1/*
2 * AES-128 CBC
3 *
4 * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
5 *
6 * This software may be distributed under the terms of the BSD license.
7 * See README for more details.
8 */
9
10#include "includes.h"
11
12#include "common.h"
13#include "aes.h"
14#include "aes_wrap.h"
15
16/**
17 * aes_128_cbc_encrypt - AES-128 CBC encryption
18 * @key: Encryption key
19 * @iv: Encryption IV for CBC mode (16 bytes)
20 * @data: Data to encrypt in-place
21 * @data_len: Length of data in bytes (must be divisible by 16)
22 * Returns: 0 on success, -1 on failure
23 */
24int aes_128_cbc_encrypt(const u8 *key, const u8 *iv, u8 *data, size_t data_len)
25{
26	void *ctx;
27	u8 cbc[AES_BLOCK_SIZE];
28	u8 *pos = data;
29	int i, j, blocks;
30
31	if (TEST_FAIL())
32		return -1;
33
34	ctx = aes_encrypt_init(key, 16);
35	if (ctx == NULL)
36		return -1;
37	os_memcpy(cbc, iv, AES_BLOCK_SIZE);
38
39	blocks = data_len / AES_BLOCK_SIZE;
40	for (i = 0; i < blocks; i++) {
41		for (j = 0; j < AES_BLOCK_SIZE; j++)
42			cbc[j] ^= pos[j];
43		aes_encrypt(ctx, cbc, cbc);
44		os_memcpy(pos, cbc, AES_BLOCK_SIZE);
45		pos += AES_BLOCK_SIZE;
46	}
47	aes_encrypt_deinit(ctx);
48	return 0;
49}
50
51
52/**
53 * aes_128_cbc_decrypt - AES-128 CBC decryption
54 * @key: Decryption key
55 * @iv: Decryption IV for CBC mode (16 bytes)
56 * @data: Data to decrypt in-place
57 * @data_len: Length of data in bytes (must be divisible by 16)
58 * Returns: 0 on success, -1 on failure
59 */
60int aes_128_cbc_decrypt(const u8 *key, const u8 *iv, u8 *data, size_t data_len)
61{
62	void *ctx;
63	u8 cbc[AES_BLOCK_SIZE], tmp[AES_BLOCK_SIZE];
64	u8 *pos = data;
65	int i, j, blocks;
66
67	if (TEST_FAIL())
68		return -1;
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}
87