| Dmitry Shmidt | 8d520ff | 2011-05-09 14:06:53 -0700 | [diff] [blame] | 1 | /* |
| 2 | * AES-128 CBC |
| 3 | * |
| 4 | * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 as |
| 8 | * published by the Free Software Foundation. |
| 9 | * |
| 10 | * Alternatively, this software may be distributed under the terms of BSD |
| 11 | * license. |
| 12 | * |
| 13 | * See README and COPYING for more details. |
| 14 | */ |
| 15 | |
| 16 | #include "includes.h" |
| 17 | |
| 18 | #include "common.h" |
| 19 | #include "aes.h" |
| 20 | #include "aes_wrap.h" |
| 21 | |
| 22 | /** |
| 23 | * aes_128_cbc_encrypt - AES-128 CBC encryption |
| 24 | * @key: Encryption key |
| 25 | * @iv: Encryption IV for CBC mode (16 bytes) |
| 26 | * @data: Data to encrypt in-place |
| 27 | * @data_len: Length of data in bytes (must be divisible by 16) |
| 28 | * Returns: 0 on success, -1 on failure |
| 29 | */ |
| 30 | int aes_128_cbc_encrypt(const u8 *key, const u8 *iv, u8 *data, size_t data_len) |
| 31 | { |
| 32 | void *ctx; |
| 33 | u8 cbc[AES_BLOCK_SIZE]; |
| 34 | u8 *pos = data; |
| 35 | int i, j, blocks; |
| 36 | |
| 37 | ctx = aes_encrypt_init(key, 16); |
| 38 | if (ctx == NULL) |
| 39 | return -1; |
| 40 | os_memcpy(cbc, iv, AES_BLOCK_SIZE); |
| 41 | |
| 42 | blocks = data_len / AES_BLOCK_SIZE; |
| 43 | for (i = 0; i < blocks; i++) { |
| 44 | for (j = 0; j < AES_BLOCK_SIZE; j++) |
| 45 | cbc[j] ^= pos[j]; |
| 46 | aes_encrypt(ctx, cbc, cbc); |
| 47 | os_memcpy(pos, cbc, AES_BLOCK_SIZE); |
| 48 | pos += AES_BLOCK_SIZE; |
| 49 | } |
| 50 | aes_encrypt_deinit(ctx); |
| 51 | return 0; |
| 52 | } |
| 53 | |
| 54 | |
| 55 | /** |
| 56 | * aes_128_cbc_decrypt - AES-128 CBC decryption |
| 57 | * @key: Decryption key |
| 58 | * @iv: Decryption IV for CBC mode (16 bytes) |
| 59 | * @data: Data to decrypt in-place |
| 60 | * @data_len: Length of data in bytes (must be divisible by 16) |
| 61 | * Returns: 0 on success, -1 on failure |
| 62 | */ |
| 63 | int aes_128_cbc_decrypt(const u8 *key, const u8 *iv, u8 *data, size_t data_len) |
| 64 | { |
| 65 | void *ctx; |
| 66 | u8 cbc[AES_BLOCK_SIZE], tmp[AES_BLOCK_SIZE]; |
| 67 | u8 *pos = data; |
| 68 | int i, j, blocks; |
| 69 | |
| 70 | ctx = aes_decrypt_init(key, 16); |
| 71 | if (ctx == NULL) |
| 72 | return -1; |
| 73 | os_memcpy(cbc, iv, AES_BLOCK_SIZE); |
| 74 | |
| 75 | blocks = data_len / AES_BLOCK_SIZE; |
| 76 | for (i = 0; i < blocks; i++) { |
| 77 | os_memcpy(tmp, pos, AES_BLOCK_SIZE); |
| 78 | aes_decrypt(ctx, pos, pos); |
| 79 | for (j = 0; j < AES_BLOCK_SIZE; j++) |
| 80 | pos[j] ^= cbc[j]; |
| 81 | os_memcpy(cbc, tmp, AES_BLOCK_SIZE); |
| 82 | pos += AES_BLOCK_SIZE; |
| 83 | } |
| 84 | aes_decrypt_deinit(ctx); |
| 85 | return 0; |
| 86 | } |