X-Git-Url: https://git.rapsys.eu/youtubedl/blobdiff_plain/3ae74f711947d73bf6627bf312edeec41cec85c3..f4d1aa5e886897099f575b17aa7ab96c198008ae:/youtube_dl/aes.py diff --git a/youtube_dl/aes.py b/youtube_dl/aes.py index 9a0c93f..7817adc 100644 --- a/youtube_dl/aes.py +++ b/youtube_dl/aes.py @@ -1,4 +1,4 @@ -__all__ = ['aes_encrypt', 'key_expansion', 'aes_ctr_decrypt', 'aes_decrypt_text'] +from __future__ import unicode_literals import base64 from math import ceil @@ -7,10 +7,11 @@ from .utils import bytes_to_intlist, intlist_to_bytes BLOCK_SIZE_BYTES = 16 + def aes_ctr_decrypt(data, key, counter): """ Decrypt with aes in counter mode - + @param {int[]} data cipher @param {int[]} key 16/24/32-Byte cipher key @param {instance} counter Instance whose next_value function (@returns {int[]} 16-Byte block) @@ -19,73 +20,123 @@ def aes_ctr_decrypt(data, key, counter): """ expanded_key = key_expansion(key) block_count = int(ceil(float(len(data)) / BLOCK_SIZE_BYTES)) - - decrypted_data=[] + + decrypted_data = [] for i in range(block_count): counter_block = counter.next_value() - block = data[i*BLOCK_SIZE_BYTES : (i+1)*BLOCK_SIZE_BYTES] - block += [0]*(BLOCK_SIZE_BYTES - len(block)) - + block = data[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES] + block += [0] * (BLOCK_SIZE_BYTES - len(block)) + cipher_counter_block = aes_encrypt(counter_block, expanded_key) decrypted_data += xor(block, cipher_counter_block) decrypted_data = decrypted_data[:len(data)] - + return decrypted_data + +def aes_cbc_decrypt(data, key, iv): + """ + Decrypt with aes in CBC mode + + @param {int[]} data cipher + @param {int[]} key 16/24/32-Byte cipher key + @param {int[]} iv 16-Byte IV + @returns {int[]} decrypted data + """ + expanded_key = key_expansion(key) + block_count = int(ceil(float(len(data)) / BLOCK_SIZE_BYTES)) + + decrypted_data = [] + previous_cipher_block = iv + for i in range(block_count): + block = data[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES] + block += [0] * (BLOCK_SIZE_BYTES - len(block)) + + decrypted_block = aes_decrypt(block, expanded_key) + decrypted_data += xor(decrypted_block, previous_cipher_block) + previous_cipher_block = block + decrypted_data = decrypted_data[:len(data)] + + return decrypted_data + + def key_expansion(data): """ Generate key schedule - + @param {int[]} data 16/24/32-Byte cipher key - @returns {int[]} 176/208/240-Byte expanded key + @returns {int[]} 176/208/240-Byte expanded key """ - data = data[:] # copy + data = data[:] # copy rcon_iteration = 1 key_size_bytes = len(data) expanded_key_size_bytes = (key_size_bytes // 4 + 7) * BLOCK_SIZE_BYTES - + while len(data) < expanded_key_size_bytes: temp = data[-4:] temp = key_schedule_core(temp, rcon_iteration) rcon_iteration += 1 - data += xor(temp, data[-key_size_bytes : 4-key_size_bytes]) - + data += xor(temp, data[-key_size_bytes: 4 - key_size_bytes]) + for _ in range(3): temp = data[-4:] - data += xor(temp, data[-key_size_bytes : 4-key_size_bytes]) - + data += xor(temp, data[-key_size_bytes: 4 - key_size_bytes]) + if key_size_bytes == 32: