335 lines
13 KiB
C
335 lines
13 KiB
C
/* crypto/rc4/rc4_enc.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"
|
|
|
|
/*-
|
|
* 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(RC4_KEY *key, size_t len, const unsigned char *indata,
|
|
unsigned char *outdata)
|
|
{
|
|
register RC4_INT *d;
|
|
register RC4_INT x, y, tx, ty;
|
|
size_t i;
|
|
|
|
x = key->x;
|
|
y = key->y;
|
|
d = key->data;
|
|
|
|
#if defined(RC4_CHUNK) && !defined(PEDANTIC)
|
|
/*-
|
|
* The original reason for implementing this(*) was the fact that
|
|
* pre-21164a Alpha CPUs don't have byte load/store instructions
|
|
* and e.g. a byte store has to be done with 64-bit load, shift,
|
|
* and, or and finally 64-bit store. Peaking data and operating
|
|
* at natural word size made it possible to reduce amount of
|
|
* instructions as well as to perform early read-ahead without
|
|
* suffering from RAW (read-after-write) hazard. This resulted
|
|
* in ~40%(**) performance improvement on 21064 box with gcc.
|
|
* But it's not only Alpha users who win here:-) Thanks to the
|
|
* early-n-wide read-ahead this implementation also exhibits
|
|
* >40% speed-up on SPARC and 20-30% on 64-bit MIPS (depending
|
|
* on sizeof(RC4_INT)).
|
|
*
|
|
* (*) "this" means code which recognizes the case when input
|
|
* and output pointers appear to be aligned at natural CPU
|
|
* word boundary
|
|
* (**) i.e. according to 'apps/openssl speed rc4' benchmark,
|
|
* crypto/rc4/rc4speed.c exhibits almost 70% speed-up...
|
|
*
|
|
* Cavets.
|
|
*
|
|
* - RC4_CHUNK="unsigned long long" should be a #1 choice for
|
|
* UltraSPARC. Unfortunately gcc generates very slow code
|
|
* (2.5-3 times slower than one generated by Sun's WorkShop
|
|
* C) and therefore gcc (at least 2.95 and earlier) should
|
|
* always be told that RC4_CHUNK="unsigned long".
|
|
*
|
|
* <appro@fy.chalmers.se>
|
|
*/
|
|
|
|
# define RC4_STEP ( \
|
|
x=(x+1) &0xff, \
|
|
tx=d[x], \
|
|
y=(tx+y)&0xff, \
|
|
ty=d[y], \
|
|
d[y]=tx, \
|
|
d[x]=ty, \
|
|
(RC4_CHUNK)d[(tx+ty)&0xff]\
|
|
)
|
|
|
|
if ((((size_t)indata & (sizeof(RC4_CHUNK) - 1)) |
|
|
((size_t)outdata & (sizeof(RC4_CHUNK) - 1))) == 0) {
|
|
RC4_CHUNK ichunk, otp;
|
|
const union {
|
|
long one;
|
|
char little;
|
|
} is_endian = {
|
|
1
|
|
};
|
|
|
|
/*-
|
|
* I reckon we can afford to implement both endian
|
|
* cases and to decide which way to take at run-time
|
|
* because the machine code appears to be very compact
|
|
* and redundant 1-2KB is perfectly tolerable (i.e.
|
|
* in case the compiler fails to eliminate it:-). By
|
|
* suggestion from Terrel Larson <terr@terralogic.net>
|
|
* who also stands for the is_endian union:-)
|
|
*
|
|
* Special notes.
