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Long Term Support Release

  • Bug fixes for general core bugs in 4.1.x will end 13 November 2023 (12 months).
  • Bug fixes for security issues in 4.1.x will end 10 November 2025 (36 months).
  • PHP version: minimum PHP 7.4.0 Note: minimum PHP version has increased since Moodle 4.0. PHP 8.0.x is supported too.

Differences Between: [Versions 310 and 401] [Versions 311 and 401] [Versions 39 and 401] [Versions 400 and 401]

   1  <?php
   2  //============================================================+
   3  // File name   : tcpdf_parser.php
   4  // Version     : 1.0.16
   5  // Begin       : 2011-05-23
   6  // Last Update : 2015-04-28
   7  // Author      : Nicola Asuni - Tecnick.com LTD - www.tecnick.com - info@tecnick.com
   8  // License     : http://www.tecnick.com/pagefiles/tcpdf/LICENSE.TXT GNU-LGPLv3
   9  // -------------------------------------------------------------------
  10  // Copyright (C) 2011-2015 Nicola Asuni - Tecnick.com LTD
  11  //
  12  // This file is part of TCPDF software library.
  13  //
  14  // TCPDF is free software: you can redistribute it and/or modify it
  15  // under the terms of the GNU Lesser General Public License as
  16  // published by the Free Software Foundation, either version 3 of the
  17  // License, or (at your option) any later version.
  18  //
  19  // TCPDF is distributed in the hope that it will be useful, but
  20  // WITHOUT ANY WARRANTY; without even the implied warranty of
  21  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  22  // See the GNU Lesser General Public License for more details.
  23  //
  24  // You should have received a copy of the License
  25  // along with TCPDF. If not, see
  26  // <http://www.tecnick.com/pagefiles/tcpdf/LICENSE.TXT>.
  27  //
  28  // See LICENSE.TXT file for more information.
  29  // -------------------------------------------------------------------
  30  //
  31  // Description : This is a PHP class for parsing PDF documents.
  32  //
  33  //============================================================+
  34  
  35  /**
  36   * @file
  37   * This is a PHP class for parsing PDF documents.<br>
  38   * @package com.tecnick.tcpdf
  39   * @author Nicola Asuni
  40   * @version 1.0.15
  41   */
  42  
  43  // include class for decoding filters
  44  require_once(dirname(__FILE__).'/include/tcpdf_filters.php');
  45  
  46  /**
  47   * @class TCPDF_PARSER
  48   * This is a PHP class for parsing PDF documents.<br>
  49   * @package com.tecnick.tcpdf
  50   * @brief This is a PHP class for parsing PDF documents..
  51   * @version 1.0.15
  52   * @author Nicola Asuni - info@tecnick.com
  53   */
  54  class TCPDF_PARSER {
  55  
  56  	 /**
  57  	  * Raw content of the PDF document.
  58  	  * @private
  59  	  */
  60  	 private $pdfdata = '';
  61  
  62  	 /**
  63  	  * XREF data.
  64  	  * @protected
  65  	  */
  66  	 protected $xref = array();
  67  
  68  	 /**
  69  	  * Array of PDF objects.
  70  	  * @protected
  71  	  */
  72  	 protected $objects = array();
  73  
  74  	 /**
  75  	  * Class object for decoding filters.
  76  	  * @private
  77  	  */
  78  	 private $FilterDecoders;
  79  
  80  	 /**
  81  	  * Array of configuration parameters.
  82  	  * @private
  83  	  */
  84  	 private $cfg = array(
  85  	 	 'die_for_errors' => false,
  86  	 	 'ignore_filter_decoding_errors' => true,
  87  	 	 'ignore_missing_filter_decoders' => true,
  88  	 );
  89  
  90  // -----------------------------------------------------------------------------
  91  
  92  	 /**
  93  	  * Parse a PDF document an return an array of objects.
  94  	  * @param string $data PDF data to parse.
  95  	  * @param array $cfg Array of configuration parameters:
  96  	  * 	 	 	 'die_for_errors' : if true termitate the program execution in case of error, otherwise thows an exception;
  97  	  * 	 	 	 'ignore_filter_decoding_errors' : if true ignore filter decoding errors;
  98  	  * 	 	 	 'ignore_missing_filter_decoders' : if true ignore missing filter decoding errors.
