1 | /* |
---|
2 | ------------------------------------------------------------------------------- |
---|
3 | lookup3.c, by Bob Jenkins, May 2006, Public Domain. |
---|
4 | These are functions for producing 32-bit hashes for hash table lookup. |
---|
5 | hashword(), hashlittle(), hashbig(), mix(), and final() are externally |
---|
6 | useful functions. Routines to test the hash are included if SELF_TEST |
---|
7 | is defined. You can use this free for any purpose. It has no warranty. |
---|
8 | |
---|
9 | You probably want to use hashlittle(). hashlittle() and hashbig() |
---|
10 | hash byte arrays. hashlittle() is is faster than hashbig() on |
---|
11 | little-endian machines. Intel and AMD are little-endian machines. |
---|
12 | |
---|
13 | If you want to find a hash of, say, exactly 7 integers, do |
---|
14 | a = i1; b = i2; c = i3; |
---|
15 | mix(a,b,c); |
---|
16 | a += i4; b += i5; c += i6; |
---|
17 | mix(a,b,c); |
---|
18 | a += i7; |
---|
19 | final(a,b,c); |
---|
20 | then use c as the hash value. If you have a variable length array of |
---|
21 | 4-byte integers to hash, use hashword(). If you have a byte array (like |
---|
22 | a character string), use hashlittle(). If you have several byte arrays, or |
---|
23 | a mix of things, see the comments above hashlittle(). |
---|
24 | |
---|
25 | Code changed for ANSI C compilers and autotools by Åukasz CieÅnik. |
---|
26 | ------------------------------------------------------------------------------- |
---|
27 | */ |
---|
28 | #ifdef HAVE_CONFIG_H |
---|
29 | # include <config.h> |
---|
30 | #endif |
---|
31 | |
---|
32 | #include <drmaa_utils/lookup3.h> |
---|
33 | |
---|
34 | #ifdef SELF_TEST |
---|
35 | #include <stdio.h> |
---|
36 | #include <time.h> |
---|
37 | #include <stdlib.h> |
---|
38 | #endif |
---|
39 | |
---|
40 | #ifndef lint |
---|
41 | static char rcsid[] |
---|
42 | # ifdef __GNUC__ |
---|
43 | __attribute__ ((unused)) |
---|
44 | # endif |
---|
45 | = "$Id: lookup3.c 13 2011-04-20 15:41:43Z mmamonski $"; |
---|
46 | #endif |
---|
47 | |
---|
48 | typedef uint32_t uint32; /* unsigned 4-byte quantities */ |
---|
49 | typedef uint16_t uint16; /* unsigned 2-byte quantities */ |
---|
50 | typedef uint8_t uint8; /* unsigned 1-byte quantities */ |
---|
51 | |
---|
52 | /* do not make any assumptions about the endianess - safer and prevents from reading not initialized memory */ |
---|
53 | # define HASH_LITTLE_ENDIAN 0 |
---|
54 | # define HASH_BIG_ENDIAN 0 |
---|
55 | |
---|
56 | #define hashsize(n) ((uint32)1<<(n)) |
---|
57 | #define hashmask(n) (hashsize(n)-1) |
---|
58 | #define rot(x,k) (((x)<<(k)) ^ ((x)>>(32-(k)))) |
---|
59 | |
---|
60 | /* |
---|
61 | ------------------------------------------------------------------------------- |
---|
62 | mix -- mix 3 32-bit values reversibly. |
---|
63 | |
---|
64 | This is reversible, so any information in (a,b,c) before mix() is |
---|
65 | still in (a,b,c) after mix(). |
---|
66 | |
---|
67 | If four pairs of (a,b,c) inputs are run through mix(), or through |
---|
68 | mix() in reverse, there are at least 32 bits of the output that |
---|
69 | are sometimes the same for one pair and different for another pair. |
---|
70 | This was tested for: |
---|
71 | * pairs that differed by one bit, by two bits, in any combination |
---|
72 | of top bits of (a,b,c), or in any combination of bottom bits of |
---|
73 | (a,b,c). |
---|