|
|
*
|
|
* - is_endian is declared automatic as doing otherwise
|
|
* (declaring static) prevents gcc from eliminating
|
|
* the redundant code;
|
|
* - compilers (those I've tried) don't seem to have
|
|
* problems eliminating either the operators guarded
|
|
* by "if (sizeof(RC4_CHUNK)==8)" or the condition
|
|
* expressions themselves so I've got 'em to replace
|
|
* corresponding #ifdefs from the previous version;
|
|
* - I chose to let the redundant switch cases when
|
|
* sizeof(RC4_CHUNK)!=8 be (were also #ifdefed
|
|
* before);
|
|
* - in case you wonder "&(sizeof(RC4_CHUNK)*8-1)" in
|
|
* [LB]ESHFT guards against "shift is out of range"
|
|
* warnings when sizeof(RC4_CHUNK)!=8
|
|
*
|
|
* <appro@fy.chalmers.se>
|
|
*/
|
|
if (!is_endian.little) { /* BIG-ENDIAN CASE */
|
|
# define BESHFT(c) (((sizeof(RC4_CHUNK)-(c)-1)*8)&(sizeof(RC4_CHUNK)*8-1))
|
|
for (; len & (0 - sizeof(RC4_CHUNK)); len -= sizeof(RC4_CHUNK)) {
|
|
ichunk = *(RC4_CHUNK *) indata;
|
|
otp = RC4_STEP << BESHFT(0);
|
|
otp |= RC4_STEP << BESHFT(1);
|
|
otp |= RC4_STEP << BESHFT(2);
|
|
otp |= RC4_STEP << BESHFT(3);
|
|
if (sizeof(RC4_CHUNK) == 8) {
|
|
otp |= RC4_STEP << BESHFT(4);
|
|
otp |= RC4_STEP << BESHFT(5);
|
|
otp |= RC4_STEP << BESHFT(6);
|
|
otp |= RC4_STEP << BESHFT(7);
|
|
}
|
|
*(RC4_CHUNK *) outdata = otp ^ ichunk;
|
|
indata += sizeof(RC4_CHUNK);
|
|
outdata += sizeof(RC4_CHUNK);
|
|
}
|
|
if (len) {
|
|
RC4_CHUNK mask = (RC4_CHUNK) - 1, ochunk;
|
|
|
|
ichunk = *(RC4_CHUNK *) indata;
|
|
ochunk = *(RC4_CHUNK *) outdata;
|
|
otp = 0;
|
|
i = BESHFT(0);
|
|
mask <<= (sizeof(RC4_CHUNK) - len) << 3;
|
|
switch (len & (sizeof(RC4_CHUNK) - 1)) {
|
|
case 7:
|
|
otp = RC4_STEP << i, i -= 8;
|
|
case 6:
|
|
otp |= RC4_STEP << i, i -= 8;
|
|
case 5:
|
|
otp |= RC4_STEP << i, i -= 8;
|
|
case 4:
|
|
otp |= RC4_STEP << i, i -= 8;
|
|
case 3:
|
|
otp |= RC4_STEP << i, i -= 8;
|
|
case 2:
|
|
otp |= RC4_STEP << i, i -= 8;
|
|
case 1:
|
|
otp |= RC4_STEP << i, i -= 8;
|
|
case 0:; /*
|
|
* it's never the case,
|
|
* but it has to be here
|
|
* for ultrix?
|
|
*/
|
|
}
|
|
ochunk &= ~mask;
|
|
ochunk |= (otp ^ ichunk) & mask;
|
|
*(RC4_CHUNK *) outdata = ochunk;
|
|
}
|
|
key->x = x;
|
|
key->y = y;
|
|
return;
|
|
} else { /* LITTLE-ENDIAN CASE */
|
|
# define LESHFT(c) (((c)*8)&(sizeof(RC4_CHUNK)*8-1))
|
|
for (; len & (0 - sizeof(RC4_CHUNK)); len -= sizeof(RC4_CHUNK)) {
|
|
ichunk = *(RC4_CHUNK *) indata;
|
|
otp = RC4_STEP;
|
|
otp |= RC4_STEP << 8;
|
|
otp |= RC4_STEP << 16;
|
|
otp |= RC4_STEP << 24;
|
|
if (sizeof(RC4_CHUNK) == 8) {
|
|
otp |= RC4_STEP << LESHFT(4);
|
|
otp |= RC4_STEP << LESHFT(5);
|
|
otp |= RC4_STEP << LESHFT(6);
|
|
otp |= RC4_STEP << LESHFT(7);
|
|
}
|
|
*(RC4_CHUNK *) outdata = otp ^ ichunk;
|
|
indata += sizeof(RC4_CHUNK);
|
|
outdata += sizeof(RC4_CHUNK);
|
|
}
|
|
if (len) {
|
|
RC4_CHUNK mask = (RC4_CHUNK) - 1, ochunk;
|
|
|
|
ichunk = *(RC4_CHUNK *) indata;
|
|
ochunk = *(RC4_CHUNK *) outdata;
|
|
otp = 0;
|
|
i = 0;
|
|
mask >>= (sizeof(RC4_CHUNK) - len) << 3;
|
|
switch (len & (sizeof(RC4_CHUNK) - 1)) {
|
|
case 7:
|
|
otp = RC4_STEP, i += 8;
|
|
case 6:
|
|
otp |= RC4_STEP << i, i += 8;
|
|
case 5:
|
|
otp |= RC4_STEP << i, i += 8;
|
|
case 4:
|
|
otp |= RC4_STEP << i, i += 8;
|
|
case 3:
|
|
otp |= RC4_STEP << i, i += 8;
|
|
case 2:
|
|
otp |= RC4_STEP << i, i += 8;
|
|
case 1:
|
|
otp |= RC4_STEP << i, i += 8;
|
|
case 0:; /*
|
|
* it's never the case,
|
|
* but it has to be here
|
|
* for ultrix?
|
|
*/
|
|
}
|
|
ochunk &= ~mask;
|
|
ochunk |= (otp ^ ichunk) & mask;
|
|
*(RC4_CHUNK *) outdata = ochunk;
|
|
}
|
|
key->x = x;
|
|
key->y = y;
|
|
return;
|
|
}
|
|
}
|
|
#endif
|
|
#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 = len >> 3;
|
|
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 = 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;
|
|
}
|