crypto/des/set_key.c

   1 /* crypto/des/set_key.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 /* set_key.c v 1.4 eay 24/9/91
  60  * 1.4 Speed up by 400% :-)
  61  * 1.3 added register declarations.
  62  * 1.2 unrolled make_key_sched a bit more
  63  * 1.1 added norm_expand_bits
  64  * 1.0 First working version
  65  */
  66 #include "des_locl.h"
  67 #include "podd.h"
  68 #include "sk.h"
  69
  70 #ifndef NOPROTO
  71 static int check_parity(const des_cblock key);
  72 #else
  73 static int check_parity();
  74 #endif
  75
  76 int des_check_key=0;
  77
  78 void des_set_odd_parity(des_cblock key)
  79         {
  80         int i;
  81
  82         for (i=0; i<DES_KEY_SZ; i++)
  83                 key[i]=odd_parity[key[i]];
  84         }
  85
  86 static int check_parity(const des_cblock key)
  87         {
  88         int i;
  89
  90         for (i=0; i<DES_KEY_SZ; i++)
  91                 {
  92                 if (key[i] != odd_parity[key[i]])
  93                         return(0);
  94                 }
  95         return(1);
  96         }
  97
  98 /* Weak and semi week keys as take from
  99  * %A D.W. Davies
 100  * %A W.L. Price
 101  * %T Security for Computer Networks
 102  * %I John Wiley & Sons
 103  * %D 1984
 104  * Many thanks to smb@ulysses.att.com (Steven Bellovin) for the reference
 105  * (and actual cblock values).
 106  */
 107 #define NUM_WEAK_KEY    16
 108 static des_cblock weak_keys[NUM_WEAK_KEY]={
 109         /* weak keys */
 110         {0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
 111         {0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE},
 112         {0x1F,0x1F,0x1F,0x1F,0x0E,0x0E,0x0E,0x0E},
 113         {0xE0,0xE0,0xE0,0xE0,0xF1,0xF1,0xF1,0xF1},
 114         /* semi-weak keys */
 115         {0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE},
 116         {0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01},
 117         {0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1},
 118         {0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E},
 119         {0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1},
 120         {0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01},
 121         {0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE},
 122         {0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E},
 123         {0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E},
 124         {0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01},
 125         {0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE},
 126         {0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}};
 127
 128 int des_is_weak_key(const des_cblock key)
 129         {
 130         int i;
 131
 132         for (i=0; i<NUM_WEAK_KEY; i++)
 133                 /* Added == 0 to comparision, I obviously don't run
 134                  * this section very often :-(, thanks to
 135                  * engineering@MorningStar.Com for the fix
 136                  * eay 93/06/29
 137                  * Another problem, I was comparing only the first 4
 138                  * bytes, 97/03/18 */
 139                 if (memcmp(weak_keys[i],key,sizeof(des_cblock)) == 0) return(1);
 140         return(0);
 141         }
 142
 143 /* NOW DEFINED IN des_local.h
 144  * See ecb_encrypt.c for a pseudo description of these macros.
 145  * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
 146  *      (b)^=(t),\
 147  *      (a)=((a)^((t)<<(n))))
 148  */
 149
 150 #define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
 151         (a)=(a)^(t)^(t>>(16-(n))))
 152
 153 /* return 0 if key parity is odd (correct),
 154  * return -1 if key parity error,
 155  * return -2 if illegal weak key.
 156  */
 157 int des_set_key(const des_cblock key, des_key_schedule schedule)
 158         {
 159         static int shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
 160         register DES_LONG c,d,t,s,t2;
 161         register const unsigned char *in;
 162         register DES_LONG *k;
 163         register int i;
 164
 165         if (des_check_key)
 166                 {
 167                 if (!check_parity(key))
 168                         return(-1);
 169
 170                 if (des_is_weak_key(key))
 171                         return(-2);
 172                 }
 173
 174         k=(DES_LONG *)schedule;
 175         in=key;
 176
 177         c2l(in,c);
 178         c2l(in,d);
 179
 180         /* do PC1 in 60 simple operations */
 181 /*      PERM_OP(d,c,t,4,0x0f0f0f0fL);
 182         HPERM_OP(c,t,-2, 0xcccc0000L);
 183         HPERM_OP(c,t,-1, 0xaaaa0000L);
 184         HPERM_OP(c,t, 8, 0x00ff0000L);
 185         HPERM_OP(c,t,-1, 0xaaaa0000L);
 186         HPERM_OP(d,t,-8, 0xff000000L);
 187         HPERM_OP(d,t, 8, 0x00ff0000L);
 188         HPERM_OP(d,t, 2, 0x33330000L);
 189         d=((d&0x00aa00aaL)<<7L)|((d&0x55005500L)>>7L)|(d&0xaa55aa55L);
 190         d=(d>>8)|((c&0xf0000000L)>>4);
 191         c&=0x0fffffffL; */
 192
 193         /* I now do it in 47 simple operations :-)
 194          * Thanks to John Fletcher (john_fletcher@lccmail.ocf.llnl.gov)
 195          * for the inspiration. :-) */
 196         PERM_OP (d,c,t,4,0x0f0f0f0fL);
 197         HPERM_OP(c,t,-2,0xcccc0000L);
 198         HPERM_OP(d,t,-2,0xcccc0000L);
 199         PERM_OP (d,c,t,1,0x55555555L);
 200         PERM_OP (c,d,t,8,0x00ff00ffL);
 201         PERM_OP (d,c,t,1,0x55555555L);
 202         d=      (((d&0x000000ffL)<<16L)| (d&0x0000ff00L)     |
 203                  ((d&0x00ff0000L)>>16L)|((c&0xf0000000L)>>4L));
 204         c&=0x0fffffffL;
 205
 206         for (i=0; i<ITERATIONS; i++)
 207                 {
 208                 if (shifts2[i])
 209                         { c=((c>>2L)|(c<<26L)); d=((d>>2L)|(d<<26L)); }
 210                 else
 211                         { c=((c>>1L)|(c<<27L)); d=((d>>1L)|(d<<27L)); }
 212                 c&=0x0fffffffL;
 213                 d&=0x0fffffffL;
 214                 /* could be a few less shifts but I am to lazy at this
 215                  * point in time to investigate */
 216                 s=      des_skb[0][ (c    )&0x3f                ]|
 217                         des_skb[1][((c>> 6)&0x03)|((c>> 7L)&0x3c)]|
 218                         des_skb[2][((c>>13)&0x0f)|((c>>14L)&0x30)]|
 219                         des_skb[3][((c>>20)&0x01)|((c>>21L)&0x06) |
 220                                                   ((c>>22L)&0x38)];
 221                 t=      des_skb[4][ (d    )&0x3f                ]|
 222                         des_skb[5][((d>> 7L)&0x03)|((d>> 8L)&0x3c)]|
 223                         des_skb[6][ (d>>15L)&0x3f                ]|
 224                         des_skb[7][((d>>21L)&0x0f)|((d>>22L)&0x30)];
 225
 226                 /* table contained 0213 4657 */
 227                 t2=((t<<16L)|(s&0x0000ffffL))&0xffffffffL;
 228                 *(k++)=ROTATE(t2,30)&0xffffffffL;
 229
 230                 t2=((s>>16L)|(t&0xffff0000L));
 231                 *(k++)=ROTATE(t2,26)&0xffffffffL;
 232                 }
 233         return(0);
 234         }
 235
 236 int des_key_sched(const des_cblock key, des_key_schedule schedule)
 237         {
 238         return(des_set_key(key,schedule));
 239         }