cbc_cksm.c revision 296465 
1/* crypto/des/cbc_cksm.c */
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#include "des_locl.h"
60
61DES_LONG DES_cbc_cksum(const unsigned char *in, DES_cblock *output,
62                       long length, DES_key_schedule *schedule,
63                       const_DES_cblock *ivec)
64{
65    register DES_LONG tout0, tout1, tin0, tin1;
66    register long l = length;
67    DES_LONG tin[2];
68    unsigned char *out = &(*output)[0];
69    const unsigned char *iv = &(*ivec)[0];
70
71    c2l(iv, tout0);
72    c2l(iv, tout1);
73    for (; l > 0; l -= 8) {
74        if (l >= 8) {
75            c2l(in, tin0);
76            c2l(in, tin1);
77        } else
78            c2ln(in, tin0, tin1, l);
79
80        tin0 ^= tout0;
81        tin[0] = tin0;
82        tin1 ^= tout1;
83        tin[1] = tin1;
84        DES_encrypt1((DES_LONG *)tin, schedule, DES_ENCRYPT);
85        /* fix 15/10/91 eay - thanks to keithr@sco.COM */
86        tout0 = tin[0];
87        tout1 = tin[1];
88    }
89    if (out != NULL) {
90        l2c(tout0, out);
91        l2c(tout1, out);
92    }
93    tout0 = tin0 = tin1 = tin[0] = tin[1] = 0;
94    /*
95     * Transform the data in tout1 so that it will match the return value
96     * that the MIT Kerberos mit_des_cbc_cksum API returns.
97     */
98    tout1 = ((tout1 >> 24L) & 0x000000FF)
99        | ((tout1 >> 8L) & 0x0000FF00)
100        | ((tout1 << 8L) & 0x00FF0000)
101        | ((tout1 << 24L) & 0xFF000000);
102    return (tout1);
103}
104