Raphaël G. Git Repositories - youtubedl/blob - youtube_dl/aes.py

   1 from __future__ import unicode_literals
   2
   3 import base64
   4 from math import ceil
   5
   6 from .utils import bytes_to_intlist, intlist_to_bytes
   7
   8 BLOCK_SIZE_BYTES = 16
   9
  10
  11 def aes_ctr_decrypt(data, key, counter):
  12     """
  13     Decrypt with aes in counter mode
  14
  15     @param {int[]} data        cipher
  16     @param {int[]} key         16/24/32-Byte cipher key
  17     @param {instance} counter  Instance whose next_value function (@returns {int[]}  16-Byte block)
  18                                returns the next counter block
  19     @returns {int[]}           decrypted data
  20     """
  21     expanded_key = key_expansion(key)
  22     block_count = int(ceil(float(len(data)) / BLOCK_SIZE_BYTES))
  23
  24     decrypted_data = []
  25     for i in range(block_count):
  26         counter_block = counter.next_value()
  27         block = data[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES]
  28         block += [0] * (BLOCK_SIZE_BYTES - len(block))
  29
  30         cipher_counter_block = aes_encrypt(counter_block, expanded_key)
  31         decrypted_data += xor(block, cipher_counter_block)
  32     decrypted_data = decrypted_data[:len(data)]
  33
  34     return decrypted_data
  35
  36
  37 def aes_cbc_decrypt(data, key, iv):
  38     """
  39     Decrypt with aes in CBC mode
  40
  41     @param {int[]} data        cipher
  42     @param {int[]} key         16/24/32-Byte cipher key
  43     @param {int[]} iv          16-Byte IV
  44     @returns {int[]}           decrypted data
  45     """
  46     expanded_key = key_expansion(key)
  47     block_count = int(ceil(float(len(data)) / BLOCK_SIZE_BYTES))
  48
  49     decrypted_data = []
  50     previous_cipher_block = iv
  51     for i in range(block_count):
  52         block = data[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES]
  53         block += [0] * (BLOCK_SIZE_BYTES - len(block))
  54
  55         decrypted_block = aes_decrypt(block, expanded_key)
  56         decrypted_data += xor(decrypted_block, previous_cipher_block)
  57         previous_cipher_block = block
  58     decrypted_data = decrypted_data[:len(data)]
  59
  60     return decrypted_data
  61
  62
  63 def key_expansion(data):
  64     """
  65     Generate key schedule
  66
  67     @param {int[]} data  16/24/32-Byte cipher key
  68     @returns {int[]}     176/208/240-Byte expanded key
  69     """
  70     data = data[:]  # copy
  71     rcon_iteration = 1
  72     key_size_bytes = len(data)
  73     expanded_key_size_bytes = (key_size_bytes // 4 + 7) * BLOCK_SIZE_BYTES
  74
  75     while len(data) < expanded_key_size_bytes:
  76         temp = data[-4:]
  77         temp = key_schedule_core(temp, rcon_iteration)
  78         rcon_iteration += 1
  79         data += xor(temp, data[-key_size_bytes: 4 - key_size_bytes])
  80
  81         for _ in range(3):
  82             temp = data[-4:]
  83             data += xor(temp, data[-key_size_bytes: 4 - key_size_bytes])
  84
  85         if key_size_bytes == 32:
  86             temp = data[-4:]
  87             temp = sub_bytes(temp)
  88             data += xor(temp, data[-key_size_bytes: 4 - key_size_bytes])
