1/* crypto/des/set_key.c */
2/* Copyright (C) 1995-1997 Eric Young (eay@mincom.oz.au)
3 * All rights reserved.
4 *
5 * This package is 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 *
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to.  The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@mincom.oz.au).
15 *
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
26 * 1. Redistributions of source code must retain the copyright
27 *    notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 *    notice, this list of conditions and the following disclaimer in the
30 *    documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 *    must display the following acknowledgement:
33 *    "This product includes cryptographic software written by
34 *     Eric Young (eay@mincom.oz.au)"
35 *    The word 'cryptographic' can be left out if the rouines from the library
36 *    being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 *    the apps directory (application code) you must include an acknowledgement:
39 *    "This product includes software written by Tim Hudson (tjh@mincom.oz.au)"
40 *
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51 * SUCH DAMAGE.
52 *
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed.  i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
57 */
58
59/* set_key.c v 1.4 eay 24/9/91
60 * 1.4 Speed up by 400% :-)
61 * 1.3 added register declarations.
62 * 1.2 unrolled make_key_sched a bit more
63 * 1.1 added norm_expand_bits
64 * 1.0 First working version
65 */
66#include "des_locl.h"
67#include "podd.h"
68#include "sk.h"
69
70#ifndef NOPROTO
71static int check_parity(des_cblock (*key));
72#else
73static int check_parity();
74#endif
75
76int des_check_key=0;
77
78void des_set_odd_parity(key)
79des_cblock (*key);
80	{
81	int i;
82
83	for (i=0; i<DES_KEY_SZ; i++)
84		(*key)[i]=odd_parity[(*key)[i]];
85	}
86
87static int check_parity(key)
88des_cblock (*key);
89	{
90	int i;
91
92	for (i=0; i<DES_KEY_SZ; i++)
93		{
94		if ((*key)[i] != odd_parity[(*key)[i]])
95			return(0);
96		}
97	return(1);
98	}
99
100/* Weak and semi week keys as take from
101 * %A D.W. Davies
102 * %A W.L. Price
103 * %T Security for Computer Networks
104 * %I John Wiley & Sons
105 * %D 1984
106 * Many thanks to smb@ulysses.att.com (Steven Bellovin) for the reference
107 * (and actual cblock values).
108 */
109#define NUM_WEAK_KEY	16
110static des_cblock weak_keys[NUM_WEAK_KEY]={
111	/* weak keys */
112	{0x01,0x01,0x01,0x01,0x01,0x01,0x01,0x01},
113	{0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE,0xFE},
114	{0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F,0x1F},
115	{0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,0xE0,0xE0},
116	/* semi-weak keys */
117	{0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE},
118	{0xFE,0x01,0xFE,0x01,0xFE,0x01,0xFE,0x01},
119	{0x1F,0xE0,0x1F,0xE0,0x0E,0xF1,0x0E,0xF1},
120	{0xE0,0x1F,0xE0,0x1F,0xF1,0x0E,0xF1,0x0E},
121	{0x01,0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1},
122	{0xE0,0x01,0xE0,0x01,0xF1,0x01,0xF1,0x01},
123	{0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E,0xFE},
124	{0xFE,0x1F,0xFE,0x1F,0xFE,0x0E,0xFE,0x0E},
125	{0x01,0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E},
126	{0x1F,0x01,0x1F,0x01,0x0E,0x01,0x0E,0x01},
127	{0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1,0xFE},
128	{0xFE,0xE0,0xFE,0xE0,0xFE,0xF1,0xFE,0xF1}};
129
130int des_is_weak_key(key)
131des_cblock (*key);
132	{
133	int i;
134
135	for (i=0; i<NUM_WEAK_KEY; i++)
136		/* Added == 0 to comparision, I obviously don't run
137		 * this section very often :-(, thanks to
138		 * engineering@MorningStar.Com for the fix
139		 * eay 93/06/29 */
140		if (memcmp(weak_keys[i],key,sizeof(key)) == 0) return(1);
141	return(0);
142	}
143
144/* NOW DEFINED IN des_local.h
145 * See ecb_encrypt.c for a pseudo description of these macros.
