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      1 /*	$NetBSD: des_setkey.c,v 1.10 2005/12/11 12:20:52 christos Exp $	*/
      2 /*	$KAME: des_setkey.c,v 1.6 2001/07/03 14:27:53 itojun Exp $	*/
      3 
      4 /* crypto/des/set_key.c */
      5 /* Copyright (C) 1995-1996 Eric Young (eay (at) mincom.oz.au)
      6  * All rights reserved.
      7  *
      8  * This file is part of an SSL implementation written
      9  * by Eric Young (eay (at) mincom.oz.au).
     10  * The implementation was written so as to conform with Netscapes SSL
     11  * specification.  This library and applications are
     12  * FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
     13  * as long as the following conditions are aheared to.
     14  *
     15  * Copyright remains Eric Young's, and as such any Copyright notices in
     16  * the code are not to be removed.  If this code is used in a product,
     17  * Eric Young should be given attribution as the author of the parts used.
     18  * This can be in the form of a textual message at program startup or
     19  * in documentation (online or textual) provided with the package.
     20  *
     21  * Redistribution and use in source and binary forms, with or without
     22  * modification, are permitted provided that the following conditions
     23  * are met:
     24  * 1. Redistributions of source code must retain the copyright
     25  *    notice, this list of conditions and the following disclaimer.
     26  * 2. Redistributions in binary form must reproduce the above copyright
     27  *    notice, this list of conditions and the following disclaimer in the
     28  *    documentation and/or other materials provided with the distribution.
     29  * 3. All advertising materials mentioning features or use of this software
     30  *    must display the following acknowledgement:
     31  *    This product includes software developed by Eric Young (eay (at) mincom.oz.au)
     32  *
     33  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
     34  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     35  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     36  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     37  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     38  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     39  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     40  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     41  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     42  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     43  * SUCH DAMAGE.
     44  *
     45  * The licence and distribution terms for any publically available version or
     46  * derivative of this code cannot be changed.  i.e. this code cannot simply be
     47  * copied and put under another distribution licence
     48  * [including the GNU Public Licence.]
     49  */
     50 
     51 /* set_key.c v 1.4 eay 24/9/91
     52  * 1.4 Speed up by 400% :-)
     53  * 1.3 added register declarations.
     54  * 1.2 unrolled make_key_sched a bit more
     55  * 1.1 added norm_expand_bits
     56  * 1.0 First working version
     57  */
     58 
     59 #include <sys/cdefs.h>
     60 __KERNEL_RCSID(0, "$NetBSD: des_setkey.c,v 1.10 2005/12/11 12:20:52 christos Exp $");
     61 
     62 #include <sys/param.h>
     63 #ifdef _KERNEL
     64 #include <sys/systm.h>
     65 #else
     66 #include <string.h>
     67 #endif
     68 #include <crypto/des/des_locl.h>
     69 #include <crypto/des/podd.h>
     70 #include <crypto/des/sk.h>
     71 
     72 int des_check_key=0;
     73 
     74 void des_set_odd_parity(des_cblock *key)
     75 {
     76 	unsigned int i;
     77 
     78 	for (i=0; i<DES_KEY_SZ; i++)
     79 		(*key)[i]=odd_parity[(*key)[i]];
     80 }
     81 
     82 int des_check_key_parity(des_cblock *key)
     83 {
     84 	unsigned int i;
     85 
     86 	for (i=0; i<DES_KEY_SZ; i++)
     87 		{
     88 		if ((*key)[i] != odd_parity[(*key)[i]])
     89 			return(0);
     90 		}
     91 	return(1);
     92 }
     93 
     94 /* Weak and semi week keys as take from
     95  * %A D.W. Davies
     96  * %A W.L. Price
     97  * %T Security for Computer Networks
     98  * %I John Wiley & Sons
     99  * %D 1984
    100  * Many thanks to smb (at) ulysses.att.com (Steven Bellovin) for the reference
    101  * (and actual cblock values).
    102  */
    103 #define NUM_WEAK_KEY	16
    104 static des_cblock weak_keys[NUM_WEAK_KEY]={
    105 	/* weak keys */
    106 	{0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
    107 	{0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE},
    108 	{0x1F,0x1F,0x1F,0x1F,0x0E,0x0E,0x0E,0x0E},
    109 	{0xE0,0xE0,0xE0,0xE0,0xF1,0xF1,0xF1,0xF1},
    110 	/* semi-weak keys */
    111 	{0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE},
    112 	{0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01},
    113 	{0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1},
    114 	{0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E},
    115 	{0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1},
    116 	{0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01},
    117 	{0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE},
    118 	{0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E},
    119 	{0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E},
    120 	{0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01},
    121 	{0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE},
    122 	{0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}};
    123 
    124 int des_is_weak_key(des_cblock *key)
    125 {
    126 	int i;
    127 
    128 	for (i=0; i<NUM_WEAK_KEY; i++)
    129 		/* Added == 0 to comparison, I obviously don't run
    130 		 * this section very often :-(, thanks to
    131 		 * engineering (at) MorningStar.Com for the fix
    132 		 * eay 93/06/29
    133 		 * Another problem, I was comparing only the first 4
    134 		 * bytes, 97/03/18 */
    135 		if (memcmp(weak_keys[i],key,sizeof(des_cblock)) == 0) return(1);
    136 	return(0);
    137 }
    138 
    139 /* NOW DEFINED IN des_local.h
    140  * See ecb_encrypt.c for a pseudo description of these macros.
