text: /* crypto/rc2/rc2_cbc.c */
  /* 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.]
   */
  
  #include <openssl/rc2.h>
  #include "rc2_locl.h"
  
  void RC2_cbc_encrypt(const unsigned char *in, unsigned char *out, long length,
  	     RC2_KEY *ks, unsigned char *iv, int encrypt)
  	{
  	register unsigned long tin0,tin1;
  	register unsigned long tout0,tout1,xor0,xor1;
  	register long l=length;
  	unsigned long tin[2];
  
  	if (encrypt)
  		{
  		c2l(iv,tout0);
  		c2l(iv,tout1);
  		iv-=8;
  		for (l-=8; l>=0; l-=8)
  			{
  			c2l(in,tin0);
  			c2l(in,tin1);
  			tin0^=tout0;
  			tin1^=tout1;
  			tin[0]=tin0;
  			tin[1]=tin1;
  			RC2_encrypt(tin,ks);
  			tout0=tin[0]; l2c(tout0,out);
  			tout1=tin[1]; l2c(tout1,out);
  			}
  		if (l != -8)
  			{
  			c2ln(in,tin0,tin1,l+8);
  			tin0^=tout0;
  			tin1^=tout1;
  			tin[0]=tin0;
  			tin[1]=tin1;
  			RC2_encrypt(tin,ks);
  			tout0=tin[0]; l2c(tout0,out);
  			tout1=tin[1]; l2c(tout1,out);
  			}
  		l2c(tout0,iv);
  		l2c(tout1,iv);
  		}
  	else
  		{
  		c2l(iv,xor0);
  		c2l(iv,xor1);
  		iv-=8;
  		for (l-=8; l>=0; l-=8)
  			{
  			c2l(in,tin0); tin[0]=tin0;
  			c2l(in,tin1); tin[1]=tin1;
  			RC2_decrypt(tin,ks);
  			tout0=tin[0]^xor0;
  			tout1=tin[1]^xor1;
  			l2c(tout0,out);
  			l2c(tout1,out);
  			xor0=tin0;
  			xor1=tin1;
  			}
  		if (l != -8)
  			{
  			c2l(in,tin0); tin[0]=tin0;
  			c2l(in,tin1); tin[1]=tin1;
  			RC2_decrypt(tin,ks);
  			tout0=tin[0]^xor0;
  			tout1=tin[1]^xor1;
  			l2cn(tout0,tout1,out,l+8);
  			xor0=tin0;
  			xor1=tin1;
  			}
  		l2c(xor0,iv);
  		l2c(xor1,iv);
  		}
  	tin0=tin1=tout0=tout1=xor0=xor1=0;
  	tin[0]=tin[1]=0;
  	}
  
  void RC2_encrypt(unsigned long *d, RC2_KEY *key)
  	{
  	int i,n;
  	register RC2_INT *p0,*p1;
  	register RC2_INT x0,x1,x2,x3,t;
  	unsigned long l;
  
  	l=d[0];
  	x0=(RC2_INT)l&0xffff;
  	x1=(RC2_INT)(l>>16L);
  	l=d[1];
  	x2=(RC2_INT)l&0xffff;
  	x3=(RC2_INT)(l>>16L);
  
  	n=3;
  	i=5;
  
  	p0=p1= &(key->data[0]);
  	for (;;)
  		{
  		t=(x0+(x1& ~x3)+(x2&x3)+ *(p0++))&0xffff;
  		x0=(t<<1)|(t>>15);
  		t=(x1+(x2& ~x0)+(x3&x0)+ *(p0++))&0xffff;
  		x1=(t<<2)|(t>>14);
  		t=(x2+(x3& ~x1)+(x0&x1)+ *(p0++))&0xffff;
  		x2=(t<<3)|(t>>13);
  		t=(x3+(x0& ~x2)+(x1&x2)+ *(p0++))&0xffff;
  		x3=(t<<5)|(t>>11);
  
  		if (--i == 0)
  			{
  			if (--n == 0) break;
  			i=(n == 2)?6:5;
  
  			x0+=p1[x3&0x3f];
  			x1+=p1[x0&0x3f];
  			x2+=p1[x1&0x3f];
  			x3+=p1[x2&0x3f];
  			}
  		}
  
  	d[0]=(unsigned long)(x0&0xffff)|((unsigned long)(x1&0xffff)<<16L);
  	d[1]=(unsigned long)(x2&0xffff)|((unsigned long)(x3&0xffff)<<16L);
  	}
  
  void RC2_decrypt(unsigned long *d, RC2_KEY *key)
  	{
  	int i,n;
  	register RC2_INT *p0,*p1;
  	register RC2_INT x0,x1,x2,x3,t;
  	unsigned long l;
  
  	l=d[0];
  	x0=(RC2_INT)l&0xffff;
  	x1=(RC2_INT)(l>>16L);
  	l=d[1];
  	x2=(RC2_INT)l&0xffff;
  	x3=(RC2_INT)(l>>16L);
  
  	n=3;
  	i=5;
  
  	p0= &(key->data[63]);
  	p1= &(key->data[0]);
  	for (;;)
  		{
  		t=((x3<<11)|(x3>>5))&0xffff;
  		x3=(t-(x0& ~x2)-(x1&x2)- *(p0--))&0xffff;
  		t=((x2<<13)|(x2>>3))&0xffff;
  		x2=(t-(x3& ~x1)-(x0&x1)- *(p0--))&0xffff;
  		t=((x1<<14)|(x1>>2))&0xffff;
  		x1=(t-(x2& ~x0)-(x3&x0)- *(p0--))&0xffff;
  		t=((x0<<15)|(x0>>1))&0xffff;
  		x0=(t-(x1& ~x3)-(x2&x3)- *(p0--))&0xffff;
  
  		if (--i == 0)
  			{
  			if (--n == 0) break;
  			i=(n == 2)?6:5;
  
  			x3=(x3-p1[x2&0x3f])&0xffff;
  			x2=(x2-p1[x1&0x3f])&0xffff;
  			x1=(x1-p1[x0&0x3f])&0xffff;
  			x0=(x0-p1[x3&0x3f])&0xffff;
  			}
  		}
  
  	d[0]=(unsigned long)(x0&0xffff)|((unsigned long)(x1&0xffff)<<16L);
  	d[1]=(unsigned long)(x2&0xffff)|((unsigned long)(x3&0xffff)<<16L);
  	}
  
  