Annotation of sys/crypto/set_key.c, Revision 1.1.1.1
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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