sl@0: /* crypto/rc2/rc2ofb64.c */
sl@0: /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
sl@0:  * All rights reserved.
sl@0:  *
sl@0:  * This package is an SSL implementation written
sl@0:  * by Eric Young (eay@cryptsoft.com).
sl@0:  * The implementation was written so as to conform with Netscapes SSL.
sl@0:  * 
sl@0:  * This library is free for commercial and non-commercial use as long as
sl@0:  * the following conditions are aheared to.  The following conditions
sl@0:  * apply to all code found in this distribution, be it the RC4, RSA,
sl@0:  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
sl@0:  * included with this distribution is covered by the same copyright terms
sl@0:  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
sl@0:  * 
sl@0:  * Copyright remains Eric Young's, and as such any Copyright notices in
sl@0:  * the code are not to be removed.
sl@0:  * If this package is used in a product, Eric Young should be given attribution
sl@0:  * as the author of the parts of the library used.
sl@0:  * This can be in the form of a textual message at program startup or
sl@0:  * in documentation (online or textual) provided with the package.
sl@0:  * 
sl@0:  * Redistribution and use in source and binary forms, with or without
sl@0:  * modification, are permitted provided that the following conditions
sl@0:  * are met:
sl@0:  * 1. Redistributions of source code must retain the copyright
sl@0:  *    notice, this list of conditions and the following disclaimer.
sl@0:  * 2. Redistributions in binary form must reproduce the above copyright
sl@0:  *    notice, this list of conditions and the following disclaimer in the
sl@0:  *    documentation and/or other materials provided with the distribution.
sl@0:  * 3. All advertising materials mentioning features or use of this software
sl@0:  *    must display the following acknowledgement:
sl@0:  *    "This product includes cryptographic software written by
sl@0:  *     Eric Young (eay@cryptsoft.com)"
sl@0:  *    The word 'cryptographic' can be left out if the rouines from the library
sl@0:  *    being used are not cryptographic related :-).
sl@0:  * 4. If you include any Windows specific code (or a derivative thereof) from 
sl@0:  *    the apps directory (application code) you must include an acknowledgement:
sl@0:  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
sl@0:  * 
sl@0:  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
sl@0:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
sl@0:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
sl@0:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
sl@0:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
sl@0:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
sl@0:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
sl@0:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
sl@0:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
sl@0:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
sl@0:  * SUCH DAMAGE.
sl@0:  * 
sl@0:  * The licence and distribution terms for any publically available version or
sl@0:  * derivative of this code cannot be changed.  i.e. this code cannot simply be
sl@0:  * copied and put under another distribution licence
sl@0:  * [including the GNU Public Licence.]
sl@0:  */
sl@0: 
sl@0: #include <openssl/rc2.h>
sl@0: #include "rc2_locl.h"
sl@0: 
sl@0: /* The input and output encrypted as though 64bit ofb mode is being
sl@0:  * used.  The extra state information to record how much of the
sl@0:  * 64bit block we have used is contained in *num;
sl@0:  */
sl@0: EXPORT_C void RC2_ofb64_encrypt(const unsigned char *in, unsigned char *out,
sl@0: 		       long length, RC2_KEY *schedule, unsigned char *ivec,
sl@0: 		       int *num)
sl@0: 	{
sl@0: 	register unsigned long v0,v1,t;
sl@0: 	register int n= *num;
sl@0: 	register long l=length;
sl@0: 	unsigned char d[8];
sl@0: 	register char *dp;
sl@0: 	unsigned long ti[2];
sl@0: 	unsigned char *iv;
sl@0: 	int save=0;
sl@0: 
sl@0: 	iv=(unsigned char *)ivec;
sl@0: 	c2l(iv,v0);
sl@0: 	c2l(iv,v1);
sl@0: 	ti[0]=v0;
sl@0: 	ti[1]=v1;
sl@0: 	dp=(char *)d;
sl@0: 	l2c(v0,dp);
sl@0: 	l2c(v1,dp);
sl@0: 	while (l--)
sl@0: 		{
sl@0: 		if (n == 0)
sl@0: 			{
sl@0: 			RC2_encrypt((unsigned long *)ti,schedule);
sl@0: 			dp=(char *)d;
sl@0: 			t=ti[0]; l2c(t,dp);
sl@0: 			t=ti[1]; l2c(t,dp);
sl@0: 			save++;
sl@0: 			}
sl@0: 		*(out++)= *(in++)^d[n];
sl@0: 		n=(n+1)&0x07;
sl@0: 		}
sl@0: 	if (save)
sl@0: 		{
sl@0: 		v0=ti[0];
sl@0: 		v1=ti[1];
sl@0: 		iv=(unsigned char *)ivec;
sl@0: 		l2c(v0,iv);
sl@0: 		l2c(v1,iv);
sl@0: 		}
sl@0: 	t=v0=v1=ti[0]=ti[1]=0;
sl@0: 	*num=n;
sl@0: 	}
sl@0: