/* crypto/des/set_key.c */
/* Copyright (C) 1995-1997 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.]
 */

/* set_key.c v 1.4 eay 24/9/91
 * 1.4 Speed up by 400% :-)
 * 1.3 added register declarations.
 * 1.2 unrolled make_key_sched a bit more
 * 1.1 added norm_expand_bits
 * 1.0 First working version
 */
#include "des/des_locl.h"
#include "des/podd.h"
#include "des/sk.h"

#ifndef NOPROTO
static int check_parity(des_cblock (*key));
#else
static int check_parity();
#endif

int des_check_key = 0;

void des_set_odd_parity(key)
des_cblock(*key);
{
	int i;

	for (i = 0; i < (int)DES_KEY_SZ; i++)
		(*key)[i] = odd_parity[(*key)[i]];
}

static int check_parity(key)
des_cblock(*key);
{
	int i;

	for (i = 0; i < (int)DES_KEY_SZ; i++) {
		if ((*key)[i] != odd_parity[(*key)[i]])
			return 0;
	}
	return 1;
}

/* Weak and semi week keys as take from
 * %A D.W. Davies
 * %A W.L. Price
 * %T Security for Computer Networks
 * %I John Wiley & Sons
 * %D 1984
 * Many thanks to smb@ulysses.att.com (Steven Bellovin) for the reference
 * (and actual cblock values).
 */
#define NUM_WEAK_KEY    16
static des_cblock weak_keys[NUM_WEAK_KEY] = {
	/* weak keys */
	{ 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01 },
	{ 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE, 0xFE },
	{ 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1F },
	{ 0xE0, 0xE0, 0xE0, 0xE0, 0xE0, 0xE0, 0xE0, 0xE0 },
	/* semi-weak keys */
	{ 0x01, 0xFE, 0x01, 0xFE, 0x01, 0xFE, 0x01, 0xFE },
	{ 0xFE, 0x01, 0xFE, 0x01, 0xFE, 0x01, 0xFE, 0x01 },
	{ 0x1F, 0xE0, 0x1F, 0xE0, 0x0E, 0xF1, 0x0E, 0xF1 },
	{ 0xE0, 0x1F, 0xE0, 0x1F, 0xF1, 0x0E, 0xF1, 0x0E },
	{ 0x01, 0xE0, 0x01, 0xE0, 0x01, 0xF1, 0x01, 0xF1 },
	{ 0xE0, 0x01, 0xE0, 0x01, 0xF1, 0x01, 0xF1, 0x01 },
	{ 0x1F, 0xFE, 0x1F, 0xFE, 0x0E, 0xFE, 0x0E, 0xFE },
	{ 0xFE, 0x1F, 0xFE, 0x1F, 0xFE, 0x0E, 0xFE, 0x0E },
	{ 0x01, 0x1F, 0x01, 0x1F, 0x01, 0x0E, 0x01, 0x0E },
	{ 0x1F, 0x01, 0x1F, 0x01, 0x0E, 0x01, 0x0E, 0x01 },
	{ 0xE0, 0xFE, 0xE0, 0xFE, 0xF1, 0xFE, 0xF1, 0xFE },
	{ 0xFE, 0xE0, 0xFE, 0xE0, 0xFE, 0xF1, 0xFE, 0xF1 }
};

int des_is_weak_key(key)
des_cblock(*key);
{
	int i;

	for (i = 0; i < NUM_WEAK_KEY; i++)
		/* Added == 0 to comparison, I obviously don't run
		 * this section very often :-(, thanks to
		 * engineering@MorningStar.Com for the fix
		 * eay 93/06/29
		 * Another problem, I was comparing only the first 4
		 * bytes, 97/03/18 */
		if (memcmp(weak_keys[i], key, sizeof(des_cblock)) == 0)
			return 1;

	return 0;
}

/* NOW DEFINED IN des_local.h
 * See ecb_encrypt.c for a pseudo description of these macros.
 * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
 *      (b)^=(t),\
 *      (a)=((a)^((t)<<(n))))
 */

#define HPERM_OP(a, t, n, m) ((t) = ((((a) << (16 - (n))) ^ (a)) & (m)), \
			      (a) = (a) ^ (t) ^ (t >> (16 - (n))))

