]>
Commit | Line | Data |
---|---|---|
58964a49 RE |
1 | /* crypto/rc4/rc4_enc.c */ |
2 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) | |
d02b48c6 RE |
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 | ||
d02b48c6 | 59 | #include "rc4.h" |
58964a49 | 60 | #include "rc4_locl.h" |
d02b48c6 RE |
61 | |
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 | |
68 | */ | |
69 | ||
6b691a5c UM |
70 | void RC4(RC4_KEY *key, unsigned long len, unsigned char *indata, |
71 | unsigned char *outdata) | |
d02b48c6 RE |
72 | { |
73 | register RC4_INT *d; | |
74 | register RC4_INT x,y,tx,ty; | |
75 | int i; | |
76 | ||
77 | x=key->x; | |
78 | y=key->y; | |
79 | d=key->data; | |
80 | ||
81 | #define LOOP(in,out) \ | |
82 | x=((x+1)&0xff); \ | |
83 | tx=d[x]; \ | |
84 | y=(tx+y)&0xff; \ | |
85 | d[x]=ty=d[y]; \ | |
86 | d[y]=tx; \ | |
87 | (out) = d[(tx+ty)&0xff]^ (in); | |
88 | ||
89 | #ifndef RC4_INDEX | |
90 | #define RC4_LOOP(a,b,i) LOOP(*((a)++),*((b)++)) | |
91 | #else | |
92 | #define RC4_LOOP(a,b,i) LOOP(a[i],b[i]) | |
93 | #endif | |
94 | ||
d02b48c6 RE |
95 | i=(int)(len>>3L); |
96 | if (i) | |
97 | { | |
98 | for (;;) | |
99 | { | |
100 | RC4_LOOP(indata,outdata,0); | |
101 | RC4_LOOP(indata,outdata,1); | |
102 | RC4_LOOP(indata,outdata,2); | |
103 | RC4_LOOP(indata,outdata,3); | |
104 | RC4_LOOP(indata,outdata,4); | |
105 | RC4_LOOP(indata,outdata,5); | |
106 | RC4_LOOP(indata,outdata,6); | |
107 | RC4_LOOP(indata,outdata,7); | |
108 | #ifdef RC4_INDEX | |
109 | indata+=8; | |
110 | outdata+=8; | |
111 | #endif | |
112 | if (--i == 0) break; | |
113 | } | |
114 | } | |
115 | i=(int)len&0x07; | |
116 | if (i) | |
117 | { | |
118 | for (;;) | |
119 | { | |
120 | RC4_LOOP(indata,outdata,0); if (--i == 0) break; | |
121 | RC4_LOOP(indata,outdata,1); if (--i == 0) break; | |
122 | RC4_LOOP(indata,outdata,2); if (--i == 0) break; | |
123 | RC4_LOOP(indata,outdata,3); if (--i == 0) break; | |
124 | RC4_LOOP(indata,outdata,4); if (--i == 0) break; | |
125 | RC4_LOOP(indata,outdata,5); if (--i == 0) break; | |
126 | RC4_LOOP(indata,outdata,6); if (--i == 0) break; | |
127 | } | |
128 | } | |
129 | key->x=x; | |
130 | key->y=y; | |
131 | } |