| /* 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) |
| /*- |
| * 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) { |
| #if defined(COBALT_WIN) |
| #pragma warning(push) |
| #pragma warning(disable : 4307) // integral constant overflow |
| #endif |
| otp |= RC4_STEP << BESHFT(4); |
| otp |= RC4_STEP << BESHFT(5); |
| otp |= RC4_STEP << BESHFT(6); |
| otp |= RC4_STEP << BESHFT(7); |
| #if defined(COBALT_WIN) |
| #pragma warning(pop) |
| #endif |
| } |
| *(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; |
| } |