/* return 0 if key parity is odd (correct),
 * return -1 if key parity error,
 * return -2 if illegal weak key.
 */
int des_set_key(key, schedule)
des_cblock(*key);
des_key_schedule schedule;
{
	static int shifts2[16] =
	{ 0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0 };
	register DES_LONG c, d, t, s, t2;
	register unsigned char *in;
	register DES_LONG *k;
	register int i;

	if (des_check_key) {
		if (!check_parity(key))
			return -1;

		if (des_is_weak_key(key))
			return -2;
	}

	k = (DES_LONG *)schedule;
	in = (unsigned char *)key;

	c2l(in, c);
	c2l(in, d);

	/* do PC1 in 60 simple operations */
/*	PERM_OP(d,c,t,4,0x0f0f0f0fL);
	HPERM_OP(c,t,-2, 0xcccc0000L);
	HPERM_OP(c,t,-1, 0xaaaa0000L);
	HPERM_OP(c,t, 8, 0x00ff0000L);
	HPERM_OP(c,t,-1, 0xaaaa0000L);
	HPERM_OP(d,t,-8, 0xff000000L);
	HPERM_OP(d,t, 8, 0x00ff0000L);
	HPERM_OP(d,t, 2, 0x33330000L);
	d=((d&0x00aa00aaL)<<7L)|((d&0x55005500L)>>7L)|(d&0xaa55aa55L);
	d=(d>>8)|((c&0xf0000000L)>>4);
	c&=0x0fffffffL; */

	/* I now do it in 47 simple operations :-)
	 * Thanks to John Fletcher (john_fletcher@lccmail.ocf.llnl.gov)
	 * for the inspiration. :-) */
	PERM_OP(d, c, t, 4, 0x0f0f0f0fL);
	HPERM_OP(c, t, -2, 0xcccc0000L);
	HPERM_OP(d, t, -2, 0xcccc0000L);
	PERM_OP(d, c, t, 1, 0x55555555L);
	PERM_OP(c, d, t, 8, 0x00ff00ffL);
	PERM_OP(d, c, t, 1, 0x55555555L);
	d =      (((d & 0x000000ffL) << 16L) | (d & 0x0000ff00L)     |
		  ((d & 0x00ff0000L) >> 16L) | ((c & 0xf0000000L) >> 4L));
	c &= 0x0fffffffL;

	for (i = 0; i < ITERATIONS; i++) {
		if (shifts2[i]) {
			c = ((c >> 2L) | (c << 26L));
			d = ((d >> 2L) | (d << 26L));
		} else { c = ((c >> 1L) | (c << 27L));
			 d =
				 ((d >> 1L) | (d << 27L));
		}
		c &= 0x0fffffffL;
		d &= 0x0fffffffL;
		/* could be a few less shifts but I am to lazy at this
		 * point in time to investigate */
		s =      des_skb[0][ (c    ) & 0x3f                ] |
		    des_skb[1][((c >> 6) & 0x03) | ((c >> 7L) & 0x3c)] |
		    des_skb[2][((c >> 13) & 0x0f) | ((c >> 14L) & 0x30)] |
		    des_skb[3][((c >> 20) & 0x01) | ((c >> 21L) & 0x06) |
			       ((c >> 22L) & 0x38)];
		t =      des_skb[4][ (d    ) & 0x3f                ] |
		    des_skb[5][((d >> 7L) & 0x03) | ((d >> 8L) & 0x3c)] |
		    des_skb[6][ (d >> 15L) & 0x3f                ] |
		    des_skb[7][((d >> 21L) & 0x0f) | ((d >> 22L) & 0x30)];

		/* table contained 0213 4657 */
		t2 = ((t << 16L) | (s & 0x0000ffffL)) & 0xffffffffL;
		*(k++) = ROTATE(t2, 30) & 0xffffffffL;

		t2 = ((s >> 16L) | (t & 0xffff0000L));
		*(k++) = ROTATE(t2, 26) & 0xffffffffL;
	}
	return 0;
}

int des_key_sched(key, schedule)
des_cblock(*key);
des_key_schedule schedule;
{
	return des_set_key(key, schedule);
}