146 * #define PERM_OP(a,b,t,n,m) ((t)=((((a)>>(n))^(b))&(m)),\
147 * 	(b)^=(t),\
148 * 	(a)=((a)^((t)<<(n))))
149 */
150
151#define HPERM_OP(a,t,n,m) ((t)=((((a)<<(16-(n)))^(a))&(m)),\
152	(a)=(a)^(t)^(t>>(16-(n))))
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 */
158int des_set_key(key, schedule)
159des_cblock (*key);
160des_key_schedule schedule;
161	{
162	static int shifts2[16]={0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0};
163	register DES_LONG c,d,t,s,t2;
164	register unsigned char *in;
165	register DES_LONG *k;
166	register int i;
167
168	if (des_check_key)
169		{
170		if (!check_parity(key))
171			return(-1);
172
173		if (des_is_weak_key(key))
174			return(-2);
175		}
176
177	k=(DES_LONG *)schedule;
178	in=(unsigned char *)key;
179
180	c2l(in,c);
181	c2l(in,d);
182
183	/* do PC1 in 60 simple operations */
184/*	PERM_OP(d,c,t,4,0x0f0f0f0fL);
185	HPERM_OP(c,t,-2, 0xcccc0000L);
186	HPERM_OP(c,t,-1, 0xaaaa0000L);
187	HPERM_OP(c,t, 8, 0x00ff0000L);
188	HPERM_OP(c,t,-1, 0xaaaa0000L);
189	HPERM_OP(d,t,-8, 0xff000000L);
190	HPERM_OP(d,t, 8, 0x00ff0000L);
191	HPERM_OP(d,t, 2, 0x33330000L);
192	d=((d&0x00aa00aaL)<<7L)|((d&0x55005500L)>>7L)|(d&0xaa55aa55L);
193	d=(d>>8)|((c&0xf0000000L)>>4);
194	c&=0x0fffffffL; */
195
196	/* I now do it in 47 simple operations :-)
197	 * Thanks to John Fletcher (john_fletcher@lccmail.ocf.llnl.gov)
198	 * for the inspiration. :-) */
199	PERM_OP (d,c,t,4,0x0f0f0f0fL);
200	HPERM_OP(c,t,-2,0xcccc0000L);
201	HPERM_OP(d,t,-2,0xcccc0000L);
202	PERM_OP (d,c,t,1,0x55555555L);
203	PERM_OP (c,d,t,8,0x00ff00ffL);
204	PERM_OP (d,c,t,1,0x55555555L);
205	d=	(((d&0x000000ffL)<<16L)| (d&0x0000ff00L)     |
206		 ((d&0x00ff0000L)>>16L)|((c&0xf0000000L)>>4L));
207	c&=0x0fffffffL;
208
209	for (i=0; i<ITERATIONS; i++)
210		{
211		if (shifts2[i])
212			{ c=((c>>2L)|(c<<26L)); d=((d>>2L)|(d<<26L)); }
213		else
214			{ c=((c>>1L)|(c<<27L)); d=((d>>1L)|(d<<27L)); }
215		c&=0x0fffffffL;
216		d&=0x0fffffffL;
217		/* could be a few less shifts but I am to lazy at this
218		 * point in time to investigate */
219		s=	des_skb[0][ (c    )&0x3f                ]|
220			des_skb[1][((c>> 6)&0x03)|((c>> 7L)&0x3c)]|
221			des_skb[2][((c>>13)&0x0f)|((c>>14L)&0x30)]|
222			des_skb[3][((c>>20)&0x01)|((c>>21L)&0x06) |
223						  ((c>>22L)&0x38)];
224		t=	des_skb[4][ (d    )&0x3f                ]|
225			des_skb[5][((d>> 7L)&0x03)|((d>> 8L)&0x3c)]|
226			des_skb[6][ (d>>15L)&0x3f                ]|
227			des_skb[7][((d>>21L)&0x0f)|((d>>22L)&0x30)];
228
229		/* table contained 0213 4657 */
230		t2=((t<<16L)|(s&0x0000ffffL))&0xffffffffL;
231		*(k++)=ROTATE(t2,30)&0xffffffffL;
232
233		t2=((s>>16L)|(t&0xffff0000L));
234		*(k++)=ROTATE(t2,26)&0xffffffffL;
235		}
236	return(0);
237	}
238
239int des_key_sched(key, schedule)
240des_cblock (*key);
241des_key_schedule schedule;
242	{
243	return(des_set_key(key,schedule));
244	}
245