  99  	  * @public
 100  	  * @since 1.0.000 (2011-05-24)
 101  	  */
 102  	public function __construct($data, $cfg=array()) {
 103  	 	 if (empty($data)) {
 104  	 	 	 $this->Error('Empty PDF data.');
 105  	 	 }
 106  	 	 // find the pdf header starting position
 107  	 	 if (($trimpos = strpos($data, '%PDF-')) === FALSE) {
 108  	 	 	 $this->Error('Invalid PDF data: missing %PDF header.');
 109  	 	 }
 110  	 	 // get PDF content string
 111  	 	 $this->pdfdata = substr($data, $trimpos);
 112  	 	 // get length
 113  	 	 $pdflen = strlen($this->pdfdata);
 114  	 	 // set configuration parameters
 115  	 	 $this->setConfig($cfg);
 116  	 	 // get xref and trailer data
 117  	 	 $this->xref = $this->getXrefData();
 118  	 	 // parse all document objects
 119  	 	 $this->objects = array();
 120  	 	 foreach ($this->xref['xref'] as $obj => $offset) {
 121  	 	 	 if (!isset($this->objects[$obj]) AND ($offset > 0)) {
 122  	 	 	 	 // decode objects with positive offset
 123  	 	 	 	 $this->objects[$obj] = $this->getIndirectObject($obj, $offset, true);
 124  	 	 	 }
 125  	 	 }
 126  	 	 // release some memory
 127  	 	 unset($this->pdfdata);
 128  	 	 $this->pdfdata = '';
 129  	 }
 130  
 131  	 /**
 132  	  * Set the configuration parameters.
 133  	  * @param array $cfg Array of configuration parameters:
 134  	  * 	 	 	 'die_for_errors' : if true termitate the program execution in case of error, otherwise thows an exception;
 135  	  * 	 	 	 'ignore_filter_decoding_errors' : if true ignore filter decoding errors;
 136  	  * 	 	 	 'ignore_missing_filter_decoders' : if true ignore missing filter decoding errors.
 137  	  * @public
 138  	  */
 139  	protected function setConfig($cfg) {
 140  	 	 if (isset($cfg['die_for_errors'])) {
 141  	 	 	 $this->cfg['die_for_errors'] = !!$cfg['die_for_errors'];
 142  	 	 }
 143  	 	 if (isset($cfg['ignore_filter_decoding_errors'])) {
 144  	 	 	 $this->cfg['ignore_filter_decoding_errors'] = !!$cfg['ignore_filter_decoding_errors'];
 145  	 	 }
 146  	 	 if (isset($cfg['ignore_missing_filter_decoders'])) {
 147  	 	 	 $this->cfg['ignore_missing_filter_decoders'] = !!$cfg['ignore_missing_filter_decoders'];
 148  	 	 }
 149  	 }
 150  
 151  	 /**
 152  	  * Return an array of parsed PDF document objects.
 153  	  * @return array Array of parsed PDF document objects.
 154  	  * @public
 155  	  * @since 1.0.000 (2011-06-26)
 156  	  */
 157  	public function getParsedData() {
 158  	 	 return array($this->xref, $this->objects);
 159  	 }
 160  
 161  	 /**
 162  	  * Get Cross-Reference (xref) table and trailer data from PDF document data.
 163  	  * @param int $offset xref offset (if know).
 164  	  * @param array $xref previous xref array (if any).
 165  	  * @return array containing xref and trailer data.
 166  	  * @protected
 167  	  * @since 1.0.000 (2011-05-24)
 168  	  */
 169  	protected function getXrefData($offset=0, $xref=array()) {
 170  	 	 if ($offset == 0) {
 171  	 	 	 // find last startxref
 172  	 	 	 if (preg_match_all('/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i', $this->pdfdata, $matches, PREG_SET_ORDER, $offset) == 0) {
 173  	 	 	 	 $this->Error('Unable to find startxref');
 174  	 	 	 }
 175  	 	 	 $matches = array_pop($matches);
 176  	 	 	 $startxref = $matches[1];
 177  	 	 } elseif (strpos($this->pdfdata, 'xref', $offset) == $offset) {
 178  	 	 	 // Already pointing at the xref table
 179  	 	 	 $startxref = $offset;
 180  	 	 } elseif (preg_match('/([0-9]+[\s][0-9]+[\s]obj)/i', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset)) {
 181  	 	 	 // Cross-Reference Stream object
 182  	 	 	 $startxref = $offset;
 183  	 	 } elseif (preg_match('/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset)) {
 184  	 	 	 // startxref found
 185  	 	 	 $startxref = $matches[1][0];
 186  	 	 } else {
 187  	 	 	 $this->Error('Unable to find startxref');
 188  	 	 }
 189  	 	 // check xref position
 190  	 	 if (strpos($this->pdfdata, 'xref', $startxref) == $startxref) {
 191  	 	 	 // Cross-Reference
 192  	 	 	 $xref = $this->decodeXref($startxref, $xref);
 193  	 	 } else {
 194  	 	 	 // Cross-Reference Stream
 195  	 	 	 $xref = $this->decodeXrefStream($startxref, $xref);
 196  	 	 }
 197  	 	 if (empty($xref)) {
 198  	 	 	 $this->Error('Unable to find xref');
 199  	 	 }
 200  	 	 return $xref;
 201  	 }
 202  
 203  	 /**
 204  	  * Decode the Cross-Reference section
 205  	  * @param int $startxref Offset at which the xref section starts (position of the 'xref' keyword).
