5 * @author Roland Haeder <webmaster@ship-simu.org>
7 * @copyright Copyright (c) 2007, 2008 Roland Haeder, 2009 - 2012 Hub Developer Team
8 * @license GNU GPL 3.0 or any newer version
9 * @link http://www.ship-simu.org
11 * This program is free software: you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation, either version 3 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program. If not, see <http://www.gnu.org/licenses/>.
24 class ChunkHandler extends BaseHandler implements HandleableChunks, Registerable {
26 * Stacker for chunks with final EOP
28 const STACKER_NAME_CHUNKS_WITH_FINAL_EOP = 'final_chunks';
29 const STACKER_NAME_CHUNKS_WITHOUT_FINAL = 'pending_chunks';
30 const STACKER_NAME_ASSEMBLED_RAW_DATA = 'chunk_raw_data';
38 const CHUNK_SPLITS_INDEX_HASH = 0;
39 const CHUNK_SPLITS_INDEX_SERIAL = 1;
40 const CHUNK_SPLITS_INDEX_RAW_DATA = 2;
43 * The final array for assembling the original package back together
45 private $finalPackageChunks = array();
48 * Array of chunk hashes
50 private $chunkHashes = array();
53 * Raw EOP chunk data in an array:
56 * 1 = Hash of last chunk
58 private $eopChunk = array();
63 private $rawPackageData = '';
66 * Protected constructor
70 protected function __construct () {
71 // Call parent constructor
72 parent::__construct(__CLASS__);
75 $this->setHandlerName('chunk');
82 * Creates an instance of this class
84 * @return $handlerInstance An instance of a chunk Handler class
86 public final static function createChunkHandler () {
88 $handlerInstance = new ChunkHandler();
91 $stackerInstance = ObjectFactory::createObjectByConfiguredName('chunk_handler_stacker_class');
94 $stackerInstance->initStacker(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP);
95 $stackerInstance->initStacker(self::STACKER_NAME_CHUNKS_WITHOUT_FINAL);
96 $stackerInstance->initStacker(self::STACKER_NAME_ASSEMBLED_RAW_DATA);
98 // Set the stacker in this handler
99 $handlerInstance->setStackerInstance($stackerInstance);
101 // Get a crypto instance ...
102 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
104 // ... and set it in this handler
105 $handlerInstance->setCryptoInstance($cryptoInstance);
107 // Get a fragmenter instance for later verification of serial numbers (e.g. if all are received)
108 $fragmenterInstance = FragmenterFactory::createFragmenterInstance('package');
110 // Set it in this handler
111 $handlerInstance->setFragmenterInstance($fragmenterInstance);
113 // Return the prepared instance
114 return $handlerInstance;
118 * Initializes the handler
122 private function initHandler () {
123 // Init finalPackageChunks
124 $this->finalPackageChunks = array(
125 // Array for package content
126 'content' => array(),
127 // ... and for the hashes
129 // ... marker for that the final array is complete for assembling all chunks
130 'is_complete' => false,
131 // ... steps done to assemble all chunks
132 'assemble_steps' => 0,
136 $this->chunkHashes = array();
139 $this->eopChunk = array(
146 * Checks whether the hash generated from package content is the same ("valid") as given
148 * @param $chunkSplits An array from a splitted chunk
149 * @return $isValid Whether the hash is "valid"
151 private function isChunkHashValid (array $chunkSplits) {
152 // Now hash the raw data again
153 $chunkHash = $this->getCryptoInstance()->hashString($chunkSplits[self::CHUNK_SPLITS_INDEX_RAW_DATA], $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH], false);
156 //* NOISY-DEBUG: */ $this->debugOutput('CHUNK-HANDLER: chunkHash=' . $chunkHash . ',chunkSplits[chunk_hash]=' . $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH] . ',chunkSplits[serial]=' . $chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL] . ',chunkSplits[raw_data]=' . $chunkSplits[self::CHUNK_SPLITS_INDEX_RAW_DATA]);
159 $isValid = ($chunkSplits[self::CHUNK_SPLITS_INDEX_HASH] === $chunkHash);
166 * Checks whether the given serial number is valid
168 * @param $serialNumber A serial number from a chunk
169 * @return $isValid Whether the serial number is valid
171 private function isSerialNumberValid ($serialNumber) {
173 $isValid = ((strlen($serialNumber) == PackageFragmenter::MAX_SERIAL_LENGTH) && ($this->bigintval($serialNumber, false) === $serialNumber));
180 * Adds the chunk to the final array which will be used for the final step
181 * which will be to assemble all chunks back to the original package content
182 * and for the final hash check.
