xref: /openbsd-src/sys/crypto/set_key.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /*	$OpenBSD: set_key.c,v 1.3 2013/11/18 18:49:53 brad 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
70 des_set_odd_parity(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
79 check_parity(des_cblock (*key))
80 {
81 	int i;
82 
83 	for (i = 0; i < DES_KEY_SZ; i++) {
84 		if ((*key)[i] != odd_parity[(*key)[i]])
85 			return(0);
86 	}
87 	return (1);
88 }
89 
90 /* Weak and semi week keys as take from
91  * %A D.W. Davies
92  * %A W.L. Price
93  * %T Security for Computer Networks
94  * %I John Wiley & Sons
95  * %D 1984
96  * Many thanks to smb@ulysses.att.com (Steven Bellovin) for the reference
97  * (and actual cblock values).
98  */
99 #define NUM_WEAK_KEY	16
100 static des_cblock weak_keys[NUM_WEAK_KEY]={
101 	/* weak keys */
102 	{0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
103 	{0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE},
104 	{0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F},
105 	{0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,0xE0},
106 	/* semi-weak keys */
107 	{0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE},
108 	{0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01},
109 	{0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1},
110 	{0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E},
111 	{0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1},
112 	{0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01},
113 	{0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE},
114 	{0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E},
115 	{0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E},
116 	{0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01},
117 	{0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE},
118 	{0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}};
119 
120 int
121 des_is_weak_key(des_cblock (*key))
122 {
123 	int i;
124 
125 	for (i = 0; i < NUM_WEAK_KEY; i++) {
126 		/* Added == 0 to comparision, I obviously don't run
127 		 * this section very often :-(, thanks to
128 		 * engineering@MorningStar.Com for the fix
129 		 * eay 93/06/29 */
130 		if (bcmp(weak_keys[i], key, sizeof(des_cblock)) == 0)
131 			return (1);
132 	}
133 	return (0);
134 }
135 
136 /* NOW DEFINED IN des_local.h
137  * See ecb_encrypt.c for a pseudo description of these macros.
138  * #define PERM_OP(a, b, t, n, m) ((t) = ((((a) >> (n))^(b)) & (m)),\
139  * 	(b)^=(t),\
140  * 	(a) = ((a)^((t) << (n))))
141  */
142 
143 #define HPERM_OP(a, t, n, m) ((t) = ((((a) << (16 - (n)))^(a)) & (m)),\
144 	(a) = (a)^(t)^(t >> (16 - (n))))
145 
146 static int shifts2[16]={0, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0};
147 
148 /* return 0 if key parity is odd (correct),
149  * return -1 if key parity error,
150  * return -2 if illegal weak key.
151  */
152 int
153 des_set_key(des_cblock (*key), 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 		if (!check_parity(key))
162 			return(-1);
163 
164 		if (des_is_weak_key(key))
165 			return(-2);
166 	}
167 
168 	k = (u_int32_t *) schedule;
169 	in = (unsigned char *) key;
170 
171 	c2l(in, c);
172 	c2l(in, d);
173 
174 	/* do PC1 in 60 simple operations */
175 /*	PERM_OP(d, c, t, 4, 0x0f0f0f0fL);
176 	HPERM_OP(c, t, -2, 0xcccc0000L);
177 	HPERM_OP(c, t, -1, 0xaaaa0000L);
178 	HPERM_OP(c, t, 8, 0x00ff0000L);
179 	HPERM_OP(c, t, -1, 0xaaaa0000L);
180 	HPERM_OP(d, t, -8, 0xff000000L);
181 	HPERM_OP(d, t, 8, 0x00ff0000L);
182 	HPERM_OP(d, t, 2, 0x33330000L);
183 	d = ((d & 0x00aa00aaL) << 7L) | ((d & 0x55005500L) >> 7L) | (d & 0xaa55aa55L);
184 	d = (d >> 8) | ((c & 0xf0000000L) >> 4);
185 	c &= 0x0fffffffL; */
186 
187 	/* I now do it in 47 simple operations :-)
188 	 * Thanks to John Fletcher (john_fletcher@lccmail.ocf.llnl.gov)
189 	 * for the inspiration. :-) */
190 	PERM_OP (d, c, t, 4, 0x0f0f0f0fL);
191 	HPERM_OP(c, t, -2, 0xcccc0000L);
192 	HPERM_OP(d, t, -2, 0xcccc0000L);
193 	PERM_OP (d, c, t, 1, 0x55555555L);
194 	PERM_OP (c, d, t, 8, 0x00ff00ffL);
195 	PERM_OP (d, c, t, 1, 0x55555555L);
196 	d = (((d & 0x000000ffL) << 16L) | (d & 0x0000ff00L) |
197 	     ((d & 0x00ff0000L) >> 16L) | ((c & 0xf0000000L) >> 4L));
198 	c &= 0x0fffffffL;
199 
200 	for (i = 0; i < ITERATIONS; i++) {
201 		if (shifts2[i])
202 			{ c = ((c >> 2L) | (c << 26L)); d = ((d >> 2L) | (d << 26L)); }
203 		else
204 			{ c = ((c >> 1L) | (c << 27L)); d = ((d >> 1L) | (d << 27L)); }
205 		c &= 0x0fffffffL;
206 		d &= 0x0fffffffL;
207 		/* could be a few less shifts but I am to lazy at this
208 		 * point in time to investigate */
209 		s = des_skb[0][ (c    ) & 0x3f                ]|
210 		    des_skb[1][((c >> 6) & 0x03) | ((c >> 7L) & 0x3c)]|
211 		    des_skb[2][((c >> 13) & 0x0f) | ((c >> 14L) & 0x30)]|
212 		    des_skb[3][((c >> 20) & 0x01) | ((c >> 21L) & 0x06) |
213 						  ((c >> 22L) & 0x38)];
214 		t = des_skb[4][ (d    ) & 0x3f                ]|
215 		    des_skb[5][((d >> 7L) & 0x03) | ((d >> 8L) & 0x3c)]|
216 		    des_skb[6][ (d >> 15L) & 0x3f                ]|
217 		    des_skb[7][((d >> 21L) & 0x0f) | ((d >> 22L) & 0x30)];
218 
219 		/* table contained 0213 4657 */
220 		*(k++) = ((t << 16L) | (s & 0x0000ffffL)) & 0xffffffffL;
221 		s = ((s >> 16L) | (t & 0xffff0000L));
222 
223 		s = (s << 4L) | (s >> 28L);
224 		*(k++) = s & 0xffffffffL;
225 	}
226 	return (0);
227 }
228 
229 int
230 des_key_sched(des_cblock (*key), des_key_schedule schedule)
231 {
232 	return (des_set_key(key, schedule));
233 }
234