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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. | |
40720ce3 | 8 | * |
d02b48c6 RE |
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). | |
40720ce3 | 15 | * |
d02b48c6 RE |
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. | |
40720ce3 | 22 | * |
d02b48c6 RE |
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 :-). | |
40720ce3 | 37 | * 4. If you include any Windows specific code (or a derivative thereof) from |
d02b48c6 RE |
38 | * the apps directory (application code) you must include an acknowledgement: |
39 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
40720ce3 | 40 | * |
d02b48c6 RE |
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. | |
40720ce3 | 52 | * |
d02b48c6 RE |
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 | ||
ec577822 | 59 | #include <openssl/rc4.h> |
58964a49 | 60 | #include "rc4_locl.h" |
d02b48c6 | 61 | |
3e8042c3 MC |
62 | /*- |
63 | * RC4 as implemented from a posting from | |
d02b48c6 RE |
64 | * Newsgroups: sci.crypt |
65 | * From: sterndark@netcom.com (David Sterndark) | |
66 | * Subject: RC4 Algorithm revealed. | |
67 | * Message-ID: <sternCvKL4B.Hyy@netcom.com> | |
68 | * Date: Wed, 14 Sep 1994 06:35:31 GMT | |
69 | */ | |
70 | ||
c236e66d | 71 | void RC4(RC4_KEY *key, unsigned long len, const unsigned char *indata, |
40720ce3 MC |
72 | unsigned char *outdata) |
73 | { | |
74 | register RC4_INT *d; | |
75 | register RC4_INT x, y, tx, ty; | |
76 | int i; | |
77 | ||
78 | x = key->x; | |
79 | y = key->y; | |
80 | d = key->data; | |
d02b48c6 | 81 | |
2dae04d0 | 82 | #if defined(RC4_CHUNK) |
40720ce3 MC |
83 | /*- |
84 | * The original reason for implementing this(*) was the fact that | |
85 | * pre-21164a Alpha CPUs don't have byte load/store instructions | |
86 | * and e.g. a byte store has to be done with 64-bit load, shift, | |
87 | * and, or and finally 64-bit store. Peaking data and operating | |
88 | * at natural word size made it possible to reduce amount of | |
89 | * instructions as well as to perform early read-ahead without | |
90 | * suffering from RAW (read-after-write) hazard. This resulted | |
91 | * in ~40%(**) performance improvement on 21064 box with gcc. | |
92 | * But it's not only Alpha users who win here:-) Thanks to the | |
93 | * early-n-wide read-ahead this implementation also exhibits | |
94 | * >40% speed-up on SPARC and 20-30% on 64-bit MIPS (depending | |
95 | * on sizeof(RC4_INT)). | |
96 | * | |
97 | * (*) "this" means code which recognizes the case when input | |
98 | * and output pointers appear to be aligned at natural CPU | |
99 | * word boundary | |
100 | * (**) i.e. according to 'apps/openssl speed rc4' benchmark, | |
101 | * crypto/rc4/rc4speed.c exhibits almost 70% speed-up... | |
102 | * | |
103 | * Cavets. | |
104 | * | |
105 | * - RC4_CHUNK="unsigned long long" should be a #1 choice for | |
106 | * UltraSPARC. Unfortunately gcc generates very slow code | |
107 | * (2.5-3 times slower than one generated by Sun's WorkShop | |
108 | * C) and therefore gcc (at least 2.95 and earlier) should | |
109 | * always be told that RC4_CHUNK="unsigned long". | |
110 | * | |
111 | * <appro@fy.chalmers.se> | |
112 | */ | |
6cc4ee03 | 113 | |
40720ce3 MC |
114 | # define RC4_STEP ( \ |
115 | x=(x+1) &0xff, \ | |
116 | tx=d[x], \ | |
117 | y=(tx+y)&0xff, \ | |
118 | ty=d[y], \ | |
119 | d[y]=tx, \ | |
120 | d[x]=ty, \ | |
121 | (RC4_CHUNK)d[(tx+ty)&0xff]\ | |
122 | ) | |
6cc4ee03 | 123 | |
40720ce3 MC |
