5 * @author Roland Haeder <webmaster@shipsimu.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.shipsimu.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->initStacks(array(
95 self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP,
96 self::STACKER_NAME_CHUNKS_WITHOUT_FINAL,
97 self::STACKER_NAME_ASSEMBLED_RAW_DATA
100 // Set the stacker in this handler
101 $handlerInstance->setStackerInstance($stackerInstance);
103 // Get a crypto instance ...
104 $cryptoInstance = ObjectFactory::createObjectByConfiguredName('crypto_class');
106 // ... and set it in this handler
107 $handlerInstance->setCryptoInstance($cryptoInstance);
109 // Get a fragmenter instance for later verification of serial numbers (e.g. if all are received)
110 $fragmenterInstance = FragmenterFactory::createFragmenterInstance('package');
112 // Set it in this handler
113 $handlerInstance->setFragmenterInstance($fragmenterInstance);
115 // Return the prepared instance
116 return $handlerInstance;
120 * Initializes the handler
124 private function initHandler () {
125 // Init finalPackageChunks
126 $this->finalPackageChunks = array(
127 // Array for package content
128 'content' => array(),
129 // ... and for the hashes
131 // ... marker for that the final array is complete for assembling all chunks
132 'is_complete' => FALSE,
133 // ... steps done to assemble all chunks
134 'assemble_steps' => 0,
138 $this->chunkHashes = array();
141 $this->eopChunk = array(
148 * Checks whether the hash generated from package content is the same ("valid") as given
150 * @param $chunkSplits An array from a splitted chunk
151 * @return $isValid Whether the hash is "valid"
153 private function isChunkHashValid (array $chunkSplits) {
155 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: chunkSplits=' . print_r($chunkSplits, TRUE));
157 // Assert on some elements
158 assert(isset($chunkSplits[self::CHUNK_SPLITS_INDEX_RAW_DATA]));
159 assert(isset($chunkSplits[self::CHUNK_SPLITS_INDEX_HASH]));
161 // Now hash the raw data again
162 $chunkHash = $this->getCryptoInstance()->hashString($chunkSplits[self::CHUNK_SPLITS_INDEX_RAW_DATA], $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH], FALSE);
165 $isValid = ($chunkSplits[self::CHUNK_SPLITS_INDEX_HASH] === $chunkHash);
168 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: chunkHash=' . $chunkHash . ',isValid=' . intval($isValid));
175 * Checks whether the given serial number is valid
177 * @param $serialNumber A serial number from a chunk
178 * @return $isValid Whether the serial number is valid
180 private function isSerialNumberValid ($serialNumber) {
182 $isValid = ((strlen($serialNumber) == PackageFragmenter::MAX_SERIAL_LENGTH) && ($this->hexval($serialNumber, FALSE) === $serialNumber));
189 * Adds the chunk to the final array which will be used for the final step
190 * which will be to assemble all chunks back to the original package content
191 * and for the final hash check.
193 * This method may throw an exception if a chunk with the same serial number
194 * has already been added to avoid mixing chunks from different packages.
196 * @param $chunkSplits An array from a splitted chunk
199 private function addChunkToFinalArray (array $chunkSplits) {
200 // Is the serial number (index 1) already been added?
201 if (isset($this->finalPackageChunks[$chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL]])) {
202 // Then throw an exception
203 throw new ChunkAlreadyAssembledException(array($this, $chunkSplits), self::EXCEPTION_CHUNK_ALREADY_ASSEMBLED);
207 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: serialNumber=' . $chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL] . ',hash=' . $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH]);
209 // Add the chunk data (index 2) to the final array and use the serial number as index
210 $this->finalPackageChunks['content'][$chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL]] = $chunkSplits[self::CHUNK_SPLITS_INDEX_RAW_DATA];
212 // ... and the hash as well
213 $this->finalPackageChunks['hashes'][$chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL]] = $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH];
217 * Marks the final array as completed, do only this if you really have all
218 * chunks together including EOP and "hash chunk".
