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 * RC4 low level APIs are deprecated for public use, but still ok for internal
12 * use.
13 */
14 #include "internal/deprecated.h"
15
16 #include <openssl/rc4.h>
17 #include "rc4_local.h"
18 #include <openssl/opensslv.h>
19
RC4_options(void)20 const char *RC4_options(void)
21 {
22 if (sizeof(RC4_INT) == 1)
23 return "rc4(char)";
24 else
25 return "rc4(int)";
26 }
27
28 /*-
29 * RC4 as implemented from a posting from
30 * Newsgroups: sci.crypt
31 * Subject: RC4 Algorithm revealed.
32 * Message-ID: <sternCvKL4B.Hyy@netcom.com>
33 * Date: Wed, 14 Sep 1994 06:35:31 GMT
34 */
35
RC4_set_key(RC4_KEY * key,int len,const unsigned char * data)36 void RC4_set_key(RC4_KEY *key, int len, const unsigned char *data)
37 {
38 register RC4_INT tmp;
39 register int id1, id2;
40 register RC4_INT *d;
41 unsigned int i;
42
43 d = &(key->data[0]);
44 key->x = 0;
45 key->y = 0;
46 id1 = id2 = 0;
47
48 #define SK_LOOP(d,n) { \
49 tmp=d[(n)]; \
50 id2 = (data[id1] + tmp + id2) & 0xff; \
51 if (++id1 == len) id1=0; \
52 d[(n)]=d[id2]; \
53 d[id2]=tmp; }
54
55 for (i = 0; i < 256; i++)
56 d[i] = i;
57 for (i = 0; i < 256; i += 4) {
58 SK_LOOP(d, i + 0);
59 SK_LOOP(d, i + 1);
60 SK_LOOP(d, i + 2);
61 SK_LOOP(d, i + 3);
62 }
63 }
64
