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 */
aes_128_cbc_encrypt(const u8 * key,const u8 * iv,u8 * data,size_t data_len)24 int 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 */
aes_128_cbc_decrypt(const u8 * key,const u8 * iv,u8 * data,size_t data_len)60 int 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