pcbc_enc.c revision 296465 
1/* crypto/des/pcbc_enc.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
61void DES_pcbc_encrypt(const unsigned char *input, unsigned char *output,
62                      long length, DES_key_schedule *schedule,
63                      DES_cblock *ivec, int enc)
64{
65    register DES_LONG sin0, sin1, xor0, xor1, tout0, tout1;
66    DES_LONG tin[2];
67    const unsigned char *in;
68    unsigned char *out, *iv;
69
70    in = input;
71    out = output;
72    iv = &(*ivec)[0];
73
74    if (enc) {
75        c2l(iv, xor0);
76        c2l(iv, xor1);
77        for (; length > 0; length -= 8) {
78            if (length >= 8) {
79                c2l(in, sin0);
80                c2l(in, sin1);
81            } else
82                c2ln(in, sin0, sin1, length);
83            tin[0] = sin0 ^ xor0;
84            tin[1] = sin1 ^ xor1;
85            DES_encrypt1((DES_LONG *)tin, schedule, DES_ENCRYPT);
86            tout0 = tin[0];
87            tout1 = tin[1];
88            xor0 = sin0 ^ tout0;
89            xor1 = sin1 ^ tout1;
90            l2c(tout0, out);
91            l2c(tout1, out);
92        }
93    } else {
94        c2l(iv, xor0);
95        c2l(iv, xor1);
96        for (; length > 0; length -= 8) {
97            c2l(in, sin0);
98            c2l(in, sin1);
99            tin[0] = sin0;
100            tin[1] = sin1;
101            DES_encrypt1((DES_LONG *)tin, schedule, DES_DECRYPT);
102            tout0 = tin[0] ^ xor0;
103            tout1 = tin[1] ^ xor1;
104            if (length >= 8) {
105                l2c(tout0, out);
106                l2c(tout1, out);
107            } else
108                l2cn(tout0, tout1, out, length);
109            xor0 = tout0 ^ sin0;
110            xor1 = tout1 ^ sin1;
111        }
112    }
113    tin[0] = tin[1] = 0;
114    sin0 = sin1 = xor0 = xor1 = tout0 = tout1 = 0;
115}
116