222 private function markFinalArrayAsCompleted () {
224 * As for now, just set the array element. If any further steps are
225 * being added, this should always be the last step.
227 $this->finalPackageChunks['is_complete'] = TRUE;
231 * Sorts the chunks array by using the serial number as a sorting key. In
232 * most situations a call of ksort() is enough to accomblish this. So this
233 * method may only call ksort() on the chunks array.
235 * This method sorts 'content' and 'hashes' so both must have used the
236 * serial numbers as array indexes.
240 private function sortChunksArray () {
241 // Sort 'content' first
242 ksort($this->finalPackageChunks['content']);
245 ksort($this->finalPackageChunks['hashes']);
249 * Prepares the package assemble by removing last chunks (last shall be
250 * hash chunk, pre-last shall be EOP chunk) and verify that all serial
251 * numbers are valid (same as PackageFragmenter class would generate).
255 private function preparePackageAssmble () {
256 // Make sure both arrays have same count (this however should always be TRUE)
257 assert(count($this->finalPackageChunks['hashes']) == count($this->finalPackageChunks['content']));
258 //* DIE: */ exit(__METHOD__ . ':finalPackageChunks='.print_r($this->finalPackageChunks['content'], TRUE));
261 * Remove last element (hash chunk) from 'hashes'. This hash will never
262 * be needed, so ignore it.
264 array_pop($this->finalPackageChunks['hashes']);
266 // ... and from 'content' as well but save it for later use
267 $this->chunkHashes = explode(PackageFragmenter::CHUNK_HASH_SEPARATOR, substr(array_pop($this->finalPackageChunks['content']), strlen(PackageFragmenter::HASH_CHUNK_IDENTIFIER)));
269 // Remove EOP chunk and keep a copy of it
270 array_pop($this->finalPackageChunks['hashes']);
271 $this->eopChunk = explode(PackageFragmenter::CHUNK_HASH_SEPARATOR, substr(array_pop($this->finalPackageChunks['content']), strlen(PackageFragmenter::END_OF_PACKAGE_IDENTIFIER)));
273 // Verify all serial numbers
274 $this->verifyChunkSerialNumbers();
278 * Verifies all chunk serial numbers by using a freshly initialized
279 * fragmenter instance. Do ALWAYS sort the array and array_pop() the hash
280 * chunk before calling this method to avoid re-requests of many chunks.
284 private function verifyChunkSerialNumbers () {
285 // Reset the serial number generator
286 $this->getFragmenterInstance()->resetSerialNumber();
288 // "Walk" through all (content) chunks
289 foreach ($this->finalPackageChunks['content'] as $serialNumber => $content) {
290 // Get next serial number
291 $nextSerial = $this->getFragmenterInstance()->getNextHexSerialNumber();
294 /* NOISY-DEBUG */ self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: serialNumber=' . $serialNumber . ',nextSerial=' . $nextSerial);
296 // Is it not the same? Then re-request it
297 if ($serialNumber != $nextSerial) {
298 // This is invalid, so remove it
299 unset($this->finalPackageChunks['content'][$serialNumber]);
300 unset($this->finalPackageChunks['hashes'][$serialNumber]);
302 // And re-request it with valid serial number (and hash chunk)
303 $this->rerequestChunkBySerialNumber($nextSerial);
309 * Assembles and verifies ("final check") chunks back together to the
310 * original package (raw data for the start). This method should only be
311 * called AFTER the EOP and final-chunk chunk have been removed.
315 private function assembleAllChunksToPackage () {
316 // If chunkHashes is not filled, don't continue
317 assert(count($this->chunkHashes) > 0);
319 // Init raw package data string
320 $this->rawPackageData = '';
322 // That went well, so start assembling all chunks
323 foreach ($this->finalPackageChunks['content'] as $serialNumber => $content) {
325 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: serialNumber=' . $serialNumber . ' - validating ...');
326 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('finalPackageChunks=' . print_r($this->finalPackageChunks, TRUE) . 'chunkHashes=' . print_r($this->chunkHashes, TRUE));
328 // Is this chunk valid? This should be the case
329 assert($this->isChunkHashValid(array(
330 self::CHUNK_SPLITS_INDEX_HASH => $this->finalPackageChunks['hashes'][$serialNumber],
331 self::CHUNK_SPLITS_INDEX_RAW_DATA => $content
334 // ... and is also in the hash chunk?
