xref: /freebsd/sys/crypto/des/des_setkey.c (revision daf1cffce2e07931f27c6c6998652e90df6ba87e)
1 /* crypto/des/set_key.c */
2 /* Copyright (C) 1995-1996 Eric Young (eay@mincom.oz.au)
3  * All rights reserved.
4  *
5  * This file is part of an SSL implementation written
6  * by Eric Young (eay@mincom.oz.au).
7  * The implementation was written so as to conform with Netscapes SSL
8  * specification.  This library and applications are
9  * FREE FOR COMMERCIAL AND NON-COMMERCIAL USE
10  * as long as the following conditions are aheared to.
11  *
12  * Copyright remains Eric Young's, and as such any Copyright notices in
13  * the code are not to be removed.  If this code is used in a product,
14  * Eric Young should be given attribution as the author of the parts used.
15  * This can be in the form of a textual message at program startup or
16  * in documentation (online or textual) provided with the package.
17  *
18  * Redistribution and use in source and binary forms, with or without
19  * modification, are permitted provided that the following conditions
20  * are met:
21  * 1. Redistributions of source code must retain the copyright
22  *    notice, this list of conditions and the following disclaimer.
23  * 2. Redistributions in binary form must reproduce the above copyright
24  *    notice, this list of conditions and the following disclaimer in the
25  *    documentation and/or other materials provided with the distribution.
26  * 3. All advertising materials mentioning features or use of this software
27  *    must display the following acknowledgement:
28  *    This product includes software developed by Eric Young (eay@mincom.oz.au)
29  *
30  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
31  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
34  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40  * SUCH DAMAGE.
41  *
42  * The licence and distribution terms for any publically available version or
43  * derivative of this code cannot be changed.  i.e. this code cannot simply be
44  * copied and put under another distribution licence
45  * [including the GNU Public Licence.]
46  *
47  * $FreeBSD$
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 <crypto/des/des_locl.h>
58 #include <crypto/des/podd.h>
59 #include <crypto/des/sk.h>
60 
61 #ifndef NOPROTO
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 /*
132 		if (memcmp(weak_keys[i],key,sizeof(key)) == 0) return(1);
133 */
134 		if (bcmp(weak_keys[i],key,sizeof(key)) == 0) return(1);
135 	return(0);
136 	}
137 
138 /* NOW DEFINED IN des_local.h
139  * See ecb_encrypt.c for a pseudo description of these macros.
140  * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
141  * 	(b)^=(t),\
142  * 	(a)=((a)^((t)<<(n))))
143  */
144 
145 #define	HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
146 	(a)=(a)^(t)^(t>>(16-(n))))
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 des_set_key(key, schedule)
153 des_cblock (*key);
154 des_key_schedule schedule;
155 	{
156 	static int shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
157 	register DES_LONG c,d,t,s;
158 	register unsigned char *in;
159 	register DES_LONG *k;
160 	register int i;
161 
162 	if (des_check_key)
163 		{
164 		if (!check_parity(key))
165 			return(-1);
166 
167 		if (des_is_weak_key(key))
168 			return(-2);
169 		}
170 
171 	k=(DES_LONG *)schedule;
172 	in=(unsigned char *)key;
173 
174 	c2l(in,c);
175 	c2l(in,d);
176 
177 	/* do PC1 in 60 simple operations */
178 /*	PERM_OP(d,c,t,4,0x0f0f0f0fL);
179 	HPERM_OP(c,t,-2, 0xcccc0000L);
180 	HPERM_OP(c,t,-1, 0xaaaa0000L);
181 	HPERM_OP(c,t, 8, 0x00ff0000L);
182 	HPERM_OP(c,t,-1, 0xaaaa0000L);
183 	HPERM_OP(d,t,-8, 0xff000000L);
184 	HPERM_OP(d,t, 8, 0x00ff0000L);
185 	HPERM_OP(d,t, 2, 0x33330000L);
186 	d=((d&0x00aa00aaL)<<7L)|((d&0x55005500L)>>7L)|(d&0xaa55aa55L);
187 	d=(d>>8)|((c&0xf0000000L)>>4);
188 	c&=0x0fffffffL; */
189 
190 	/* I now do it 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>> 6)&0x03)|((c>> 7L)&0x3c)]|
215 			des_skb[2][((c>>13)&0x0f)|((c>>14L)&0x30)]|
216 			des_skb[3][((c>>20)&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 		*(k++)=((t<<16L)|(s&0x0000ffffL))&0xffffffffL;
225 		s=     ((s>>16L)|(t&0xffff0000L));
226 
227 		s=(s<<4L)|(s>>28L);
228 		*(k++)=s&0xffffffffL;
229 		}
230 	return(0);
231 	}
232 
233 int des_key_sched(key, schedule)
234 des_cblock (*key);
235 des_key_schedule schedule;
236 	{
237 	return(des_set_key(key,schedule));
238 	}
239