« back to all changes in this revision
Viewing changes to crypto/rc4_enc.c
- browse files at revision 4
- compare with another revision
- download diff
- download tarball
- view history from revision 4
- Committer: Bazaar Package Importer
- Author(s): Tomas Fasth
- Date: 2005-05-24 13:31:34 UTC
- mfrom: (1.1.1 upstream)
- Revision ID: james.westby@ubuntu.com-20050524133134-6hn24gprfmo91sfv
Tags: 1.4.1-1
New upstream release.
- files added:
- Makefile.in
- files removed:
- ChangeLog
- crypto
- files modified:
- README
- doc/keymap-names.txt *
added
removed
crypto/rc4_enc.c
1
/* crypto/rc4/rc4_enc.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 "rc4.h"
60
61
/* RC4 as implemented from a posting from
62
* Newsgroups: sci.crypt
63
* From: sterndark@netcom.com (David Sterndark)
64
* Subject: RC4 Algorithm revealed.
65
* Message-ID: <sternCvKL4B.Hyy@netcom.com>
66
* Date: Wed, 14 Sep 1994 06:35:31 GMT
67
*/
68
69
void RC4(RC4_KEY *key, unsigned long len, const unsigned char *indata,
70
unsigned char *outdata)
71
{
72
register RC4_INT *d;
73
register RC4_INT x,y,tx,ty;
74
int i;
75
76
x=key->x;
77
y=key->y;
78
d=key->data;
79
80
#if defined(RC4_CHUNK)
81
/*
82
* The original reason for implementing this(*) was the fact that
83
* pre-21164a Alpha CPUs don't have byte load/store instructions
84
* and e.g. a byte store has to be done with 64-bit load, shift,
85
* and, or and finally 64-bit store. Peaking data and operating
86
* at natural word size made it possible to reduce amount of
87
* instructions as well as to perform early read-ahead without
88
* suffering from RAW (read-after-write) hazard. This resulted
89
* in ~40%(**) performance improvement on 21064 box with gcc.
90
* But it's not only Alpha users who win here:-) Thanks to the
91
* early-n-wide read-ahead this implementation also exhibits
92
* >40% speed-up on SPARC and 20-30% on 64-bit MIPS (depending
93
* on sizeof(RC4_INT)).
94
*
95
* (*) "this" means code which recognizes the case when input
96
* and output pointers appear to be aligned at natural CPU
97
* word boundary
98
* (**) i.e. according to 'apps/openssl speed rc4' benchmark,
99
* crypto/rc4/rc4speed.c exhibits almost 70% speed-up...
100
*
101
* Cavets.
102
*
103
* - RC4_CHUNK="unsigned long long" should be a #1 choice for
104
* UltraSPARC. Unfortunately gcc generates very slow code
105
* (2.5-3 times slower than one generated by Sun's WorkShop
106
* C) and therefore gcc (at least 2.95 and earlier) should
107
* always be told that RC4_CHUNK="unsigned long".
108
*
109
* <appro@fy.chalmers.se>
110
*/
111
112
# define RC4_STEP ( \
113
x=(x+1) &0xff, \
114
tx=d[x], \
115
y=(tx+y)&0xff, \
116
ty=d[y], \
117
d[y]=tx, \
118
d[x]=ty, \
119
(RC4_CHUNK)d[(tx+ty)&0xff]\
120
)
121
122
if ( ( ((unsigned long)indata & (sizeof(RC4_CHUNK)-1)) |
123
((unsigned long)outdata & (sizeof(RC4_CHUNK)-1)) ) == 0 )
124
{
125
RC4_CHUNK ichunk,otp;
126
const union { long one; char little; } is_endian = {1};
127
128
/*
129
* I reckon we can afford to implement both endian
130
* cases and to decide which way to take at run-time
131
* because the machine code appears to be very compact
132
* and redundant 1-2KB is perfectly tolerable (i.e.
