1 /* $KAME: des_setkey.c,v 1.7 2001/09/10 04:03:58 itojun Exp $ */
2
3 /* crypto/des/set_key.c */
4
5 /* Copyright (C) 1995-1996 Eric Young ([email protected])
6 * All rights reserved.
7 *
8 * This file is part of an SSL implementation written
9 * by Eric Young ([email protected]).
10 * The implementation was written so as to conform with Netscapes SSL
11 * specification. This library and applications are
12 * FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
13 * as long as the following conditions are aheared to.
14 *
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed. If this code is used in a product,
17 * Eric Young should be given attribution as the author of the parts used.
18 * This can be in the form of a textual message at program startup or
19 * in documentation (online or textual) provided with the package.
20 *
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
23 * are met:
24 * 1. Redistributions of source code must retain the copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in the
28 * documentation and/or other materials provided with the distribution.
29 * 3. All advertising materials mentioning features or use of this software
30 * must display the following acknowledgement:
31 * This product includes software developed by Eric Young ([email protected])
32 *
33 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
34 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
35 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
36 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
37 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
38 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
39 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
41 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
42 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
43 * SUCH DAMAGE.
44 *
45 * The licence and distribution terms for any publically available version or
46 * derivative of this code cannot be changed. i.e. this code cannot simply be
47 * copied and put under another distribution licence
48 * [including the GNU Public Licence.]
49 */
50
51 /* set_key.c v 1.4 eay 24/9/91
52 * 1.4 Speed up by 400% :-)
53 * 1.3 added register declarations.
54 * 1.2 unrolled make_key_sched a bit more
55 * 1.1 added norm_expand_bits
56 * 1.0 First working version
57 */
58
59 #include <sys/cdefs.h>
60 #include <sys/param.h>
61 #include <sys/systm.h>
62 #include <crypto/des/des_locl.h>
63 #include <crypto/des/podd.h>
64 #include <crypto/des/sk.h>
65
66 int des_check_key=0;
67
des_set_odd_parity(unsigned char * key)68 void des_set_odd_parity(unsigned char *key)
69 {
70 int i;
71
72 for (i=0; i<DES_KEY_SZ; i++)
73 key[i]=odd_parity[key[i]];
74 }
75
des_check_key_parity(const unsigned char * key)76 int des_check_key_parity(const unsigned char *key)
77 {
78 int i;
79
80 for (i=0; i<DES_KEY_SZ; i++)
81 {
82 if (key[i] != odd_parity[key[i]])
83 return(0);
84 }
85 return(1);
86 }
87
88 /* Weak and semi week keys as take from
89 * %A D.W. Davies
90 * %A W.L. Price
91 * %T Security for Computer Networks
92 * %I John Wiley & Sons
93 * %D 1984
94 * Many thanks to [email protected] (Steven Bellovin) for the reference
95 * (and actual cblock values).
96 */
97 #define NUM_WEAK_KEY 16
98 static des_cblock weak_keys[NUM_WEAK_KEY]={
99 /* weak keys */
100 {0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
101 {0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE},
102 {0x1F,0x1F,0x1F,0x1F,0x0E,0x0E,0x0E,0x0E},
103 {0xE0,0xE0,0xE0,0xE0,0xF1,0xF1,0xF1,0xF1},
104 /* semi-weak keys */
105 {0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE},
106 {0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01},
107 {0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1},
108 {0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E},
109 {0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1},
110 {0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01},
111 {0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE},
112 {0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E},
113 {0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E},
114 {0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01},
115 {0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE},
116 {0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}};
117
des_is_weak_key(const unsigned char * key)118 int des_is_weak_key(const unsigned char *key)
119 {
120 int i;
121
122 for (i=0; i<NUM_WEAK_KEY; i++)
123 /* Added == 0 to comparison, I obviously don't run
124 * this section very often :-(, thanks to
125 * [email protected] for the fix
126 * eay 93/06/29
127 * Another problem, I was comparing only the first 4
128 * bytes, 97/03/18 */
129 if (memcmp(weak_keys[i],key,sizeof(des_cblock)) == 0) return(1);
130 return(0);
131 }
132
133 /* NOW DEFINED IN des_local.h
134 * See ecb_encrypt.c for a pseudo description of these macros.