temp = data[-4:] temp = sub_bytes(temp) - data += xor(temp, data[-key_size_bytes : 4-key_size_bytes]) - - for _ in range(3 if key_size_bytes == 32 else 2 if key_size_bytes == 24 else 0): + data += xor(temp, data[-key_size_bytes: 4 - key_size_bytes]) + + for _ in range(3 if key_size_bytes == 32 else 2 if key_size_bytes == 24 else 0): temp = data[-4:] - data += xor(temp, data[-key_size_bytes : 4-key_size_bytes]) + data += xor(temp, data[-key_size_bytes: 4 - key_size_bytes]) data = data[:expanded_key_size_bytes] - + return data + def aes_encrypt(data, expanded_key): """ Encrypt one block with aes - + @param {int[]} data 16-Byte state - @param {int[]} expanded_key 176/208/240-Byte expanded key + @param {int[]} expanded_key 176/208/240-Byte expanded key @returns {int[]} 16-Byte cipher """ rounds = len(expanded_key) // BLOCK_SIZE_BYTES - 1 - + data = xor(data, expanded_key[:BLOCK_SIZE_BYTES]) - for i in range(1, rounds+1): + for i in range(1, rounds + 1): data = sub_bytes(data) data = shift_rows(data) if i != rounds: data = mix_columns(data) - data = xor(data, expanded_key[i*BLOCK_SIZE_BYTES : (i+1)*BLOCK_SIZE_BYTES]) - + data = xor(data, expanded_key[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES]) + + return data + + +def aes_decrypt(data, expanded_key): + """ + Decrypt one block with aes + + @param {int[]} data 16-Byte cipher + @param {int[]} expanded_key 176/208/240-Byte expanded key + @returns {int[]} 16-Byte state + """ + rounds = len(expanded_key) // BLOCK_SIZE_BYTES - 1 + + for i in range(rounds, 0, -1): + data = xor(data, expanded_key[i * BLOCK_SIZE_BYTES: (i + 1) * BLOCK_SIZE_BYTES]) + if i != rounds: + data = mix_columns_inv(data) + data = shift_rows_inv(data) + data = sub_bytes_inv(data) + data = xor(data, expanded_key[:BLOCK_SIZE_BYTES]) + return data + def aes_decrypt_text(data, password, key_size_bytes): """ Decrypt text @@ -93,33 +144,34 @@ def aes_decrypt_text(data, password, key_size_bytes): - The cipher key is retrieved by encrypting the first 16 Byte of 'password' with the first 'key_size_bytes' Bytes from 'password' (if necessary filled with 0's) - Mode of operation is 'counter' - + @param {str} data Base64 encoded string @param {str,unicode} password Password (will be encoded with utf-8) @param {int} key_size_bytes Possible values: 16 for 128-Bit, 24 for 192-Bit or 32 for 256-Bit @returns {str} Decrypted data """ NONCE_LENGTH_BYTES = 8 - - data = bytes_to_intlist(base64.b64decode(data)) + + data = bytes_to_intlist(base64.b64decode(data.encode('utf-8'))) password = bytes_to_intlist(password.encode('utf-8')) - - key = password[:key_size_bytes] + [0]*(key_size_bytes - len(password)) + + key = password[:key_size_bytes] + [0] * (key_size_bytes - len(password)) key = aes_encrypt(key[:BLOCK_SIZE_BYTES], key_expansion(key)) * (key_size_bytes // BLOCK_SIZE_BYTES) - + nonce = data[:NONCE_LENGTH_BYTES] cipher = data[NONCE_LENGTH_BYTES:] - + class Counter: - __value = nonce + [0]*(BLOCK_SIZE_BYTES - NONCE_LENGTH_BYTES) + __value = nonce + [0] * (BLOCK_SIZE_BYTES - NONCE_LENGTH_BYTES) + def next_value(self): temp = self.