 206  	  * @param array $xref Previous xref array (if any).
 207  	  * @return array containing xref and trailer data.
 208  	  * @protected
 209  	  * @since 1.0.000 (2011-06-20)
 210  	  */
 211  	protected function decodeXref($startxref, $xref=array()) {
 212  	 	 $startxref += 4; // 4 is the length of the word 'xref'
 213  	 	 // skip initial white space chars: \x00 null (NUL), \x09 horizontal tab (HT), \x0A line feed (LF), \x0C form feed (FF), \x0D carriage return (CR), \x20 space (SP)
 214  	 	 $offset = $startxref + strspn($this->pdfdata, "\x00\x09\x0a\x0c\x0d\x20", $startxref);
 215  	 	 // initialize object number
 216  	 	 $obj_num = 0;
 217  	 	 // search for cross-reference entries or subsection
 218  	 	 while (preg_match('/([0-9]+)[\x20]([0-9]+)[\x20]?([nf]?)(\r\n|[\x20]?[\r\n])/', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset) > 0) {
 219  	 	 	 if ($matches[0][1] != $offset) {
 220  	 	 	 	 // we are on another section
 221  	 	 	 	 break;
 222  	 	 	 }
 223  	 	 	 $offset += strlen($matches[0][0]);
 224  	 	 	 if ($matches[3][0] == 'n') {
 225  	 	 	 	 // create unique object index: [object number]_[generation number]
 226  	 	 	 	 $index = $obj_num.'_'.intval($matches[2][0]);
 227  	 	 	 	 // check if object already exist
 228  	 	 	 	 if (!isset($xref['xref'][$index])) {
 229  	 	 	 	 	 // store object offset position
 230  	 	 	 	 	 $xref['xref'][$index] = intval($matches[1][0]);
 231  	 	 	 	 }
 232  	 	 	 	 ++$obj_num;
 233  	 	 	 } elseif ($matches[3][0] == 'f') {
 234  	 	 	 	 ++$obj_num;
 235  	 	 	 } else {
 236  	 	 	 	 // object number (index)
 237  	 	 	 	 $obj_num = intval($matches[1][0]);
 238  	 	 	 }
 239  	 	 }
 240  	 	 // get trailer data
 241  	 	 if (preg_match('/trailer[\s]*<<(.*)>>/isU', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset) > 0) {
 242  	 	 	 $trailer_data = $matches[1][0];
 243  	 	 	 if (!isset($xref['trailer']) OR empty($xref['trailer'])) {
 244  	 	 	 	 // get only the last updated version
 245  	 	 	 	 $xref['trailer'] = array();
 246  	 	 	 	 // parse trailer_data
 247  	 	 	 	 if (preg_match('/Size[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) {
 248  	 	 	 	 	 $xref['trailer']['size'] = intval($matches[1]);
 249  	 	 	 	 }
 250  	 	 	 	 if (preg_match('/Root[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
 251  	 	 	 	 	 $xref['trailer']['root'] = intval($matches[1]).'_'.intval($matches[2]);
 252  	 	 	 	 }
 253  	 	 	 	 if (preg_match('/Encrypt[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
 254  	 	 	 	 	 $xref['trailer']['encrypt'] = intval($matches[1]).'_'.intval($matches[2]);
 255  	 	 	 	 }
 256  	 	 	 	 if (preg_match('/Info[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
 257  	 	 	 	 	 $xref['trailer']['info'] = intval($matches[1]).'_'.intval($matches[2]);
 258  	 	 	 	 }
 259  	 	 	 	 if (preg_match('/ID[\s]*[\[][\s]*[<]([^>]*)[>][\s]*[<]([^>]*)[>]/i', $trailer_data, $matches) > 0) {
 260  	 	 	 	 	 $xref['trailer']['id'] = array();
 261  	 	 	 	 	 $xref['trailer']['id'][0] = $matches[1];
 262  	 	 	 	 	 $xref['trailer']['id'][1] = $matches[2];
 263  	 	 	 	 }
 264  	 	 	 }
 265  	 	 	 if (preg_match('/Prev[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) {
 266  	 	 	 	 // get previous xref
 267  	 	 	 	 $xref = $this->getXrefData(intval($matches[1]), $xref);
 268  	 	 	 }
 269  	 	 } else {
 270  	 	 	 $this->Error('Unable to find trailer');
 271  	 	 }
 272  	 	 return $xref;
 273  	 }
 274  
 275  	 /**
 276  	  * Decode the Cross-Reference Stream section
 277  	  * @param int $startxref Offset at which the xref section starts.