74 | * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed |
---|
75 | the output delta to a Gray code (a^(a>>1)) so a string of 1's (as |
---|
76 | is commonly produced by subtraction) look like a single 1-bit |
---|
77 | difference. |
---|
78 | * the base values were pseudorandom, all zero but one bit set, or |
---|
79 | all zero plus a counter that starts at zero. |
---|
80 | |
---|
81 | Some k values for my "a-=c; a^=rot(c,k); c+=b;" arrangement that |
---|
82 | satisfy this are |
---|
83 | 4 6 8 16 19 4 |
---|
84 | 9 15 3 18 27 15 |
---|
85 | 14 9 3 7 17 3 |
---|
86 | Well, "9 15 3 18 27 15" didn't quite get 32 bits diffing |
---|
87 | for "differ" defined as + with a one-bit base and a two-bit delta. I |
---|
88 | used http://burtleburtle.net/bob/hash/avalanche.html to choose |
---|
89 | the operations, constants, and arrangements of the variables. |
---|
90 | |
---|
91 | This does not achieve avalanche. There are input bits of (a,b,c) |
---|
92 | that fail to affect some output bits of (a,b,c), especially of a. The |
---|
93 | most thoroughly mixed value is c, but it doesn't really even achieve |
---|
94 | avalanche in c. |
---|
95 | |
---|
96 | This allows some parallelism. Read-after-writes are good at doubling |
---|
97 | the number of bits affected, so the goal of mixing pulls in the opposite |
---|
98 | direction as the goal of parallelism. I did what I could. Rotates |
---|
99 | seem to cost as much as shifts on every machine I could lay my hands |
---|
100 | on, and rotates are much kinder to the top and bottom bits, so I used |
---|
101 | rotates. |
---|
102 | ------------------------------------------------------------------------------- |
---|
103 | */ |
---|
104 | #define mix(a,b,c) \ |
---|
105 | { \ |
---|
106 | a -= c; a ^= rot(c, 4); c += b; \ |
---|
107 | b -= a; b ^= rot(a, 6); a += c; \ |
---|
108 | c -= b; c ^= rot(b, 8); b += a; \ |
---|
109 | a -= c; a ^= rot(c,16); c += b; \ |
---|
110 | b -= a; b ^= rot(a,19); a += c; \ |
---|
111 | c -= b; c ^= rot(b, 4); b += a; \ |
---|
112 | } |
---|
113 | |
---|
114 | /* |
---|
115 | ------------------------------------------------------------------------------- |
---|
116 | final -- final mixing of 3 32-bit values (a,b,c) into c |
---|
117 | |
---|
118 | Pairs of (a,b,c) values differing in only a few bits will usually |
---|
119 | produce values of c that look totally different. This was tested for |
---|
120 | * pairs that differed by one bit, by two bits, in any combination |
---|
121 | of top bits of (a,b,c), or in any combination of bottom bits of |
---|
122 | (a,b,c). |
---|
123 | * "differ" is defined as +, -, ^, or ~^. For + and -, I transformed |
---|
124 | the output delta to a Gray code (a^(a>>1)) so a string of 1's (as |
---|
125 | is commonly produced by subtraction) look like a single 1-bit |
---|
126 | difference. |
---|
127 | * the base values were pseudorandom, all zero but one bit set, or |
---|
128 | all zero plus a counter that starts at zero. |
---|
129 | |
---|
130 | These constants passed: |
---|
131 | 14 11 25 16 4 14 24 |
---|
132 | 12 14 25 16 4 14 24 |
---|
133 | and these came close: |
---|
134 | 4 8 15 26 3 22 24 |
---|
135 | 10 8 15 26 3 22 24 |
---|
136 | 11 8 15 26 3 22 24 |
---|
137 | ------------------------------------------------------------------------------- |
---|
138 | */ |
---|
139 | #define final(a,b,c) \ |
---|
140 | { \ |
---|
