1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
4 * This package is an SSL implementation written
5 * by Eric Young (eay@cryptsoft.com).
6 * The implementation was written so as to conform with Netscapes SSL.
8 * This library is free for commercial and non-commercial use as long as
9 * the following conditions are aheared to. The following conditions
10 * apply to all code found in this distribution, be it the RC4, RSA,
11 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
12 * included with this distribution is covered by the same copyright terms
13 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15 * Copyright remains Eric Young's, and as such any Copyright notices in
16 * the code are not to be removed.
17 * If this package is used in a product, Eric Young should be given attribution
18 * as the author of the parts of the library used.
19 * This can be in the form of a textual message at program startup or
20 * in documentation (online or textual) provided with the package.
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
25 * 1. Redistributions of source code must retain the copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 * 3. All advertising materials mentioning features or use of this software
31 * must display the following acknowledgement:
32 * "This product includes cryptographic software written by
33 * Eric Young (eay@cryptsoft.com)"
34 * The word 'cryptographic' can be left out if the rouines from the library
35 * being used are not cryptographic related :-).
36 * 4. If you include any Windows specific code (or a derivative thereof) from
37 * the apps directory (application code) you must include an acknowledgement:
38 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52 * The licence and distribution terms for any publically available version or
53 * derivative of this code cannot be changed. i.e. this code cannot simply be
54 * copied and put under another distribution licence
55 * [including the GNU Public Licence.]
61 * The input and output are loaded in multiples of 8 bits. What this means is
62 * that if you have numbits=12 and length=2 the first 12 bits will be
63 * retrieved from the first byte and half the second. The second 12 bits
64 * will come from the 3rd and half the 4th byte.
66 void DES_ofb_encrypt(const unsigned char *in, unsigned char *out, int numbits,
67 long length, DES_key_schedule *schedule,
70 register DES_LONG d0, d1, vv0, vv1, v0, v1, n = (numbits + 7) / 8;
71 register DES_LONG mask0, mask1;
72 register long l = length;
73 register int num = numbits;
84 mask1 = (1L << (num - 32)) - 1;
89 mask0 = (1L << num) - 1;
101 DES_encrypt1((DES_LONG *)ti, schedule, DES_ENCRYPT);
106 d0 = (d0 ^ vv0) & mask0;
107 d1 = (d1 ^ vv1) & mask1;
108 l2cn(d0, d1, out, n);
114 } else if (num == 64) {
117 } else if (num > 32) { /* && num != 64 */
118 v0 = ((v1 >> (num - 32)) | (vv0 << (64 - num))) & 0xffffffffL;
119 v1 = ((vv0 >> (num - 32)) | (vv1 << (64 - num))) & 0xffffffffL;
120 } else { /* num < 32 */
122 v0 = ((v0 >> num) | (v1 << (32 - num))) & 0xffffffffL;
123 v1 = ((v1 >> num) | (vv0 << (32 - num))) & 0xffffffffL;
129 v0 = v1 = d0 = d1 = ti[0] = ti[1] = vv0 = vv1 = 0;