1 /* 2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. 3 * 4 * Licensed under the OpenSSL license (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/rc4.h> 11 #include "rc4_local.h" 12 #include <openssl/opensslv.h> 13 14 const char *RC4_options(void) 15 { 16 if (sizeof(RC4_INT) == 1) 17 return "rc4(char)"; 18 else 19 return "rc4(int)"; 20 } 21 22 /*- 23 * RC4 as implemented from a posting from 24 * Newsgroups: sci.crypt 25 * Subject: RC4 Algorithm revealed. 26 * Message-ID: <sternCvKL4B.Hyy@netcom.com> 27 * Date: Wed, 14 Sep 1994 06:35:31 GMT 28 */ 29 30 void RC4_set_key(RC4_KEY *key, int len, const unsigned char *data) 31 { 32 register RC4_INT tmp; 33 register int id1, id2; 34 register RC4_INT *d; 35 unsigned int i; 36 37 d = &(key->data[0]); 38 key->x = 0; 39 key->y = 0; 40 id1 = id2 = 0; 41 42 #define SK_LOOP(d,n) { \ 43 tmp=d[(n)]; \ 44 id2 = (data[id1] + tmp + id2) & 0xff; \ 45 if (++id1 == len) id1=0; \ 46 d[(n)]=d[id2]; \ 47 d[id2]=tmp; } 48 49 for (i = 0; i < 256; i++) 50 d[i] = i; 51 for (i = 0; i < 256; i += 4) { 52 SK_LOOP(d, i + 0); 53 SK_LOOP(d, i + 1); 54 SK_LOOP(d, i + 2); 55 SK_LOOP(d, i + 3); 56 } 57 } 58