounds) - - # unmap the block again into the output - for k in range(4): - # iterate over the rows - for l in range(4): - output[(k*4)+l] = block[(k+(l*4))] - return output - - # decrypts a 128 bit input block against the given key of size specified - def decrypt(self, iput, key, size): - output = [0] * 16 - # the number of rounds - nbrRounds = 0 - # the 128 bit block to decode - block = [0] * 16 - # set the number of rounds - if size == self.keySize["SIZE_128"]: nbrRounds = 10 - elif size == self.keySize["SIZE_192"]: nbrRounds = 12 - elif size == self.keySize["SIZE_256"]: nbrRounds = 14 - else: return None - - # the expanded keySize - expandedKeySize = 16*(nbrRounds+1) - - # Set the block values, for the block: - # a0,0 a0,1 a0,2 a0,3 - # a1,0 a1,1 a1,2 a1,3 - # a2,0 a2,1 a2,2 a2,3 - # a3,0 a3,1 a3,2 a3,3 - # the mapping order is a0,0 a1,0 a2,0 a3,0 a0,1 a1,1 ... a2,3 a3,3 - - # iterate over the columns - for i in range(4): - # iterate over the rows - for j in range(4): - block[(i+(j*4))] = iput[(i*4)+j] - # expand the key into an 176, 208, 240 bytes key - expandedKey = self.expandKey(key, size, expandedKeySize) - # decrypt the block using the expandedKey - block = self.aes_invMain(block, expandedKey, nbrRounds) - # unmap the block again into the output - for k in range(4): - # iterate over the rows - for l in range(4): - output[(k*4)+l] = block[(k+(l*4))] - return output - - -class AESModeOfOperation(object): - - aes = AES() - - # structure of supported modes of operation - modeOfOperation = dict(OFB=0, CFB=1, CBC=2) - - # converts a 16 character string into a number array - def convertString(self, string, start, end, mode): - if end - start > 16: end = start + 16 - if mode == self.modeOfOperation["CBC"]: ar = [0] * 16 - else: ar = [] - - i = start - j = 0 - while len(ar) < end - start: - ar.append(0) - while i < end: - ar[j] = ord(string[i]) - j += 1 - i += 1 - return ar - - # Mode of Operation Encryption - # stringIn - Input String - # mode - mode of type modeOfOperation - # hexKey - a hex key of the bit length size - # size - the bit length of the key - # hexIV - the 128 bit hex Initilization Vector - def encrypt(self, stringIn, mode, key, size, IV): - if len(key) % size: - return None - if len(IV) % 16: - return None - # the AES input/output - plaintext = [] - iput = [0] * 16 - output = [] - ciphertext = [0] * 16 - # the output cipher string - cipherOut = [] - # char firstRound - firstRound = True - if stringIn != None: - for j in range(int(math.ceil(float(len(stringIn))/16))): - start = j*16 - end = j*16+16 - if end > len(stringIn): - end = len(stringIn) - plaintext = self.convertString(stringIn, start, end, mode) - # print 'PT@%s:%s' % (j, plaintext) - if mode == self.modeOfOperation["CFB"]: - if firstRound: - output = self.aes.encrypt(IV, key, size) - firstRound = False - else: - output = self.aes.encrypt(iput, key, size) - for i in range(16): - if len(plaintext)-1 < i: - ciphertext[i] = 0 ^ output[i] - elif len(output)-1 < i: - ciphertext[i] = plaintext[i] ^ 0 - elif len(plaintext)-1 < i and len(output) < i: - ciphertext[i] = 0 ^ 0 - else: - ciphertext[i] = plaintext[i] ^ output[i] - for k in range(end-start): - cipherOut.append(ciphertext[k]) - iput = ciphertext - elif mode == self.modeOfOperation["OFB"]: - if firstRound: - output = self.aes.encrypt(IV, key, size) - firstRound = False - else: - output = self.aes.encrypt(iput, key, size) - for i in range(16): - if len(plaintext)-1 < i: - ciphertext[i] = 0 ^ output[i] - elif len(output)-1 < i: - ciphertext[i] = plaintext[i] ^ 0 - elif len(plaintext)-1 < i and len(output) < i: - ciphertext[i] = 0 ^ 0 - else: - ciphertext[i] = plaintext[i] ^ output[i] - for k in range(end-start): - cipherOut.append(ciphertext[k]) - iput = output - elif mode == self.modeOfOperation["CBC"]: - for i in range(16): - if firstRound: - iput[i] = plaintext[i] ^ IV[i] - else: - iput[i] = plaintext[i] ^ ciphertext[i] - # print 'IP@%s:%s' % (j, iput) - firstRound = False - ciphertext = self.aes.encrypt(iput, key, size) - # always 16 bytes because of the padding for CBC - for k in range(16): - cipherOut.append(ciphertext[k]) - return mode, len(stringIn), cipherOut - - # Mode of Operation Decryption - # cipherIn - Encrypted String - # originalsize - The unencrypted string length - required for CBC - # mode - mode of type modeOfOperation - # key - a number array of the bit