 278  	  * @param array $xref Previous xref array (if any).
 279  	  * @return array containing xref and trailer data.
 280  	  * @protected
 281  	  * @since 1.0.003 (2013-03-16)
 282  	  */
 283  	protected function decodeXrefStream($startxref, $xref=array()) {
 284  	 	 // try to read Cross-Reference Stream
 285  	 	 $xrefobj = $this->getRawObject($startxref);
 286  	 	 $xrefcrs = $this->getIndirectObject($xrefobj[1], $startxref, true);
 287  	 	 if (!isset($xref['trailer']) OR empty($xref['trailer'])) {
 288  	 	 	 // get only the last updated version
 289  	 	 	 $xref['trailer'] = array();
 290  	 	 	 $filltrailer = true;
 291  	 	 } else {
 292  	 	 	 $filltrailer = false;
 293  	 	 }
 294  	 	 if (!isset($xref['xref'])) {
 295  	 	 	 $xref['xref'] = array();
 296  	 	 }
 297  	 	 $valid_crs = false;
 298  	 	 $columns = 0;
 299  	 	 $sarr = $xrefcrs[0][1];
 300  	 	 if (!is_array($sarr)) {
 301  	 	 	 $sarr = array();
 302  	 	 }
 303  	 	 foreach ($sarr as $k => $v) {
 304  	 	 	 if (($v[0] == '/') AND ($v[1] == 'Type') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == '/') AND ($sarr[($k +1)][1] == 'XRef'))) {
 305  	 	 	 	 $valid_crs = true;
 306  	 	 	 } elseif (($v[0] == '/') AND ($v[1] == 'Index') AND (isset($sarr[($k +1)]))) {
 307  	 	 	 	 // first object number in the subsection
 308  	 	 	 	 $index_first = intval($sarr[($k +1)][1][0][1]);
 309  	 	 	 	 // number of entries in the subsection
 310  	 	 	 	 $index_entries = intval($sarr[($k +1)][1][1][1]);
 311  	 	 	 } elseif (($v[0] == '/') AND ($v[1] == 'Prev') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'numeric'))) {
 312  	 	 	 	 // get previous xref offset
 313  	 	 	 	 $prevxref = intval($sarr[($k +1)][1]);
 314  	 	 	 } elseif (($v[0] == '/') AND ($v[1] == 'W') AND (isset($sarr[($k +1)]))) {
 315  	 	 	 	 // number of bytes (in the decoded stream) of the corresponding field
 316  	 	 	 	 $wb = array();
 317  	 	 	 	 $wb[0] = intval($sarr[($k +1)][1][0][1]);
 318  	 	 	 	 $wb[1] = intval($sarr[($k +1)][1][1][1]);
 319  	 	 	 	 $wb[2] = intval($sarr[($k +1)][1][2][1]);
 320  	 	 	 } elseif (($v[0] == '/') AND ($v[1] == 'DecodeParms') AND (isset($sarr[($k +1)][1]))) {
 321  	 	 	 	 $decpar = $sarr[($k +1)][1];
 322  	 	 	 	 foreach ($decpar as $kdc => $vdc) {
 323  	 	 	 	 	 if (($vdc[0] == '/') AND ($vdc[1] == 'Columns') AND (isset($decpar[($kdc +1)]) AND ($decpar[($kdc +1)][0] == 'numeric'))) {
 324  	 	 	 	 	 	 $columns = intval($decpar[($kdc +1)][1]);
 325  	 	 	 	 	 } elseif (($vdc[0] == '/') AND ($vdc[1] == 'Predictor') AND (isset($decpar[($kdc +1)]) AND ($decpar[($kdc +1)][0] == 'numeric'))) {
 326  	 	 	 	 	 	 $predictor = intval($decpar[($kdc +1)][1]);
 327  	 	 	 	 	 }
 328  	 	 	 	 }
 329  	 	 	 } elseif ($filltrailer) {
 330  	 	 	 	 if (($v[0] == '/') AND ($v[1] == 'Size') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'numeric'))) {
 331  	 	 	 	 	 $xref['trailer']['size'] = $sarr[($k +1)][1];
 332  	 	 	 	 } elseif (($v[0] == '/') AND ($v[1] == 'Root') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'objref'))) {
 333  	 	 	 	 	 $xref['trailer']['root'] = $sarr[($k +1)][1];
 334  	 	 	 	 } elseif (($v[0] == '/') AND ($v[1] == 'Info') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'objref'))) {