184 * This method may throw an exception if a chunk with the same serial number
185 * has already been added to avoid mixing chunks from different packages.
187 * @param $chunkSplits An array from a splitted chunk
190 private function addChunkToFinalArray (array $chunkSplits) {
191 // Is the serial number (index 1) already been added?
192 if (isset($this->finalPackageChunks[$chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL]])) {
193 // Then throw an exception
194 throw new ChunkAlreadyAssembledException(array($this, $chunkSplits), self::EXCEPTION_CHUNK_ALREADY_ASSEMBLED);
198 //* NOISY-DEBUG: */ $this->debugOutput('CHUNK-HANDLER: serialNumber=' . $chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL] . ',hash=' . $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH]);
200 // Add the chunk data (index 2) to the final array and use the serial number as index
201 $this->finalPackageChunks['content'][$chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL]] = $chunkSplits[self::CHUNK_SPLITS_INDEX_RAW_DATA];
203 // ... and the hash as well
204 $this->finalPackageChunks['hashes'][$chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL]] = $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH];
208 * Marks the final array as completed, do only this if you really have all
209 * chunks together including EOP and "hash chunk".
213 private function markFinalArrayAsCompleted () {
215 * As for now, just set the array element. If any further steps are
216 * being added, this should always be the last step.
218 $this->finalPackageChunks['is_complete'] = true;
222 * Sorts the chunks array by using the serial number as a sorting key. In
223 * most situations a call of ksort() is enough to accomblish this. So this
224 * method may only call ksort() on the chunks array.
226 * This method sorts 'content' and 'hashes' so both must have used the
227 * serial numbers as array indexes.
231 private function sortChunksArray () {
232 // Sort 'content' first
233 ksort($this->finalPackageChunks['content']);
236 ksort($this->finalPackageChunks['hashes']);
240 * Prepares the package assemble by removing last chunks (last shall be
241 * hash chunk, pre-last shall be EOP chunk) and verify that all serial
242 * numbers are valid (same as PackageFragmenter class would generate).
246 private function preparePackageAssmble () {
247 // Make sure both arrays have same count (this however should always be true)
248 assert(count($this->finalPackageChunks['hashes']) == count($this->finalPackageChunks['content']));
249 //* DIE: */ die('finalPackageChunks='.print_r($this->finalPackageChunks['content'],true));
252 * Remove last element (hash chunk) from 'hashes'. This hash will never
253 * be needed, so ignore it.
255 array_pop($this->finalPackageChunks['hashes']);
257 // ... and from 'content' as well but save it for later use
258 $this->chunkHashes = explode(PackageFragmenter::CHUNK_HASH_SEPARATOR, substr(array_pop($this->finalPackageChunks['content']), strlen(PackageFragmenter::HASH_CHUNK_IDENTIFIER)));
260 // Remove EOP chunk and keep a copy of it
261 array_pop($this->finalPackageChunks['hashes']);
262 $this->eopChunk = explode(PackageFragmenter::CHUNK_HASH_SEPARATOR, substr(array_pop($this->finalPackageChunks['content']), strlen(PackageFragmenter::END_OF_PACKAGE_IDENTIFIER)));
264 // Verify all serial numbers
265 $this->verifyChunkSerialNumbers();
269 * Verifies all chunk serial numbers by using a freshly initialized
270 * fragmenter instance. Do ALWAYS sort the array and array_pop() the hash
271 * chunk before calling this method to avoid re-requests of many chunks.
275 private function verifyChunkSerialNumbers () {
276 // Reset the serial number generator
277 $this->getFragmenterInstance()->resetSerialNumber();
279 // "Walk" through all (content) chunks
280 foreach ($this->finalPackageChunks['content'] as $serialNumber => $content) {
281 // Get next serial number
282 $nextSerial = $this->getFragmenterInstance()->getNextHexSerialNumber();
285 //* NOISY-DEBUG */ $this->debugOutput('CHUNK-HANDLER: serialNumber=' . $serialNumber . ',nextSerial=' . $nextSerial);
287 // Is it not the same? Then re-request it
288 if ($serialNumber != $nextSerial) {
289 // This is invalid, so remove it
290 unset($this->finalPackageChunks['content'][$serialNumber]);
291 unset($this->finalPackageChunks['hashes'][$serialNumber]);
293 // And re-request it with valid serial number (and hash chunk)
294 $this->rerequestChunkBySerialNumber($nextSerial);
300 * Assembles and verifies ("final check") chunks back together to the
301 * original package (raw data for the start). This method should only be
302 * called AFTER the EOP and final-chunk chunk have been removed.
