Overview
Comment: | OFMapTable: Rotate hash by a random number of bits
By rotating the hash by a random number of bits, an attacker needs to |
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SHA3-256: |
4857107479fb6749a6aa9b749276d01a |
User & Date: | js on 2012-12-06 11:00:54 |
Other Links: | manifest | tags |
Context
2012-12-06
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16:20 | OFHTTPRequestDelegate: Method name improvement. check-in: c64cb4c5f2 user: js tags: trunk | |
11:00 | OFMapTable: Rotate hash by a random number of bits check-in: 4857107479 user: js tags: trunk | |
11:00 | Add of_random(). check-in: f675979cf0 user: js tags: trunk | |
Changes
Modified src/OFMapTable.h from [5b6730706a] to [91b9317d21].
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47 48 49 50 51 52 53 54 55 56 57 58 59 60 | @interface OFMapTable: OFObject <OFCopying, OFFastEnumeration> { of_map_table_functions_t keyFunctions, valueFunctions; struct of_map_table_bucket **buckets; uint32_t minCapacity, capacity, count; unsigned long mutations; uint32_t seed; } /*! * @brief Creates a new OFMapTable with the specified key and value functions. * * @param keyFunctions A structure of functions for handling keys * @param valueFunctions A structure of functions for handling values | > | 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 | @interface OFMapTable: OFObject <OFCopying, OFFastEnumeration> { of_map_table_functions_t keyFunctions, valueFunctions; struct of_map_table_bucket **buckets; uint32_t minCapacity, capacity, count; unsigned long mutations; uint32_t seed; uint8_t rotate; } /*! * @brief Creates a new OFMapTable with the specified key and value functions. * * @param keyFunctions A structure of functions for handling keys * @param valueFunctions A structure of functions for handling values |
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Modified src/OFMapTable.m from [ecdbc341ea] to [fda4d04529].
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149 150 151 152 153 154 155 | minCapacity = capacity; buckets = [self allocMemoryWithSize: sizeof(*buckets) count: capacity]; memset(buckets, 0, capacity * sizeof(*buckets)); | | > > | 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 | minCapacity = capacity; buckets = [self allocMemoryWithSize: sizeof(*buckets) count: capacity]; memset(buckets, 0, capacity * sizeof(*buckets)); if (of_hash_seed != 0) { seed = of_random(); rotate = of_random() & 0x1F; } } @catch (id e) { [self release]; @throw e; } return self; } |
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228 229 230 231 232 233 234 | @try { uint32_t i; for (i = 0; i < capacity; i++) if (buckets[i] != NULL && buckets[i] != &deleted) [copy OF_setValue: buckets[i]->value forKey: buckets[i]->key | > | > | 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 | @try { uint32_t i; for (i = 0; i < capacity; i++) if (buckets[i] != NULL && buckets[i] != &deleted) [copy OF_setValue: buckets[i]->value forKey: buckets[i]->key hash: OF_ROR( buckets[i]->hash ^ seed, rotate)]; } @catch (id e) { [copy release]; @throw e; } copy->minCapacity = MIN_CAPACITY; |
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253 254 255 256 257 258 259 | uint32_t i, hash, last; if (key == NULL) @throw [OFInvalidArgumentException exceptionWithClass: [self class] selector: _cmd]; | | | 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 | uint32_t i, hash, last; if (key == NULL) @throw [OFInvalidArgumentException exceptionWithClass: [self class] selector: _cmd]; hash = OF_ROL(keyFunctions.hash(key) ^ seed, rotate); last = capacity; for (i = hash & (capacity - 1); i < last && buckets[i] != NULL; i++) { if (buckets[i] == &deleted) continue; if (keyFunctions.equal(buckets[i]->key, key)) |
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285 286 287 288 289 290 291 292 293 294 295 296 297 298 | return NULL; } - (void)OF_resizeForCount: (uint32_t)newCount { uint32_t i, fullness, newCapacity, newSeed = 0, seedUpdate = 0; struct of_map_table_bucket **newBuckets; if (newCount > UINT32_MAX || newCount > UINT32_MAX / sizeof(*buckets) || newCount > UINT32_MAX / 8) @throw [OFOutOfRangeException exceptionWithClass: [self class]]; fullness = newCount * 8 / capacity; | > | 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 | return NULL; } - (void)OF_resizeForCount: (uint32_t)newCount { uint32_t i, fullness, newCapacity, newSeed = 0, seedUpdate = 0; struct of_map_table_bucket **newBuckets; uint8_t newRotate = 0; if (newCount > UINT32_MAX || newCount > UINT32_MAX / sizeof(*buckets) || newCount > UINT32_MAX / 8) @throw [OFOutOfRangeException exceptionWithClass: [self class]]; fullness = newCount * 8 / capacity; |