 335  	 	 	 	 	 $xref['trailer']['info'] = $sarr[($k +1)][1];
 336  	 	 	 	 } elseif (($v[0] == '/') AND ($v[1] == 'Encrypt') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'objref'))) {
 337  	 	 	 	 	 $xref['trailer']['encrypt'] = $sarr[($k +1)][1];
 338  	 	 	 	 } elseif (($v[0] == '/') AND ($v[1] == 'ID') AND (isset($sarr[($k +1)]))) {
 339  	 	 	 	 	 $xref['trailer']['id'] = array();
 340  	 	 	 	 	 $xref['trailer']['id'][0] = $sarr[($k +1)][1][0][1];
 341  	 	 	 	 	 $xref['trailer']['id'][1] = $sarr[($k +1)][1][1][1];
 342  	 	 	 	 }
 343  	 	 	 }
 344  	 	 }
 345  	 	 // decode data
 346  	 	 if ($valid_crs AND isset($xrefcrs[1][3][0])) {
 347  	 	 	 // number of bytes in a row
 348  	 	 	 $rowlen = ($columns + 1);
 349  	 	 	 // convert the stream into an array of integers
 350  	 	 	 $sdata = unpack('C*', $xrefcrs[1][3][0]);
 351  	 	 	 // split the rows
 352  	 	 	 $sdata = array_chunk($sdata, $rowlen);
 353  	 	 	 // initialize decoded array
 354  	 	 	 $ddata = array();
 355  	 	 	 // initialize first row with zeros
 356  	 	 	 $prev_row = array_fill (0, $rowlen, 0);
 357  	 	 	 // for each row apply PNG unpredictor
 358  	 	 	 foreach ($sdata as $k => $row) {
 359  	 	 	 	 // initialize new row
 360  	 	 	 	 $ddata[$k] = array();
 361  	 	 	 	 // get PNG predictor value
 362  	 	 	 	 $predictor = (10 + $row[0]);
 363  	 	 	 	 // for each byte on the row
 364  	 	 	 	 for ($i=1; $i<=$columns; ++$i) {
 365  	 	 	 	 	 // new index
 366  	 	 	 	 	 $j = ($i - 1);
 367  	 	 	 	 	 $row_up = $prev_row[$j];
 368  	 	 	 	 	 if ($i == 1) {
 369  	 	 	 	 	 	 $row_left = 0;
 370  	 	 	 	 	 	 $row_upleft = 0;
 371  	 	 	 	 	 } else {
 372  	 	 	 	 	 	 $row_left = $row[($i - 1)];
 373  	 	 	 	 	 	 $row_upleft = $prev_row[($j - 1)];
 374  	 	 	 	 	 }
 375  	 	 	 	 	 switch ($predictor) {
 376  	 	 	 	 	 	 case 10: { // PNG prediction (on encoding, PNG None on all rows)
 377  	 	 	 	 	 	 	 $ddata[$k][$j] = $row[$i];
 378  	 	 	 	 	 	 	 break;
 379  	 	 	 	 	 	 }
 380  	 	 	 	 	 	 case 11: { // PNG prediction (on encoding, PNG Sub on all rows)
 381  	 	 	 	 	 	 	 $ddata[$k][$j] = (($row[$i] + $row_left) & 0xff);
 382  	 	 	 	 	 	 	 break;
 383  	 	 	 	 	 	 }
 384  	 	 	 	 	 	 case 12: { // PNG prediction (on encoding, PNG Up on all rows)
 385  	 	 	 	 	 	 	 $ddata[$k][$j] = (($row[$i] + $row_up) & 0xff);
 386  	 	 	 	 	 	 	 break;
 387  	 	 	 	 	 	 }
 388  	 	 	 	 	 	 case 13: { // PNG prediction (on encoding, PNG Average on all rows)
 389  	 	 	 	 	 	 	 $ddata[$k][$j] = (($row[$i] + (($row_left + $row_up) / 2)) & 0xff);
 390  	 	 	 	 	 	 	 break;
 391  	 	 	 	 	 	 }
 392  	 	 	 	 	 	 case 14: { // PNG prediction (on encoding, PNG Paeth on all rows)
 393  	 	 	 	 	 	 	 // initial estimate
 394  	 	 	 	 	 	 	 $p = ($row_left + $row_up - $row_upleft);
 395  	 	 	 	 	 	 	 // distances
 396  	 	 	 	 	 	 	 $pa = abs($p - $row_left);
 397  	 	 	 	 	 	 	 $pb = abs($p - $row_up);
 398  	 	 	 	 	 	 	 $pc = abs($p - $row_upleft);
 399  	 	 	 	 	 	 	 $pmin = min($pa, $pb, $pc);
 400  	 	 	 	 	 	 	 // return minimum distance
 401  	 	 	 	 	 	 	 switch ($pmin) {
 402  	 	 	 	 	 	 	 	 case $pa: {
 403  	 	 	 	 	 	 	 	 	 $ddata[$k][$j] = (($row[$i] + $row_left) & 0xff);
