fragattacks/src/crypto/aes-cbc.c
Jouni Malinen 8e2c104fa1 Resolve some sparse warnings
Mainly, this is including header files to get definitions for functions
which is good to verify that the parameters match. None of these are
issues that would have shown as incorrect behavior of the program.
2009-11-25 00:57:00 +02:00

87 lines
2.1 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.h"
#include "aes_wrap.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[AES_BLOCK_SIZE];
u8 *pos = data;
int i, j, blocks;
ctx = aes_encrypt_init(key, 16);
if (ctx == NULL)
return -1;
os_memcpy(cbc, iv, AES_BLOCK_SIZE);
blocks = data_len / AES_BLOCK_SIZE;
for (i = 0; i < blocks; i++) {
for (j = 0; j < AES_BLOCK_SIZE; j++)
cbc[j] ^= pos[j];
aes_encrypt(ctx, cbc, cbc);
os_memcpy(pos, cbc, AES_BLOCK_SIZE);
pos += AES_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[AES_BLOCK_SIZE], tmp[AES_BLOCK_SIZE];
u8 *pos = data;
int i, j, blocks;
ctx = aes_decrypt_init(key, 16);
if (ctx == NULL)
return -1;
os_memcpy(cbc, iv, AES_BLOCK_SIZE);
blocks = data_len / AES_BLOCK_SIZE;
for (i = 0; i < blocks; i++) {
os_memcpy(tmp, pos, AES_BLOCK_SIZE);
aes_decrypt(ctx, pos, pos);
for (j = 0; j < AES_BLOCK_SIZE; j++)
pos[j] ^= cbc[j];
os_memcpy(cbc, tmp, AES_BLOCK_SIZE);
pos += AES_BLOCK_SIZE;
}
aes_decrypt_deinit(ctx);
return 0;
}