306 private function assembleAllChunksToPackage () {
307 // If chunkHashes is not filled, don't continue
308 assert(count($this->chunkHashes) > 0);
310 // Init raw package data string
311 $this->rawPackageData = '';
313 // That went well, so start assembling all chunks
314 foreach ($this->finalPackageChunks['content'] as $serialNumber => $content) {
316 //* NOISY-DEBUG: */ $this->debugOutput('CHUNK-HANDLER: serialNumber=' . $serialNumber . ' - validating ...');
317 //* NOISY-DEBUG: */ $this->debugOutput('finalPackageChunks=' . print_r($this->finalPackageChunks,true) . 'chunkHashes=' . print_r($this->chunkHashes,true));
319 // Is this chunk valid? This should be the case
320 assert($this->isChunkHashValid(array(
321 self::CHUNK_SPLITS_INDEX_HASH => $this->finalPackageChunks['hashes'][$serialNumber],
322 self::CHUNK_SPLITS_INDEX_RAW_DATA => $content
325 // ... and is also in the hash chunk?
326 assert(in_array($this->finalPackageChunks['hashes'][$serialNumber], $this->chunkHashes));
328 // Verification okay, add it to the raw data
329 $this->rawPackageData .= $content;
333 //* NOISY-DEBUG: */ $this->debugOutput('CHUNK-HANDLER: eopChunk[1]=' . $this->eopChunk[1] . ',' . chr(10) . 'index=' . (count($this->chunkHashes) - 2) . ',' . chr(10) . 'chunkHashes='.print_r($this->chunkHashes,true));
335 // The last chunk hash must match with the one from eopChunk[1]
336 assert($this->eopChunk[1] == $this->chunkHashes[count($this->chunkHashes) - 2]);
340 * Verifies the finally assembled raw package data by comparing it against
345 private function verifyRawPackageData () {
346 // Hash the raw package data for final verification
347 $finalHash = $this->getCryptoInstance()->hashString($this->rawPackageData, $this->eopChunk[0], false);
350 assert($finalHash == $this->eopChunk[0]);
354 * Adds all chunks if the last one verifies as a 'final chunk'.
356 * @param $chunks An array with chunks, the last one should be a 'final'
358 * @throws FinalChunkVerificationException If the final chunk does not start with 'EOP:'
360 public function addAllChunksWithFinal (array $chunks) {
361 // Validate final chunk
362 if (!$this->isValidFinalChunk($chunks)) {
363 // Last chunk is not valid
364 throw new FinalChunkVerificationException(array($this, $chunks), BaseListener::EXCEPTION_FINAL_CHUNK_VERIFICATION);
367 // Do we have some pending chunks (no final)?
368 while (!$this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_CHUNKS_WITHOUT_FINAL)) {
369 // Then get it first and add it before the EOP chunks
370 array_unshift($chunks, $this->getStackerInstance()->popNamed(self::STACKER_NAME_CHUNKS_WITHOUT_FINAL));
373 // Add all chunks to the FIFO stacker
374 foreach ($chunks as $chunk) {
376 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP, $chunk);
381 * Adds all chunks and wait for more (e.g. incomplete transmission)
383 * @param $chunks An array with chunks, the last one should be a 'final'
386 public function addAllChunksWait (array $chunks) {
387 // Add all chunks to the FIFO stacker
388 foreach ($chunks as $chunk) {
390 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_CHUNKS_WITHOUT_FINAL, $chunk);
395 * Checks whether unhandled chunks are available
397 * @return $unhandledChunks Whether unhandled chunks are left
399 public function ifUnhandledChunksWithFinalAvailable () {
400 // Simply check if the stacker is not empty
401 $unhandledChunks = $this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP) === false;
404 return $unhandledChunks;
408 * Handles available chunks by processing one-by-one (not all together,
409 * this would slow-down the whole application) with the help of an
414 public function handleAvailableChunksWithFinal () {
415 // First check if there are undhandled chunks available
416 assert($this->ifUnhandledChunksWithFinalAvailable());
418 // Get an entry from the stacker
419 $chunk = $this->getStackerInstance()->popNamed(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP);
421 // Split the string with proper separator character
422 $chunkSplits = explode(PackageFragmenter::CHUNK_DATA_HASH_SEPARATOR, $chunk);
425 * Make sure three elements are always found:
430 assert(count($chunkSplits) == 3);
432 // Is the generated hash from data same ("valid") as given hash?
