251 lines
9.3 KiB
C
251 lines
9.3 KiB
C
/* crypto/aes/aes_cfb.c -*- mode:C; c-file-style: "eay" -*- */
|
|
/* ====================================================================
|
|
* Copyright (c) 1998-2002 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.
|
|
* ====================================================================
|
|
*
|
|
*/
|
|
/* 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
|
|
# define NDEBUG
|
|
# endif
|
|
#endif
|
|
#include <assert.h>
|
|
|
|
#include <openssl/aes.h>
|
|
#include "aes_locl.h"
|
|
#include "e_os.h"
|
|
|
|
/* 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,
|
|
const unsigned long length, const AES_KEY *key,
|
|
unsigned char *ivec, int *num, const int enc) {
|
|
|
|
unsigned int n;
|
|
unsigned long l = length;
|
|
unsigned char c;
|
|
|
|
assert(in && out && key && ivec && num);
|
|
|
|
n = *num;
|
|
|
|
if (enc) {
|
|
while (l--) {
|
|
if (n == 0) {
|
|
AES_encrypt(ivec, ivec, key);
|
|
}
|
|
ivec[n] = *(out++) = *(in++) ^ ivec[n];
|
|
n = (n+1) % AES_BLOCK_SIZE;
|
|
}
|
|
} else {
|
|
while (l--) {
|
|
if (n == 0) {
|
|
AES_encrypt(ivec, ivec, key);
|
|
}
|
|
c = *(in);
|
|
*(out++) = *(in++) ^ ivec[n];
|
|
ivec[n] = c;
|
|
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 */
|
|
/* Untested, once it is working, it will be optimised */
|
|
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;
|
|
unsigned char ovec[AES_BLOCK_SIZE*2];
|
|
|
|
assert(in && out && key && ivec);
|
|
if(enc)
|
|
{
|
|
/* construct the new IV */
|
|
AES_encrypt(ivec,ovec,key);
|
|
/* encrypt the input */
|
|
for(n=0 ; n < (nbits+7)/8 ; ++n)
|
|
out[n]=in[n]^ovec[n];
|
|
/* fill in the first half of the new IV with the current IV */
|
|
memcpy(ovec,ivec,AES_BLOCK_SIZE);
|
|
/* and put the ciphertext in the second half */
|
|
memcpy(ovec+AES_BLOCK_SIZE,out,(nbits+7)/8);
|
|
/* shift ovec left most of the bits... */
|
|
memmove(ovec,ovec+nbits/8,AES_BLOCK_SIZE+(nbits%8 ? 1 : 0));
|
|
/* now the remaining bits */
|
|
if(nbits%8 != 0)
|
|
for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
|
|
{
|
|
ovec[n]<<=nbits%8;
|
|
ovec[n]|=ovec[n+1]>>(8-nbits%8);
|
|
}
|
|
/* finally, move it back into place */
|
|
memcpy(ivec,ovec,AES_BLOCK_SIZE);
|
|
}
|
|
else
|
|
{
|
|
/* construct the new IV in the first half of ovec */
|
|
AES_encrypt(ivec,ovec,key);
|
|
/* decrypt the input */
|
|
for(n=0 ; n < (nbits+7)/8 ; ++n)
|
|
out[n]=in[n]^ovec[n];
|
|
/* fill in the first half of the new IV with the current IV */
|
|
memcpy(ovec,ivec,AES_BLOCK_SIZE);
|
|
/* append the ciphertext */
|
|
memcpy(ovec+AES_BLOCK_SIZE,in,(nbits+7)/8);
|
|
/* shift ovec left most of the bits... */
|
|
memmove(ovec,ovec+nbits/8,AES_BLOCK_SIZE+(nbits%8 ? 1 : 0));
|
|
/* now the remaining bits */
|
|
if(nbits%8 != 0)
|
|
for(n=0 ; n < AES_BLOCK_SIZE ; ++n)
|
|
{
|
|
ovec[n]<<=nbits%8;
|
|
ovec[n]|=ovec[n+1]>>(8-nbits%8);
|
|
}
|
|
/* finally, move it back into place */
|
|
memcpy(ivec,ovec,AES_BLOCK_SIZE);
|
|
}
|
|
/* 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);
|
|
}
|
|
|