1 /* crypto/rc4/rc4_enc.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
5 * This package is an SSL implementation written
6 * by Eric Young (eay@cryptsoft.com).
7 * The implementation was written so as to conform with Netscapes SSL.
9 * This library is free for commercial and non-commercial use as long as
10 * the following conditions are aheared to. The following conditions
11 * apply to all code found in this distribution, be it the RC4, RSA,
12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
13 * included with this distribution is covered by the same copyright terms
14 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
16 * Copyright remains Eric Young's, and as such any Copyright notices in
17 * the code are not to be removed.
18 * If this package is used in a product, Eric Young should be given attribution
19 * as the author of the parts of the library used.
20 * This can be in the form of a textual message at program startup or
21 * in documentation (online or textual) provided with the package.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
26 * 1. Redistributions of source code must retain the copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
31 * 3. All advertising materials mentioning features or use of this software
32 * must display the following acknowledgement:
33 * "This product includes cryptographic software written by
34 * Eric Young (eay@cryptsoft.com)"
35 * The word 'cryptographic' can be left out if the rouines from the library
36 * being used are not cryptographic related :-).
37 * 4. If you include any Windows specific code (or a derivative thereof) from
38 * the apps directory (application code) you must include an acknowledgement:
39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53 * The licence and distribution terms for any publically available version or
54 * derivative of this code cannot be changed. i.e. this code cannot simply be
55 * copied and put under another distribution licence
56 * [including the GNU Public Licence.]
59 #include <openssl/rc4.h>
62 /* RC4 as implemented from a posting from
63 * Newsgroups: sci.crypt
64 * From: sterndark@netcom.com (David Sterndark)
65 * Subject: RC4 Algorithm revealed.
66 * Message-ID: <sternCvKL4B.Hyy@netcom.com>
67 * Date: Wed, 14 Sep 1994 06:35:31 GMT
70 void RC4(RC4_KEY *key, unsigned long len, unsigned char *indata,
71 unsigned char *outdata)
74 register RC4_INT x,y,tx,ty;
81 #if defined(RC4_CHUNK) && (defined(L_ENDIAN) || defined(B_ENDIAN))
83 * The original reason for implementing this(*) was the fact that
84 * pre-21164a Alpha CPUs don't have byte load/store instructions
85 * and e.g. a byte store has to be done with 64-bit load, shift,
86 * and, or and finally 64-bit store. Peaking data and operating
87 * at natural word size made it possible to reduce amount of
88 * instructions as well as to perform early read-ahead without
89 * suffering from RAW (read-after-write) hazard. This resulted
90 * in >40%(**) performance improvement (on 21064 box with gcc).
91 * But it's not only Alpha users who win here:-) Thanks to the
92 * early-n-wide read-ahead this implementation also exhibits
93 * >40% speed-up on SPARC and almost 20% on MIPS.
95 * (*) "this" means code which recognizes the case when input
96 * and output pointers appear to be aligned at natural CPU
98 * (**) i.e. according to 'apps/openssl speed rc4' benchmark,
99 * crypto/rc4/rc4speed.c exhibits almost 70% speed-up.
101 * <appro@fy.chalmers.se>
111 (RC4_CHUNK)d[(tx+ty)&0xff]\
114 #if defined(L_ENDIAN)
115 # define SHFT(c) ((c)*8)
116 # define MASK(i) (((RC4_CHUNK)-1)>>((sizeof(RC4_CHUNK)-(i))<<3))
118 #elif defined(B_ENDIAN)
119 # define SHFT(c) ((sizeof(RC4_CHUNK)-(c)-1)*8)
120 # define MASK(i) (((RC4_CHUNK)-1)<<((sizeof(RC4_CHUNK)-(i))<<3))
123 # error "L_ENDIAN or B_ENDIAN *must* be defined!"
126 if ( ( ((unsigned long)indata & (sizeof(RC4_CHUNK)-1)) |
127 ((unsigned long)outdata & (sizeof(RC4_CHUNK)-1)) ) == 0
129 RC4_CHUNK ichunk,cipher;
131 for (;len&-sizeof(RC4_CHUNK);len-=sizeof(RC4_CHUNK)) {
132 ichunk = *(RC4_CHUNK *)indata;
133 cipher = RC4_STEP<<SHFT(0);
134 cipher |= RC4_STEP<<SHFT(1);
135 cipher |= RC4_STEP<<SHFT(2);
136 cipher |= RC4_STEP<<SHFT(3);
137 #ifdef RC4_CHUNK_IS_64_BIT
138 cipher |= RC4_STEP<<SHFT(4);
139 cipher |= RC4_STEP<<SHFT(5);
140 cipher |= RC4_STEP<<SHFT(6);
141 cipher |= RC4_STEP<<SHFT(7);
143 *(RC4_CHUNK *)outdata = cipher^ichunk;
144 indata += sizeof(RC4_CHUNK);
145 outdata += sizeof(RC4_CHUNK);
148 RC4_CHUNK mask,ochunk;
150 ichunk = *(RC4_CHUNK *)indata;
151 ochunk = *(RC4_CHUNK *)outdata;
156 #ifdef RC4_CHUNK_IS_64_BIT
157 case 7: cipher = RC4_STEP<<SHFT(0), i+=SHINC;
158 case 6: cipher |= RC4_STEP<<i, i+=SHINC;
159 case 5: cipher |= RC4_STEP<<i, i+=SHINC;
160 case 4: cipher |= RC4_STEP<<i, i+=SHINC;
161 case 3: cipher |= RC4_STEP<<i, i+=SHINC;
163 case 3: cipher = RC4_STEP<<SHFT(0), i+=SHINC;
165 case 2: cipher |= RC4_STEP<<i, i+=SHINC;
166 case 1: cipher |= RC4_STEP<<i, i+=SHINC;
167 case 0: ; /* it's never the case, but it
168 has to be here for ultrix? */
171 ochunk |= (cipher^ichunk) & mask;
172 *(RC4_CHUNK *)outdata = ochunk;
178 #define LOOP(in,out) \
184 (out) = d[(tx+ty)&0xff]^ (in);
187 #define RC4_LOOP(a,b,i) LOOP(*((a)++),*((b)++))
189 #define RC4_LOOP(a,b,i) LOOP(a[i],b[i])
197 RC4_LOOP(indata,outdata,0);
198 RC4_LOOP(indata,outdata,1);
199 RC4_LOOP(indata,outdata,2);
200 RC4_LOOP(indata,outdata,3);
201 RC4_LOOP(indata,outdata,4);
202 RC4_LOOP(indata,outdata,5);
203 RC4_LOOP(indata,outdata,6);
204 RC4_LOOP(indata,outdata,7);
217 RC4_LOOP(indata,outdata,0); if (--i == 0) break;
218 RC4_LOOP(indata,outdata,1); if (--i == 0) break;
219 RC4_LOOP(indata,outdata,2); if (--i == 0) break;
220 RC4_LOOP(indata,outdata,3); if (--i == 0) break;
221 RC4_LOOP(indata,outdata,4); if (--i == 0) break;
222 RC4_LOOP(indata,outdata,5); if (--i == 0) break;
223 RC4_LOOP(indata,outdata,6); if (--i == 0) break;