Annotation of sys/crypto/set_key.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: set_key.c,v 1.2 2002/10/27 13:24:26 miod Exp $ */
! 2:
! 3: /* lib/des/set_key.c */
! 4: /* Copyright (C) 1995 Eric Young (eay@mincom.oz.au)
! 5: * All rights reserved.
! 6: *
! 7: * This file is part of an SSL implementation written
! 8: * by Eric Young (eay@mincom.oz.au).
! 9: * The implementation was written so as to conform with Netscapes SSL
! 10: * specification. This library and applications are
! 11: * FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
! 12: * as long as the following conditions are aheared to.
! 13: *
! 14: * Copyright remains Eric Young's, and as such any Copyright notices in
! 15: * the code are not to be removed. If this code is used in a product,
! 16: * Eric Young should be given attribution as the author of the parts used.
! 17: * This can be in the form of a textual message at program startup or
! 18: * in documentation (online or textual) provided with the package.
! 19: *
! 20: * Redistribution and use in source and binary forms, with or without
! 21: * modification, are permitted provided that the following conditions
! 22: * are met:
! 23: * 1. Redistributions of source code must retain the copyright
! 24: * notice, this list of conditions and the following disclaimer.
! 25: * 2. Redistributions in binary form must reproduce the above copyright
! 26: * notice, this list of conditions and the following disclaimer in the
! 27: * documentation and/or other materials provided with the distribution.
! 28: * 3. All advertising materials mentioning features or use of this software
! 29: * must display the following acknowledgement:
! 30: * This product includes software developed by Eric Young (eay@mincom.oz.au)
! 31: *
! 32: * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
! 33: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 34: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 35: * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
! 36: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 37: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 38: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 39: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 40: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 41: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 42: * SUCH DAMAGE.
! 43: *
! 44: * The licence and distribution terms for any publically available version or
! 45: * derivative of this code cannot be changed. i.e. this code cannot simply be
! 46: * copied and put under another distribution licence
! 47: * [including the GNU Public Licence.]
! 48: */
! 49:
! 50: /* set_key.c v 1.4 eay 24/9/91
! 51: * 1.4 Speed up by 400% :-)
! 52: * 1.3 added register declarations.
! 53: * 1.2 unrolled make_key_sched a bit more
! 54: * 1.1 added norm_expand_bits
! 55: * 1.0 First working version
! 56: */
! 57: #include "des_locl.h"
! 58: #include "podd.h"
! 59: #include "sk.h"
! 60:
! 61: #ifdef PROTO
! 62: static int check_parity(des_cblock (*key));
! 63: #else
! 64: static int check_parity();
! 65: #endif
! 66:
! 67: int des_check_key=0;
! 68:
! 69: void des_set_odd_parity(key)
! 70: des_cblock (*key);
! 71: {
! 72: int i;
! 73:
! 74: for (i=0; i<DES_KEY_SZ; i++)
! 75: (*key)[i]=odd_parity[(*key)[i]];
! 76: }
! 77:
! 78: static int check_parity(key)
! 79: des_cblock (*key);
! 80: {
! 81: int i;
! 82:
! 83: for (i=0; i<DES_KEY_SZ; i++)
! 84: {
! 85: if ((*key)[i] != odd_parity[(*key)[i]])
! 86: return(0);
! 87: }
! 88: return(1);
! 89: }
! 90:
! 91: /* Weak and semi week keys as take from
! 92: * %A D.W. Davies
! 93: * %A W.L. Price
! 94: * %T Security for Computer Networks
! 95: * %I John Wiley & Sons
! 96: * %D 1984
! 97: * Many thanks to smb@ulysses.att.com (Steven Bellovin) for the reference
! 98: * (and actual cblock values).
! 99: */
! 100: #define NUM_WEAK_KEY 16
! 101: static des_cblock weak_keys[NUM_WEAK_KEY]={
! 102: /* weak keys */
! 103: {0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
! 104: {0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE},
! 105: {0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F},
! 106: {0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,0xE0},
! 107: /* semi-weak keys */
! 108: {0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE},
! 109: {0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01},
! 110: {0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1},
! 111: {0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E},
! 112: {0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1},
! 113: {0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01},
! 114: {0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE},
! 115: {0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E},
! 116: {0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E},
! 117: {0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01},
! 118: {0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE},
! 119: {0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}};
! 120:
! 121: int des_is_weak_key(key)
! 122: des_cblock (*key);
! 123: {
! 124: int i;
! 125:
! 126: for (i=0; i<NUM_WEAK_KEY; i++)
! 127: /* Added == 0 to comparision, I obviously don't run
! 128: * this section very often :-(, thanks to
! 129: * engineering@MorningStar.Com for the fix
! 130: * eay 93/06/29 */
! 131: if (bcmp(weak_keys[i],key,sizeof(des_cblock)) == 0) return(1);
! 132: return(0);
! 133: }
! 134:
! 135: /* NOW DEFINED IN des_local.h
! 136: * See ecb_encrypt.c for a pseudo description of these macros.
! 137: * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
! 138: * (b)^=(t),\
! 139: * (a)=((a)^((t)<<(n))))
! 140: */
! 141:
! 142: #define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
! 143: (a)=(a)^(t)^(t>>(16-(n))))
! 144:
! 145: static int shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
! 146:
! 147: /* return 0 if key parity is odd (correct),
! 148: * return -1 if key parity error,
! 149: * return -2 if illegal weak key.
! 150: */
! 151: int des_set_key(key, schedule)
! 152: des_cblock (*key);
! 153: des_key_schedule schedule;
! 154: {
! 155: register u_int32_t c,d,t,s;
! 156: register unsigned char *in;
! 157: register u_int32_t *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=(u_int32_t *)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: }
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