sys/crypto/des/des_setkey.c

   1 /*      $NetBSD: des_setkey.c,v 1.8.6.1 2005/03/04 16:40:52 skrll 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@mincom.oz.au)
   6  * All rights reserved.
   7  *
   8  * This file is part of an SSL implementation written
   9  * by Eric Young (eay@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@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 1.8.6.1 2005/03/04 16:40:52 skrll 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@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@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@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 }