 404  	 	 	 	 	 	 	 	 	 break;
 405  	 	 	 	 	 	 	 	 }
 406  	 	 	 	 	 	 	 	 case $pb: {
 407  	 	 	 	 	 	 	 	 	 $ddata[$k][$j] = (($row[$i] + $row_up) & 0xff);
 408  	 	 	 	 	 	 	 	 	 break;
 409  	 	 	 	 	 	 	 	 }
 410  	 	 	 	 	 	 	 	 case $pc: {
 411  	 	 	 	 	 	 	 	 	 $ddata[$k][$j] = (($row[$i] + $row_upleft) & 0xff);
 412  	 	 	 	 	 	 	 	 	 break;
 413  	 	 	 	 	 	 	 	 }
 414  	 	 	 	 	 	 	 }
 415  	 	 	 	 	 	 	 break;
 416  	 	 	 	 	 	 }
 417  	 	 	 	 	 	 default: { // PNG prediction (on encoding, PNG optimum)
 418  	 	 	 	 	 	 	 $this->Error('Unknown PNG predictor');
 419  	 	 	 	 	 	 	 break;
 420  	 	 	 	 	 	 }
 421  	 	 	 	 	 }
 422  	 	 	 	 }
 423  	 	 	 	 $prev_row = $ddata[$k];
 424  	 	 	 } // end for each row
 425  	 	 	 // complete decoding
 426  	 	 	 $sdata = array();
 427  	 	 	 // for every row
 428  	 	 	 foreach ($ddata as $k => $row) {
 429  	 	 	 	 // initialize new row
 430  	 	 	 	 $sdata[$k] = array(0, 0, 0);
 431  	 	 	 	 if ($wb[0] == 0) {
 432  	 	 	 	 	 // default type field
 433  	 	 	 	 	 $sdata[$k][0] = 1;
 434  	 	 	 	 }
 435  	 	 	 	 $i = 0; // count bytes in the row
 436  	 	 	 	 // for every column
 437  	 	 	 	 for ($c = 0; $c < 3; ++$c) {
 438  	 	 	 	 	 // for every byte on the column
 439  	 	 	 	 	 for ($b = 0; $b < $wb[$c]; ++$b) {
 440  	 	 	 	 	 	 if (isset($row[$i])) {
 441  	 	 	 	 	 	 	 $sdata[$k][$c] += ($row[$i] << (($wb[$c] - 1 - $b) * 8));
 442  	 	 	 	 	 	 }
 443  	 	 	 	 	 	 ++$i;
 444  	 	 	 	 	 }
 445  	 	 	 	 }
 446  	 	 	 }
 447  	 	 	 $ddata = array();
 448  	 	 	 // fill xref
 449  	 	 	 if (isset($index_first)) {
 450  	 	 	 	 $obj_num = $index_first;
 451  	 	 	 } else {
 452  	 	 	 	 $obj_num = 0;
 453  	 	 	 }
 454  	 	 	 foreach ($sdata as $k => $row) {
 455  	 	 	 	 switch ($row[0]) {
 456  	 	 	 	 	 case 0: { // (f) linked list of free objects
 457  	 	 	 	 	 	 break;
 458  	 	 	 	 	 }
 459  	 	 	 	 	 case 1: { // (n) objects that are in use but are not compressed
 460  	 	 	 	 	 	 // create unique object index: [object number]_[generation number]
 461  	 	 	 	 	 	 $index = $obj_num.'_'.$row[2];
 462  	 	 	 	 	 	 // check if object already exist
 463  	 	 	 	 	 	 if (!isset($xref['xref'][$index])) {
 464  	 	 	 	 	 	 	 // store object offset position
 465  	 	 	 	 	 	 	 $xref['xref'][$index] = $row[1];
 466  	 	 	 	 	 	 }
 467  	 	 	 	 	 	 break;
 468  	 	 	 	 	 }
 469  	 	 	 	 	 case 2: { // compressed objects
 470  	 	 	 	 	 	 // $row[1] = object number of the object stream in which this object is stored
 471  	 	 	 	 	 	 // $row[2] = index of this object within the object stream
 472  	 	 	 	 	 	 $index = $row[1].'_0_'.$row[2];
 473  	 	 	 	 	 	 $xref['xref'][$index] = -1;
 474  	 	 	 	 	 	 break;
 475  	 	 	 	 	 }
 476  	 	 	 	 	 default: { // null objects
 477  	 	 	 	 	 	 break;
 478  	 	 	 	 	 }
 479  	 	 	 	 }
 480  	 	 	 	 ++$obj_num;
 481  	 	 	 }
 482  	 	 } // end decoding data
 483  	 	 if (isset($prevxref)) {
 484  	 	 	 // get previous xref
 485  	 	 	 $xref = $this->getXrefData($prevxref, $xref);
 486  	 	 }
 487  	 	 return $xref;
 488  	 }
 489  
 490  	 /**
 491  	  * Get object type, raw value and offset to next object
 492  	  * @param int $offset Object offset.
