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/*
* AES-128 CTR
*
* 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_ctr_encrypt - AES-128 CTR mode encryption
* @key: Key for encryption (16 bytes)
* @nonce: Nonce for counter mode (16 bytes)
* @data: Data to encrypt in-place
* @data_len: Length of data in bytes
* Returns: 0 on success, -1 on failure
*/
int aes_128_ctr_encrypt(const u8 *key, const u8 *nonce,
u8 *data, size_t data_len)
{
void *ctx;
size_t j, len, left = data_len;
int i;
u8 *pos = data;
u8 counter[AES_BLOCK_SIZE], buf[AES_BLOCK_SIZE];
ctx = aes_encrypt_init(key, 16);
if (ctx == NULL)
return -1;
os_memcpy(counter, nonce, AES_BLOCK_SIZE);
while (left > 0) {
aes_encrypt(ctx, counter, buf);
len = (left < AES_BLOCK_SIZE) ? left : AES_BLOCK_SIZE;
for (j = 0; j < len; j++)
pos[j] ^= buf[j];
pos += len;
left -= len;
for (i = AES_BLOCK_SIZE - 1; i >= 0; i--) {
counter[i]++;
if (counter[i])
break;
}
}
aes_encrypt_deinit(ctx);
return 0;
}
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