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 }