text: /* crypto/rc4/rc4_skey.c */
  /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   * All rights reserved.
   *
   * This package is an SSL implementation written
   * by Eric Young (eay@cryptsoft.com).
   * The implementation was written so as to conform with Netscapes SSL.
   * 
   * This library is free for commercial and non-commercial use as long as
   * the following conditions are aheared to.  The following conditions
   * apply to all code found in this distribution, be it the RC4, RSA,
   * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
   * included with this distribution is covered by the same copyright terms
   * except that the holder is Tim Hudson (tjh@cryptsoft.com).
   * 
   * Copyright remains Eric Young's, and as such any Copyright notices in
   * the code are not to be removed.
   * If this package is used in a product, Eric Young should be given attribution
   * as the author of the parts of the library used.
   * This can be in the form of a textual message at program startup or
   * in documentation (online or textual) provided with the package.
   * 
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   * 3. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *    "This product includes cryptographic software written by
   *     Eric Young (eay@cryptsoft.com)"
   *    The word 'cryptographic' can be left out if the rouines from the library
   *    being used are not cryptographic related :-).
   * 4. If you include any Windows specific code (or a derivative thereof) from 
   *    the apps directory (application code) you must include an acknowledgement:
   *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
   * 
   * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   * 
   * The licence and distribution terms for any publically available version or
   * derivative of this code cannot be changed.  i.e. this code cannot simply be
   * copied and put under another distribution licence
   * [including the GNU Public Licence.]
   */
  
  #include <openssl/rc4.h>
  #include "rc4_locl.h"
  #include <openssl/opensslv.h>
  #include <openssl/crypto.h>
  #ifdef OPENSSL_FIPS
  #include <openssl/fips.h>
  #endif
  
  
  const char RC4_version[]="RC4" OPENSSL_VERSION_PTEXT;
  
  const char *RC4_options(void)
  	{
  #ifdef RC4_INDEX
  	if (sizeof(RC4_INT) == 1)
  		return("rc4(idx,char)");
  	else
  		return("rc4(idx,int)");
  #else
  	if (sizeof(RC4_INT) == 1)
  		return("rc4(ptr,char)");
  	else
  		return("rc4(ptr,int)");
  #endif
  	}
  
  /* RC4 as implemented from a posting from
   * Newsgroups: sci.crypt
   * From: sterndark@netcom.com (David Sterndark)
   * Subject: RC4 Algorithm revealed.
   * Message-ID: <sternCvKL4B.Hyy@netcom.com>
   * Date: Wed, 14 Sep 1994 06:35:31 GMT
   */
  
  #ifdef OPENSSL_FIPS
  void private_RC4_set_key(RC4_KEY *key, int len, const unsigned char *data)
  #else
  void RC4_set_key(RC4_KEY *key, int len, const unsigned char *data)
  #endif
  	{
          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; }
  
  #if defined(OPENSSL_CPUID_OBJ) && !defined(OPENSSL_NO_ASM)
  # if	defined(__i386)   || defined(__i386__)   || defined(_M_IX86) || \
  	defined(__INTEL__) || \
  	defined(__x86_64) || defined(__x86_64__) || defined(_M_AMD64)
  	if (sizeof(RC4_INT) > 1) {
  		/*
  		 * Unlike all other x86 [and x86_64] implementations,
  		 * Intel P4 core [including EM64T] was found to perform
  		 * poorly with wider RC4_INT. Performance improvement
  		 * for IA-32 hand-coded assembler turned out to be 2.8x
  		 * if re-coded for RC4_CHAR! It's however inappropriate
  		 * to just switch to RC4_CHAR for x86[_64], as non-P4
  		 * implementations suffer from significant performance
  		 * losses then, e.g. PIII exhibits >2x deterioration,
  		 * and so does Opteron. In order to assure optimal
  		 * all-round performance, we detect P4 at run-time by
  		 * checking upon reserved bit 20 in CPU capability
  		 * vector and set up compressed key schedule, which is
  		 * recognized by correspondingly updated assembler
  		 * module... Bit 20 is set up by OPENSSL_ia32_cpuid.
  		 *
  		 *				<appro@fy.chalmers.se>
  		 */
  #ifdef OPENSSL_FIPS
  		unsigned long *ia32cap_ptr = OPENSSL_ia32cap_loc();
  		if (ia32cap_ptr && (*ia32cap_ptr & (1<<28))) {
  #else
  		if (OPENSSL_ia32cap_P & (1<<28)) {
  #endif
  			unsigned char *cp=(unsigned char *)d;
  
  			for (i=0;i<256;i++) cp[i]=i;
  			for (i=0;i<256;i++) SK_LOOP(cp,i);
  			/* mark schedule as compressed! */
  			d[256/sizeof(RC4_INT)]=-1;
  			return;
  		}
  	}
  # endif
  #endif
  	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);
  		}
  	}
      
  