set_key.c revision 55714
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 70static int check_parity(const_des_cblock *key); 71OPENSSL_GLOBAL int des_check_key=0; 72 73void des_set_odd_parity(des_cblock *key) 74 { 75 int i; 76 77 for (i=0; i<DES_KEY_SZ; i++) 78 (*key)[i]=odd_parity[(*key)[i]]; 79 } 80 81static int check_parity(const_des_cblock *key) 82 { 83 int i; 84 85 for (i=0; i<DES_KEY_SZ; i++) 86 { 87 if ((*key)[i] != odd_parity[(*key)[i]]) 88 return(0); 89 } 90 return(1); 91 } 92 93/* Weak and semi week keys as take from 94 * %A D.W. Davies 95 * %A W.L. Price 96 * %T Security for Computer Networks 97 * %I John Wiley & Sons 98 * %D 1984 99 * Many thanks to smb@ulysses.att.com (Steven Bellovin) for the reference 100 * (and actual cblock values). 101 */ 102#define NUM_WEAK_KEY 16 103static des_cblock weak_keys[NUM_WEAK_KEY]={ 104 /* weak keys */ 105 {0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01}, 106 {0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE}, 107 {0x1F,0x1F,0x1F,0x1F,0x0E,0x0E,0x0E,0x0E}, 108 {0xE0,0xE0,0xE0,0xE0,0xF1,0xF1,0xF1,0xF1}, 109 /* semi-weak keys */ 110 {0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE}, 111 {0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01}, 112 {0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1}, 113 {0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E}, 114 {0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1}, 115 {0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01}, 116 {0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE}, 117 {0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E}, 118 {0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E}, 119 {0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01}, 120 {0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE}, 121 {0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}}; 122 123int des_is_weak_key(const_des_cblock *key) 124 { 125 int i; 126 127 for (i=0; i<NUM_WEAK_KEY; i++) 128 /* Added == 0 to comparision, I obviously don't run 129 * this section very often :-(, thanks to 130 * engineering@MorningStar.Com for the fix 131 * eay 93/06/29 132 * Another problem, I was comparing only the first 4 133 * bytes, 97/03/18 */ 134 if (memcmp(weak_keys[i],key,sizeof(des_cblock)) == 0) return(1); 135 return(0); 136 } 137 138/* NOW DEFINED IN des_local.h 139 * See ecb_encrypt.c for a pseudo description of these macros. 140 * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\ 141 * (b)^=(t),\ 142 * (a)=((a)^((t)<<(n)))) 143 */ 144 145#define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\ 146 (a)=(a)^(t)^(t>>(16-(n)))) 147 148/* return 0 if key parity is odd (correct), 149 * return -1 if key parity error, 150 * return -2 if illegal weak key. 151 */ 152int des_set_key(const_des_cblock *key, 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,t2; 156 register const 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 = &schedule->ks.deslong[0]; 170 in = &(*key)[0]; 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 t2=((t<<16L)|(s&0x0000ffffL))&0xffffffffL; 223 *(k++)=ROTATE(t2,30)&0xffffffffL; 224 225 t2=((s>>16L)|(t&0xffff0000L)); 226 *(k++)=ROTATE(t2,26)&0xffffffffL; 227 } 228 return(0); 229 } 230 231int des_key_sched(const_des_cblock *key, des_key_schedule schedule) 232 { 233 return(des_set_key(key,schedule)); 234 } 235