bsd/crypto/des/des_setkey.c

   1 /* crypto/des/set_key.c */
   2 /* Copyright (C) 1995-1996 Eric Young (eay@mincom.oz.au)
   3  * All rights reserved.
   4  *
   5  * This file is part of an SSL implementation written
   6  * by Eric Young (eay@mincom.oz.au).
   7  * The implementation was written so as to conform with Netscapes SSL
   8  * specification.  This library and applications are
   9  * FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
  10  * as long as the following conditions are aheared to.
  11  *
  12  * Copyright remains Eric Young's, and as such any Copyright notices in
  13  * the code are not to be removed.  If this code is used in a product,
  14  * Eric Young should be given attribution as the author of the parts used.
  15  * This can be in the form of a textual message at program startup or
  16  * in documentation (online or textual) provided with the package.
  17  *
  18  * Redistribution and use in source and binary forms, with or without
  19  * modification, are permitted provided that the following conditions
  20  * are met:
  21  * 1. Redistributions of source code must retain the copyright
  22  *    notice, this list of conditions and the following disclaimer.
  23  * 2. Redistributions in binary form must reproduce the above copyright
  24  *    notice, this list of conditions and the following disclaimer in the
  25  *    documentation and/or other materials provided with the distribution.
  26  * 3. All advertising materials mentioning features or use of this software
  27  *    must display the following acknowledgement:
  28  *    This product includes software developed by Eric Young (eay@mincom.oz.au)
  29  *
  30  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  40  * SUCH DAMAGE.
  41  *
  42  * The licence and distribution terms for any publically available version or
  43  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  44  * copied and put under another distribution licence
  45  * [including the GNU Public Licence.]
  46  */
  47
  48 /* set_key.c v 1.4 eay 24/9/91
  49  * 1.4 Speed up by 400% :-)
  50  * 1.3 added register declarations.
  51  * 1.2 unrolled make_key_sched a bit more
  52  * 1.1 added norm_expand_bits
  53  * 1.0 First working version
  54  */
  55 #include <crypto/des/des_locl.h>
  56 #include <crypto/des/podd.h>
  57 #include <crypto/des/sk.h>
  58
  59 #ifndef NOPROTO
  60 static int check_parity(des_cblock (*key));
  61 #else
  62 static int check_parity();
  63 #endif
  64
  65 int des_check_key=0;
  66
  67 void des_set_odd_parity(key)
  68 des_cblock (*key);
  69         {
  70         int i;
  71
  72         for (i=0; i<DES_KEY_SZ; i++)
  73                 (*key)[i]=odd_parity[(*key)[i]];
  74         }
  75
  76 static int check_parity(key)
  77 des_cblock (*key);
  78         {
  79         int i;
  80
  81         for (i=0; i<DES_KEY_SZ; i++)
  82                 {
  83                 if ((*key)[i] != odd_parity[(*key)[i]])
  84                         return(0);
  85                 }
  86         return(1);
  87         }
  88
  89 /* Weak and semi week keys as take from
  90  * %A D.W. Davies
  91  * %A W.L. Price
  92  * %T Security for Computer Networks
  93  * %I John Wiley & Sons
  94  * %D 1984
  95  * Many thanks to smb@ulysses.att.com (Steven Bellovin) for the reference
  96  * (and actual cblock values).
  97  */
  98 #define NUM_WEAK_KEY    16
  99 static des_cblock weak_keys[NUM_WEAK_KEY]={
 100         /* weak keys */
 101         {0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
 102         {0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE},
 103         {0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F},
 104         {0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,0xE0},
 105         /* semi-weak keys */
 106         {0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE},
 107         {0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01},
 108         {0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1},
 109         {0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E},
 110         {0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1},
 111         {0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01},
 112         {0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE},
 113         {0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E},
 114         {0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E},
 115         {0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01},
 116         {0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE},
 117         {0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}};
 118
 119 int des_is_weak_key(key)
 120 des_cblock (*key);
 121         {
 122         int i;
 123
 124         for (i=0; i<NUM_WEAK_KEY; i++)
 125                 /* Added == 0 to comparision, I obviously don't run
 126                  * this section very often :-(, thanks to
 127                  * engineering@MorningStar.Com for the fix
 128                  * eay 93/06/29 */
 129 /*
 130                 if (memcmp(weak_keys[i],key,sizeof(key)) == 0) return(1);
 131 */
 132                 if (bcmp(weak_keys[i],key,sizeof(key)) == 0) return(1);
 133         return(0);
 134         }
 135
 136 /* NOW DEFINED IN des_local.h
 137  * See ecb_encrypt.c for a pseudo description of these macros.
