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 <openssl/rc2.h>
11#include "rc2_local.h"
12
13/*
14 * The input and output encrypted as though 64bit ofb mode is being used.
15 * The extra state information to record how much of the 64bit block we have
16 * used is contained in *num;
17 */
18void RC2_ofb64_encrypt(const unsigned char *in, unsigned char *out,
19 long length, RC2_KEY *schedule, unsigned char *ivec,
20 int *num)
21{
22 register unsigned long v0, v1, t;
23 register int n = *num;
24 register long l = length;
25 unsigned char d[8];
26 register char *dp;
27 unsigned long ti[2];
28 unsigned char *iv;
29 int save = 0;
30
31 iv = (unsigned char *)ivec;
32 c2l(iv, v0);
33 c2l(iv, v1);
34 ti[0] = v0;
35 ti[1] = v1;
36 dp = (char *)d;
37 l2c(v0, dp);
38 l2c(v1, dp);
39 while (l--) {
40 if (n == 0) {
41 RC2_encrypt((unsigned long *)ti, schedule);
42 dp = (char *)d;
43 t = ti[0];
44 l2c(t, dp);
45 t = ti[1];
46 l2c(t, dp);
47 save++;
48 }
49 *(out++) = *(in++) ^ d[n];
50 n = (n + 1) & 0x07;
51 }
52 if (save) {
53 v0 = ti[0];
54 v1 = ti[1];
55 iv = (unsigned char *)ivec;
56 l2c(v0, iv);
57 l2c(v1, iv);
58 }
59 t = v0 = v1 = ti[0] = ti[1] = 0;
60 *num = n;
61}
62