  89
  90         for _ in range(3 if key_size_bytes == 32 else 2 if key_size_bytes == 24 else 0):
  91             temp = data[-4:]
  92             data += xor(temp, data[-key_size_bytes: 4 - key_size_bytes])
  93     data = data[:expanded_key_size_bytes]
  94
  95     return data
  96
  97
  98 def aes_encrypt(data, expanded_key):
  99     """
 100     Encrypt one block with aes
 101
 102     @param {int[]} data          16-Byte state
 103     @param {int[]} expanded_key  176/208/240-Byte expanded key
 104     @returns {int[]}             16-Byte cipher
 105     """
 106     rounds = len(expanded_key) // BLOCK_SIZE_BYTES - 1
 107
 108     data = xor(data, expanded_key[:BLOCK_SIZE_BYTES])
 109     for i in range(1, rounds + 1):
 110         data = sub_bytes(data)
 111         data = shift_rows(data)
 112         if i != rounds:
 113             data = mix_columns(data)
 114         data = xor(data, expanded_key[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES])
 115
 116     return data
 117
 118
 119 def aes_decrypt(data, expanded_key):
 120     """
 121     Decrypt one block with aes
 122
 123     @param {int[]} data          16-Byte cipher
 124     @param {int[]} expanded_key  176/208/240-Byte expanded key
 125     @returns {int[]}             16-Byte state
 126     """
 127     rounds = len(expanded_key) // BLOCK_SIZE_BYTES - 1
 128
 129     for i in range(rounds, 0, -1):
 130         data = xor(data, expanded_key[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES])
 131         if i != rounds:
 132             data = mix_columns_inv(data)
 133         data = shift_rows_inv(data)
 134         data = sub_bytes_inv(data)
 135     data = xor(data, expanded_key[:BLOCK_SIZE_BYTES])
 136
 137     return data
 138
 139
 140 def aes_decrypt_text(data, password, key_size_bytes):
 141     """
 142     Decrypt text
 143     - The first 8 Bytes of decoded 'data' are the 8 high Bytes of the counter
 144     - The cipher key is retrieved by encrypting the first 16 Byte of 'password'
 145       with the first 'key_size_bytes' Bytes from 'password' (if necessary filled with 0's)
 146     - Mode of operation is 'counter'
 147
 148     @param {str} data                    Base64 encoded string
 149     @param {str,unicode} password        Password (will be encoded with utf-8)
 150     @param {int} key_size_bytes          Possible values: 16 for 128-Bit, 24 for 192-Bit or 32 for 256-Bit
 151     @returns {str}                       Decrypted data
 152     """
 153     NONCE_LENGTH_BYTES = 8
 154
 155     data = bytes_to_intlist(base64.b64decode(data.encode('utf-8')))
 156     password = bytes_to_intlist(password.encode('utf-8'))
 157
 158     key = password[:key_size_bytes] + [0] * (key_size_bytes - len(password))
 159     key = aes_encrypt(key[:BLOCK_SIZE_BYTES], key_expansion(key)) * (key_size_bytes // BLOCK_SIZE_BYTES)
 160
 161     nonce = data[:NONCE_LENGTH_BYTES]
 162     cipher = data[NONCE_LENGTH_BYTES:]
 163
 164     class Counter(object):
 165         __value = nonce + [0] * (BLOCK_SIZE_BYTES - NONCE_LENGTH_BYTES)
 166
 167         def next_value(self):
 168             temp = self.__value
 169             self.__value = inc(self.__value)
