NetBSD-5.0.2/crypto/dist/openssl/crypto/aes/aes_cfb.c
/* crypto/aes/aes_cfb.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"
#include "e_os.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 cfb 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_cfb128_encrypt(const unsigned char *in, unsigned char *out,
unsigned long length, const AES_KEY *key,
unsigned char *ivec, int *num, const int enc) {
unsigned int n;
unsigned long l = 0;
assert(in && out && key && ivec && num);
n = *num;
#if !defined(OPENSSL_SMALL_FOOTPRINT)
if (AES_BLOCK_SIZE%sizeof(size_t) == 0) { /* always true actually */
if (enc) {
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)
goto enc_unaligned;
#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);
}
} else {
if (n) {
while (length) {
unsigned char c;
*(out++) = ivec[n] ^ (c = *(in++)); ivec[n] = c;
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)
goto dec_unaligned;
#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 t = *(size_t*)(in+l+i);
*(size_t*)(out+l+i) = *(size_t*)(ivec+i) ^ t;
*(size_t*)(ivec+i) = t;
}
l += AES_BLOCK_SIZE;
}
if (l < length) {
AES_encrypt(ivec, ivec, key);
do { unsigned char c;
out[l] = ivec[n] ^ (c = in[l]); ivec[n] = c;
l++; n++;
} while (l < length);
}
}
*num = n;
return;
}
#endif
/* this code would be commonly eliminated by x86* compiler */
if (enc) {
#if defined(STRICT_ALIGNMENT) && !defined(OPENSSL_SMALL_FOOTPRINT)
enc_unaligned:
#endif
while (l<length) {
if (n == 0) {
AES_encrypt(ivec, ivec, key);
}
out[l] = ivec[n] ^= in[l];
l++;
n = (n+1) % AES_BLOCK_SIZE;
}
} else {
#if defined(STRICT_ALIGNMENT) && !defined(OPENSSL_SMALL_FOOTPRINT)
dec_unaligned:
#endif
while (l<length) {
unsigned char c;
if (n == 0) {
AES_encrypt(ivec, ivec, key);
}
out[l] = ivec[n] ^ (c = in[l]); ivec[n] = c;
l++;
n = (n+1) % AES_BLOCK_SIZE;
}
}
*num=n;
}
/* This expects a single block of size nbits for both in and out. Note that
it corrupts any extra bits in the last byte of out */
void AES_cfbr_encrypt_block(const unsigned char *in,unsigned char *out,
const int nbits,const AES_KEY *key,
unsigned char *ivec,const int enc)
{
int n,rem,num;
unsigned char ovec[AES_BLOCK_SIZE*2 + 1]; /* +1 because we dererefence (but don't use) one byte off the end */
if (nbits<=0 || nbits>128) return;
/* fill in the first half of the new IV with the current IV */
memcpy(ovec,ivec,AES_BLOCK_SIZE);
/* construct the new IV */
AES_encrypt(ivec,ivec,key);
num = (nbits+7)/8;
if (enc) /* encrypt the input */
for(n=0 ; n < num ; ++n)
out[n] = (ovec[AES_BLOCK_SIZE+n] = in[n] ^ ivec[n]);
else /* decrypt the input */
for(n=0 ; n < num ; ++n)
out[n] = (ovec[AES_BLOCK_SIZE+n] = in[n]) ^ ivec[n];
/* shift ovec left... */
rem = nbits%8;
num = nbits/8;
if(rem==0)
memcpy(ivec,ovec+num,AES_BLOCK_SIZE);
else
for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
ivec[n] = ovec[n+num]<<rem | ovec[n+num+1]>>(8-rem);
/* it is not necessary to cleanse ovec, since the IV is not secret */
}
/* N.B. This expects the input to be packed, MS bit first */
void AES_cfb1_encrypt(const unsigned char *in, unsigned char *out,
const unsigned long length, const AES_KEY *key,
unsigned char *ivec, int *num, const int enc)
{
unsigned int n;
unsigned char c[1],d[1];
assert(in && out && key && ivec && num);
assert(*num == 0);
memset(out,0,(length+7)/8);
for(n=0 ; n < length ; ++n)
{
c[0]=(in[n/8]&(1 << (7-n%8))) ? 0x80 : 0;
AES_cfbr_encrypt_block(c,d,1,key,ivec,enc);
out[n/8]=(out[n/8]&~(1 << (7-n%8)))|((d[0]&0x80) >> (n%8));
}
}
void AES_cfb8_encrypt(const unsigned char *in, unsigned char *out,
const unsigned long length, const AES_KEY *key,
unsigned char *ivec, int *num, const int enc)
{
unsigned int n;
assert(in && out && key && ivec && num);
assert(*num == 0);
for(n=0 ; n < length ; ++n)
AES_cfbr_encrypt_block(&in[n],&out[n],8,key,ivec,enc);
}