124 | if ((((unsigned long)indata & (sizeof(RC4_CHUNK) - 1)) | |
125 | ((unsigned long)outdata & (sizeof(RC4_CHUNK) - 1))) == 0) { | |
126 | RC4_CHUNK ichunk, otp; | |
127 | const union { | |
128 | long one; | |
129 | char little; | |
130 | } is_endian = { | |
131 | 1 | |
132 | }; | |
6cc4ee03 | 133 | |
40720ce3 MC |
134 | /*- |
135 | * I reckon we can afford to implement both endian | |
136 | * cases and to decide which way to take at run-time | |
137 | * because the machine code appears to be very compact | |
138 | * and redundant 1-2KB is perfectly tolerable (i.e. | |
139 | * in case the compiler fails to eliminate it:-). By | |
140 | * suggestion from Terrel Larson <terr@terralogic.net> | |
141 | * who also stands for the is_endian union:-) | |
142 | * | |
143 | * Special notes. | |
144 | * | |
145 | * - is_endian is declared automatic as doing otherwise | |
146 | * (declaring static) prevents gcc from eliminating | |
147 | * the redundant code; | |
148 | * - compilers (those I've tried) don't seem to have | |
149 | * problems eliminating either the operators guarded | |
150 | * by "if (sizeof(RC4_CHUNK)==8)" or the condition | |
151 | * expressions themselves so I've got 'em to replace | |
152 | * corresponding #ifdefs from the previous version; | |
153 | * - I chose to let the redundant switch cases when | |
154 | * sizeof(RC4_CHUNK)!=8 be (were also #ifdefed | |
155 | * before); | |
156 | * - in case you wonder "&(sizeof(RC4_CHUNK)*8-1)" in | |
157 | * [LB]ESHFT guards against "shift is out of range" | |
158 | * warnings when sizeof(RC4_CHUNK)!=8 | |
159 | * | |
160 | * <appro@fy.chalmers.se> | |
161 | */ | |
162 | if (!is_endian.little) { /* BIG-ENDIAN CASE */ | |
163 | # define BESHFT(c) (((sizeof(RC4_CHUNK)-(c)-1)*8)&(sizeof(RC4_CHUNK)*8-1)) | |
164 | for (; len & ~(sizeof(RC4_CHUNK) - 1); len -= sizeof(RC4_CHUNK)) { | |
165 | ichunk = *(RC4_CHUNK *) indata; | |
166 | otp = RC4_STEP << BESHFT(0); | |
167 | otp |= RC4_STEP << BESHFT(1); | |
168 | otp |= RC4_STEP << BESHFT(2); | |
169 | otp |= RC4_STEP << BESHFT(3); | |
170 | if (sizeof(RC4_CHUNK) == 8) { | |
171 | otp |= RC4_STEP << BESHFT(4); | |
172 | otp |= RC4_STEP << BESHFT(5); | |
173 | otp |= RC4_STEP << BESHFT(6); | |
174 | otp |= RC4_STEP << BESHFT(7); | |
175 | } | |
176 | *(RC4_CHUNK *) outdata = otp ^ ichunk; | |
177 | indata += sizeof(RC4_CHUNK); | |
178 | outdata += sizeof(RC4_CHUNK); | |
179 | } | |
180 | if (len) { | |
181 | RC4_CHUNK mask = (RC4_CHUNK) - 1, ochunk; | |
6cc4ee03 | 182 | |
40720ce3 MC |
183 | ichunk = *(RC4_CHUNK *) indata; |
184 | ochunk = *(RC4_CHUNK *) outdata; | |
185 | otp = 0; | |
186 | i = BESHFT(0); | |
187 | mask <<= (sizeof(RC4_CHUNK) - len) << 3; | |
188 | switch (len & (sizeof(RC4_CHUNK) - 1)) { | |
189 | case 7: | |
190 | otp = RC4_STEP << i, i -= 8; | |
191 | case 6: | |
192 | otp |= RC4_STEP << i, i -= 8; | |
193 | case 5: | |
194 | otp |= RC4_STEP << i, i -= 8; | |
195 | case 4: | |
196 | otp |= RC4_STEP << i, i -= 8; | |
197 | case 3: | |
198 | otp |= RC4_STEP << i, i -= 8; | |
199 | case 2: | |
200 | otp |= RC4_STEP << i, i -= 8; | |
201 | case 1: | |
202 | otp |= RC4_STEP << i, i -= 8; | |
203 | case 0:; /* | |
204 | * it's never the case, | |
205 | * but it has to be here | |
206 | * for ultrix? | |
207 | */ | |
208 | } | |
209 | ochunk &= ~mask; | |
210 | ochunk |= (otp ^ ichunk) & mask; | |
211 | *(RC4_CHUNK *) outdata = ochunk; | |
212 | } | |
213 | key->x = x; | |
214 | key->y = y; | |
215 | return; | |
216 | } else { /* LITTLE-ENDIAN CASE */ | |