141 | c ^= b; c -= rot(b,14); \ |
---|
142 | a ^= c; a -= rot(c,11); \ |
---|
143 | b ^= a; b -= rot(a,25); \ |
---|
144 | c ^= b; c -= rot(b,16); \ |
---|
145 | a ^= c; a -= rot(c,4); \ |
---|
146 | b ^= a; b -= rot(a,14); \ |
---|
147 | c ^= b; c -= rot(b,24); \ |
---|
148 | } |
---|
149 | |
---|
150 | /** |
---|
151 | * This works on all machines. To be useful, it requires |
---|
152 | * -- that the key be an array of uint32's, and |
---|
153 | * -- that all your machines have the same endianness, and |
---|
154 | * -- that the length be the number of uint32's in the key |
---|
155 | |
---|
156 | * The function hashword() is identical to hashlittle() on little-endian |
---|
157 | * machines, and identical to hashbig() on big-endian machines, |
---|
158 | * except that the length has to be measured in uint32s rather than in |
---|
159 | * bytes. hashlittle() is more complicated than hashword() only because |
---|
160 | * hashlittle() has to dance around fitting the key bytes into registers. |
---|
161 | * |
---|
162 | * @param k the key, an array of uint32 values |
---|
163 | * @param length the length of the key, in uint32s |
---|
164 | * @param initval the previous hash, or an arbitrary value |
---|
165 | */ |
---|
166 | uint32 hashword( const uint32 *k, size_t length, uint32 initval ) |
---|
167 | { |
---|
168 | uint32 a,b,c; |
---|
169 | |
---|
170 | /* Set up the internal state */ |
---|
171 | a = b = c = 0xdeadbeef + (((uint32)length)<<2) + initval; |
---|
172 | |
---|
173 | /*------------------------------------------------- handle most of the key */ |
---|
174 | while (length > 3) |
---|
175 | { |
---|
176 | a += k[0]; |
---|
177 | b += k[1]; |
---|
178 | c += k[2]; |
---|
179 | mix(a,b,c); |
---|
180 | length -= 3; |
---|
181 | k += 3; |
---|
182 | } |
---|
183 | |
---|
184 | /*--------------------------------------------- handle the last 3 uint32's */ |
---|
185 | switch(length) /* all the case statements fall through */ |
---|
186 | { |
---|
187 | case 3 : c+=k[2]; |
---|
188 | case 2 : b+=k[1]; |
---|
189 | case 1 : a+=k[0]; |
---|
190 | final(a,b,c); |
---|
191 | case 0: /* case 0: nothing left to add */ |
---|
192 | break; |
---|
193 | } |
---|
194 | /*------------------------------------------------------ report the result */ |
---|
195 | return c; |
---|
196 | } |
---|
197 | |
---|
198 | |
---|
199 | /** |
---|
200 | * hashlittle() -- hash a variable-length key into a 32-bit value |
---|
201 | * @param k the key (the unaligned variable-length array of bytes) |
---|
202 | * @param length the length of the key, counting by bytes |
---|
203 | * @param initval can be any 4-byte value |
---|
204 | * |
---|
205 | * Returns a 32-bit value. Every bit of the key affects every bit of |
---|
206 | * the return value. Two keys differing by one or two bits will have |
---|
207 | * totally different hash values. |
---|
208 | * |
---|
209 | * The best hash table sizes are powers of 2. There is no need to do |
---|
210 | * mod a prime (mod is sooo slow!). If you need less than 32 bits, |
---|
211 | * use a bitmask. For example, if you need only 10 bits, do |
---|
212 | * h = (h & hashmask(10)); |
---|
213 | * In which case, the hash table should have hashsize(10) elements. |
---|
214 | * |
---|
215 | * If you are hashing n strings (uint8 **)k, do it like this: |
---|
216 | * for (i=0, h=0; i<n; ++i) h = hashlittle( k[i], len[i], h); |
---|
217 | * |
---|
