projects / thirdparty / hostap.git / blame
| Commit | Line | Data |
|---|---|---|
| 4c9e03e0 JB |
1 | /* |
| 2 | * AES-128 CTR | |
| 3 | * | |
| 4 | * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi> | |
| 5 | * | |
| 0f3d578e JM |
6 | * This software may be distributed under the terms of the BSD license. |
| 7 | * See README for more details. | |
| 4c9e03e0 JB |
8 | */ |
| 9 | ||
| 10 | #include "includes.h" | |
| 11 | ||
| 12 | #include "common.h" | |
| 1ba787b9 | 13 | #include "aes.h" |
| 8e2c104f | 14 | #include "aes_wrap.h" |
| 4c9e03e0 JB |
15 | |
| 16 | /** | |
| 17 | * aes_128_ctr_encrypt - AES-128 CTR mode encryption | |
| 18 | * @key: Key for encryption (16 bytes) | |
| 19 | * @nonce: Nonce for counter mode (16 bytes) | |
| 20 | * @data: Data to encrypt in-place | |
| 21 | * @data_len: Length of data in bytes | |
| 22 | * Returns: 0 on success, -1 on failure | |
| 23 | */ | |
| 24 | int aes_128_ctr_encrypt(const u8 *key, const u8 *nonce, | |
| 25 | u8 *data, size_t data_len) | |
| 26 | { | |
| 27 | void *ctx; | |
| 28 | size_t j, len, left = data_len; | |
| 29 | int i; | |
| 30 | u8 *pos = data; | |
| 1ba787b9 | 31 | u8 counter[AES_BLOCK_SIZE], buf[AES_BLOCK_SIZE]; |
| 4c9e03e0 JB |
32 | |
| 33 | ctx = aes_encrypt_init(key, 16); | |
| 34 | if (ctx == NULL) | |
| 35 | return -1; | |
| 1ba787b9 | 36 | os_memcpy(counter, nonce, AES_BLOCK_SIZE); |
| 4c9e03e0 JB |
37 | |
| 38 | while (left > 0) { | |
| 39 | aes_encrypt(ctx, counter, buf); | |
| 40 | ||
| 1ba787b9 | 41 | len = (left < AES_BLOCK_SIZE) ? left : AES_BLOCK_SIZE; |
| 4c9e03e0 JB |
42 | for (j = 0; j < len; j++) |
| 43 | pos[j] ^= buf[j]; | |
| 44 | pos += len; | |
| 45 | left -= len; | |
| 46 | ||
| 1ba787b9 | 47 | for (i = AES_BLOCK_SIZE - 1; i >= 0; i--) { |
| 4c9e03e0 JB |
48 | counter[i]++; |
| 49 | if (counter[i]) | |
| 50 | break; | |
| 51 | } | |
| 52 | } | |
| 53 | aes_encrypt_deinit(ctx); | |
| 54 | return 0; | |
| 55 | } |