6.0 KiB
* crypto/rc4/rc4_enc.org * /* Copyright (C) 1995-1997 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:
-
- Redistributions of source code must retain the copyright
- notice, this list of conditions and the following disclaimer.
-
- 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.
-
- 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 :-).
-
- 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.]
*/
/* WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
- Always modify rc4_enc.org since rc4_enc.c is automatically generated from
- it during SSLeay configuration.
- WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING
*/
#include "rc4.h"
/* if this is defined data[i] is used instead of *data, this is a %20
- speedup on x86 */
#define RC4_INDEX
char *RC4_version="RC4 part of SSLeay 0.8.1b 29-Jun-1998";
char *RC4_options() { #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
*/
void RC4_set_key(key, len, data) RC4_KEY *key; int len; register unsigned char *data; { register RC4_INT tmp; register int id1,id2; register RC4_INT *d; unsigned int i;
d= &(key->data[0]); for (i=0; i<256; i++) d[i]=i; key->x = 0; key->y = 0; id1=id2=0;
#define SK_LOOP(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+=4) { SK_LOOP(i+0); SK_LOOP(i+1); SK_LOOP(i+2); SK_LOOP(i+3); } }
void RC4(key, len, indata, outdata) RC4_KEY *key; unsigned long len; unsigned char *indata; unsigned char *outdata; { register RC4_INT *d; register RC4_INT x,y,tx,ty; int i;
x=key->x; y=key->y; d=key->data;
#define LOOP(in,out) \ x=((x+1)&0xff); \ tx=d[x]; \ y=(tx+y)&0xff; \ d[x]=ty=d[y]; \ d[y]=tx; \ (out) = d[(tx+ty)&0xff]^ (in);
#ifndef RC4_INDEX #define RC4_LOOP(a,b,i) LOOP(*((a)++),*((b)++)) #else #define RC4_LOOP(a,b,i) LOOP(a[i],b[i]) #endif
i= -(int)len;
i=(int)(len>>3L);
if (i)
{
for (;;)
{
RC4_LOOP(indata,outdata,0);
RC4_LOOP(indata,outdata,1);
RC4_LOOP(indata,outdata,2);
RC4_LOOP(indata,outdata,3);
RC4_LOOP(indata,outdata,4);
RC4_LOOP(indata,outdata,5);
RC4_LOOP(indata,outdata,6);
RC4_LOOP(indata,outdata,7);
#ifdef RC4_INDEX
indata+=8;
outdata+=8;
#endif
if (–i == 0) break;
}
}
i=(int)len&0x07;
if (i)
{
for (;;)
{
RC4_LOOP(indata,outdata,0); if (–i = 0) break;
RC4_LOOP(indata,outdata,1); if (--i =
0) break;
RC4_LOOP(indata,outdata,2); if (–i = 0) break;
RC4_LOOP(indata,outdata,3); if (--i =
0) break;
RC4_LOOP(indata,outdata,4); if (–i = 0) break;
RC4_LOOP(indata,outdata,5); if (--i =
0) break;
RC4_LOOP(indata,outdata,6); if (–i == 0) break;
}
}
key->x=x;
key->y=y;
}