xref: /freebsd/sys/crypto/des/des_setkey.c (revision ae83180158c4c937f170e31eff311b18c0286a93)
1 /*	$FreeBSD$	*/
2 /*	$KAME: des_setkey.c,v 1.7 2001/09/10 04:03:58 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 #include <sys/param.h>
59 #include <sys/systm.h>
60 #include <crypto/des/des_locl.h>
61 #include <crypto/des/podd.h>
62 #include <crypto/des/sk.h>
63 
64 int des_check_key=0;
65 
66 void des_set_odd_parity(des_cblock *key)
67 {
68 	int i;
69 
70 	for (i=0; i<DES_KEY_SZ; i++)
71 		(*key)[i]=odd_parity[(*key)[i]];
72 }
73 
74 int des_check_key_parity(des_cblock *key)
75 {
76 	int i;
77 
78 	for (i=0; i<DES_KEY_SZ; i++)
79 		{
80 		if ((*key)[i] != odd_parity[(*key)[i]])
81 			return(0);
82 		}
83 	return(1);
84 }
85 
86 /* Weak and semi week keys as take from
87  * %A D.W. Davies
88  * %A W.L. Price
89  * %T Security for Computer Networks
90  * %I John Wiley & Sons
91  * %D 1984
92  * Many thanks to smb@ulysses.att.com (Steven Bellovin) for the reference
93  * (and actual cblock values).
94  */
95 #define NUM_WEAK_KEY	16
96 static des_cblock weak_keys[NUM_WEAK_KEY]={
97 	/* weak keys */
98 	{0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
99 	{0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE},
100 	{0x1F,0x1F,0x1F,0x1F,0x0E,0x0E,0x0E,0x0E},
101 	{0xE0,0xE0,0xE0,0xE0,0xF1,0xF1,0xF1,0xF1},
102 	/* semi-weak keys */
103 	{0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE},
104 	{0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01},
105 	{0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1},
106 	{0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E},
107 	{0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1},
108 	{0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01},
109 	{0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE},
110 	{0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E},
111 	{0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E},
112 	{0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01},
113 	{0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE},
114 	{0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}};
115 
116 int des_is_weak_key(des_cblock *key)
117 {
118 	int i;
119 
120 	for (i=0; i<NUM_WEAK_KEY; i++)
121 		/* Added == 0 to comparison, I obviously don't run
122 		 * this section very often :-(, thanks to
123 		 * engineering@MorningStar.Com for the fix
124 		 * eay 93/06/29
125 		 * Another problem, I was comparing only the first 4
126 		 * bytes, 97/03/18 */
127 		if (memcmp(weak_keys[i],key,sizeof(des_cblock)) == 0) return(1);
128 	return(0);
129 }
130 
131 /* NOW DEFINED IN des_local.h
132  * See ecb_encrypt.c for a pseudo description of these macros.
133  * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
134  * 	(b)^=(t),\
135  * 	(a)=((a)^((t)<<(n))))
136  */
137 
138 #define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
139 	(a)=(a)^(t)^(t>>(16-(n))))
140 
141 int des_set_key(des_cblock *key, des_key_schedule schedule)
142 {
143 	if (des_check_key)
144 	{
145 		return des_set_key_checked(key, schedule);
146 	}
147 	else
148 	{
149 		des_set_key_unchecked(key, schedule);
150 		return 0;
151 	}
152 }
153 
154 /* return 0 if key parity is odd (correct),
155  * return -1 if key parity error,
156  * return -2 if illegal weak key.
157  */
158 int des_set_key_checked(des_cblock *key, des_key_schedule schedule)
159 {
160 	if (!des_check_key_parity(key))
161 		return(-1);
162 	if (des_is_weak_key(key))
163 		return(-2);
164 	des_set_key_unchecked(key, schedule);
165 	return 0;
166 }
167 
168 void des_set_key_unchecked(des_cblock *key, des_key_schedule schedule)
169 {
170 	static int shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
171 	register DES_LONG c,d,t,s,t2;
172 	register const unsigned char *in;
173 	register DES_LONG *k;
174 	register int i;
175 
176 	k = &schedule->ks.deslong[0];
177 	in = &(*key)[0];
178 
179 	c2l(in,c);
180 	c2l(in,d);
181 
182 	/* do PC1 in 47 simple operations :-)
183 	 * Thanks to John Fletcher (john_fletcher@lccmail.ocf.llnl.gov)
184 	 * for the inspiration. :-) */
185 	PERM_OP (d,c,t,4,0x0f0f0f0fL);
186 	HPERM_OP(c,t,-2,0xcccc0000L);
187 	HPERM_OP(d,t,-2,0xcccc0000L);
188 	PERM_OP (d,c,t,1,0x55555555L);
189 	PERM_OP (c,d,t,8,0x00ff00ffL);
190 	PERM_OP (d,c,t,1,0x55555555L);
191 	d=	(((d&0x000000ffL)<<16L)| (d&0x0000ff00L)     |
192 		 ((d&0x00ff0000L)>>16L)|((c&0xf0000000L)>>4L));
193 	c&=0x0fffffffL;
194 
195 	for (i=0; i<ITERATIONS; i++)
196 	{
197 		if (shifts2[i])
198 			{ c=((c>>2L)|(c<<26L)); d=((d>>2L)|(d<<26L)); }
199 		else
200 			{ c=((c>>1L)|(c<<27L)); d=((d>>1L)|(d<<27L)); }
201 		c&=0x0fffffffL;
202 		d&=0x0fffffffL;
203 		/* could be a few less shifts but I am to lazy at this
204 	 	* point in time to investigate */
205 		s=	des_skb[0][ (c    )&0x3f                ]|
206 			des_skb[1][((c>> 6L)&0x03)|((c>> 7L)&0x3c)]|
207 			des_skb[2][((c>>13L)&0x0f)|((c>>14L)&0x30)]|
208 			des_skb[3][((c>>20L)&0x01)|((c>>21L)&0x06) |
209 						  	((c>>22L)&0x38)];
210 		t=	des_skb[4][ (d    )&0x3f                ]|
211 			des_skb[5][((d>> 7L)&0x03)|((d>> 8L)&0x3c)]|
212 			des_skb[6][ (d>>15L)&0x3f                ]|
213 			des_skb[7][((d>>21L)&0x0f)|((d>>22L)&0x30)];
214 
215 		/* table contained 0213 4657 */
216 		t2=((t<<16L)|(s&0x0000ffffL))&0xffffffffL;
217 		*(k++)=ROTATE(t2,30)&0xffffffffL;
218 
219 		t2=((s>>16L)|(t&0xffff0000L));
220 		*(k++)=ROTATE(t2,26)&0xffffffffL;
221 	}
222 }
223 
224 int des_key_sched(des_cblock *key, des_key_schedule schedule)
225 {
226 	return(des_set_key(key,schedule));
227 }
228 
229 void des_fixup_key_parity(des_cblock *key)
230 {
231 	des_set_odd_parity(key);
232 }
233