1 /* crypto/rc4/rc4_skey.c */ 2 /* Copyright (C) 1995-1998 Eric Young (eay (at) cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay (at) cryptsoft.com). 7 * The implementation was written so as to conform with Netscapes SSL. 8 * 9 * This library is free for commercial and non-commercial use as long as 10 * the following conditions are aheared to. The following conditions 11 * apply to all code found in this distribution, be it the RC4, RSA, 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13 * included with this distribution is covered by the same copyright terms 14 * except that the holder is Tim Hudson (tjh (at) cryptsoft.com). 15 * 16 * Copyright remains Eric Young's, and as such any Copyright notices in 17 * the code are not to be removed. 18 * If this package is used in a product, Eric Young should be given attribution 19 * as the author of the parts of the library used. 20 * This can be in the form of a textual message at program startup or 21 * in documentation (online or textual) provided with the package. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 3. All advertising materials mentioning features or use of this software 32 * must display the following acknowledgement: 33 * "This product includes cryptographic software written by 34 * Eric Young (eay (at) cryptsoft.com)" 35 * The word 'cryptographic' can be left out if the rouines from the library 36 * being used are not cryptographic related :-). 37 * 4. If you include any Windows specific code (or a derivative thereof) from 38 * the apps directory (application code) you must include an acknowledgement: 39 * "This product includes software written by Tim Hudson (tjh (at) cryptsoft.com)" 40 * 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 * SUCH DAMAGE. 52 * 53 * The licence and distribution terms for any publically available version or 54 * derivative of this code cannot be changed. i.e. this code cannot simply be 55 * copied and put under another distribution licence 56 * [including the GNU Public Licence.] 57 */ 58 59 #include <openssl/rc4.h> 60 #include "rc4_locl.h" 61 #include <openssl/opensslv.h> 62 63 const char RC4_version[]="RC4" OPENSSL_VERSION_PTEXT; 64 65 const char *RC4_options(void) 66 { 67 #ifdef RC4_INDEX 68 if (sizeof(RC4_INT) == 1) 69 return("rc4(idx,char)"); 70 else 71 return("rc4(idx,int)"); 72 #else 73 if (sizeof(RC4_INT) == 1) 74 return("rc4(ptr,char)"); 75 else 76 return("rc4(ptr,int)"); 77 #endif 78 } 79 80 /* RC4 as implemented from a posting from 81 * Newsgroups: sci.crypt 82 * From: sterndark (at) netcom.com (David Sterndark) 83 * Subject: RC4 Algorithm revealed. 84 * Message-ID: <sternCvKL4B.Hyy (at) netcom.com> 85 * Date: Wed, 14 Sep 1994 06:35:31 GMT 86 */ 87 88 void private_RC4_set_key(RC4_KEY *key, int len, const unsigned char *data) 89 { 90 register RC4_INT tmp; 91 register int id1,id2; 92 register RC4_INT *d; 93 unsigned int i; 94 95 d= &(key->data[0]); 96 key->x = 0; 97 key->y = 0; 98 id1=id2=0; 99 100 #define SK_LOOP(d,n) { \ 101 tmp=d[(n)]; \ 102 id2 = (data[id1] + tmp + id2) & 0xff; \ 103 if (++id1 == len) id1=0; \ 104 d[(n)]=d[id2]; \ 105 d[id2]=tmp; } 106 107 for (i=0; i < 256; i++) d[i]=i; 108 for (i=0; i < 256; i+=4) 109 { 110 SK_LOOP(d,i+0); 111 SK_LOOP(d,i+1); 112 SK_LOOP(d,i+2); 113 SK_LOOP(d,i+3); 114 } 115 } 116 117