 170             return temp
 171
 172     decrypted_data = aes_ctr_decrypt(cipher, key, Counter())
 173     plaintext = intlist_to_bytes(decrypted_data)
 174
 175     return plaintext
 176
 177 RCON = (0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36)
 178 SBOX = (0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 0xFE, 0xD7, 0xAB, 0x76,
 179         0xCA, 0x82, 0xC9, 0x7D, 0xFA, 0x59, 0x47, 0xF0, 0xAD, 0xD4, 0xA2, 0xAF, 0x9C, 0xA4, 0x72, 0xC0,
 180         0xB7, 0xFD, 0x93, 0x26, 0x36, 0x3F, 0xF7, 0xCC, 0x34, 0xA5, 0xE5, 0xF1, 0x71, 0xD8, 0x31, 0x15,
 181         0x04, 0xC7, 0x23, 0xC3, 0x18, 0x96, 0x05, 0x9A, 0x07, 0x12, 0x80, 0xE2, 0xEB, 0x27, 0xB2, 0x75,
 182         0x09, 0x83, 0x2C, 0x1A, 0x1B, 0x6E, 0x5A, 0xA0, 0x52, 0x3B, 0xD6, 0xB3, 0x29, 0xE3, 0x2F, 0x84,
 183         0x53, 0xD1, 0x00, 0xED, 0x20, 0xFC, 0xB1, 0x5B, 0x6A, 0xCB, 0xBE, 0x39, 0x4A, 0x4C, 0x58, 0xCF,
 184         0xD0, 0xEF, 0xAA, 0xFB, 0x43, 0x4D, 0x33, 0x85, 0x45, 0xF9, 0x02, 0x7F, 0x50, 0x3C, 0x9F, 0xA8,
 185         0x51, 0xA3, 0x40, 0x8F, 0x92, 0x9D, 0x38, 0xF5, 0xBC, 0xB6, 0xDA, 0x21, 0x10, 0xFF, 0xF3, 0xD2,
 186         0xCD, 0x0C, 0x13, 0xEC, 0x5F, 0x97, 0x44, 0x17, 0xC4, 0xA7, 0x7E, 0x3D, 0x64, 0x5D, 0x19, 0x73,
 187         0x60, 0x81, 0x4F, 0xDC, 0x22, 0x2A, 0x90, 0x88, 0x46, 0xEE, 0xB8, 0x14, 0xDE, 0x5E, 0x0B, 0xDB,
 188         0xE0, 0x32, 0x3A, 0x0A, 0x49, 0x06, 0x24, 0x5C, 0xC2, 0xD3, 0xAC, 0x62, 0x91, 0x95, 0xE4, 0x79,
 189         0xE7, 0xC8, 0x37, 0x6D, 0x8D, 0xD5, 0x4E, 0xA9, 0x6C, 0x56, 0xF4, 0xEA, 0x65, 0x7A, 0xAE, 0x08,
 190         0xBA, 0x78, 0x25, 0x2E, 0x1C, 0xA6, 0xB4, 0xC6, 0xE8, 0xDD, 0x74, 0x1F, 0x4B, 0xBD, 0x8B, 0x8A,
 191         0x70, 0x3E, 0xB5, 0x66, 0x48, 0x03, 0xF6, 0x0E, 0x61, 0x35, 0x57, 0xB9, 0x86, 0xC1, 0x1D, 0x9E,
 192         0xE1, 0xF8, 0x98, 0x11, 0x69, 0xD9, 0x8E, 0x94, 0x9B, 0x1E, 0x87, 0xE9, 0xCE, 0x55, 0x28, 0xDF,
 193         0x8C, 0xA1, 0x89, 0x0D, 0xBF, 0xE6, 0x42, 0x68, 0x41, 0x99, 0x2D, 0x0F, 0xB0, 0x54, 0xBB, 0x16)
 194 SBOX_INV = (0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
 195             0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
 196             0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
 197             0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
 198             0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
 199             0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
 200             0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
 201             0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
 202             0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
 203             0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
 204             0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
 205             0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
 206             0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
 207             0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
 208             0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
 209             0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d)
 210 MIX_COLUMN_MATRIX = ((0x2, 0x3, 0x1, 0x1),
 211                      (0x1, 0x2, 0x3, 0x1),
