1 /*
2 * Copyright 1995-2020 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 /*
11 * CAST low level APIs are deprecated for public use, but still ok for
12 * internal use.
13 */
14 #include "internal/deprecated.h"
15
16 #include <openssl/cast.h>
17 #include "cast_local.h"
18
19 /*
20 * The input and output encrypted as though 64bit ofb mode is being used.
21 * The extra state information to record how much of the 64bit block we have
22 * used is contained in *num;
23 */
CAST_ofb64_encrypt(const unsigned char * in,unsigned char * out,long length,const CAST_KEY * schedule,unsigned char * ivec,int * num)24 void CAST_ofb64_encrypt(const unsigned char *in, unsigned char *out,
25 long length, const CAST_KEY *schedule,
26 unsigned char *ivec, int *num)
27 {
28 register CAST_LONG v0, v1, t;
29 register int n = *num;
30 register long l = length;
31 unsigned char d[8];
32 register char *dp;
33 CAST_LONG ti[2];
34 unsigned char *iv;
35 int save = 0;
36
37 iv = ivec;
38 n2l(iv, v0);
39 n2l(iv, v1);
40 ti[0] = v0;
41 ti[1] = v1;
42 dp = (char *)d;
43 l2n(v0, dp);
44 l2n(v1, dp);
45 while (l--) {
46 if (n == 0) {
47 CAST_encrypt((CAST_LONG *)ti, schedule);
48 dp = (char *)d;
49 t = ti[0];
50 l2n(t, dp);
51 t = ti[1];
52 l2n(t, dp);
53 save++;
54 }
55 *(out++) = *(in++) ^ d[n];
56 n = (n + 1) & 0x07;
57 }
58 if (save) {
59 v0 = ti[0];
60 v1 = ti[1];
61 iv = ivec;
62 l2n(v0, iv);
63 l2n(v1, iv);
64 }
65 t = v0 = v1 = ti[0] = ti[1] = 0;
66 *num = n;
67 }
68