433 if (!$this->isChunkHashValid($chunkSplits)) {
435 $this->debugOutput('CHUNK-HANDLER: Chunk content is not validating against given hash.');
437 // Re-request this chunk (trust the hash in index # 0)
438 $this->rerequestChunkBySplitsArray($chunkSplits);
440 // Don't process this chunk
444 // Is the serial number valid (chars 0-9, length equals PackageFragmenter::MAX_SERIAL_LENGTH)?
445 if (!$this->isSerialNumberValid($chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL])) {
447 $this->debugOutput('CHUNK-HANDLER: Chunk serial number�for hash ' . $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH] . ' is invalid.');
449 // Re-request this chunk
450 $this->rerequestChunkBySplitsArray($chunkSplits);
452 // Don't process this chunk
457 * It is now known that (as long as the hash algorithm has no
458 * collisions) the content is the same as the sender sends it to this
461 * And also the serial number is valid (basicly) at this point. Now the
462 * chunk can be added to the final array.
464 $this->addChunkToFinalArray($chunkSplits);
466 // Is the stack now empty?
467 if ($this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP)) {
468 // Then mark the final array as complete
469 $this->markFinalArrayAsCompleted();
474 * Checks whether unassembled chunks are available (ready) in final array
476 * @return $unassembledChunksAvailable Whether unassembled chunks are available
478 public function ifUnassembledChunksAvailable () {
479 // For now do only check the array element 'is_complete'
480 $unassembledChunksAvailable = ($this->finalPackageChunks['is_complete'] === true);
483 return $unassembledChunksAvailable;
487 * Assembles all chunks (except EOP and "hash chunk") back together to the original package data.
489 * This is done by the following steps:
491 * 1) Sort the final array with ksort(). This will bring the "hash
492 * chunk" up to the last array index and the EOP chunk to the
493 * pre-last array index
494 * 2) Assemble all chunks except two last (see above step)
495 * 3) While so, do the final check on all hashes
496 * 4) If the package is assembled back together, hash it again for
497 * the very final verification.
501 public function assembleChunksFromFinalArray () {
502 // Make sure the final array is really completed
503 assert($this->ifUnassembledChunksAvailable());
506 $this->finalPackageChunks['assemble_steps']++;
509 switch ($this->finalPackageChunks['assemble_steps']) {
510 case 1: // Sort the chunks array (the serial number shall act as a sorting key)
511 $this->sortChunksArray();
514 case 2: // Prepare the assemble by removing last two indexes
515 $this->preparePackageAssmble();
518 case 3: // Assemble all chunks back together to the original package
519 $this->assembleAllChunksToPackage();
522 case 4: // Verify the raw data by hashing it again
523 $this->verifyRawPackageData();
526 case 5: // Re-initialize handler to reset it to the old state
527 $this->initHandler();
530 default: // Invalid step found
531 $this->debugOutput('CHUNK-HANDLER: Invalid step ' . $this->finalPackageChunks['assemble_steps'] . ' detected.');
537 * Checks whether the raw package data has been assembled back together.
538 * This can be safely assumed when rawPackageData is not empty and the
539 * collection of all chunks is false (because initHandler() will reset it).
541 * @return $isRawPackageDataAvailable Whether raw package data is available
543 public function ifRawPackageDataIsAvailable () {
545 $isRawPackageDataAvailable = ((!empty($this->rawPackageData)) && (!$this->ifUnassembledChunksAvailable()));
548 return $isRawPackageDataAvailable;
552 * Handles the finally assembled raw package data by feeding it into another
553 * stacker for further decoding/processing.
557 public function handledAssembledRawPackageData () {
558 // Assert to make sure that there is raw package data available
559 assert($this->ifRawPackageDataIsAvailable());
561 // Then feed it into the next stacker
562 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_ASSEMBLED_RAW_DATA, $this->rawPackageData);
565 $this->rawPackageData = '';