i_skey.c revision 61828
161828Smarkm/* crypto/idea/i_skey.c */
261828Smarkm/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
361828Smarkm * All rights reserved.
461828Smarkm *
561828Smarkm * This package is an SSL implementation written
661828Smarkm * by Eric Young (eay@cryptsoft.com).
761828Smarkm * The implementation was written so as to conform with Netscapes SSL.
861828Smarkm *
961828Smarkm * This library is free for commercial and non-commercial use as long as
1061828Smarkm * the following conditions are aheared to.  The following conditions
1161828Smarkm * apply to all code found in this distribution, be it the RC4, RSA,
1261828Smarkm * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
1361828Smarkm * included with this distribution is covered by the same copyright terms
1461828Smarkm * except that the holder is Tim Hudson (tjh@cryptsoft.com).
1561828Smarkm *
1661828Smarkm * Copyright remains Eric Young's, and as such any Copyright notices in
1761828Smarkm * the code are not to be removed.
1861828Smarkm * If this package is used in a product, Eric Young should be given attribution
1961828Smarkm * as the author of the parts of the library used.
2061828Smarkm * This can be in the form of a textual message at program startup or
2161828Smarkm * in documentation (online or textual) provided with the package.
2261828Smarkm *
2361828Smarkm * Redistribution and use in source and binary forms, with or without
2461828Smarkm * modification, are permitted provided that the following conditions
2561828Smarkm * are met:
2661828Smarkm * 1. Redistributions of source code must retain the copyright
2761828Smarkm *    notice, this list of conditions and the following disclaimer.
2861828Smarkm * 2. Redistributions in binary form must reproduce the above copyright
2961828Smarkm *    notice, this list of conditions and the following disclaimer in the
3061828Smarkm *    documentation and/or other materials provided with the distribution.
3161828Smarkm * 3. All advertising materials mentioning features or use of this software
3261828Smarkm *    must display the following acknowledgement:
3361828Smarkm *    "This product includes cryptographic software written by
3461828Smarkm *     Eric Young (eay@cryptsoft.com)"
3561828Smarkm *    The word 'cryptographic' can be left out if the rouines from the library
3661828Smarkm *    being used are not cryptographic related :-).
3761828Smarkm * 4. If you include any Windows specific code (or a derivative thereof) from
3861828Smarkm *    the apps directory (application code) you must include an acknowledgement:
3961828Smarkm *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
4061828Smarkm *
4161828Smarkm * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
4261828Smarkm * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
4361828Smarkm * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
4461828Smarkm * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
4561828Smarkm * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
4661828Smarkm * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
4761828Smarkm * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
4861828Smarkm * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
4961828Smarkm * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
5061828Smarkm * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
5161828Smarkm * SUCH DAMAGE.
5261828Smarkm *
5361828Smarkm * The licence and distribution terms for any publically available version or
5461828Smarkm * derivative of this code cannot be changed.  i.e. this code cannot simply be
5561828Smarkm * copied and put under another distribution licence
5661828Smarkm * [including the GNU Public Licence.]