 493  	  * @return array containing object type, raw value and offset to next object
 494  	  * @protected
 495  	  * @since 1.0.000 (2011-06-20)
 496  	  */
 497  	protected function getRawObject($offset=0) {
 498  	 	 $objtype = ''; // object type to be returned
 499  	 	 $objval = ''; // object value to be returned
 500  	 	 // skip initial white space chars: \x00 null (NUL), \x09 horizontal tab (HT), \x0A line feed (LF), \x0C form feed (FF), \x0D carriage return (CR), \x20 space (SP)
 501  	 	 $offset += strspn($this->pdfdata, "\x00\x09\x0a\x0c\x0d\x20", $offset);
 502  	 	 // get first char
 503  	 	 $char = $this->pdfdata[$offset];
 504  	 	 // get object type
 505  	 	 switch ($char) {
 506  	 	 	 case '%': { // \x25 PERCENT SIGN
 507  	 	 	 	 // skip comment and search for next token
 508  	 	 	 	 $next = strcspn($this->pdfdata, "\r\n", $offset);
 509  	 	 	 	 if ($next > 0) {
 510  	 	 	 	 	 $offset += $next;
 511  	 	 	 	 	 return $this->getRawObject($offset);
 512  	 	 	 	 }
 513  	 	 	 	 break;
 514  	 	 	 }
 515  	 	 	 case '/': { // \x2F SOLIDUS
 516  	 	 	 	 // name object
 517  	 	 	 	 $objtype = $char;
 518  	 	 	 	 ++$offset;
 519  	 	 	 	 if (preg_match('/^([^\x00\x09\x0a\x0c\x0d\x20\s\x28\x29\x3c\x3e\x5b\x5d\x7b\x7d\x2f\x25]+)/', substr($this->pdfdata, $offset, 256), $matches) == 1) {
 520  	 	 	 	 	 $objval = $matches[1]; // unescaped value
 521  	 	 	 	 	 $offset += strlen($objval);
 522  	 	 	 	 }
 523  	 	 	 	 break;
 524  	 	 	 }
 525  	 	 	 case '(':   // \x28 LEFT PARENTHESIS
 526  	 	 	 case ')': { // \x29 RIGHT PARENTHESIS
 527  	 	 	 	 // literal string object
 528  	 	 	 	 $objtype = $char;
 529  	 	 	 	 ++$offset;
 530  	 	 	 	 $strpos = $offset;
 531  	 	 	 	 if ($char == '(') {
 532  	 	 	 	 	 $open_bracket = 1;
 533  	 	 	 	 	 while ($open_bracket > 0) {
 534  	 	 	 	 	 	 if (!isset($this->pdfdata[$strpos])) {
 535  	 	 	 	 	 	 	 break;
 536  	 	 	 	 	 	 }
 537  	 	 	 	 	 	 $ch = $this->pdfdata[$strpos];
 538  	 	 	 	 	 	 switch ($ch) {
 539  	 	 	 	 	 	 	 case '\\': { // REVERSE SOLIDUS (5Ch) (Backslash)
 540  	 	 	 	 	 	 	 	 // skip next character
 541  	 	 	 	 	 	 	 	 ++$strpos;
 542  	 	 	 	 	 	 	 	 break;
 543  	 	 	 	 	 	 	 }
 544  	 	 	 	 	 	 	 case '(': { // LEFT PARENHESIS (28h)
 545  	 	 	 	 	 	 	 	 ++$open_bracket;
 546  	 	 	 	 	 	 	 	 break;
 547  	 	 	 	 	 	 	 }
 548  	 	 	 	 	 	 	 case ')': { // RIGHT PARENTHESIS (29h)
 549  	 	 	 	 	 	 	 	 --$open_bracket;
 550  	 	 	 	 	 	 	 	 break;
 551  	 	 	 	 	 	 	 }
 552  	 	 	 	 	 	 }
 553  	 	 	 	 	 	 ++$strpos;
 554  	 	 	 	 	 }
