86 lines
2 KiB
C
86 lines
2 KiB
C
|
/*
|
||
|
|
* AES-128 CBC
|
||
|
|
*
|
||
|
|
* Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
|
||
|
|
*
|
||
|
|
* This program is free software; you can redistribute it and/or modify
|
||
|
|
* it under the terms of the GNU General Public License version 2 as
|
||
|
|
* published by the Free Software Foundation.
|
||
|
|
*
|
||
|
|
* Alternatively, this software may be distributed under the terms of BSD
|
||
|
|
* license.
|
||
|
|
*
|
||
|
|
* See README and COPYING for more details.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "includes.h"
|
||
|
|
|
||
|
|
#include "common.h"
|
||
|
|
#include "aes_i.h"
|
||
|
|
|
||
|
|
/**
|
||
|
|
* aes_128_cbc_encrypt - AES-128 CBC encryption
|
||
|
|
* @key: Encryption key
|
||
|
|
* @iv: Encryption IV for CBC mode (16 bytes)
|
||
|
|
* @data: Data to encrypt in-place
|
||
|
|
* @data_len: Length of data in bytes (must be divisible by 16)
|
||
|
|
* Returns: 0 on success, -1 on failure
|
||
|
|
*/
|
||
|
|
int aes_128_cbc_encrypt(const u8 *key, const u8 *iv, u8 *data, size_t data_len)
|
||
|
|
{
|
||
|
|
void *ctx;
|
||
|
|
u8 cbc[BLOCK_SIZE];
|
||
|
|
u8 *pos = data;
|
||
|
|
int i, j, blocks;
|
||
|
|
|
||
|
|
ctx = aes_encrypt_init(key, 16);
|
||
|
|
if (ctx == NULL)
|
||
|
|
return -1;
|
||
|
|
os_memcpy(cbc, iv, BLOCK_SIZE);
|
||
|
|
|
||
|
|
blocks = data_len / BLOCK_SIZE;
|
||
|
|
for (i = 0; i < blocks; i++) {
|
||
|
|
for (j = 0; j < BLOCK_SIZE; j++)
|
||
|
|
cbc[j] ^= pos[j];
|
||
|
|
aes_encrypt(ctx, cbc, cbc);
|
||
|
|
os_memcpy(pos, cbc, BLOCK_SIZE);
|
||
|
|
pos += BLOCK_SIZE;
|
||
|
|
}
|
||
|
|
aes_encrypt_deinit(ctx);
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/**
|
||
|
|
* aes_128_cbc_decrypt - AES-128 CBC decryption
|
||
|
|
* @key: Decryption key
|
||
|
|
* @iv: Decryption IV for CBC mode (16 bytes)
|
||
|
|
* @data: Data to decrypt in-place
|
||
|
|
* @data_len: Length of data in bytes (must be divisible by 16)
|
||
|
|
* Returns: 0 on success, -1 on failure
|
||
|
|
*/
|
||
|
|
int aes_128_cbc_decrypt(const u8 *key, const u8 *iv, u8 *data, size_t data_len)
|
||
|
|
{
|
||
|
|
void *ctx;
|
||
|
|
u8 cbc[BLOCK_SIZE], tmp[BLOCK_SIZE];
|
||
|
|
u8 *pos = data;
|
||
|
|
int i, j, blocks;
|
||
|
|
|
||
|
|
ctx = aes_decrypt_init(key, 16);
|
||
|
|
if (ctx == NULL)
|
||
|
|
return -1;
|
||
|
|
os_memcpy(cbc, iv, BLOCK_SIZE);
|
||
|
|
|
||
|
|
blocks = data_len / BLOCK_SIZE;
|
||
|
|
for (i = 0; i < blocks; i++) {
|
||
|
|
os_memcpy(tmp, pos, BLOCK_SIZE);
|
||
|
|
aes_decrypt(ctx, pos, pos);
|
||
|
|
for (j = 0; j < BLOCK_SIZE; j++)
|
||
|
|
pos[j] ^= cbc[j];
|
||
|
|
os_memcpy(cbc, tmp, BLOCK_SIZE);
|
||
|
|
pos += BLOCK_SIZE;
|
||
|
|
}
|
||
|
|
aes_decrypt_deinit(ctx);
|
||
|
|
return 0;
|
||
|
|
}
|