 212                      (0x1, 0x1, 0x2, 0x3),
 213                      (0x3, 0x1, 0x1, 0x2))
 214 MIX_COLUMN_MATRIX_INV = ((0xE, 0xB, 0xD, 0x9),
 215                          (0x9, 0xE, 0xB, 0xD),
 216                          (0xD, 0x9, 0xE, 0xB),
 217                          (0xB, 0xD, 0x9, 0xE))
 218 RIJNDAEL_EXP_TABLE = (0x01, 0x03, 0x05, 0x0F, 0x11, 0x33, 0x55, 0xFF, 0x1A, 0x2E, 0x72, 0x96, 0xA1, 0xF8, 0x13, 0x35,
 219                       0x5F, 0xE1, 0x38, 0x48, 0xD8, 0x73, 0x95, 0xA4, 0xF7, 0x02, 0x06, 0x0A, 0x1E, 0x22, 0x66, 0xAA,
 220                       0xE5, 0x34, 0x5C, 0xE4, 0x37, 0x59, 0xEB, 0x26, 0x6A, 0xBE, 0xD9, 0x70, 0x90, 0xAB, 0xE6, 0x31,
 221                       0x53, 0xF5, 0x04, 0x0C, 0x14, 0x3C, 0x44, 0xCC, 0x4F, 0xD1, 0x68, 0xB8, 0xD3, 0x6E, 0xB2, 0xCD,
 222                       0x4C, 0xD4, 0x67, 0xA9, 0xE0, 0x3B, 0x4D, 0xD7, 0x62, 0xA6, 0xF1, 0x08, 0x18, 0x28, 0x78, 0x88,
 223                       0x83, 0x9E, 0xB9, 0xD0, 0x6B, 0xBD, 0xDC, 0x7F, 0x81, 0x98, 0xB3, 0xCE, 0x49, 0xDB, 0x76, 0x9A,
 224                       0xB5, 0xC4, 0x57, 0xF9, 0x10, 0x30, 0x50, 0xF0, 0x0B, 0x1D, 0x27, 0x69, 0xBB, 0xD6, 0x61, 0xA3,
 225                       0xFE, 0x19, 0x2B, 0x7D, 0x87, 0x92, 0xAD, 0xEC, 0x2F, 0x71, 0x93, 0xAE, 0xE9, 0x20, 0x60, 0xA0,
 226                       0xFB, 0x16, 0x3A, 0x4E, 0xD2, 0x6D, 0xB7, 0xC2, 0x5D, 0xE7, 0x32, 0x56, 0xFA, 0x15, 0x3F, 0x41,
 227                       0xC3, 0x5E, 0xE2, 0x3D, 0x47, 0xC9, 0x40, 0xC0, 0x5B, 0xED, 0x2C, 0x74, 0x9C, 0xBF, 0xDA, 0x75,
 228                       0x9F, 0xBA, 0xD5, 0x64, 0xAC, 0xEF, 0x2A, 0x7E, 0x82, 0x9D, 0xBC, 0xDF, 0x7A, 0x8E, 0x89, 0x80,
 229                       0x9B, 0xB6, 0xC1, 0x58, 0xE8, 0x23, 0x65, 0xAF, 0xEA, 0x25, 0x6F, 0xB1, 0xC8, 0x43, 0xC5, 0x54,
 230                       0xFC, 0x1F, 0x21, 0x63, 0xA5, 0xF4, 0x07, 0x09, 0x1B, 0x2D, 0x77, 0x99, 0xB0, 0xCB, 0x46, 0xCA,
 231                       0x45, 0xCF, 0x4A, 0xDE, 0x79, 0x8B, 0x86, 0x91, 0xA8, 0xE3, 0x3E, 0x42, 0xC6, 0x51, 0xF3, 0x0E,
 232                       0x12, 0x36, 0x5A, 0xEE, 0x29, 0x7B, 0x8D, 0x8C, 0x8F, 0x8A, 0x85, 0x94, 0xA7, 0xF2, 0x0D, 0x17,
 233                       0x39, 0x4B, 0xDD, 0x7C, 0x84, 0x97, 0xA2, 0xFD, 0x1C, 0x24, 0x6C, 0xB4, 0xC7, 0x52, 0xF6, 0x01)
 234 RIJNDAEL_LOG_TABLE = (0x00, 0x00, 0x19, 0x01, 0x32, 0x02, 0x1a, 0xc6, 0x4b, 0xc7, 0x1b, 0x68, 0x33, 0xee, 0xdf, 0x03,
 235                       0x64, 0x04, 0xe0, 0x0e, 0x34, 0x8d, 0x81, 0xef, 0x4c, 0x71, 0x08, 0xc8, 0xf8, 0x69, 0x1c, 0xc1,
 236                       0x7d, 0xc2, 0x1d, 0xb5, 0xf9, 0xb9, 0x27, 0x6a, 0x4d, 0xe4, 0xa6, 0x72, 0x9a, 0xc9, 0x09, 0x78,
 237                       0x65, 0x2f, 0x8a, 0x05, 0x21, 0x0f, 0xe1, 0x24, 0x12, 0xf0, 0x82, 0x45, 0x35, 0x93, 0xda, 0x8e,
 238                       0x96, 0x8f, 0xdb, 0xbd, 0x36, 0xd0, 0xce, 0x94, 0x13, 0x5c, 0xd2, 0xf1, 0x40, 0x46, 0x83, 0x38,
 239                       0x66, 0xdd, 0xfd, 0x30, 0xbf, 0x06, 0x8b, 0x62, 0xb3, 0x25, 0xe2, 0x98, 0x22, 0x88, 0x91, 0x10,
 240                       0x7e, 0x6e, 0x48, 0xc3, 0xa3, 0xb6, 0x1e, 0x42, 0x3a, 0x6b, 0x28, 0x54, 0xfa, 0x85, 0x3d, 0xba,
 241                       0x2b, 0x79, 0x0a, 0x15, 0x9b, 0x9f, 0x5e, 0xca, 0x4e, 0xd4, 0xac, 0xe5, 0xf3, 0x73, 0xa7, 0x57,
