sys/crypto/des/des_setkey.c

   1 /*      $FreeBSD: src/sys/crypto/des/des_setkey.c,v 1.7 2004/06/14 00:38:16 obrien Exp $        */
   2 /*      $KAME: des_setkey.c,v 1.7 2001/09/10 04:03:58 itojun Exp $      */
   3
   4 /* crypto/des/set_key.c */
   5
   6 /* Copyright (C) 1995-1996 Eric Young (eay@mincom.oz.au)
   7  * All rights reserved.
   8  *
   9  * This file is part of an SSL implementation written
  10  * by Eric Young (eay@mincom.oz.au).
  11  * The implementation was written so as to conform with Netscapes SSL
  12  * specification.  This library and applications are
  13  * FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
  14  * as long as the following conditions are aheared to.
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.  If this code is used in a product,
  18  * Eric Young should be given attribution as the author of the parts used.
  19  * This can be in the form of a textual message at program startup or
  20  * in documentation (online or textual) provided with the package.
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  * 3. All advertising materials mentioning features or use of this software
  31  *    must display the following acknowledgement:
  32  *    This product includes software developed by Eric Young (eay@mincom.oz.au)
  33  *
  34  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  35  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  36  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  37  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  38  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  39  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  40  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  41  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  42  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  43  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  44  * SUCH DAMAGE.
  45  *
  46  * The licence and distribution terms for any publically available version or
  47  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  48  * copied and put under another distribution licence
  49  * [including the GNU Public Licence.]
  50  */
  51
  52 /* set_key.c v 1.4 eay 24/9/91
  53  * 1.4 Speed up by 400% :-)
  54  * 1.3 added register declarations.
  55  * 1.2 unrolled make_key_sched a bit more
  56  * 1.1 added norm_expand_bits
  57  * 1.0 First working version
  58  */
  59 #include <sys/param.h>
  60 #include <sys/systm.h>
  61 #include <crypto/des/des_locl.h>
  62 #include <crypto/des/podd.h>
  63 #include <crypto/des/sk.h>
  64
  65 int des_check_key=0;
  66
  67 void des_set_odd_parity(des_cblock *key)
  68 {
  69         int i;
  70
  71         for (i=0; i<DES_KEY_SZ; i++)
  72                 (*key)[i]=odd_parity[(*key)[i]];
  73 }
  74
  75 int des_check_key_parity(des_cblock *key)
  76 {
  77         int i;
  78
  79         for (i=0; i<DES_KEY_SZ; i++)
  80                 {
  81                 if ((*key)[i] != odd_parity[(*key)[i]])
  82                         return(0);
  83                 }
  84         return(1);
  85 }
  86
  87 /* Weak and semi week keys as take from
  88  * %A D.W. Davies
  89  * %A W.L. Price
  90  * %T Security for Computer Networks
  91  * %I John Wiley & Sons
  92  * %D 1984
  93  * Many thanks to smb@ulysses.att.com (Steven Bellovin) for the reference
  94  * (and actual cblock values).
  95  */
  96 #define NUM_WEAK_KEY    16
  97 static des_cblock weak_keys[NUM_WEAK_KEY]={
  98         /* weak keys */
  99         {0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
 100         {0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE},
 101         {0x1F,0x1F,0x1F,0x1F,0x0E,0x0E,0x0E,0x0E},
 102         {0xE0,0xE0,0xE0,0xE0,0xF1,0xF1,0xF1,0xF1},
 103         /* semi-weak keys */
 104         {0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE},
 105         {0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01},
 106         {0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1},
 107         {0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E},
 108         {0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1},
 109         {0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01},
 110         {0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE},
 111         {0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E},
 112         {0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E},
 113         {0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01},
 114         {0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE},
 115         {0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}};
 116
 117 int des_is_weak_key(des_cblock *key)
 118 {
 119         int i;
 120
 121         for (i=0; i<NUM_WEAK_KEY; i++)
 122                 /* Added == 0 to comparison, I obviously don't run
 123                  * this section very often :-(, thanks to
 124                  * engineering@MorningStar.Com for the fix
 125                  * eay 93/06/29
 126                  * Another problem, I was comparing only the first 4
 127                  * bytes, 97/03/18 */
 128                 if (memcmp(weak_keys[i],key,sizeof(des_cblock)) == 0) return(1);
 129         return(0);
 130 }
 131
 132 /* NOW DEFINED IN des_local.h
 133  * See ecb_encrypt.c for a pseudo description of these macros.