218 | * By Bob Jenkins, 2006. bob_jenkins@burtleburtle.net. You may use this |
---|
219 | * code any way you wish, private, educational, or commercial. It's free. |
---|
220 | * |
---|
221 | * Use for hash table lookup, or anything where one collision in 2^^32 is |
---|
222 | * acceptable. Do NOT use for cryptographic purposes. |
---|
223 | */ |
---|
224 | uint32 hashlittle( const void *key, size_t length, uint32 initval ) |
---|
225 | { |
---|
226 | uint32 a,b,c; |
---|
227 | |
---|
228 | /* Set up the internal state */ |
---|
229 | a = b = c = 0xdeadbeef + ((uint32)length) + initval; |
---|
230 | |
---|
231 | if (HASH_LITTLE_ENDIAN && !((((uint8 *)key)-(uint8 *)0) & 0x3)) { |
---|
232 | const uint32 *k = key; /* read 32-bit chunks */ |
---|
233 | |
---|
234 | /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */ |
---|
235 | while (length > 12) |
---|
236 | { |
---|
237 | a += k[0]; |
---|
238 | b += k[1]; |
---|
239 | c += k[2]; |
---|
240 | mix(a,b,c); |
---|
241 | length -= 12; |
---|
242 | k += 3; |
---|
243 | } |
---|
244 | |
---|
245 | /*----------------------------- handle the last (probably partial) block */ |
---|
246 | switch(length) |
---|
247 | { |
---|
248 | case 12: c+=k[2]; b+=k[1]; a+=k[0]; break; |
---|
249 | case 11: c+=k[2]&0xffffff; b+=k[1]; a+=k[0]; break; |
---|
250 | case 10: c+=k[2]&0xffff; b+=k[1]; a+=k[0]; break; |
---|
251 | case 9 : c+=k[2]&0xff; b+=k[1]; a+=k[0]; break; |
---|
252 | case 8 : b+=k[1]; a+=k[0]; break; |
---|
253 | case 7 : b+=k[1]&0xffffff; a+=k[0]; break; |
---|
254 | case 6 : b+=k[1]&0xffff; a+=k[0]; break; |
---|
255 | case 5 : b+=k[1]&0xff; a+=k[0]; break; |
---|
256 | case 4 : a+=k[0]; break; |
---|
257 | case 3 : a+=k[0]&0xffffff; break; |
---|
258 | case 2 : a+=k[0]&0xffff; break; |
---|
259 | case 1 : a+=k[0]&0xff; break; |
---|
260 | case 0 : return c; /* zero length strings require no mixing */ |
---|
261 | } |
---|
262 | |
---|
263 | } else if (HASH_LITTLE_ENDIAN && !((((uint8 *)key)-(uint8 *)0) & 0x1)) { |
---|
264 | const uint16 *k = key; /* read 16-bit chunks */ |
---|
265 | |
---|
266 | /*--------------- all but last block: aligned reads and different mixing */ |
---|
267 | while (length > 12) |
---|
268 | { |
---|
269 | a += k[0] + (((uint32)k[1])<<16); |
---|
270 | b += k[2] + (((uint32)k[3])<<16); |
---|
271 | c += k[4] + (((uint32)k[5])<<16); |
---|
272 | mix(a,b,c); |
---|
273 | length -= 12; |
---|
274 | k += 6; |
---|
275 | } |
---|
276 | |
---|
277 | /*----------------------------- handle the last (probably partial) block */ |
---|
278 | switch(length) |
---|
279 | { |
---|
280 | case 12: c+=k[4]+(((uint32)k[5])<<16); |
---|
281 | b+=k[2]+(((uint32)k[3])<<16); |
---|
282 | a+=k[0]+(((uint32)k[1])<<16); |
---|
283 | break; |
---|
284 | case 11: c+=((uint32)(k[5]&0xff))<<16;/* fall through */ |
---|
285 | case 10: c+=k[4]; |
---|
286 | b+=k[2]+(((uint32)k[3])<<16); |
---|
287 | a+=k[0]+(((uint32)k[1])<<16); |
---|
288 | break; |
---|
289 | case 9 : c+=k[4]&0xff; /* fall through */ |
---|
290 | case 8 : b+=k[2]+(((uint32)k[3])<<16); |
---|
291 | a+=k[0]+(((uint32)k[1])<<16); |
---|
292 | break; |
---|
293 | case 7 : b+=((uint32)(k[3]&0xff))<<16;/* fall through */ |
---|
294 | case 6 : b+=k[2]; |
---|
295 | a+=k[0]+(((uint32)k[1])<<16); |
---|
296 | break; |
---|
297 | case 5 : b+=k[2]&0xff; /* fall through */ |
---|
298 | case 4 : a+=k[0]+(((uint32)k[1])<<16); |
---|
299 | break; |
