1e1051a39Sopenharmony_ci/* 2e1051a39Sopenharmony_ci * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved. 3e1051a39Sopenharmony_ci * 4e1051a39Sopenharmony_ci * Licensed under the Apache License 2.0 (the "License"). You may not use 5e1051a39Sopenharmony_ci * this file except in compliance with the License. You can obtain a copy 6e1051a39Sopenharmony_ci * in the file LICENSE in the source distribution or at 7e1051a39Sopenharmony_ci * https://www.openssl.org/source/license.html 8e1051a39Sopenharmony_ci */ 9e1051a39Sopenharmony_ci 10e1051a39Sopenharmony_ci/* 11e1051a39Sopenharmony_ci * RC4 low level APIs are deprecated for public use, but still ok for internal 12e1051a39Sopenharmony_ci * use. 13e1051a39Sopenharmony_ci */ 14e1051a39Sopenharmony_ci#include "internal/deprecated.h" 15e1051a39Sopenharmony_ci 16e1051a39Sopenharmony_ci#include <openssl/rc4.h> 17e1051a39Sopenharmony_ci#include "rc4_local.h" 18e1051a39Sopenharmony_ci 19e1051a39Sopenharmony_ci/*- 20e1051a39Sopenharmony_ci * RC4 as implemented from a posting from 21e1051a39Sopenharmony_ci * Newsgroups: sci.crypt 22e1051a39Sopenharmony_ci * Subject: RC4 Algorithm revealed. 23e1051a39Sopenharmony_ci * Message-ID: <sternCvKL4B.Hyy@netcom.com> 24e1051a39Sopenharmony_ci * Date: Wed, 14 Sep 1994 06:35:31 GMT 25e1051a39Sopenharmony_ci */ 26e1051a39Sopenharmony_ci 27e1051a39Sopenharmony_civoid RC4(RC4_KEY *key, size_t len, const unsigned char *indata, 28e1051a39Sopenharmony_ci unsigned char *outdata) 29e1051a39Sopenharmony_ci{ 30e1051a39Sopenharmony_ci register RC4_INT *d; 31e1051a39Sopenharmony_ci register RC4_INT x, y, tx, ty; 32e1051a39Sopenharmony_ci size_t i; 33e1051a39Sopenharmony_ci 34e1051a39Sopenharmony_ci x = key->x; 35e1051a39Sopenharmony_ci y = key->y; 36e1051a39Sopenharmony_ci d = key->data; 37e1051a39Sopenharmony_ci 38e1051a39Sopenharmony_ci#define LOOP(in,out) \ 39e1051a39Sopenharmony_ci x=((x+1)&0xff); \ 40e1051a39Sopenharmony_ci tx=d[x]; \ 41e1051a39Sopenharmony_ci y=(tx+y)&0xff; \ 42e1051a39Sopenharmony_ci d[x]=ty=d[y]; \ 43e1051a39Sopenharmony_ci d[y]=tx; \ 44e1051a39Sopenharmony_ci (out) = d[(tx+ty)&0xff]^ (in); 45e1051a39Sopenharmony_ci 46e1051a39Sopenharmony_ci i = len >> 3; 47e1051a39Sopenharmony_ci if (i) { 48e1051a39Sopenharmony_ci for (;;) { 49e1051a39Sopenharmony_ci LOOP(indata[0], outdata[0]); 50e1051a39Sopenharmony_ci LOOP(indata[1], outdata[1]); 51e1051a39Sopenharmony_ci LOOP(indata[2], outdata[2]); 52e1051a39Sopenharmony_ci LOOP(indata[3], outdata[3]); 53e1051a39Sopenharmony_ci LOOP(indata[4], outdata[4]); 54e1051a39Sopenharmony_ci LOOP(indata[5], outdata[5]); 55e1051a39Sopenharmony_ci LOOP(indata[6], outdata[6]); 56e1051a39Sopenharmony_ci LOOP(indata[7], outdata[7]); 57e1051a39Sopenharmony_ci indata += 8; 58e1051a39Sopenharmony_ci outdata += 8; 59e1051a39Sopenharmony_ci if (--i == 0) 60e1051a39Sopenharmony_ci break; 61e1051a39Sopenharmony_ci } 62e1051a39Sopenharmony_ci } 63e1051a39Sopenharmony_ci i = len & 0x07; 64e1051a39Sopenharmony_ci if (i) { 65e1051a39Sopenharmony_ci for (;;) { 66e1051a39Sopenharmony_ci LOOP(indata[0], outdata[0]); 67e1051a39Sopenharmony_ci if (--i == 0) 68e1051a39Sopenharmony_ci break; 69e1051a39Sopenharmony_ci LOOP(indata[1], outdata[1]); 70e1051a39Sopenharmony_ci if (--i == 0) 71e1051a39Sopenharmony_ci break; 72e1051a39Sopenharmony_ci LOOP(indata[2], outdata[2]); 73e1051a39Sopenharmony_ci if (--i == 0) 74e1051a39Sopenharmony_ci break; 75e1051a39Sopenharmony_ci LOOP(indata[3], outdata[3]); 76e1051a39Sopenharmony_ci if (--i == 0) 77e1051a39Sopenharmony_ci break; 78e1051a39Sopenharmony_ci LOOP(indata[4], outdata[4]); 79e1051a39Sopenharmony_ci if (--i == 0) 80e1051a39Sopenharmony_ci break; 81e1051a39Sopenharmony_ci LOOP(indata[5], outdata[5]); 82e1051a39Sopenharmony_ci if (--i == 0) 83e1051a39Sopenharmony_ci break; 84e1051a39Sopenharmony_ci LOOP(indata[6], outdata[6]); 85e1051a39Sopenharmony_ci if (--i == 0) 86e1051a39Sopenharmony_ci break; 87e1051a39Sopenharmony_ci } 88e1051a39Sopenharmony_ci } 89e1051a39Sopenharmony_ci key->x = x; 90e1051a39Sopenharmony_ci key->y = y; 91e1051a39Sopenharmony_ci} 92