135 * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
136 * (b)^=(t),\
137 * (a)=((a)^((t)<<(n))))
138 */
139
140 #define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
141 (a)=(a)^(t)^(t>>(16-(n))))
142
des_set_key(const unsigned char * key,des_key_schedule schedule)143 int des_set_key(const unsigned char *key, des_key_schedule schedule)
144 {
145 if (des_check_key)
146 {
147 return des_set_key_checked(key, schedule);
148 }
149 else
150 {
151 des_set_key_unchecked(key, schedule);
152 return 0;
153 }
154 }
155
156 /* return 0 if key parity is odd (correct),
157 * return -1 if key parity error,
158 * return -2 if illegal weak key.
159 */
des_set_key_checked(const unsigned char * key,des_key_schedule schedule)160 int des_set_key_checked(const unsigned char *key, des_key_schedule schedule)
161 {
162 if (!des_check_key_parity(key))
163 return(-1);
164 if (des_is_weak_key(key))
165 return(-2);
166 des_set_key_unchecked(key, schedule);
167 return 0;
168 }
169
des_set_key_unchecked(const unsigned char * key,des_key_schedule schedule)170 void des_set_key_unchecked(const unsigned char *key, des_key_schedule schedule)
171 {
172 static int shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
173 DES_LONG c,d,t,s,t2;
174 const unsigned char *in;
175 DES_LONG *k;
176 int i;
177
178 k = &schedule->ks.deslong[0];
179 in = key;
180
181 c2l(in,c);
182 c2l(in,d);
183
184 /* do PC1 in 47 simple operations :-)
185 * Thanks to John Fletcher ([email protected])
186 * for the inspiration. :-) */
187 PERM_OP (d,c,t,4,0x0f0f0f0fL);
188 HPERM_OP(c,t,-2,0xcccc0000L);
189 HPERM_OP(d,t,-2,0xcccc0000L);
190 PERM_OP (d,c,t,1,0x55555555L);
191 PERM_OP (c,d,t,8,0x00ff00ffL);
192 PERM_OP (d,c,t,1,0x55555555L);
193 d= (((d&0x000000ffL)<<16L)| (d&0x0000ff00L) |
194 ((d&0x00ff0000L)>>16L)|((c&0xf0000000L)>>4L));
195 c&=0x0fffffffL;
196
197 for (i=0; i<ITERATIONS; i++)
198 {
199 if (shifts2[i])
200 { c=((c>>2L)|(c<<26L)); d=((d>>2L)|(d<<26L)); }
201 else
202 { c=((c>>1L)|(c<<27L)); d=((d>>1L)|(d<<27L)); }
203 c&=0x0fffffffL;
204 d&=0x0fffffffL;
205 /* could be a few less shifts but I am to lazy at this
206 * point in time to investigate */
207 s= des_skb[0][ (c )&0x3f ]|
208 des_skb[1][((c>> 6L)&0x03)|((c>> 7L)&0x3c)]|
209 des_skb[2][((c>>13L)&0x0f)|((c>>14L)&0x30)]|
210 des_skb[3][((c>>20L)&0x01)|((c>>21L)&0x06) |
211 ((c>>22L)&0x38)];
212 t= des_skb[4][ (d )&0x3f ]|
213 des_skb[5][((d>> 7L)&0x03)|((d>> 8L)&0x3c)]|
214 des_skb[6][ (d>>15L)&0x3f ]|
215 des_skb[7][((d>>21L)&0x0f)|((d>>22L)&0x30)];
216
217 /* table contained 0213 4657 */
218 t2=((t<<16L)|(s&0x0000ffffL))&0xffffffffL;
219 *(k++)=ROTATE(t2,30)&0xffffffffL;
220
221 t2=((s>>16L)|(t&0xffff0000L));
222 *(k++)=ROTATE(t2,26)&0xffffffffL;
223 }
224 }
225
des_key_sched(const unsigned char * key,des_key_schedule schedule)226 int des_key_sched(const unsigned char *key, des_key_schedule schedule)
227 {
228 return(des_set_key(key,schedule));
229 }
230
des_fixup_key_parity(unsigned char * key)231 void des_fixup_key_parity(unsigned char *key)
232 {
233 des_set_odd_parity(key);
234 }
235