rc4_skey.c
1.37 KB
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/*
* Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <openssl/rc4.h>
#include "rc4_locl.h"
#include <openssl/opensslv.h>
const char *RC4_options(void)
{
if (sizeof(RC4_INT) == 1)
return "rc4(char)";
else
return "rc4(int)";
}
/*-
* RC4 as implemented from a posting from
* Newsgroups: sci.crypt
* Subject: RC4 Algorithm revealed.
* Message-ID: <sternCvKL4B.Hyy@netcom.com>
* Date: Wed, 14 Sep 1994 06:35:31 GMT
*/
void RC4_set_key(RC4_KEY *key, int len, const unsigned char *data)
{
register RC4_INT tmp;
register int id1, id2;
register RC4_INT *d;
unsigned int i;
d = &(key->data[0]);
key->x = 0;
key->y = 0;
id1 = id2 = 0;
#define SK_LOOP(d,n) { \
tmp=d[(n)]; \
id2 = (data[id1] + tmp + id2) & 0xff; \
if (++id1 == len) id1=0; \
d[(n)]=d[id2]; \
d[id2]=tmp; }
for (i = 0; i < 256; i++)
d[i] = i;
for (i = 0; i < 256; i += 4) {
SK_LOOP(d, i + 0);
SK_LOOP(d, i + 1);
SK_LOOP(d, i + 2);
SK_LOOP(d, i + 3);
}
}