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Reimplement AES_ofb128_encrypt.

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This commit is contained in:
Andy Polyakov 2006-06-05 10:40:54 +00:00
parent bcfd3d68f5
commit 41fc5f2dbe
1 changed files with 49 additions and 61 deletions
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110
crypto/aes/aes_ofb.c
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@ -1,6 +1,6 @@
/* crypto/aes/aes_ofb.c -*- mode:C; c-file-style: "eay" -*- */
/* ====================================================================
* Copyright (c) 1998-2002 The OpenSSL Project. All rights reserved.
* 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
@ -48,62 +48,6 @@
* ====================================================================
*
*/
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* 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 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 acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS 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 AUTHOR OR 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.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#ifndef AES_DEBUG
# ifndef NDEBUG
@ -115,26 +59,70 @@
#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,
const unsigned long length, const AES_KEY *key,
unsigned long length, const AES_KEY *key,
unsigned char *ivec, int *num) {
unsigned int n;
unsigned long l=length;
unsigned long l=0;
assert(in && out && key && ivec && num);
n = *num;
while (l--) {
#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++) = *(in++) ^ ivec[n];
out[l] = ivec[n] ^ in[l];
l++;
n = (n+1) % AES_BLOCK_SIZE;
}