__value self.__value = inc(self.__value) return temp - + decrypted_data = aes_ctr_decrypt(cipher, key, Counter()) plaintext = intlist_to_bytes(decrypted_data) - + return plaintext RCON = (0x8d, 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36) @@ -139,64 +191,141 @@ SBOX = (0x63, 0x7C, 0x77, 0x7B, 0xF2, 0x6B, 0x6F, 0xC5, 0x30, 0x01, 0x67, 0x2B, 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) -MIX_COLUMN_MATRIX = ((2,3,1,1), - (1,2,3,1), - (1,1,2,3), - (3,1,1,2)) +SBOX_INV = (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) +MIX_COLUMN_MATRIX = ((0x2, 0x3, 0x1, 0x1), + (0x1, 0x2, 0x3, 0x1), + (0x1, 0x1, 0x2, 0x3), + (0x3, 0x1, 0x1, 0x2)) +MIX_COLUMN_MATRIX_INV = ((0xE, 0xB, 0xD, 0x9), + (0x9, 0xE, 0xB, 0xD), + (0xD, 0x9, 0xE, 0xB), + (0xB, 0xD, 0x9, 0xE)) +RIJNDAEL_EXP_TABLE = (0x01, 0x03, 0x05, 0x0F, 0x11, 0x33, 0x55, 0xFF, 0x1A, 0x2E, 0x72, 0x96, 0xA1, 0xF8, 0x13, 0x35, + 0x5F, 0xE1, 0x38, 0x48, 0xD8, 0x73, 0x95, 0xA4, 0xF7, 0x02, 0x06, 0x0A, 0x1E, 0x22, 0x66, 0xAA, + 0xE5, 0x34, 0x5C, 0xE4, 0x37, 0x59, 0xEB, 0x26, 0x6A, 0xBE, 0xD9, 0x70, 0x90, 0xAB, 0xE6, 0x31, + 0x53, 0xF5, 0x04, 0x0C, 0x14, 0x3C, 0x44, 0xCC, 0x4F, 0xD1, 0x68, 0xB8, 0xD3, 0x6E, 0xB2, 0xCD, + 0x4C, 0xD4, 0x67, 0xA9, 0xE0, 0x3B, 0x4D, 0xD7, 0x62, 0xA6, 0xF1, 0x08, 0x18, 0x28, 0x78, 0x88, + 0x83, 0x9E, 0xB9, 0xD0, 0x6B, 0xBD, 0xDC, 0x7F, 0x81, 0x98, 0xB3, 0xCE, 0x49, 0xDB, 0x76, 0x9A, + 0xB5, 0xC4, 0x57, 0xF9, 0x10, 0x30, 0x50, 0xF0, 0x0B, 0x1D, 0x27, 0x69, 0xBB, 0xD6, 0x61, 0xA3, + 0xFE, 0x19, 0x2B, 0x7D, 0x87, 0x92, 0xAD, 0xEC, 0x2F, 0x71, 0x93, 0xAE, 0xE9, 0x20, 0x60, 0xA0, + 0xFB, 0x16, 0x3A, 0x4E, 0xD2, 0x6D, 0xB7, 0xC2, 0x5D, 0xE7, 0x32, 0x56, 0xFA, 0x15, 0x3F, 0x41, + 0xC3, 0x5E, 0xE2, 0x3D, 0x47, 0xC9, 0x40, 0xC0, 0x5B, 0xED, 0x2C, 0x74, 0x9C, 0xBF, 0xDA, 0x75, + 0x9F, 0xBA, 0xD5, 0x64, 0xAC, 0xEF, 0x2A, 0x7E, 0x82, 0x9D, 0xBC, 0xDF, 0x7A, 0x8E, 0x89, 0x80, + 0x9B, 0xB6, 0xC1, 0x58, 0xE8, 0x23, 0x65, 0xAF, 0xEA, 0x25, 0x6F, 0xB1, 0xC8, 0x43, 0xC5, 0x54, + 0xFC, 0x1F, 0x21, 0x63, 0xA5, 0xF4, 0x07, 0x09, 0x1B, 0x2D, 0x77, 0x99, 0xB0, 0xCB, 0x46, 0xCA, + 0x45, 0xCF, 0x4A, 0xDE, 0x79, 0x8B, 0x86, 0x91, 0xA8, 0xE3, 0x3E, 0x42, 0xC6, 0x51, 0xF3, 0x0E, + 0x12, 0x36, 0x5A, 0xEE, 0x29, 0x7B, 0x8D, 0x8C, 0x8F, 0x8A, 0x85, 0x94, 0xA7, 0xF2, 0x0D, 0x17, + 0x39, 0x4B, 0xDD, 0x7C, 0x84, 0x97, 0xA2, 0xFD, 0x1C, 0x24, 0x6C, 0xB4, 0xC7, 0x52, 0xF6, 0x01) +RIJNDAEL_LOG_TABLE = (0x00, 0x00, 0x19, 0x01, 0x32, 0x02, 0x1a, 0xc6, 0x4b, 0xc7, 0x1b, 0x68, 0x33, 0xee, 0xdf, 0x03, + 0x64, 0x04, 0xe0, 0x0e, 0x34, 0x8d, 0x81, 0xef, 0x4c, 0x71, 0x08, 0xc8, 0xf8, 0x69, 0x1c, 0xc1, + 0x7d, 0xc2, 0x1d, 0xb5, 0xf9, 0xb9, 0x27, 0x6a, 0x4d, 0xe4, 0xa6, 0x72, 0x9a, 0xc9, 0x09, 0x78, + 0x65, 0x2f, 0x8a, 0x05, 0x21, 0x0f, 0xe1, 0x24, 0x12, 0xf0, 0x82, 0x45, 0x35, 0x93, 0xda, 0x8e, + 0x96, 0x8f, 0xdb, 0xbd, 0x36, 0xd0, 0xce, 0x94, 0x13, 0x5c, 0xd2, 0xf1, 0x40, 0x46, 0x83, 0x38, + 0x66, 0xdd, 0xfd, 0x30, 0xbf, 0x06, 0x8b, 0x62, 0xb3, 0x25, 0xe2, 0x98, 0x22, 0x88, 0x91, 0x10, + 0x7e, 0x6e, 0x48, 0xc3, 0xa3, 0xb6, 0x1e, 0x42, 0x3a, 0x6b, 0x28, 0x54, 