---|
300 | case 3 : a+=((uint32)(k[1]&0xff))<<16;/* fall through */ |
---|
301 | case 2 : a+=k[0]; |
---|
302 | break; |
---|
303 | case 1 : a+=k[0]&0xff; |
---|
304 | break; |
---|
305 | case 0 : return c; /* zero length requires no mixing */ |
---|
306 | } |
---|
307 | |
---|
308 | } else { /* need to read the key one byte at a time */ |
---|
309 | const uint8 *k = key; |
---|
310 | |
---|
311 | /*--------------- all but the last block: affect some 32 bits of (a,b,c) */ |
---|
312 | while (length > 12) |
---|
313 | { |
---|
314 | a += k[0]; |
---|
315 | a += ((uint32)k[1])<<8; |
---|
316 | a += ((uint32)k[2])<<16; |
---|
317 | a += ((uint32)k[3])<<24; |
---|
318 | b += k[4]; |
---|
319 | b += ((uint32)k[5])<<8; |
---|
320 | b += ((uint32)k[6])<<16; |
---|
321 | b += ((uint32)k[7])<<24; |
---|
322 | c += k[8]; |
---|
323 | c += ((uint32)k[9])<<8; |
---|
324 | c += ((uint32)k[10])<<16; |
---|
325 | c += ((uint32)k[11])<<24; |
---|
326 | mix(a,b,c); |
---|
327 | length -= 12; |
---|
328 | k += 12; |
---|
329 | } |
---|
330 | |
---|
331 | /*-------------------------------- last block: affect all 32 bits of (c) */ |
---|
332 | switch(length) /* all the case statements fall through */ |
---|
333 | { |
---|
334 | case 12: c+=((uint32)k[11])<<24; |
---|
335 | case 11: c+=((uint32)k[10])<<16; |
---|
336 | case 10: c+=((uint32)k[9])<<8; |
---|
337 | case 9 : c+=k[8]; |
---|
338 | case 8 : b+=((uint32)k[7])<<24; |
---|
339 | case 7 : b+=((uint32)k[6])<<16; |
---|
340 | case 6 : b+=((uint32)k[5])<<8; |
---|
341 | case 5 : b+=k[4]; |
---|
342 | case 4 : a+=((uint32)k[3])<<24; |
---|
343 | case 3 : a+=((uint32)k[2])<<16; |
---|
344 | case 2 : a+=((uint32)k[1])<<8; |
---|
345 | case 1 : a+=k[0]; |
---|
346 | break; |
---|
347 | case 0 : return c; |
---|
348 | } |
---|
349 | } |
---|
350 | |
---|
351 | final(a,b,c); |
---|
352 | return c; |
---|
353 | } |
---|
354 | |
---|
355 | |
---|
356 | |
---|
357 | /** |
---|
358 | * hashbig(): |
---|
359 | * This is the same as hashword() on big-endian machines. It is different |
---|
360 | * from hashlittle() on all machines. hashbig() takes advantage of |
---|
361 | * big-endian byte ordering. |
---|
362 | */ |
---|
363 | uint32 hashbig( const void *key, size_t length, uint32 initval ) |
---|
364 | { |
---|
365 | uint32 a,b,c; |
---|
366 | |
---|
367 | /* Set up the internal state */ |
---|
368 | a = b = c = 0xdeadbeef + ((uint32)length) + initval; |
---|
369 | |
---|
370 | if (HASH_BIG_ENDIAN && !((((uint8 *)key)-(uint8 *)0) & 0x3)) { |
---|
371 | const uint32 *k = key; /* read 32-bit chunks */ |
---|
372 | |
---|
373 | /*------ all but last block: aligned reads and affect 32 bits of (a,b,c) */ |
---|
374 | while (length > 12) |
---|
375 | { |
---|
376 | a += k[0]; |
---|
377 | b += k[1]; |
---|
378 | c += k[2]; |
---|
379 | mix(a,b,c); |
---|
380 | length -= 12; |
---|
381 | k += 3; |
---|
382 | } |
---|
383 | |
---|
384 | /*----------------------------- handle the last (probably partial) block */ |
---|
385 | switch(length) |
---|
386 | { |
---|
387 | case 12: c+=k[2]; b+=k[1]; a+=k[0]; break; |
---|
388 | case 11: c+=k[2]<<8; b+=k[1]; a+=k[0]; break; |
---|
389 | case 10: c+=k[2]<<16; b+=k[1]; a+=k[0]; break; |
---|
390 | case 9 : c+=k[2]<<24; b+=k[1]; a+=k[0]; break; |
---|
391 | case 8 : b+=k[1]; a+=k[0]; break; |
---|
392 | case 7 : b+=k[1]<<8; a+=k[0]; break; |
---|
393 | case 6 : b+=k[1]<<16; a+=k[0]; break; |