5761828Smarkm * $FreeBSD: head/crypto/openssl/crypto/idea/i_skey.c 61828 2000-06-19 21:09:27Z markm $
5861828Smarkm */
5961828Smarkm
6061828Smarkm#include <openssl/idea.h>
6161828Smarkm#include "idea_lcl.h"
6261828Smarkm
6361828Smarkmstatic IDEA_INT inverse(unsigned int xin);
6461828Smarkmvoid idea_set_encrypt_key(unsigned char *key, IDEA_KEY_SCHEDULE *ks)
6561828Smarkm	{
6661828Smarkm	int i;
6761828Smarkm	register IDEA_INT *kt,*kf,r0,r1,r2;
6861828Smarkm
6961828Smarkm	kt= &(ks->data[0][0]);
7061828Smarkm	n2s(key,kt[0]); n2s(key,kt[1]); n2s(key,kt[2]); n2s(key,kt[3]);
7161828Smarkm	n2s(key,kt[4]); n2s(key,kt[5]); n2s(key,kt[6]); n2s(key,kt[7]);
7261828Smarkm
7361828Smarkm	kf=kt;
7461828Smarkm	kt+=8;
7561828Smarkm	for (i=0; i<6; i++)
7661828Smarkm		{
7761828Smarkm		r2= kf[1];
7861828Smarkm		r1= kf[2];
7961828Smarkm		*(kt++)= ((r2<<9) | (r1>>7))&0xffff;
8061828Smarkm		r0= kf[3];
8161828Smarkm		*(kt++)= ((r1<<9) | (r0>>7))&0xffff;
8261828Smarkm		r1= kf[4];
8361828Smarkm		*(kt++)= ((r0<<9) | (r1>>7))&0xffff;
8461828Smarkm		r0= kf[5];
8561828Smarkm		*(kt++)= ((r1<<9) | (r0>>7))&0xffff;
8661828Smarkm		r1= kf[6];
8761828Smarkm		*(kt++)= ((r0<<9) | (r1>>7))&0xffff;
8861828Smarkm		r0= kf[7];
8961828Smarkm		*(kt++)= ((r1<<9) | (r0>>7))&0xffff;
9061828Smarkm		r1= kf[0];
9161828Smarkm		if (i >= 5) break;
9261828Smarkm		*(kt++)= ((r0<<9) | (r1>>7))&0xffff;
9361828Smarkm		*(kt++)= ((r1<<9) | (r2>>7))&0xffff;
9461828Smarkm		kf+=8;
9561828Smarkm		}
9661828Smarkm	}
9761828Smarkm
9861828Smarkmvoid idea_set_decrypt_key(IDEA_KEY_SCHEDULE *ek, IDEA_KEY_SCHEDULE *dk)
9961828Smarkm	{
10061828Smarkm	int r;
10161828Smarkm	register IDEA_INT *fp,*tp,t;
10261828Smarkm
10361828Smarkm	tp= &(dk->data[0][0]);
10461828Smarkm	fp= &(ek->data[8][0]);
10561828Smarkm	for (r=0; r<9; r++)
10661828Smarkm		{
10761828Smarkm		*(tp++)=inverse(fp[0]);
10861828Smarkm		*(tp++)=((int)(0x10000L-fp[2])&0xffff);
10961828Smarkm		*(tp++)=((int)(0x10000L-fp[1])&0xffff);
11061828Smarkm		*(tp++)=inverse(fp[3]);
11161828Smarkm		if (r == 8) break;
11261828Smarkm		fp-=6;
11361828Smarkm		*(tp++)=fp[4];
11461828Smarkm		*(tp++)=fp[5];
11561828Smarkm		}
11661828Smarkm
11761828Smarkm	tp= &(dk->data[0][0]);
11861828Smarkm	t=tp[1];
11961828Smarkm	tp[1]=tp[2];
12061828Smarkm	tp[2]=t;
12161828Smarkm
12261828Smarkm	t=tp[49];
12361828Smarkm	tp[49]=tp[50];
12461828Smarkm	tp[50]=t;
12561828Smarkm	}
12661828Smarkm
12761828Smarkm/* taken directly from the 'paper' I'll have a look at it later */
12861828Smarkmstatic IDEA_INT inverse(unsigned int xin)
12961828Smarkm	{
13061828Smarkm	long n1,n2,q,r,b1,b2,t;
13161828Smarkm
13261828Smarkm	if (xin == 0)
13361828Smarkm		b2=0;
13461828Smarkm	else
13561828Smarkm		{
13661828Smarkm		n1=0x10001;
13761828Smarkm		n2=xin;
13861828Smarkm		b2=1;
13961828Smarkm		b1=0;
14061828Smarkm
14161828Smarkm		do	{
14261828Smarkm			r=(n1%n2);
14361828Smarkm			q=(n1-r)/n2;
14461828Smarkm			if (r == 0)
14561828Smarkm				{ if (b2 < 0) b2=0x10001+b2; }
14661828Smarkm			else
14761828Smarkm				{
14861828Smarkm				n1=n2;
14961828Smarkm				n2=r;
15061828Smarkm				t=b2;
15161828Smarkm				b2=b1-q*b2;
15261828Smarkm				b1=t;
15361828Smarkm				}
15461828Smarkm			} while (r != 0);
15561828Smarkm		}
15661828Smarkm	return((IDEA_INT)b2);
15761828Smarkm	}
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