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1 | /* crypto/rc4/rc4_enc.org */ |
2 | /* Copyright (C) 1995-1997 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 | /* WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING | |
60 | * | |
61 | * Always modify rc4_enc.org since rc4_enc.c is automatically generated from | |
62 | * it during SSLeay configuration. | |
63 | * WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING WARNING | |
64 | */ | |
65 | ||
66 | #include "rc4.h" | |
67 | ||
68 | /* if this is defined data[i] is used instead of *data, this is a %20 | |
69 | * speedup on x86 */ | |
70 | #undef RC4_INDEX | |
71 | ||
72 | char *RC4_version="RC4 part of SSLeay 0.8.1a 24-Jun-1998"; | |
73 | ||
74 | char *RC4_options() | |
75 | { | |
76 | #ifdef RC4_INDEX | |
77 | if (sizeof(RC4_INT) == 1) | |
78 | return("rc4(idx,char)"); | |
79 | else | |
80 | return("rc4(idx,int)"); | |
81 | #else | |
82 | if (sizeof(RC4_INT) == 1) | |
83 | return("rc4(ptr,char)"); | |
84 | else | |
85 | return("rc4(ptr,int)"); | |
86 | #endif | |
87 | } | |
88 | ||
89 | /* RC4 as implemented from a posting from | |
90 | * Newsgroups: sci.crypt | |
91 | * From: sterndark@netcom.com (David Sterndark) | |
92 | * Subject: RC4 Algorithm revealed. | |
93 | * Message-ID: <sternCvKL4B.Hyy@netcom.com> | |
94 | * Date: Wed, 14 Sep 1994 06:35:31 GMT | |
95 | */ | |
96 | ||
97 | void RC4_set_key(key, len, data) | |
98 | RC4_KEY *key; | |
99 | int len; | |
100 | register unsigned char *data; | |
101 | { | |
102 | register RC4_INT tmp; | |
103 | register int id1,id2; | |
104 | register RC4_INT *d; | |
105 | unsigned int i; | |
106 | ||
107 | d= &(key->data[0]); | |
108 | for (i=0; i<256; i++) | |
109 | d[i]=i; | |
110 | key->x = 0; | |
111 | key->y = 0; | |
112 | id1=id2=0; | |
113 | ||
114 | #define SK_LOOP(n) { \ | |
115 | tmp=d[(n)]; \ | |
116 | id2 = (data[id1] + tmp + id2) & 0xff; \ | |
117 | if (++id1 == len) id1=0; \ | |
118 | d[(n)]=d[id2]; \ | |
119 | d[id2]=tmp; } | |
120 | ||
121 | for (i=0; i < 256; i+=4) | |
122 | { | |
123 | SK_LOOP(i+0); | |
124 | SK_LOOP(i+1); | |
125 | SK_LOOP(i+2); | |
126 | SK_LOOP(i+3); | |
127 | } | |
128 | } | |
129 | ||
130 | void RC4(key, len, indata, outdata) | |
131 | RC4_KEY *key; | |
132 | unsigned long len; | |
133 | unsigned char *indata; | |
134 | unsigned char *outdata; | |
135 | { | |
136 | register RC4_INT *d; | |
137 | register RC4_INT x,y,tx,ty; | |
138 | int i; | |
139 | ||
140 | x=key->x; | |
141 | y=key->y; | |
142 | d=key->data; | |
143 | ||
144 | #define LOOP(in,out) \ | |
145 | x=((x+1)&0xff); \ | |
146 | tx=d[x]; \ | |
147 | y=(tx+y)&0xff; \ | |
148 | d[x]=ty=d[y]; \ | |
149 | d[y]=tx; \ | |
150 | (out) = d[(tx+ty)&0xff]^ (in); | |
151 | ||
152 | #ifndef RC4_INDEX | |
153 | #define RC4_LOOP(a,b,i) LOOP(*((a)++),*((b)++)) | |
154 | #else | |
155 | #define RC4_LOOP(a,b,i) LOOP(a[i],b[i]) | |
156 | #endif | |
157 | ||
158 | i= -(int)len; | |
159 | i=(int)(len>>3L); | |
160 | if (i) | |
161 | { | |
162 | for (;;) | |
163 | { | |
164 | RC4_LOOP(indata,outdata,0); | |
165 | RC4_LOOP(indata,outdata,1); | |
166 | RC4_LOOP(indata,outdata,2); | |
167 | RC4_LOOP(indata,outdata,3); | |
168 | RC4_LOOP(indata,outdata,4); | |
169 | RC4_LOOP(indata,outdata,5); | |
170 | RC4_LOOP(indata,outdata,6); | |
171 | RC4_LOOP(indata,outdata,7); | |
172 | #ifdef RC4_INDEX | |
173 | indata+=8; | |
174 | outdata+=8; | |
175 | #endif | |
176 | if (--i == 0) break; | |
177 | } | |
178 | } | |
179 | i=(int)len&0x07; | |
180 | if (i) | |
181 | { | |
182 | for (;;) | |
183 | { | |
184 | RC4_LOOP(indata,outdata,0); if (--i == 0) break; | |
185 | RC4_LOOP(indata,outdata,1); if (--i == 0) break; | |
186 | RC4_LOOP(indata,outdata,2); if (--i == 0) break; | |
187 | RC4_LOOP(indata,outdata,3); if (--i == 0) break; | |
188 | RC4_LOOP(indata,outdata,4); if (--i == 0) break; | |
189 | RC4_LOOP(indata,outdata,5); if (--i == 0) break; | |
190 | RC4_LOOP(indata,outdata,6); if (--i == 0) break; | |
191 | } | |
192 | } | |
193 | key->x=x; | |
194 | key->y=y; | |
195 | } |