length size - # size - the bit length of the key - # IV - the 128 bit number array Initilization Vector - def decrypt(self, cipherIn, originalsize, mode, key, size, IV): - # cipherIn = unescCtrlChars(cipherIn) - if len(key) % size: - return None - if len(IV) % 16: - return None - # the AES input/output - ciphertext = [] - iput = [] - output = [] - plaintext = [0] * 16 - # the output plain text string - stringOut = '' - # char firstRound - firstRound = True - if cipherIn != None: - for j in range(int(math.ceil(float(len(cipherIn))/16))): - start = j*16 - end = j*16+16 - if j*16+16 > len(cipherIn): - end = len(cipherIn) - ciphertext = cipherIn[start:end] - if mode == self.modeOfOperation["CFB"]: - if firstRound: - output = self.aes.encrypt(IV, key, size) - firstRound = False - else: - output = self.aes.encrypt(iput, key, size) - for i in range(16): - if len(output)-1 < i: - plaintext[i] = 0 ^ ciphertext[i] - elif len(ciphertext)-1 < i: - plaintext[i] = output[i] ^ 0 - elif len(output)-1 < i and len(ciphertext) < i: - plaintext[i] = 0 ^ 0 - else: - plaintext[i] = output[i] ^ ciphertext[i] - for k in range(end-start): - stringOut += chr(plaintext[k]) - iput = ciphertext - elif mode == self.modeOfOperation["OFB"]: - if firstRound: - output = self.aes.encrypt(IV, key, size) - firstRound = False - else: - output = self.aes.encrypt(iput, key, size) - for i in range(16): - if len(output)-1 < i: - plaintext[i] = 0 ^ ciphertext[i] - elif len(ciphertext)-1 < i: - plaintext[i] = output[i] ^ 0 - elif len(output)-1 < i and len(ciphertext) < i: - plaintext[i] = 0 ^ 0 - else: - plaintext[i] = output[i] ^ ciphertext[i] - for k in range(end-start): - stringOut += chr(plaintext[k]) - iput = output - elif mode == self.modeOfOperation["CBC"]: - output = self.aes.decrypt(ciphertext, key, size) - for i in range(16): - if firstRound: - plaintext[i] = IV[i] ^ output[i] - else: - plaintext[i] = iput[i] ^ output[i] - firstRound = False - if originalsize is not None and originalsize < end: - for k in range(originalsize-start): - stringOut += chr(plaintext[k]) - else: - for k in range(end-start): - stringOut += chr(plaintext[k]) - iput = ciphertext - return stringOut - - -def encryptData(key, data, mode=AESModeOfOperation.modeOfOperation["CBC"]): - """encrypt `data` using `key` - - `key` should be a string of bytes. - - returned cipher is a string of bytes prepended with the initialization - vector. - - """ - key = map(ord, key) - data = append_PKCS7_padding(data) - keysize = len(key) - assert keysize in AES.keySize.values(), 'invalid key size: %s' % keysize - # create a new iv using random data - iv = [ord(i) for i in os.urandom(16)] - moo = AESModeOfOperation() - (mode, length, ciph) = moo.encrypt(data, mode, key, keysize, iv) - # With padding, the original length does not need to be known. It's a bad - # idea to store the original message length. - # prepend the iv. - return ''.join(map(chr, iv)) + ''.join(map(chr, ciph)) - -def decryptData(key, data, mode=AESModeOfOperation.modeOfOperation["CBC"]): - """decrypt `data` using `key` - - `key` should be a string of bytes. - - `data` should have the initialization vector prepended as a string or - ordinal values. - - """ - - key = map(ord, key) - keysize = len(key) - assert keysize in AES.keySize.values(), 'invalid key size: %s' % keysize - # iv is first 16 bytes - iv = map(ord, data[:16]) - data = map(ord, data[16:]) - moo = AESModeOfOperation() - decr = moo.decrypt(data, None, mode, key, keysize, iv) - decr = strip_PKCS7_padding(decr) - return decr - -def generateRandomKey(keysize): - """Generates a key from random data of length `keysize`. - - The returned key is a string of bytes. - - """ - if keysize not in (16, 24, 32): - emsg = 'Invalid keysize, %s. Should be one of (16, 24, 32).' - raise ValueError, emsg % keysize - return os.urandom(keysize) - -if __name__ == "__main__": - moo = AESModeOfOperation() - cleartext = "This is a test!" - cypherkey = [143,194,34,208,145,203,230,143,177,246,97,206,145,92,255,84] - iv = [103,35,148,239,76,213,47,118,255,222,123,176,106,134,98,92] - mode, orig_len, ciph = moo.encrypt(cleartext, moo.modeOfOperation["CBC"], - cypherkey, moo.aes.keySize["SIZE_128"], iv) - print 'm=%s, ol=%s (%s), ciph=%s' % (mode, orig_len, len(cleartext), ciph) - decr = moo.decrypt(ciph, orig_len, mode, cypherkey, - moo.aes.keySize["SIZE_128"], iv) - print decr - |