---|
394 | case 5 : b+=k[1]<<24; a+=k[0]; break; |
---|
395 | case 4 : a+=k[0]; break; |
---|
396 | case 3 : a+=k[0]<<8; break; |
---|
397 | case 2 : a+=k[0]<<16; break; |
---|
398 | case 1 : a+=k[0]<<24; break; |
---|
399 | case 0 : return c; /* zero length strings require no mixing */ |
---|
400 | } |
---|
401 | |
---|
402 | } else { /* need to read the key one byte at a time */ |
---|
403 | const uint8 *k = key; |
---|
404 | |
---|
405 | /*--------------- all but the last block: affect some 32 bits of (a,b,c) */ |
---|
406 | while (length > 12) |
---|
407 | { |
---|
408 | a += ((uint32)k[0])<<24; |
---|
409 | a += ((uint32)k[1])<<16; |
---|
410 | a += ((uint32)k[2])<<8; |
---|
411 | a += ((uint32)k[3]); |
---|
412 | b += ((uint32)k[4])<<24; |
---|
413 | b += ((uint32)k[5])<<16; |
---|
414 | b += ((uint32)k[6])<<8; |
---|
415 | b += ((uint32)k[7]); |
---|
416 | c += ((uint32)k[8])<<24; |
---|
417 | c += ((uint32)k[9])<<16; |
---|
418 | c += ((uint32)k[10])<<8; |
---|
419 | c += ((uint32)k[11]); |
---|
420 | mix(a,b,c); |
---|
421 | length -= 12; |
---|
422 | k += 12; |
---|
423 | } |
---|
424 | |
---|
425 | /*-------------------------------- last block: affect all 32 bits of (c) */ |
---|
426 | switch(length) /* all the case statements fall through */ |
---|
427 | { |
---|
428 | case 12: c+=((uint32)k[11])<<24; |
---|
429 | case 11: c+=((uint32)k[10])<<16; |
---|
430 | case 10: c+=((uint32)k[9])<<8; |
---|
431 | case 9 : c+=k[8]; |
---|
432 | case 8 : b+=((uint32)k[7])<<24; |
---|
433 | case 7 : b+=((uint32)k[6])<<16; |
---|
434 | case 6 : b+=((uint32)k[5])<<8; |
---|
435 | case 5 : b+=k[4]; |
---|
436 | case 4 : a+=((uint32)k[3])<<24; |
---|
437 | case 3 : a+=((uint32)k[2])<<16; |
---|
438 | case 2 : a+=((uint32)k[1])<<8; |
---|
439 | case 1 : a+=k[0]; |
---|
440 | break; |
---|
441 | case 0 : return c; |
---|
442 | } |
---|
443 | } |
---|
444 | |
---|
445 | final(a,b,c); |
---|
446 | return c; |
---|
447 | } |
---|
448 | |
---|
449 | |
---|
450 | #ifdef SELF_TEST |
---|
451 | |
---|
452 | /* used for timings */ |
---|
453 | void driver1(void) |
---|
454 | { |
---|
455 | uint8 buf[256]; |
---|
456 | uint32 i; |
---|
457 | uint32 h=0; |
---|
458 | time_t a,z; |
---|
459 | |
---|
460 | time(&a); |
---|
461 | for (i=0; i<256; ++i) buf[i] = 'x'; |
---|
462 | for (i=0; i<1; ++i) |
---|
463 | { |
---|
464 | h = hashlittle(&buf[0],1,h); |
---|
465 | } |
---|
466 | time(&z); |
---|
467 | if (z-a > 0) printf("time %ld %.8lx\n", z-a, h); |
---|
468 | } |
---|
469 | |
---|
470 | /* check that every input bit changes every output bit half the time */ |
---|
471 | #define HASHSTATE 1 |
---|
472 | #define HASHLEN 1 |
---|
473 | #define MAXPAIR 60 |
---|
474 | #define MAXLEN 70 |
---|
475 | void driver2(void) |
---|
476 | { |
---|
477 | uint8 qa[MAXLEN+1], qb[MAXLEN+2], *a = &qa[0], *b = &qb[1]; |
---|
478 | uint32 c[HASHSTATE], d[HASHSTATE], i, j=0, k, l, m, z; |
---|
479 | uint32 e[HASHSTATE],f[HASHSTATE],g[HASHSTATE],h[HASHSTATE]; |
---|
480 | uint32 x[HASHSTATE],y[HASHSTATE]; |
---|
481 | uint32 hlen; |
---|
482 | |
---|
483 | printf("No more than %d trials should ever be needed \n",MAXPAIR/2); |
---|
484 | for (hlen=0; hlen < MAXLEN; ++hlen) |
---|
485 | { |
---|
486 | z=0; |
---|
487 | for (i=0; i<hlen; ++i) /*----------------------- for each input byte, */ |
---|
488 | { |
---|
489 | for (j=0; j<8; ++j) /*------------------------ for each input bit, */ |