 138  * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
 139  *      (b)^=(t),\
 140  *      (a)=((a)^((t)<<(n))))
 141  */
 142
 143 #define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
 144         (a)=(a)^(t)^(t>>(16-(n))))
 145
 146 /* return 0 if key parity is odd (correct),
 147  * return -1 if key parity error,
 148  * return -2 if illegal weak key.
 149  */
 150 int des_set_key(key, schedule)
 151 des_cblock (*key);
 152 des_key_schedule schedule;
 153         {
 154         static int shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
 155         register DES_LONG c,d,t,s;
 156         register unsigned char *in;
 157         register DES_LONG *k;
 158         register int i;
 159
 160         if (des_check_key)
 161                 {
 162                 if (!check_parity(key))
 163                         return(-1);
 164
 165                 if (des_is_weak_key(key))
 166                         return(-2);
 167                 }
 168
 169         k=(DES_LONG *)schedule;
 170         in=(unsigned char *)key;
 171
 172         c2l(in,c);
 173         c2l(in,d);
 174
 175         /* do PC1 in 60 simple operations */
 176 /*      PERM_OP(d,c,t,4,0x0f0f0f0fL);
 177         HPERM_OP(c,t,-2, 0xcccc0000L);
 178         HPERM_OP(c,t,-1, 0xaaaa0000L);
 179         HPERM_OP(c,t, 8, 0x00ff0000L);
 180         HPERM_OP(c,t,-1, 0xaaaa0000L);
 181         HPERM_OP(d,t,-8, 0xff000000L);
 182         HPERM_OP(d,t, 8, 0x00ff0000L);
 183         HPERM_OP(d,t, 2, 0x33330000L);
 184         d=((d&0x00aa00aaL)<<7L)|((d&0x55005500L)>>7L)|(d&0xaa55aa55L);
 185         d=(d>>8)|((c&0xf0000000L)>>4);
 186         c&=0x0fffffffL; */
 187
 188         /* I now do it in 47 simple operations :-)
 189          * Thanks to John Fletcher (john_fletcher@lccmail.ocf.llnl.gov)
 190          * for the inspiration. :-) */
 191         PERM_OP (d,c,t,4,0x0f0f0f0fL);
 192         HPERM_OP(c,t,-2,0xcccc0000L);
 193         HPERM_OP(d,t,-2,0xcccc0000L);
 194         PERM_OP (d,c,t,1,0x55555555L);
 195         PERM_OP (c,d,t,8,0x00ff00ffL);
 196         PERM_OP (d,c,t,1,0x55555555L);
 197         d=      (((d&0x000000ffL)<<16L)| (d&0x0000ff00L)     |
 198                  ((d&0x00ff0000L)>>16L)|((c&0xf0000000L)>>4L));
 199         c&=0x0fffffffL;
 200
 201         for (i=0; i<ITERATIONS; i++)
 202                 {
 203                 if (shifts2[i])
 204                         { c=((c>>2L)|(c<<26L)); d=((d>>2L)|(d<<26L)); }
 205                 else
 206                         { c=((c>>1L)|(c<<27L)); d=((d>>1L)|(d<<27L)); }
 207                 c&=0x0fffffffL;
 208                 d&=0x0fffffffL;
 209                 /* could be a few less shifts but I am to lazy at this
 210                  * point in time to investigate */
 211                 s=      des_skb[0][ (c    )&0x3f                ]|
 212                         des_skb[1][((c>> 6)&0x03)|((c>> 7L)&0x3c)]|
 213                         des_skb[2][((c>>13)&0x0f)|((c>>14L)&0x30)]|
 214                         des_skb[3][((c>>20)&0x01)|((c>>21L)&0x06) |
 215                                                   ((c>>22L)&0x38)];
 216                 t=      des_skb[4][ (d    )&0x3f                ]|
 217                         des_skb[5][((d>> 7L)&0x03)|((d>> 8L)&0x3c)]|
 218                         des_skb[6][ (d>>15L)&0x3f                ]|
 219                         des_skb[7][((d>>21L)&0x0f)|((d>>22L)&0x30)];
 220
 221                 /* table contained 0213 4657 */
 222                 *(k++)=((t<<16L)|(s&0x0000ffffL))&0xffffffffL;
 223                 s=     ((s>>16L)|(t&0xffff0000L));
 224
 225                 s=(s<<4L)|(s>>28L);
 226                 *(k++)=s&0xffffffffL;
 227                 }
 228         return(0);
 229         }
 230
 231 int des_key_sched(key, schedule)
 232 des_cblock (*key);
 233 des_key_schedule schedule;
 234         {
 235         return(des_set_key(key,schedule));
 236         }