/* 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 */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];    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);    }