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311 312 313 314 315 316 317 318 319 320 321 322 323 | for (i = 0; i < newCapacity; i++) newBuckets[i] = NULL; if (of_hash_seed != 0) { newSeed = of_random(); seedUpdate = seed ^ newSeed; } for (i = 0; i < capacity; i++) { if (buckets[i] != NULL && buckets[i] != &deleted) { uint32_t j, last; | > > | > > | 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 | for (i = 0; i < newCapacity; i++) newBuckets[i] = NULL; if (of_hash_seed != 0) { newSeed = of_random(); seedUpdate = seed ^ newSeed; newRotate = of_random() & 0x1F; } for (i = 0; i < capacity; i++) { if (buckets[i] != NULL && buckets[i] != &deleted) { uint32_t j, last; buckets[i]->hash = OF_ROL( OF_ROR(buckets[i]->hash, rotate) ^ seedUpdate, newRotate); last = newCapacity; j = buckets[i]->hash & (newCapacity - 1); for (; j < last && newBuckets[j] != NULL; j++); /* In case the last bucket is already used */ |
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342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 | } } [self freeMemory: buckets]; buckets = newBuckets; capacity = newCapacity; seed = newSeed; } - (void)OF_setValue: (void*)value forKey: (void*)key hash: (uint32_t)hash { uint32_t i, last, seededHash; void *old; if (key == NULL || value == NULL) @throw [OFInvalidArgumentException exceptionWithClass: [self class] selector: _cmd]; last = capacity; | > | | 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 | } } [self freeMemory: buckets]; buckets = newBuckets; capacity = newCapacity; seed = newSeed; rotate = newRotate; } - (void)OF_setValue: (void*)value forKey: (void*)key hash: (uint32_t)hash { uint32_t i, last, seededHash; void *old; if (key == NULL || value == NULL) @throw [OFInvalidArgumentException exceptionWithClass: [self class] selector: _cmd]; last = capacity; seededHash = OF_ROL(hash ^ seed, rotate); for (i = seededHash & (capacity - 1); i < last && buckets[i] != NULL; i++) { if (buckets[i] == &deleted) continue; if (keyFunctions.equal(buckets[i]->key, key)) |
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387 388 389 390 391 392 393 | /* Key not in dictionary */ if (i >= last || buckets[i] == NULL || buckets[i] == &deleted || !keyFunctions.equal(buckets[i]->key, key)) { struct of_map_table_bucket *bucket; [self OF_resizeForCount: count + 1]; | | | 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 | /* Key not in dictionary */ if (i >= last || buckets[i] == NULL || buckets[i] == &deleted || !keyFunctions.equal(buckets[i]->key, key)) { struct of_map_table_bucket *bucket; [self OF_resizeForCount: count + 1]; seededHash = OF_ROL(hash ^ seed, rotate); mutations++; last = capacity; for (i = seededHash & (capacity - 1); i < last && buckets[i] != NULL && buckets[i] != &deleted; i++); |
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454 455 456 457 458 459 460 | uint32_t i, hash, last; if (key == NULL) @throw [OFInvalidArgumentException exceptionWithClass: [self class] selector: _cmd]; | | | 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 | uint32_t i, hash, last; if (key == NULL) @throw [OFInvalidArgumentException exceptionWithClass: [self class] selector: _cmd]; hash = OF_ROL(keyFunctions.hash(key) ^ seed, rotate); last = capacity; for (i = hash & (capacity - 1); i < last && buckets[i] != NULL; i++) { if (buckets[i] == &deleted) continue; if (keyFunctions.equal(buckets[i]->key, key)) { |
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Modified src/macros.h from [ba733f14be] to [6b2bc955be].
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321 322 323 324 325 326 327 328 329 330 331 332 333 334 | #if defined(__MACH__) && defined(__arm__) # define OF_IOS #endif #define OF_ROL(value, bits) \ (((value) << ((bits) % (sizeof(value) * 8))) | \ (value) >> (sizeof(value) * 8 - ((bits) % (sizeof(value) * 8)))) #define OF_HASH_INIT(hash) hash = of_hash_seed #define OF_HASH_ADD(hash, byte) \ { \ hash += (uint8_t)(byte); \ hash += (hash << 10); \ hash ^= (hash >> 6); \ | > > > | 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 | #if defined(__MACH__) && defined(__arm__) # define OF_IOS #endif #define OF_ROL(value, bits) \ (((value) << ((bits) % (sizeof(value) * 8))) | \ (value) >> (sizeof(value) * 8 - ((bits) % (sizeof(value) * 8)))) #define OF_ROR(value, bits) \ (((value) >> ((bits) % (sizeof(value) * 8))) | \ (value) << (sizeof(value) * 8 - ((bits) % (sizeof(value) * 8)))) #define OF_HASH_INIT(hash) hash = of_hash_seed #define OF_HASH_ADD(hash, byte) \ { \ hash += (uint8_t)(byte); \ hash += (hash << 10); \ hash ^= (hash >> 6); \ |
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