1 /*        $NetBSD: des_setkey.c,v 1.10 2005/12/11 12:20:52 christos Exp $       */
2 /*        $KAME: des_setkey.c,v 1.6 2001/07/03 14:27:53 itojun Exp $  */
3 
4 /* crypto/des/set_key.c */
5 /* Copyright (C) 1995-1996 Eric Young (eay@mincom.oz.au)
6  * All rights reserved.
7  *
8  * This file is part of an SSL implementation written
9  * by Eric Young (eay@mincom.oz.au).
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 (eay@mincom.oz.au)
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 __KERNEL_RCSID(0, "$NetBSD: des_setkey.c,v 1.10 2005/12/11 12:20:52 christos Exp $");
61 
62 #include <sys/param.h>
63 #ifdef _KERNEL
64 #include <sys/systm.h>
65 #else
66 #include <string.h>
67 #endif
68 #include <crypto/des/des_locl.h>
69 #include <crypto/des/podd.h>
70 #include <crypto/des/sk.h>
71 
72 int des_check_key=0;
73 
des_set_odd_parity(des_cblock * key)74 void des_set_odd_parity(des_cblock *key)
75 {
76           unsigned int i;
77 
78           for (i=0; i<DES_KEY_SZ; i++)
79                     (*key)[i]=odd_parity[(*key)[i]];
80 }
81 
des_check_key_parity(des_cblock * key)82 int des_check_key_parity(des_cblock *key)
83 {
84           unsigned int i;
85 
86           for (i=0; i<DES_KEY_SZ; i++)
87                     {
88                     if ((*key)[i] != odd_parity[(*key)[i]])
89                               return(0);
90                     }
91           return(1);
92 }
93 
94 /* Weak and semi week keys as take from
95  * %A D.W. Davies
96  * %A W.L. Price
97  * %T Security for Computer Networks
98  * %I John Wiley & Sons
99  * %D 1984
100  * Many thanks to smb@ulysses.att.com (Steven Bellovin) for the reference
101  * (and actual cblock values).
102  */
103 #define NUM_WEAK_KEY          16
104 static des_cblock weak_keys[NUM_WEAK_KEY]={
105           /* weak keys */
106           {0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
107           {0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE},
108           {0x1F,0x1F,0x1F,0x1F,0x0E,0x0E,0x0E,0x0E},
109           {0xE0,0xE0,0xE0,0xE0,0xF1,0xF1,0xF1,0xF1},
110           /* semi-weak keys */
111           {0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE},
112           {0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01},
113           {0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1},
114           {0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E},
115           {0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1},
116           {0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01},
117           {0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE},
118           {0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E},
119           {0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E},
120           {0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01},
121           {0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE},
122           {0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}};
123 
des_is_weak_key(des_cblock * key)124 int des_is_weak_key(des_cblock *key)
125 {
126           int i;
127 
128           for (i=0; i<NUM_WEAK_KEY; i++)
129                     /* Added == 0 to comparison, I obviously don't run
130                      * this section very often :-(, thanks to
131                      * engineering@MorningStar.Com for the fix
132                      * eay 93/06/29
133                      * Another problem, I was comparing only the first 4
134                      * bytes, 97/03/18 */
135                     if (memcmp(weak_keys[i],key,sizeof(des_cblock)) == 0) return(1);
136           return(0);
137 }
138 
139 /* NOW DEFINED IN des_local.h
140  * See ecb_encrypt.c for a pseudo description of these macros.
141  * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
142  *        (b)^=(t),\
143  *        (a)=((a)^((t)<<(n))))
144  */
145 
146 #define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
147           (a)=(a)^(t)^(t>>(16-(n))))
148 
des_set_key(des_cblock * key,des_key_schedule schedule)149 int des_set_key(des_cblock *key, des_key_schedule schedule)
150 {
151           if (des_check_key)
152           {
153                     return des_set_key_checked(key, schedule);
154           }
155           else
156           {
157                     des_set_key_unchecked(key, schedule);
158                     return 0;
159           }
160 }
161 
162 /* return 0 if key parity is odd (correct),
163  * return -1 if key parity error,
164  * return -2 if illegal weak key.
