1/*
2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10#include "des_local.h"
11
12/*
13 * The input and output encrypted as though 64bit ofb mode is being used.
14 * The extra state information to record how much of the 64bit block we have
15 * used is contained in *num;
16 */
17void DES_ofb64_encrypt(register const unsigned char *in,
18 register unsigned char *out, long length,
19 DES_key_schedule *schedule, DES_cblock *ivec, int *num)
20{
21 register DES_LONG v0, v1, t;
22 register int n = *num;
23 register long l = length;
24 DES_cblock d;
25 register unsigned char *dp;
26 DES_LONG ti[2];
27 unsigned char *iv;
28 int save = 0;
29
30 iv = &(*ivec)[0];
31 c2l(iv, v0);
32 c2l(iv, v1);
33 ti[0] = v0;
34 ti[1] = v1;
35 dp = d;
36 l2c(v0, dp);
37 l2c(v1, dp);
38 while (l--) {
39 if (n == 0) {
40 DES_encrypt1(ti, schedule, DES_ENCRYPT);
41 dp = d;
42 t = ti[0];
43 l2c(t, dp);
44 t = ti[1];
45 l2c(t, dp);
46 save++;
47 }
48 *(out++) = *(in++) ^ d[n];
49 n = (n + 1) & 0x07;
50 }
51 if (save) {
52 v0 = ti[0];
53 v1 = ti[1];
54 iv = &(*ivec)[0];
55 l2c(v0, iv);
56 l2c(v1, iv);
57 }
58 t = v0 = v1 = ti[0] = ti[1] = 0;
59 *num = n;
60}
61