0xfa, 0x85, 0x3d, 0xba, + 0x2b, 0x79, 0x0a, 0x15, 0x9b, 0x9f, 0x5e, 0xca, 0x4e, 0xd4, 0xac, 0xe5, 0xf3, 0x73, 0xa7, 0x57, + 0xaf, 0x58, 0xa8, 0x50, 0xf4, 0xea, 0xd6, 0x74, 0x4f, 0xae, 0xe9, 0xd5, 0xe7, 0xe6, 0xad, 0xe8, + 0x2c, 0xd7, 0x75, 0x7a, 0xeb, 0x16, 0x0b, 0xf5, 0x59, 0xcb, 0x5f, 0xb0, 0x9c, 0xa9, 0x51, 0xa0, + 0x7f, 0x0c, 0xf6, 0x6f, 0x17, 0xc4, 0x49, 0xec, 0xd8, 0x43, 0x1f, 0x2d, 0xa4, 0x76, 0x7b, 0xb7, + 0xcc, 0xbb, 0x3e, 0x5a, 0xfb, 0x60, 0xb1, 0x86, 0x3b, 0x52, 0xa1, 0x6c, 0xaa, 0x55, 0x29, 0x9d, + 0x97, 0xb2, 0x87, 0x90, 0x61, 0xbe, 0xdc, 0xfc, 0xbc, 0x95, 0xcf, 0xcd, 0x37, 0x3f, 0x5b, 0xd1, + 0x53, 0x39, 0x84, 0x3c, 0x41, 0xa2, 0x6d, 0x47, 0x14, 0x2a, 0x9e, 0x5d, 0x56, 0xf2, 0xd3, 0xab, + 0x44, 0x11, 0x92, 0xd9, 0x23, 0x20, 0x2e, 0x89, 0xb4, 0x7c, 0xb8, 0x26, 0x77, 0x99, 0xe3, 0xa5, + 0x67, 0x4a, 0xed, 0xde, 0xc5, 0x31, 0xfe, 0x18, 0x0d, 0x63, 0x8c, 0x80, 0xc0, 0xf7, 0x70, 0x07) + def sub_bytes(data): return [SBOX[x] for x in data] + +def sub_bytes_inv(data): + return [SBOX_INV[x] for x in data] + + def rotate(data): return data[1:] + [data[0]] + def key_schedule_core(data, rcon_iteration): data = rotate(data) data = sub_bytes(data) data[0] = data[0] ^ RCON[rcon_iteration] - + return data + def xor(data1, data2): - return [x^y for x, y in zip(data1, data2)] + return [x ^ y for x, y in zip(data1, data2)] + + +def rijndael_mul(a, b): + if(a == 0 or b == 0): + return 0 + return RIJNDAEL_EXP_TABLE[(RIJNDAEL_LOG_TABLE[a] + RIJNDAEL_LOG_TABLE[b]) % 0xFF] -def mix_column(data): + +def mix_column(data, matrix): data_mixed = [] for row in range(4): mixed = 0 for column in range(4): - addend = data[column] - if MIX_COLUMN_MATRIX[row][column] in (2,3): - addend <<= 1 - if addend > 0xff: - addend &= 0xff - addend ^= 0x1b - if MIX_COLUMN_MATRIX[row][column] == 3: - addend ^= data[column] - mixed ^= addend & 0xff + # xor is (+) and (-) + mixed ^= rijndael_mul(data[column], matrix[row][column]) data_mixed.append(mixed) return data_mixed -def mix_columns(data): + +def mix_columns(data, matrix=MIX_COLUMN_MATRIX): data_mixed = [] for i in range(4): - column = data[i*4 : (i+1)*4] - data_mixed += mix_column(column) + column = data[i * 4: (i + 1) * 4] + data_mixed += mix_column(column, matrix) return data_mixed + +def mix_columns_inv(data): + return mix_columns(data, MIX_COLUMN_MATRIX_INV) + + def shift_rows(data): data_shifted = [] for column in range(4): for row in range(4): - data_shifted.append( data[((column + row) & 0b11) * 4 + row] ) + data_shifted.append(data[((column + row) & 0b11) * 4 + row]) return data_shifted + +def shift_rows_inv(data): + data_shifted = [] + for column in range(4): + for row in range(4): + data_shifted.append(data[((column - row) & 0b11) * 4 + row]) + return data_shifted + + def inc(data): - data = data[:] # copy - for i in range(len(data)-1,-1,-1): + data = data[:] # copy + for i in range(len(data) - 1, -1, -1): if data[i] == 255: data[i] = 0 else: data[i] = data[i] + 1 break return data + +__all__ = ['aes_encrypt', 'key_expansion', 'aes_ctr_decrypt', 'aes_cbc_decrypt', 'aes_decrypt_text']