130 lines
4.2 KiB
C
130 lines
4.2 KiB
C
/* crypto/aes/aes_ofb.c -*- mode:C; c-file-style: "eay" -*- */
|
|
/* ====================================================================
|
|
* Copyright (c) 2002-2006 The OpenSSL Project. All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
*
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
*
|
|
* 3. All advertising materials mentioning features or use of this
|
|
* software must display the following acknowledgment:
|
|
* "This product includes software developed by the OpenSSL Project
|
|
* for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
|
|
*
|
|
* 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
|
|
* endorse or promote products derived from this software without
|
|
* prior written permission. For written permission, please contact
|
|
* openssl-core@openssl.org.
|
|
*
|
|
* 5. Products derived from this software may not be called "OpenSSL"
|
|
* nor may "OpenSSL" appear in their names without prior written
|
|
* permission of the OpenSSL Project.
|
|
*
|
|
* 6. Redistributions of any form whatsoever must retain the following
|
|
* acknowledgment:
|
|
* "This product includes software developed by the OpenSSL Project
|
|
* for use in the OpenSSL Toolkit (http://www.openssl.org/)"
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
|
|
* EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
|
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
|
|
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
|
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
|
|
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
|
|
* OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
* ====================================================================
|
|
*
|
|
*/
|
|
|
|
#ifndef AES_DEBUG
|
|
# ifndef NDEBUG
|
|
# define NDEBUG
|
|
# endif
|
|
#endif
|
|
#include <assert.h>
|
|
|
|
#include <openssl/aes.h>
|
|
#include "aes_locl.h"
|
|
|
|
#define STRICT_ALIGNMENT
|
|
#if defined(__i386) || defined(__i386__) || \
|
|
defined(__x86_64) || defined(__x86_64__) || \
|
|
defined(_M_IX86) || defined(_M_AMD64) || defined(_M_X64)
|
|
# undef STRICT_ALIGNMENT
|
|
#endif
|
|
|
|
/* The input and output encrypted as though 128bit ofb mode is being
|
|
* used. The extra state information to record how much of the
|
|
* 128bit block we have used is contained in *num;
|
|
*/
|
|
void AES_ofb128_encrypt(const unsigned char *in, unsigned char *out,
|
|
size_t length, const AES_KEY *key,
|
|
unsigned char *ivec, int *num) {
|
|
|
|
unsigned int n;
|
|
size_t l=0;
|
|
|
|
assert(in && out && key && ivec && num);
|
|
|
|
n = *num;
|
|
|
|
#if !defined(OPENSSL_SMALL_FOOTPRINT)
|
|
if (AES_BLOCK_SIZE%sizeof(size_t) == 0) do { /* always true actually */
|
|
if (n) {
|
|
while (length) {
|
|
*(out++) = ivec[n] ^ *(in++);
|
|
length--;
|
|
if(!(n = (n + 1) % AES_BLOCK_SIZE))
|
|
break;
|
|
}
|
|
}
|
|
#if defined(STRICT_ALIGNMENT)
|
|
if (((size_t)in|(size_t)out|(size_t)ivec)%sizeof(size_t) != 0)
|
|
break;
|
|
#endif
|
|
while ((l + AES_BLOCK_SIZE) <= length) {
|
|
unsigned int i;
|
|
AES_encrypt(ivec, ivec, key);
|
|
for (i=0;i<AES_BLOCK_SIZE;i+=sizeof(size_t)) {
|
|
*(size_t*)(out+l+i) =
|
|
*(size_t*)(ivec+i) ^ *(size_t*)(in+l+i);
|
|
}
|
|
l += AES_BLOCK_SIZE;
|
|
}
|
|
|
|
if (l < length) {
|
|
AES_encrypt(ivec, ivec, key);
|
|
do { out[l] = ivec[n] ^ in[l];
|
|
l++; n++;
|
|
} while (l < length);
|
|
}
|
|
*num = n;
|
|
return;
|
|
} while(0);
|
|
#endif
|
|
|
|
/* this code would be commonly eliminated by x86* compiler */
|
|
while (l<length) {
|
|
if (n == 0) {
|
|
AES_encrypt(ivec, ivec, key);
|
|
}
|
|
out[l] = ivec[n] ^ in[l];
|
|
l++;
|
|
n = (n+1) % AES_BLOCK_SIZE;
|
|
}
|
|
|
|
*num=n;
|
|
}
|