165  */
des_set_key_checked(des_cblock * key,des_key_schedule schedule)166 int des_set_key_checked(des_cblock *key, des_key_schedule schedule)
167 {
168           if (!des_check_key_parity(key))
169                     return(-1);
170           if (des_is_weak_key(key))
171                     return(-2);
172           des_set_key_unchecked(key, schedule);
173           return 0;
174 }
175 
des_set_key_unchecked(des_cblock * key,des_key_schedule schedule)176 void des_set_key_unchecked(des_cblock *key, des_key_schedule schedule)
177 {
178           static int shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
179           register DES_LONG c,d,t,s,t2;
180           register const unsigned char *in;
181           register DES_LONG *k;
182           register int i;
183 
184           k = &schedule->ks.deslong[0];
185           in = &(*key)[0];
186 
187           c2l(in,c);
188           c2l(in,d);
189 
190           /* do PC1 in 47 simple operations :-)
191            * Thanks to John Fletcher (john_fletcher@lccmail.ocf.llnl.gov)
192            * for the inspiration. :-) */
193           PERM_OP (d,c,t,4,0x0f0f0f0fL);
194           HPERM_OP(c,t,-2,0xcccc0000L);
195           HPERM_OP(d,t,-2,0xcccc0000L);
196           PERM_OP (d,c,t,1,0x55555555L);
197           PERM_OP (c,d,t,8,0x00ff00ffL);
198           PERM_OP (d,c,t,1,0x55555555L);
199           d=        (((d&0x000000ffL)<<16L)| (d&0x0000ff00L)     |
200                      ((d&0x00ff0000L)>>16L)|((c&0xf0000000L)>>4L));
201           c&=0x0fffffffL;
202 
203           for (i=0; i<ITERATIONS; i++)
204           {
205                     if (shifts2[i])
206                               { c=((c>>2L)|(c<<26L)); d=((d>>2L)|(d<<26L)); }
207                     else
208                               { c=((c>>1L)|(c<<27L)); d=((d>>1L)|(d<<27L)); }
209                     c&=0x0fffffffL;
210                     d&=0x0fffffffL;
211                     /* could be a few less shifts but I am to lazy at this
212                     * point in time to investigate */
213                     s=        des_skb[0][ (c    )&0x3f                ]|
214                               des_skb[1][((c>> 6L)&0x03)|((c>> 7L)&0x3c)]|
215                               des_skb[2][((c>>13L)&0x0f)|((c>>14L)&0x30)]|
216                               des_skb[3][((c>>20L)&0x01)|((c>>21L)&0x06) |
217                                                                       ((c>>22L)&0x38)];
218                     t=        des_skb[4][ (d    )&0x3f                ]|
219                               des_skb[5][((d>> 7L)&0x03)|((d>> 8L)&0x3c)]|
220                               des_skb[6][ (d>>15L)&0x3f                ]|
221                               des_skb[7][((d>>21L)&0x0f)|((d>>22L)&0x30)];
222 
223                     /* table contained 0213 4657 */
224                     t2=((t<<16L)|(s&0x0000ffffL))&0xffffffffL;
225                     *(k++)=ROTATE(t2,30)&0xffffffffL;
226 
227                     t2=((s>>16L)|(t&0xffff0000L));
228                     *(k++)=ROTATE(t2,26)&0xffffffffL;
229           }
230 }
231 
des_key_sched(des_cblock * key,des_key_schedule schedule)232 int des_key_sched(des_cblock *key, des_key_schedule schedule)
233 {
234           return(des_set_key(key,schedule));
235 }
236 
des_fixup_key_parity(des_cblock * key)237 void des_fixup_key_parity(des_cblock *key)
238 {
239           des_set_odd_parity(key);
240 }
241