335 assert(in_array($this->finalPackageChunks['hashes'][$serialNumber], $this->chunkHashes));
337 // Verification okay, add it to the raw data
338 $this->rawPackageData .= $content;
342 /* NOISY-DEBUG: */ self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: eopChunk[1]=' . $this->eopChunk[1] . ',' . chr(10) . 'index=' . (count($this->chunkHashes) - 2) . ',' . chr(10) . 'chunkHashes='.print_r($this->chunkHashes, TRUE));
344 // The last chunk hash must match with the one from eopChunk[1]
345 assert($this->eopChunk[1] == $this->chunkHashes[count($this->chunkHashes) - 2]);
349 * Verifies the finally assembled raw package data by comparing it against
354 private function verifyRawPackageData () {
355 // Hash the raw package data for final verification
356 $finalHash = $this->getCryptoInstance()->hashString($this->rawPackageData, $this->eopChunk[0], FALSE);
359 assert($finalHash == $this->eopChunk[0]);
363 * Adds all chunks if the last one verifies as a 'final chunk'.
365 * @param $chunks An array with chunks, the last one should be a 'final'
367 * @throws FinalChunkVerificationException If the final chunk does not start with 'EOP:'
369 public function addAllChunksWithFinal (array $chunks) {
370 // Try to validate the final chunk
372 // Validate final chunk
373 $this->isValidFinalChunk($chunks);
374 } catch (AssertionException $e) {
375 // Last chunk is not valid
376 throw new FinalChunkVerificationException(array($this, $chunks, $e), BaseListener::EXCEPTION_FINAL_CHUNK_VERIFICATION);
379 // Do we have some pending chunks (no final)?
380 while (!$this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_CHUNKS_WITHOUT_FINAL)) {
381 // Then get it first and add it before the EOP chunks
382 array_unshift($chunks, $this->getStackerInstance()->popNamed(self::STACKER_NAME_CHUNKS_WITHOUT_FINAL));
385 // Add all chunks to the FIFO stacker
386 foreach ($chunks as $chunk) {
388 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP, $chunk);
393 * Adds all chunks and wait for more (e.g. incomplete transmission)
395 * @param $chunks An array with chunks, the last one should be a 'final'
398 public function addAllChunksWait (array $chunks) {
399 // Add all chunks to the FIFO stacker
400 foreach ($chunks as $chunk) {
402 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_CHUNKS_WITHOUT_FINAL, $chunk);
407 * Checks whether unhandled chunks are available
409 * @return $unhandledChunks Whether unhandled chunks are left
411 public function ifUnhandledChunksWithFinalAvailable () {
412 // Simply check if the stacker is not empty
413 $unhandledChunks = $this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP) === FALSE;
416 return $unhandledChunks;
420 * Handles available chunks by processing one-by-one (not all together,
421 * this would slow-down the whole application) with the help of an
426 public function handleAvailableChunksWithFinal () {
427 // First check if there are undhandled chunks available
428 assert($this->ifUnhandledChunksWithFinalAvailable());
430 // Get an entry from the stacker
431 $chunk = $this->getStackerInstance()->popNamed(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP);
433 // Split the string with proper separator character
434 $chunkSplits = explode(PackageFragmenter::CHUNK_DATA_HASH_SEPARATOR, $chunk);
437 * Make sure three elements are always found:
442 assert(count($chunkSplits) == 3);
444 // Is the generated hash from data same ("valid") as given hash?
445 if (!$this->isChunkHashValid($chunkSplits)) {
447 self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Chunk content is not validating against given hash.');
449 // Re-request this chunk (trust the hash in index # 0)
450 $this->rerequestChunkBySplitsArray($chunkSplits);
452 // Don't process this chunk
456 // Is the serial number valid (chars 0-9, length equals PackageFragmenter::MAX_SERIAL_LENGTH)?