 242                       0xaf, 0x58, 0xa8, 0x50, 0xf4, 0xea, 0xd6, 0x74, 0x4f, 0xae, 0xe9, 0xd5, 0xe7, 0xe6, 0xad, 0xe8,
 243                       0x2c, 0xd7, 0x75, 0x7a, 0xeb, 0x16, 0x0b, 0xf5, 0x59, 0xcb, 0x5f, 0xb0, 0x9c, 0xa9, 0x51, 0xa0,
 244                       0x7f, 0x0c, 0xf6, 0x6f, 0x17, 0xc4, 0x49, 0xec, 0xd8, 0x43, 0x1f, 0x2d, 0xa4, 0x76, 0x7b, 0xb7,
 245                       0xcc, 0xbb, 0x3e, 0x5a, 0xfb, 0x60, 0xb1, 0x86, 0x3b, 0x52, 0xa1, 0x6c, 0xaa, 0x55, 0x29, 0x9d,
 246                       0x97, 0xb2, 0x87, 0x90, 0x61, 0xbe, 0xdc, 0xfc, 0xbc, 0x95, 0xcf, 0xcd, 0x37, 0x3f, 0x5b, 0xd1,
 247                       0x53, 0x39, 0x84, 0x3c, 0x41, 0xa2, 0x6d, 0x47, 0x14, 0x2a, 0x9e, 0x5d, 0x56, 0xf2, 0xd3, 0xab,
 248                       0x44, 0x11, 0x92, 0xd9, 0x23, 0x20, 0x2e, 0x89, 0xb4, 0x7c, 0xb8, 0x26, 0x77, 0x99, 0xe3, 0xa5,
 249                       0x67, 0x4a, 0xed, 0xde, 0xc5, 0x31, 0xfe, 0x18, 0x0d, 0x63, 0x8c, 0x80, 0xc0, 0xf7, 0x70, 0x07)
 250
 251
 252 def sub_bytes(data):
 253     return [SBOX[x] for x in data]
 254
 255
 256 def sub_bytes_inv(data):
 257     return [SBOX_INV[x] for x in data]
 258
 259
 260 def rotate(data):
 261     return data[1:] + [data[0]]
 262
 263
 264 def key_schedule_core(data, rcon_iteration):
 265     data = rotate(data)
 266     data = sub_bytes(data)
 267     data[0] = data[0] ^ RCON[rcon_iteration]
 268
 269     return data
 270
 271
 272 def xor(data1, data2):
 273     return [x ^ y for x, y in zip(data1, data2)]
 274
 275
 276 def rijndael_mul(a, b):
 277     if(a == 0 or b == 0):
 278         return 0
 279     return RIJNDAEL_EXP_TABLE[(RIJNDAEL_LOG_TABLE[a] + RIJNDAEL_LOG_TABLE[b]) % 0xFF]
 280
 281
 282 def mix_column(data, matrix):
 283     data_mixed = []
 284     for row in range(4):
 285         mixed = 0
 286         for column in range(4):
 287             # xor is (+) and (-)
 288             mixed ^= rijndael_mul(data[column], matrix[row][column])
 289         data_mixed.append(mixed)
 290     return data_mixed
 291
 292
 293 def mix_columns(data, matrix=MIX_COLUMN_MATRIX):
 294     data_mixed = []
 295     for i in range(4):
 296         column = data[i * 4: (i + 1) * 4]
 297         data_mixed += mix_column(column, matrix)
 298     return data_mixed
 299
 300
 301 def mix_columns_inv(data):
 302     return mix_columns(data, MIX_COLUMN_MATRIX_INV)
 303
 304
 305 def shift_rows(data):
 306     data_shifted = []
 307     for column in range(4):
 308         for row in range(4):
 309             data_shifted.append(data[((column + row) & 0b11) * 4 + row])
 310     return data_shifted
 311
 312
 313 def shift_rows_inv(data):
 314     data_shifted = []
 315     for column in range(4):
 316         for row in range(4):
 317             data_shifted.append(data[((column - row) & 0b11) * 4 + row])
 318     return data_shifted
 319
 320
 321 def inc(data):
 322     data = data[:]  # copy
 323     for i in range(len(data) - 1, -1, -1):
 324         if data[i] == 255:
 325             data[i] = 0
 326         else:
 327             data[i] = data[i] + 1
 328             break
 329     return data
 330
 331 __all__ = ['aes_encrypt', 'key_expansion', 'aes_ctr_decrypt', 'aes_cbc_decrypt', 'aes_decrypt_text']