xref: /openbsd/lib/libcrypto/des/des_cksum.c (revision cc54cb09)
1 /* $OpenBSD: des_cksum.c,v 1.1 2024/08/31 15:56:09 jsing Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@cryptsoft.com).
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@cryptsoft.com).
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@cryptsoft.com)"
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@cryptsoft.com)"
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 /* From "Message Authentication"  R.R. Jueneman, S.M. Matyas, C.H. Meyer
60  * IEEE Communications Magazine Sept 1985 Vol. 23 No. 9 p 29-40
61  * This module in only based on the code in this paper and is
62  * almost definitely not the same as the MIT implementation.
63  */
64 #include "des_local.h"
65 
66 /* bug fix for dos - 7/6/91 - Larry hughes@logos.ucs.indiana.edu */
67 #define Q_B0(a)	(((DES_LONG)(a)))
68 #define Q_B1(a)	(((DES_LONG)(a))<<8)
69 #define Q_B2(a)	(((DES_LONG)(a))<<16)
70 #define Q_B3(a)	(((DES_LONG)(a))<<24)
71 
72 /* used to scramble things a bit */
73 /* Got the value MIT uses via brute force :-) 2/10/90 eay */
74 #define NOISE	((DES_LONG)83653421L)
75 
76 DES_LONG
DES_cbc_cksum(const unsigned char * in,DES_cblock * output,long length,DES_key_schedule * schedule,const_DES_cblock * ivec)77 DES_cbc_cksum(const unsigned char *in, DES_cblock *output,
78     long length, DES_key_schedule *schedule,
79     const_DES_cblock *ivec)
80 {
81 	DES_LONG tout0, tout1, tin0, tin1;
82 	long l = length;
83 	DES_LONG tin[2];
84 	unsigned char *out = &(*output)[0];
85 	const unsigned char *iv = &(*ivec)[0];
86 
87 	c2l(iv, tout0);
88 	c2l(iv, tout1);
89 	for (; l > 0; l -= 8) {
90 		if (l >= 8) {
91 			c2l(in, tin0);
92 			c2l(in, tin1);
93 		} else
94 			c2ln(in, tin0, tin1, l);
95 
96 		tin0 ^= tout0;
97 		tin[0] = tin0;
98 		tin1 ^= tout1;
99 		tin[1] = tin1;
100 		DES_encrypt1((DES_LONG *)tin, schedule, DES_ENCRYPT);
101 		/* fix 15/10/91 eay - thanks to keithr@sco.COM */
102 		tout0 = tin[0];
103 		tout1 = tin[1];
104 	}
105 	if (out != NULL) {
106 		l2c(tout0, out);
107 		l2c(tout1, out);
108 	}
109 	tout0 = tin0 = tin1 = tin[0] = tin[1] = 0;
110 	/*
111 	  Transform the data in tout1 so that it will
112 	  match the return value that the MIT Kerberos
113 	  mit_des_cbc_cksum API returns.
114 	*/
115 	tout1 = ((tout1 >> 24L) & 0x000000FF) |
116 	    ((tout1 >> 8L) & 0x0000FF00) |
117 	    ((tout1 << 8L) & 0x00FF0000) |
118 	    ((tout1 << 24L) & 0xFF000000);
119 	return (tout1);
120 }
121 LCRYPTO_ALIAS(DES_cbc_cksum);
122 
123 DES_LONG
DES_quad_cksum(const unsigned char * input,DES_cblock output[],long length,int out_count,DES_cblock * seed)124 DES_quad_cksum(const unsigned char *input, DES_cblock output[],
125     long length, int out_count, DES_cblock *seed)
126 {
127 	DES_LONG z0, z1, t0, t1;
128 	int i;
129 	long l;
130 	const unsigned char *cp;
131 	DES_LONG *lp;
132 
133 	if (out_count < 1)
134 		out_count = 1;
135 	lp = (DES_LONG *)&(output[0])[0];
136 
137 	z0 = Q_B0((*seed)[0])|Q_B1((*seed)[1])|Q_B2((*seed)[2])|Q_B3(
138 	    (*seed)[3]);
139 	z1 = Q_B0((*seed)[4])|Q_B1((*seed)[5])|Q_B2((*seed)[6])|Q_B3(
140 	    (*seed)[7]);
141 
142 	for (i = 0; ((i < 4) && (i < out_count)); i++) {
143 		cp = input;
144 		l = length;
145 		while (l > 0) {
146 			if (l > 1) {
147 				t0 = (DES_LONG)(*(cp++));
148 				t0 |= (DES_LONG)Q_B1(*(cp++));
149 				l--;
150 			} else
151 				t0 = (DES_LONG)(*(cp++));
152 			l--;
153 			/* add */
154 			t0 += z0;
155 			t0 &= 0xffffffffL;
156 			t1 = z1;
157 			/* square, well sort of square */
158 			z0 = ((((t0*t0) & 0xffffffffL) +
159 			    ((t1*t1) & 0xffffffffL)) & 0xffffffffL) %
160 			    0x7fffffffL;
161 			z1 = ((t0*((t1 + NOISE) & 0xffffffffL)) & 0xffffffffL) %
162 			    0x7fffffffL;
163 		}
164 		if (lp != NULL) {
165 			/* The MIT library assumes that the checksum is
166 			 * composed of 2*out_count 32 bit ints */
167 			*lp++ = z0;
168 			*lp++ = z1;
169 		}
170 	}
171 	return (z0);
172 }
173 LCRYPTO_ALIAS(DES_quad_cksum);
174