 134  * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
 135  *      (b)^=(t),\
 136  *      (a)=((a)^((t)<<(n))))
 137  */
 138
 139 #define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
 140         (a)=(a)^(t)^(t>>(16-(n))))
 141
 142 int des_set_key(des_cblock *key, des_key_schedule schedule)
 143 {
 144         if (des_check_key)
 145         {
 146                 return des_set_key_checked(key, schedule);
 147         }
 148         else
 149         {
 150                 des_set_key_unchecked(key, schedule);
 151                 return 0;
 152         }
 153 }
 154
 155 /* return 0 if key parity is odd (correct),
 156  * return -1 if key parity error,
 157  * return -2 if illegal weak key.
 158  */
 159 int des_set_key_checked(des_cblock *key, des_key_schedule schedule)
 160 {
 161         if (!des_check_key_parity(key))
 162                 return(-1);
 163         if (des_is_weak_key(key))
 164                 return(-2);
 165         des_set_key_unchecked(key, schedule);
 166         return 0;
 167 }
 168
 169 void des_set_key_unchecked(des_cblock *key, des_key_schedule schedule)
 170 {
 171         static int shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
 172         DES_LONG c,d,t,s,t2;
 173         const unsigned char *in;
 174         DES_LONG *k;
 175         int i;
 176
 177         k = &schedule->ks.deslong[0];
 178         in = &(*key)[0];
 179
 180         c2l(in,c);
 181         c2l(in,d);
 182
 183         /* do PC1 in 47 simple operations :-)
 184          * Thanks to John Fletcher (john_fletcher@lccmail.ocf.llnl.gov)
 185          * for the inspiration. :-) */
 186         PERM_OP (d,c,t,4,0x0f0f0f0fL);
 187         HPERM_OP(c,t,-2,0xcccc0000L);
 188         HPERM_OP(d,t,-2,0xcccc0000L);
 189         PERM_OP (d,c,t,1,0x55555555L);
 190         PERM_OP (c,d,t,8,0x00ff00ffL);
 191         PERM_OP (d,c,t,1,0x55555555L);
 192         d=      (((d&0x000000ffL)<<16L)| (d&0x0000ff00L)     |
 193                  ((d&0x00ff0000L)>>16L)|((c&0xf0000000L)>>4L));
 194         c&=0x0fffffffL;
 195
 196         for (i=0; i<ITERATIONS; i++)
 197         {
 198                 if (shifts2[i])
 199                         { c=((c>>2L)|(c<<26L)); d=((d>>2L)|(d<<26L)); }
 200                 else
 201                         { c=((c>>1L)|(c<<27L)); d=((d>>1L)|(d<<27L)); }
 202                 c&=0x0fffffffL;
 203                 d&=0x0fffffffL;
 204                 /* could be a few less shifts but I am to lazy at this
 205                 * point in time to investigate */
 206                 s=      des_skb[0][ (c    )&0x3f                ]|
 207                         des_skb[1][((c>> 6L)&0x03)|((c>> 7L)&0x3c)]|
 208                         des_skb[2][((c>>13L)&0x0f)|((c>>14L)&0x30)]|
 209                         des_skb[3][((c>>20L)&0x01)|((c>>21L)&0x06) |
 210                                                         ((c>>22L)&0x38)];
 211                 t=      des_skb[4][ (d    )&0x3f                ]|
 212                         des_skb[5][((d>> 7L)&0x03)|((d>> 8L)&0x3c)]|
 213                         des_skb[6][ (d>>15L)&0x3f                ]|
 214                         des_skb[7][((d>>21L)&0x0f)|((d>>22L)&0x30)];
 215
 216                 /* table contained 0213 4657 */
 217                 t2=((t<<16L)|(s&0x0000ffffL))&0xffffffffL;
 218                 *(k++)=ROTATE(t2,30)&0xffffffffL;
 219
 220                 t2=((s>>16L)|(t&0xffff0000L));
 221                 *(k++)=ROTATE(t2,26)&0xffffffffL;
 222         }
 223 }
 224
 225 int des_key_sched(des_cblock *key, des_key_schedule schedule)
 226 {
 227         return(des_set_key(key,schedule));
 228 }
 229
 230 void des_fixup_key_parity(des_cblock *key)
 231 {
 232         des_set_odd_parity(key);
 233 }