---|
490 | { |
---|
491 | for (m=1; m<8; ++m) /*------------ for serveral possible initvals, */ |
---|
492 | { |
---|
493 | for (l=0; l<HASHSTATE; ++l) e[l]=f[l]=g[l]=h[l]=x[l]=y[l]=~((uint32)0); |
---|
494 | |
---|
495 | /*---- check that every output bit is affected by that input bit */ |
---|
496 | for (k=0; k<MAXPAIR; k+=2) |
---|
497 | { |
---|
498 | uint32 finished=1; |
---|
499 | /* keys have one bit different */ |
---|
500 | for (l=0; l<hlen+1; ++l) {a[l] = b[l] = (uint8)0;} |
---|
501 | /* have a and b be two keys differing in only one bit */ |
---|
502 | a[i] ^= (k<<j); |
---|
503 | a[i] ^= (k>>(8-j)); |
---|
504 | c[0] = hashlittle(a, hlen, m); |
---|
505 | b[i] ^= ((k+1)<<j); |
---|
506 | b[i] ^= ((k+1)>>(8-j)); |
---|
507 | d[0] = hashlittle(b, hlen, m); |
---|
508 | /* check every bit is 1, 0, set, and not set at least once */ |
---|
509 | for (l=0; l<HASHSTATE; ++l) |
---|
510 | { |
---|
511 | e[l] &= (c[l]^d[l]); |
---|
512 | f[l] &= ~(c[l]^d[l]); |
---|
513 | g[l] &= c[l]; |
---|
514 | h[l] &= ~c[l]; |
---|
515 | x[l] &= d[l]; |
---|
516 | y[l] &= ~d[l]; |
---|
517 | if (e[l]|f[l]|g[l]|h[l]|x[l]|y[l]) finished=0; |
---|
518 | } |
---|
519 | if (finished) break; |
---|
520 | } |
---|
521 | if (k>z) z=k; |
---|
522 | if (k==MAXPAIR) |
---|
523 | { |
---|
524 | printf("Some bit didn't change: "); |
---|
525 | printf("%.8lx %.8lx %.8lx %.8lx %.8lx %.8lx ", |
---|
526 | e[0],f[0],g[0],h[0],x[0],y[0]); |
---|
527 | printf("i %ld j %ld m %ld len %ld\n",i,j,m,hlen); |
---|
528 | } |
---|
529 | if (z==MAXPAIR) goto done; |
---|
530 | } |
---|
531 | } |
---|
532 | } |
---|
533 | done: |
---|
534 | if (z < MAXPAIR) |
---|
535 | { |
---|
536 | printf("Mix success %2ld bytes %2ld initvals ",i,m); |
---|
537 | printf("required %ld trials\n",z/2); |
---|
538 | } |
---|
539 | } |
---|
540 | printf("\n"); |
---|
541 | } |
---|
542 | |
---|
543 | /* Check for reading beyond the end of the buffer and alignment problems */ |
---|
544 | void driver3(void) |
---|
545 | { |
---|
546 | uint8 buf[MAXLEN+20], *b; |
---|
547 | uint32 len; |
---|
548 | uint8 q[] = "This is the time for all good men to come to the aid of their country..."; |
---|
549 | uint32 dummy1; |
---|
550 | uint8 qq[] = "xThis is the time for all good men to come to the aid of their country..."; |
---|
551 | uint32 dummy2; |
---|
552 | uint8 qqq[] = "xxThis is the time for all good men to come to the aid of their country..."; |
---|
553 | uint32 dummy3; |
---|
554 | uint8 qqqq[] = "xxxThis is the time for all good men to come to the aid of their country..."; |
---|
555 | uint32 h,i,j,ref,x,y; |
---|
556 | uint8 *p; |
---|
557 | |
---|
558 | printf("Endianness. These lines should all be the same (for values filled in):\n"); |
---|
559 | printf("%.8lx %.8lx %.8lx\n", |
---|
560 | hashword((uint32 *)q, (sizeof(q)-1)/4, 13), |
---|
561 | hashword((uint32 *)q, (sizeof(q)-5)/4, 13), |
---|
562 | hashword((uint32 *)q, (sizeof(q)-9)/4, 13)); |
---|
563 | p = q; |
---|
564 | printf("%.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx\n", |
---|
565 | hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13), |
---|
566 | hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13), |
---|
567 | hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13), |
---|
568 | hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13), |
---|
569 | hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13), |