133
* in case the compiler fails to eliminate it:-). By
134
* suggestion from Terrel Larson <terr@terralogic.net>
135
* who also stands for the is_endian union:-)
136
*
137
* Special notes.
138
*
139
* - is_endian is declared automatic as doing otherwise
140
* (declaring static) prevents gcc from eliminating
141
* the redundant code;
142
* - compilers (those I've tried) don't seem to have
143
* problems eliminating either the operators guarded
144
* by "if (sizeof(RC4_CHUNK)==8)" or the condition
145
* expressions themselves so I've got 'em to replace
146
* corresponding #ifdefs from the previous version;
147
* - I chose to let the redundant switch cases when
148
* sizeof(RC4_CHUNK)!=8 be (were also #ifdefed
149
* before);
150
* - in case you wonder "&(sizeof(RC4_CHUNK)*8-1)" in
151
* [LB]ESHFT guards against "shift is out of range"
152
* warnings when sizeof(RC4_CHUNK)!=8
153
*
154
* <appro@fy.chalmers.se>
155
*/
156
if (!is_endian.little)
157
{ /* BIG-ENDIAN CASE */
158
# define BESHFT(c) (((sizeof(RC4_CHUNK)-(c)-1)*8)&(sizeof(RC4_CHUNK)*8-1))
159
for (;len&-sizeof(RC4_CHUNK);len-=sizeof(RC4_CHUNK))
160
{
161
ichunk = *(RC4_CHUNK *)indata;
162
otp = RC4_STEP<<BESHFT(0);
163
otp |= RC4_STEP<<BESHFT(1);
164
otp |= RC4_STEP<<BESHFT(2);
165
otp |= RC4_STEP<<BESHFT(3);
166
if (sizeof(RC4_CHUNK)==8)
167
{
168
otp |= RC4_STEP<<BESHFT(4);
169
otp |= RC4_STEP<<BESHFT(5);
170
otp |= RC4_STEP<<BESHFT(6);
171
otp |= RC4_STEP<<BESHFT(7);
172
}
173
*(RC4_CHUNK *)outdata = otp^ichunk;
174
indata += sizeof(RC4_CHUNK);
175
outdata += sizeof(RC4_CHUNK);
176
}
177
if (len)
178
{
179
RC4_CHUNK mask=(RC4_CHUNK)-1, ochunk;
180
181
ichunk = *(RC4_CHUNK *)indata;
182
ochunk = *(RC4_CHUNK *)outdata;
183
otp = 0;
184
i = BESHFT(0);
185
mask <<= (sizeof(RC4_CHUNK)-len)<<3;
186
switch (len&(sizeof(RC4_CHUNK)-1))
187
{
188
case 7: otp = RC4_STEP<<i, i-=8;
189
case 6: otp |= RC4_STEP<<i, i-=8;
190
case 5: otp |= RC4_STEP<<i, i-=8;
191
case 4: otp |= RC4_STEP<<i, i-=8;
192
case 3: otp |= RC4_STEP<<i, i-=8;
193
case 2: otp |= RC4_STEP<<i, i-=8;
194
case 1: otp |= RC4_STEP<<i, i-=8;
195
case 0: ; /*
196
* it's never the case,
197
* but it has to be here
198
* for ultrix?