457 if (!$this->isSerialNumberValid($chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL])) {
459 self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Chunk serial number ' . $chunkSplits[self::CHUNK_SPLITS_INDEX_SERIAL] . ' for hash ' . $chunkSplits[self::CHUNK_SPLITS_INDEX_HASH] . ' is invalid.');
461 // Re-request this chunk
462 $this->rerequestChunkBySplitsArray($chunkSplits);
464 // Don't process this chunk
469 * It is now known that (as long as the hash algorithm has no
470 * collisions) the content is the same as the sender sends it to this
473 * And also the serial number is valid (basicly) at this point. Now the
474 * chunk can be added to the final array.
476 $this->addChunkToFinalArray($chunkSplits);
478 // Is the stack now empty?
479 if ($this->getStackerInstance()->isStackEmpty(self::STACKER_NAME_CHUNKS_WITH_FINAL_EOP)) {
480 // Then mark the final array as complete
481 $this->markFinalArrayAsCompleted();
486 * Checks whether unassembled chunks are available (ready) in final array
488 * @return $unassembledChunksAvailable Whether unassembled chunks are available
490 public function ifUnassembledChunksAvailable () {
491 // For now do only check the array element 'is_complete'
492 $unassembledChunksAvailable = ($this->finalPackageChunks['is_complete'] === TRUE);
495 return $unassembledChunksAvailable;
499 * Assembles all chunks (except EOP and "hash chunk") back together to the original package data.
501 * This is done by the following steps:
503 * 1) Sort the final array with ksort(). This will bring the "hash
504 * chunk" up to the last array index and the EOP chunk to the
505 * pre-last array index
506 * 2) Assemble all chunks except two last (see above step)
507 * 3) While so, do the final check on all hashes
508 * 4) If the package is assembled back together, hash it again for
509 * the very final verification.
513 public function assembleChunksFromFinalArray () {
514 // Make sure the final array is really completed
515 assert($this->ifUnassembledChunksAvailable());
518 $this->finalPackageChunks['assemble_steps']++;
521 switch ($this->finalPackageChunks['assemble_steps']) {
522 case 1: // Sort the chunks array (the serial number shall act as a sorting key)
523 $this->sortChunksArray();
526 case 2: // Prepare the assemble by removing last two indexes
527 $this->preparePackageAssmble();
530 case 3: // Assemble all chunks back together to the original package
531 $this->assembleAllChunksToPackage();
534 case 4: // Verify the raw data by hashing it again
535 $this->verifyRawPackageData();
538 case 5: // Re-initialize handler to reset it to the old state
539 $this->initHandler();
542 default: // Invalid step found
543 self::createDebugInstance(__CLASS__)->debugOutput('CHUNK-HANDLER[' . __METHOD__ . ':' . __LINE__ . ']: Invalid step ' . $this->finalPackageChunks['assemble_steps'] . ' detected.');
549 * Checks whether the raw package data has been assembled back together.
550 * This can be safely assumed when rawPackageData is not empty and the
551 * collection of all chunks is FALSE (because initHandler() will reset it).
553 * @return $isRawPackageDataAvailable Whether raw package data is available
555 public function ifRawPackageDataIsAvailable () {
557 $isRawPackageDataAvailable = ((!empty($this->rawPackageData)) && (!$this->ifUnassembledChunksAvailable()));
560 return $isRawPackageDataAvailable;
564 * Handles the finally assembled raw package data by feeding it into another
565 * stacker for further decoding/processing.
569 public function handledAssembledRawPackageData () {
570 // Assert to make sure that there is raw package data available
571 assert($this->ifRawPackageDataIsAvailable());
573 // Then feed it into the next stacker
574 $this->getStackerInstance()->pushNamed(self::STACKER_NAME_ASSEMBLED_RAW_DATA, $this->rawPackageData);
577 $this->rawPackageData = '';