---|
570 | hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13)); |
---|
571 | p = &qq[1]; |
---|
572 | printf("%.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx\n", |
---|
573 | hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13), |
---|
574 | hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13), |
---|
575 | hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13), |
---|
576 | hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13), |
---|
577 | hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13), |
---|
578 | hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13)); |
---|
579 | p = &qqq[2]; |
---|
580 | printf("%.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx\n", |
---|
581 | hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13), |
---|
582 | hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13), |
---|
583 | hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13), |
---|
584 | hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13), |
---|
585 | hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13), |
---|
586 | hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13)); |
---|
587 | p = &qqqq[3]; |
---|
588 | printf("%.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx %.8lx\n", |
---|
589 | hashlittle(p, sizeof(q)-1, 13), hashlittle(p, sizeof(q)-2, 13), |
---|
590 | hashlittle(p, sizeof(q)-3, 13), hashlittle(p, sizeof(q)-4, 13), |
---|
591 | hashlittle(p, sizeof(q)-5, 13), hashlittle(p, sizeof(q)-6, 13), |
---|
592 | hashlittle(p, sizeof(q)-7, 13), hashlittle(p, sizeof(q)-8, 13), |
---|
593 | hashlittle(p, sizeof(q)-9, 13), hashlittle(p, sizeof(q)-10, 13), |
---|
594 | hashlittle(p, sizeof(q)-11, 13), hashlittle(p, sizeof(q)-12, 13)); |
---|
595 | printf("\n"); |
---|
596 | for (h=0, b=buf+1; h<8; ++h, ++b) |
---|
597 | { |
---|
598 | for (i=0; i<MAXLEN; ++i) |
---|
599 | { |
---|
600 | len = i; |
---|
601 | for (j=0; j<i; ++j) *(b+j)=0; |
---|
602 | |
---|
603 | /* these should all be equal */ |
---|
604 | ref = hashlittle(b, len, (uint32)1); |
---|
605 | *(b+i)=(uint8)~0; |
---|
606 | *(b-1)=(uint8)~0; |
---|
607 | x = hashlittle(b, len, (uint32)1); |
---|
608 | y = hashlittle(b, len, (uint32)1); |
---|
609 | if ((ref != x) || (ref != y)) |
---|
610 | { |
---|
611 | printf("alignment error: %.8lx %.8lx %.8lx %ld %ld\n",ref,x,y,h,i); |
---|
612 | } |
---|
613 | } |
---|
614 | } |
---|
615 | } |
---|
616 | |
---|
617 | /* check for problems with nulls */ |
---|
618 | void driver4(void) |
---|
619 | { |
---|
620 | uint8 buf[1]; |
---|
621 | uint32 h,i,state[HASHSTATE]; |
---|
622 | |
---|
623 | |
---|
624 | buf[0] = ~0; |
---|
625 | for (i=0; i<HASHSTATE; ++i) state[i] = 1; |
---|
626 | printf("These should all be different\n"); |
---|
627 | for (i=0, h=0; i<8; ++i) |
---|
628 | { |
---|
629 | h = hashlittle(buf, (uint32)0, h); |
---|
630 | printf("%2ld 0-byte strings, hash is %.8lx\n", i, h); |
---|
631 | } |
---|
632 | } |
---|
633 | |
---|
634 | |
---|
635 | int main() |
---|
636 | { |
---|
637 | driver1(); /* test that the key is hashed: used for timings */ |
---|
638 | driver2(); /* test that whole key is hashed thoroughly */ |
---|
639 | driver3(); /* test that nothing but the key is hashed */ |
---|
640 | driver4(); /* test hashing multiple buffers (all buffers are null) */ |
---|
641 | return 1; |
---|
642 | } |
---|
643 | |
---|
644 | #endif /* SELF_TEST */ |
---|