217 | # define LESHFT(c) (((c)*8)&(sizeof(RC4_CHUNK)*8-1)) | |
218 | for (; len & ~(sizeof(RC4_CHUNK) - 1); len -= sizeof(RC4_CHUNK)) { | |
219 | ichunk = *(RC4_CHUNK *) indata; | |
220 | otp = RC4_STEP; | |
221 | otp |= RC4_STEP << 8; | |
222 | otp |= RC4_STEP << 16; | |
223 | otp |= RC4_STEP << 24; | |
224 | if (sizeof(RC4_CHUNK) == 8) { | |
225 | otp |= RC4_STEP << LESHFT(4); | |
226 | otp |= RC4_STEP << LESHFT(5); | |
227 | otp |= RC4_STEP << LESHFT(6); | |
228 | otp |= RC4_STEP << LESHFT(7); | |
229 | } | |
230 | *(RC4_CHUNK *) outdata = otp ^ ichunk; | |
231 | indata += sizeof(RC4_CHUNK); | |
232 | outdata += sizeof(RC4_CHUNK); | |
233 | } | |
234 | if (len) { | |
235 | RC4_CHUNK mask = (RC4_CHUNK) - 1, ochunk; | |
2dae04d0 | 236 | |
40720ce3 MC |
237 | ichunk = *(RC4_CHUNK *) indata; |
238 | ochunk = *(RC4_CHUNK *) outdata; | |
239 | otp = 0; | |
240 | i = 0; | |
241 | mask >>= (sizeof(RC4_CHUNK) - len) << 3; | |
242 | switch (len & (sizeof(RC4_CHUNK) - 1)) { | |
243 | case 7: | |
244 | otp = RC4_STEP, i += 8; | |
245 | case 6: | |
246 | otp |= RC4_STEP << i, i += 8; | |
247 | case 5: | |
248 | otp |= RC4_STEP << i, i += 8; | |
249 | case 4: | |
250 | otp |= RC4_STEP << i, i += 8; | |
251 | case 3: | |
252 | otp |= RC4_STEP << i, i += 8; | |
253 | case 2: | |
254 | otp |= RC4_STEP << i, i += 8; | |
255 | case 1: | |
256 | otp |= RC4_STEP << i, i += 8; | |
257 | case 0:; /* | |
258 | * it's never the case, | |
259 | * but it has to be here | |
260 | * for ultrix? | |
261 | */ | |
262 | } | |
263 | ochunk &= ~mask; | |
264 | ochunk |= (otp ^ ichunk) & mask; | |
265 | *(RC4_CHUNK *) outdata = ochunk; | |
266 | } | |
267 | key->x = x; | |
268 | key->y = y; | |
269 | return; | |
270 | } | |
271 | } | |
6cc4ee03 | 272 | #endif |
d02b48c6 | 273 | #define LOOP(in,out) \ |
40720ce3 MC |
274 | x=((x+1)&0xff); \ |
275 | tx=d[x]; \ | |
276 | y=(tx+y)&0xff; \ | |
277 | d[x]=ty=d[y]; \ | |
278 | d[y]=tx; \ | |
279 | (out) = d[(tx+ty)&0xff]^ (in); | |
d02b48c6 RE |
280 | |
281 | #ifndef RC4_INDEX | |
40720ce3 | 282 | # define RC4_LOOP(a,b,i) LOOP(*((a)++),*((b)++)) |
d02b48c6 | 283 | #else |
40720ce3 | 284 | # define RC4_LOOP(a,b,i) LOOP(a[i],b[i]) |
d02b48c6 RE |
285 | #endif |
286 | ||
40720ce3 MC |
287 | i = (int)(len >> 3L); |
288 | if (i) { | |
289 | for (;;) { | |
290 | RC4_LOOP(indata, outdata, 0); | |
291 | RC4_LOOP(indata, outdata, 1); | |
292 | RC4_LOOP(indata, outdata, 2); | |
293 | RC4_LOOP(indata, outdata, 3); | |
294 | RC4_LOOP(indata, outdata, 4); | |
295 | RC4_LOOP(indata, outdata, 5); | |
296 | RC4_LOOP(indata, outdata, 6); | |
297 | RC4_LOOP(indata, outdata, 7); | |
d02b48c6 | 298 | #ifdef RC4_INDEX |
40720ce3 MC |
299 | indata += 8; |
300 | outdata += 8; | |
d02b48c6 | 301 | #endif |
40720ce3 MC |
302 | if (--i == 0) |
303 | break; | |
304 | } | |
305 | } | |
306 | i = (int)len & 0x07; | |
307 | if (i) { | |
308 | for (;;) { | |
309 | RC4_LOOP(indata, outdata, 0); | |
310 | if (--i == 0) | |
311 | break; | |
312 | RC4_LOOP(indata, outdata, 1); | |
313 | if (--i == 0) | |
314 | break; | |
315 | RC4_LOOP(indata, outdata, 2); | |
316 | if (--i == 0) | |
317 | break; | |
318 | RC4_LOOP(indata, outdata, 3); | |
319 | if (--i == 0) | |
320 | break; | |
321 | RC4_LOOP(indata, outdata, 4); | |
322 | if (--i == 0) | |
323 | break; | |
324 | RC4_LOOP(indata, outdata, 5); | |
325 | if (--i == 0) | |
326 | break; | |
327 | RC4_LOOP(indata, outdata, 6); | |
328 | if (--i == 0) | |
329 | break; | |
330 | } | |
331 | } | |
332 | key->x = x; | |
333 | key->y = y; | |
334 | } |