    141  * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
    142  * 	(b)^=(t),\
    143  * 	(a)=((a)^((t)<<(n))))
    144  */
    145 
    146 #define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
    147 	(a)=(a)^(t)^(t>>(16-(n))))
    148 
    149 int des_set_key(des_cblock *key, des_key_schedule schedule)
    150 {
    151 	if (des_check_key)
    152 	{
    153 		return des_set_key_checked(key, schedule);
    154 	}
    155 	else
    156 	{
    157 		des_set_key_unchecked(key, schedule);
    158 		return 0;
    159 	}
    160 }
    161 
    162 /* return 0 if key parity is odd (correct),
    163  * return -1 if key parity error,
    164  * return -2 if illegal weak key.
    165  */
    166 int des_set_key_checked(des_cblock *key, des_key_schedule schedule)
    167 {
    168 	if (!des_check_key_parity(key))
    169 		return(-1);
    170 	if (des_is_weak_key(key))
    171 		return(-2);
    172 	des_set_key_unchecked(key, schedule);
    173 	return 0;
    174 }
    175 
    176 void des_set_key_unchecked(des_cblock *key, des_key_schedule schedule)
    177 {
    178 	static int shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
    179 	register DES_LONG c,d,t,s,t2;
    180 	register const unsigned char *in;
    181 	register DES_LONG *k;
    182 	register int i;
    183 
    184 	k = &schedule->ks.deslong[0];
    185 	in = &(*key)[0];
    186 
    187 	c2l(in,c);
    188 	c2l(in,d);
    189 
    190 	/* do PC1 in 47 simple operations :-)
    191 	 * Thanks to John Fletcher (john_fletcher (at) lccmail.ocf.llnl.gov)
    192 	 * for the inspiration. :-) */
    193 	PERM_OP (d,c,t,4,0x0f0f0f0fL);
    194 	HPERM_OP(c,t,-2,0xcccc0000L);
    195 	HPERM_OP(d,t,-2,0xcccc0000L);
    196 	PERM_OP (d,c,t,1,0x55555555L);
    197 	PERM_OP (c,d,t,8,0x00ff00ffL);
    198 	PERM_OP (d,c,t,1,0x55555555L);
    199 	d=	(((d&0x000000ffL)<<16L)| (d&0x0000ff00L)     |
    200 		 ((d&0x00ff0000L)>>16L)|((c&0xf0000000L)>>4L));
    201 	c&=0x0fffffffL;
    202 
    203 	for (i=0; i<ITERATIONS; i++)
    204 	{
    205 		if (shifts2[i])
    206 			{ c=((c>>2L)|(c<<26L)); d=((d>>2L)|(d<<26L)); }
    207 		else
    208 			{ c=((c>>1L)|(c<<27L)); d=((d>>1L)|(d<<27L)); }
    209 		c&=0x0fffffffL;
    210 		d&=0x0fffffffL;
    211 		/* could be a few less shifts but I am to lazy at this
    212 	 	* point in time to investigate */
    213 		s=	des_skb[0][ (c    )&0x3f                ]|
    214 			des_skb[1][((c>> 6L)&0x03)|((c>> 7L)&0x3c)]|
    215 			des_skb[2][((c>>13L)&0x0f)|((c>>14L)&0x30)]|
    216 			des_skb[3][((c>>20L)&0x01)|((c>>21L)&0x06) |
    217 						  	((c>>22L)&0x38)];
    218 		t=	des_skb[4][ (d    )&0x3f                ]|
    219 			des_skb[5][((d>> 7L)&0x03)|((d>> 8L)&0x3c)]|
    220 			des_skb[6][ (d>>15L)&0x3f                ]|
    221 			des_skb[7][((d>>21L)&0x0f)|((d>>22L)&0x30)];
    222 
    223 		/* table contained 0213 4657 */
    224 		t2=((t<<16L)|(s&0x0000ffffL))&0xffffffffL;
    225 		*(k++)=ROTATE(t2,30)&0xffffffffL;
    226 
    227 		t2=((s>>16L)|(t&0xffff0000L));
    228 		*(k++)=ROTATE(t2,26)&0xffffffffL;
    229 	}
    230 }
    231 
    232 int des_key_sched(des_cblock *key, des_key_schedule schedule)
    233 {
    234 	return(des_set_key(key,schedule));
    235 }
    236 
    237 void des_fixup_key_parity(des_cblock *key)
    238 {
    239 	des_set_odd_parity(key);
    240 }
    241