18dbcf02cSchristos /*
28dbcf02cSchristos * AES-128 CBC
38dbcf02cSchristos *
48dbcf02cSchristos * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
58dbcf02cSchristos *
6e604d861Schristos * This software may be distributed under the terms of the BSD license.
7e604d861Schristos * See README for more details.
88dbcf02cSchristos */
98dbcf02cSchristos
108dbcf02cSchristos #include "includes.h"
118dbcf02cSchristos
128dbcf02cSchristos #include "common.h"
138dbcf02cSchristos #include "aes.h"
148dbcf02cSchristos #include "aes_wrap.h"
158dbcf02cSchristos
168dbcf02cSchristos /**
178dbcf02cSchristos * aes_128_cbc_encrypt - AES-128 CBC encryption
188dbcf02cSchristos * @key: Encryption key
198dbcf02cSchristos * @iv: Encryption IV for CBC mode (16 bytes)
208dbcf02cSchristos * @data: Data to encrypt in-place
218dbcf02cSchristos * @data_len: Length of data in bytes (must be divisible by 16)
228dbcf02cSchristos * Returns: 0 on success, -1 on failure
238dbcf02cSchristos */
aes_128_cbc_encrypt(const u8 * key,const u8 * iv,u8 * data,size_t data_len)248dbcf02cSchristos int aes_128_cbc_encrypt(const u8 *key, const u8 *iv, u8 *data, size_t data_len)
258dbcf02cSchristos {
268dbcf02cSchristos void *ctx;
278dbcf02cSchristos u8 cbc[AES_BLOCK_SIZE];
288dbcf02cSchristos u8 *pos = data;
298dbcf02cSchristos int i, j, blocks;
308dbcf02cSchristos
31*36ebd06eSchristos if (TEST_FAIL())
32*36ebd06eSchristos return -1;
33*36ebd06eSchristos
348dbcf02cSchristos ctx = aes_encrypt_init(key, 16);
358dbcf02cSchristos if (ctx == NULL)
368dbcf02cSchristos return -1;
378dbcf02cSchristos os_memcpy(cbc, iv, AES_BLOCK_SIZE);
388dbcf02cSchristos
398dbcf02cSchristos blocks = data_len / AES_BLOCK_SIZE;
408dbcf02cSchristos for (i = 0; i < blocks; i++) {
418dbcf02cSchristos for (j = 0; j < AES_BLOCK_SIZE; j++)
428dbcf02cSchristos cbc[j] ^= pos[j];
438dbcf02cSchristos aes_encrypt(ctx, cbc, cbc);
448dbcf02cSchristos os_memcpy(pos, cbc, AES_BLOCK_SIZE);
458dbcf02cSchristos pos += AES_BLOCK_SIZE;
468dbcf02cSchristos }
478dbcf02cSchristos aes_encrypt_deinit(ctx);
488dbcf02cSchristos return 0;
498dbcf02cSchristos }
508dbcf02cSchristos
518dbcf02cSchristos
528dbcf02cSchristos /**
538dbcf02cSchristos * aes_128_cbc_decrypt - AES-128 CBC decryption
548dbcf02cSchristos * @key: Decryption key
558dbcf02cSchristos * @iv: Decryption IV for CBC mode (16 bytes)
568dbcf02cSchristos * @data: Data to decrypt in-place
578dbcf02cSchristos * @data_len: Length of data in bytes (must be divisible by 16)
588dbcf02cSchristos * Returns: 0 on success, -1 on failure
598dbcf02cSchristos */
aes_128_cbc_decrypt(const u8 * key,const u8 * iv,u8 * data,size_t data_len)608dbcf02cSchristos int aes_128_cbc_decrypt(const u8 *key, const u8 *iv, u8 *data, size_t data_len)
618dbcf02cSchristos {
628dbcf02cSchristos void *ctx;
638dbcf02cSchristos u8 cbc[AES_BLOCK_SIZE], tmp[AES_BLOCK_SIZE];
648dbcf02cSchristos u8 *pos = data;
658dbcf02cSchristos int i, j, blocks;
668dbcf02cSchristos
67*36ebd06eSchristos if (TEST_FAIL())
68*36ebd06eSchristos return -1;
69*36ebd06eSchristos
708dbcf02cSchristos ctx = aes_decrypt_init(key, 16);
718dbcf02cSchristos if (ctx == NULL)
728dbcf02cSchristos return -1;
738dbcf02cSchristos os_memcpy(cbc, iv, AES_BLOCK_SIZE);
748dbcf02cSchristos
758dbcf02cSchristos blocks = data_len / AES_BLOCK_SIZE;
768dbcf02cSchristos for (i = 0; i < blocks; i++) {
778dbcf02cSchristos os_memcpy(tmp, pos, AES_BLOCK_SIZE);
788dbcf02cSchristos aes_decrypt(ctx, pos, pos);
798dbcf02cSchristos for (j = 0; j < AES_BLOCK_SIZE; j++)
808dbcf02cSchristos pos[j] ^= cbc[j];
818dbcf02cSchristos os_memcpy(cbc, tmp, AES_BLOCK_SIZE);
828dbcf02cSchristos pos += AES_BLOCK_SIZE;
838dbcf02cSchristos }
848dbcf02cSchristos aes_decrypt_deinit(ctx);
858dbcf02cSchristos return 0;
868dbcf02cSchristos }
87