199
*/
200
}
201
ochunk &= ~mask;
202
ochunk |= (otp^ichunk) & mask;
203
*(RC4_CHUNK *)outdata = ochunk;
204
}
205
key->x=x;
206
key->y=y;
207
return;
208
}
209
else
210
{ /* LITTLE-ENDIAN CASE */
211
# define LESHFT(c) (((c)*8)&(sizeof(RC4_CHUNK)*8-1))
212
for (;len&-sizeof(RC4_CHUNK);len-=sizeof(RC4_CHUNK))
213
{
214
ichunk = *(RC4_CHUNK *)indata;
215
otp = RC4_STEP;
216
otp |= RC4_STEP<<8;
217
otp |= RC4_STEP<<16;
218
otp |= RC4_STEP<<24;
219
if (sizeof(RC4_CHUNK)==8)
220
{
221
otp |= RC4_STEP<<LESHFT(4);
222
otp |= RC4_STEP<<LESHFT(5);
223
otp |= RC4_STEP<<LESHFT(6);
224
otp |= RC4_STEP<<LESHFT(7);
225
}
226
*(RC4_CHUNK *)outdata = otp^ichunk;
227
indata += sizeof(RC4_CHUNK);
228
outdata += sizeof(RC4_CHUNK);
229
}
230
if (len)
231
{
232
RC4_CHUNK mask=(RC4_CHUNK)-1, ochunk;
233
234
ichunk = *(RC4_CHUNK *)indata;
235
ochunk = *(RC4_CHUNK *)outdata;
236
otp = 0;
237
i = 0;
238
mask >>= (sizeof(RC4_CHUNK)-len)<<3;
239
switch (len&(sizeof(RC4_CHUNK)-1))
240
{
241
case 7: otp = RC4_STEP, i+=8;
242
case 6: otp |= RC4_STEP<<i, i+=8;
243
case 5: otp |= RC4_STEP<<i, i+=8;
244
case 4: otp |= RC4_STEP<<i, i+=8;
245
case 3: otp |= RC4_STEP<<i, i+=8;
246
case 2: otp |= RC4_STEP<<i, i+=8;
247
case 1: otp |= RC4_STEP<<i, i+=8;
248
case 0: ; /*
249
* it's never the case,
250
* but it has to be here
251
* for ultrix?
252
*/
253
}
254
ochunk &= ~mask;
255
ochunk |= (otp^ichunk) & mask;
256
*(RC4_CHUNK *)outdata = ochunk;
257
}
258
key->x=x;
259
key->y=y;
260
return;
261
}
262
}
263
#endif
264
#define LOOP(in,out) \
265
x=((x+1)&0xff); \
266
tx=d[x]; \
267
y=(tx+y)&0xff; \
268
d[x]=ty=d[y]; \
269
d[y]=tx; \
270
(out) = d[(tx+ty)&0xff]^ (in);
271
272
#ifndef RC4_INDEX
273
#define RC4_LOOP(a,b,i) LOOP(*((a)++),*((b)++))
274
#else
275
#define RC4_LOOP(a,b,i) LOOP(a[i],b[i])
276
#endif
277
278
i=(int)(len>>3L);
279
if (i)
280
{
281
for (;;)
282
{
283
RC4_LOOP(indata,outdata,0);
284
RC4_LOOP(indata,outdata,1);
285
RC4_LOOP(indata,outdata,2);
286
RC4_LOOP(indata,outdata,3);
287
RC4_LOOP(indata,outdata,4);
288
RC4_LOOP(indata,outdata,5);
289
RC4_LOOP(indata,outdata,6);
290
RC4_LOOP(indata,outdata,7);
291
#ifdef RC4_INDEX
292
indata+=8;
293
outdata+=8;
294
#endif
295
if (--i == 0) break;
296
}
297
}
298
i=(int)len&0x07;
299
if (i)
300
{
301
for (;;)
302
{
303
RC4_LOOP(indata,outdata,0); if (--i == 0) break;
304
RC4_LOOP(indata,outdata,1); if (--i == 0) break;
305
RC4_LOOP(indata,outdata,2); if (--i == 0) break;
306
RC4_LOOP(indata,outdata,3); if (--i == 0) break;
307
RC4_LOOP(indata,outdata,4); if (--i == 0) break;
308
RC4_LOOP(indata,outdata,5); if (--i == 0) break;
309
RC4_LOOP(indata,outdata,6); if (--i == 0) break;
310
}
311
}
312
key->x=x;
313
key->y=y;
314
}
Loggerhead is a web-based interface for Breezy
Version: 2.0.1