1 /* crypto/rc4/rc4_skey.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3 * All rights reserved.
4 *
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.
8 *
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).
15 *
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.
22 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
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)"
40 *
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
51 * SUCH DAMAGE.
52 *
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.]
57 */
58
59 #include <openssl/rc4.h>
60 #include "rc4_locl.h"
61 #include <openssl/opensslv.h>
62
63 const char RC4_version[]="RC4" OPENSSL_VERSION_PTEXT;
64
RC4_options(void)65 const char *RC4_options(void)
66 {
67 #ifdef RC4_INDEX
68 if (sizeof(RC4_INT) == 1)
69 return("rc4(idx,char)");
70 else
71 return("rc4(idx,int)");
72 #else
73 if (sizeof(RC4_INT) == 1)
74 return("rc4(ptr,char)");
75 else
76 return("rc4(ptr,int)");
77 #endif
78 }
79
80 /* RC4 as implemented from a posting from
81 * Newsgroups: sci.crypt
82 * From: sterndark@netcom.com (David Sterndark)
83 * Subject: RC4 Algorithm revealed.
84 * Message-ID: <sternCvKL4B.Hyy@netcom.com>
85 * Date: Wed, 14 Sep 1994 06:35:31 GMT
86 */
87
RC4_set_key(RC4_KEY * key,int len,const unsigned char * data)88 void RC4_set_key(RC4_KEY *key, int len, const unsigned char *data)
89 {
90 register RC4_INT tmp;
91 register int id1,id2;
92 register RC4_INT *d;
93 unsigned int i;
94
95 d= &(key->data[0]);
96 key->x = 0;
97 key->y = 0;
98 id1=id2=0;
99
100 #define SK_LOOP(d,n) { \
101 tmp=d[(n)]; \
102 id2 = (data[id1] + tmp + id2) & 0xff; \
103 if (++id1 == len) id1=0; \
104 d[(n)]=d[id2]; \
105 d[id2]=tmp; }
106
107 #if defined(OPENSSL_CPUID_OBJ) && !defined(OPENSSL_NO_ASM)
108 # if defined(__i386) || defined(__i386__) || defined(_M_IX86) || \
109 defined(__INTEL__) || \
110 defined(__x86_64) || defined(__x86_64__) || defined(_M_AMD64)
111 if (sizeof(RC4_INT) > 1) {
112 /*
113 * Unlike all other x86 [and x86_64] implementations,
114 * Intel P4 core [including EM64T] was found to perform
115 * poorly with wider RC4_INT. Performance improvement
116 * for IA-32 hand-coded assembler turned out to be 2.8x
117 * if re-coded for RC4_CHAR! It's however inappropriate
118 * to just switch to RC4_CHAR for x86[_64], as non-P4
119 * implementations suffer from significant performance
120 * losses then, e.g. PIII exhibits >2x deterioration,
121 * and so does Opteron. In order to assure optimal
122 * all-round performance, we detect P4 at run-time by
123 * checking upon reserved bit 20 in CPU capability
124 * vector and set up compressed key schedule, which is
125 * recognized by correspondingly updated assembler
126 * module... Bit 20 is set up by OPENSSL_ia32_cpuid.
127 *
128 * <appro@fy.chalmers.se>
129 */
130 if (OPENSSL_ia32cap_P & (1<<20)) {
131 unsigned char *cp=(unsigned char *)d;
132
133 for (i=0;i<256;i++) cp[i]=i;
134 for (i=0;i<256;i++) SK_LOOP(cp,i);
135 /* mark schedule as compressed! */
136 d[256/sizeof(RC4_INT)]=-1;
137 return;
138 }
139 }
140 # endif
141 #endif
142 for (i=0; i < 256; i++) d[i]=i;
143 for (i=0; i < 256; i+=4)
144 {
145 SK_LOOP(d,i+0);
146 SK_LOOP(d,i+1);
147 SK_LOOP(d,i+2);
148 SK_LOOP(d,i+3);
149 }
150 }
151
152