 555  	 	 	 	 	 $objval = substr($this->pdfdata, $offset, ($strpos - $offset - 1));
 556  	 	 	 	 	 $offset = $strpos;
 557  	 	 	 	 }
 558  	 	 	 	 break;
 559  	 	 	 }
 560  	 	 	 case '[':   // \x5B LEFT SQUARE BRACKET
 561  	 	 	 case ']': { // \x5D RIGHT SQUARE BRACKET
 562  	 	 	 	 // array object
 563  	 	 	 	 $objtype = $char;
 564  	 	 	 	 ++$offset;
 565  	 	 	 	 if ($char == '[') {
 566  	 	 	 	 	 // get array content
 567  	 	 	 	 	 $objval = array();
 568  	 	 	 	 	 do {
 569  	 	 	 	 	 	 // get element
 570  	 	 	 	 	 	 $element = $this->getRawObject($offset);
 571  	 	 	 	 	 	 $offset = $element[2];
 572  	 	 	 	 	 	 $objval[] = $element;
 573  	 	 	 	 	 } while ($element[0] != ']');
 574  	 	 	 	 	 // remove closing delimiter
 575  	 	 	 	 	 array_pop($objval);
 576  	 	 	 	 }
 577  	 	 	 	 break;
 578  	 	 	 }
 579  	 	 	 case '<':   // \x3C LESS-THAN SIGN
 580  	 	 	 case '>': { // \x3E GREATER-THAN SIGN
 581  	 	 	 	 if (isset($this->pdfdata[($offset + 1)]) AND ($this->pdfdata[($offset + 1)] == $char)) {
 582  	 	 	 	 	 // dictionary object
 583  	 	 	 	 	 $objtype = $char.$char;
 584  	 	 	 	 	 $offset += 2;
 585  	 	 	 	 	 if ($char == '<') {
 586  	 	 	 	 	 	 // get array content
 587  	 	 	 	 	 	 $objval = array();
 588  	 	 	 	 	 	 do {
 589  	 	 	 	 	 	 	 // get element
 590  	 	 	 	 	 	 	 $element = $this->getRawObject($offset);
 591  	 	 	 	 	 	 	 $offset = $element[2];
 592  	 	 	 	 	 	 	 $objval[] = $element;
 593  	 	 	 	 	 	 } while ($element[0] != '>>');
 594  	 	 	 	 	 	 // remove closing delimiter
 595  	 	 	 	 	 	 array_pop($objval);
 596  	 	 	 	 	 }
 597  	 	 	 	 } else {
 598  	 	 	 	 	 // hexadecimal string object
 599  	 	 	 	 	 $objtype = $char;
 600  	 	 	 	 	 ++$offset;
 601  	 	 	 	 	 if (($char == '<') AND (preg_match('/^([0-9A-Fa-f\x09\x0a\x0c\x0d\x20]+)>/iU', substr($this->pdfdata, $offset), $matches) == 1)) {
 602  	 	 	 	 	 	 // remove white space characters
 603  	 	 	 	 	 	 $objval = strtr($matches[1], "\x09\x0a\x0c\x0d\x20", '');
 604  	 	 	 	 	 	 $offset += strlen($matches[0]);
 605  	 	 	 	 	 } elseif (($endpos = strpos($this->pdfdata, '>', $offset)) !== FALSE) {
 606  	 	 	 	 	 	 $offset = $endpos + 1;
 607                      }
 608  	 	 	 	 }
 609  	 	 	 	 break;
 610  	 	 	 }
 611  	 	 	 default: {
 612  	 	 	 	 if (substr($this->pdfdata, $offset, 6) == 'endobj') {
 613  	 	 	 	 	 // indirect object
 614  	 	 	 	 	 $objtype = 'endobj';
 615  	 	 	 	 	 $offset += 6;
 616  	 	 	 	 } elseif (substr($this->pdfdata, $offset, 4) == 'null') {
 617  	 	 	 	 	 // null object
 618  	 	 	 	 	 $objtype = 'null';
 619  	 	 	 	 	 $offset += 4;
 620  	 	 	 	 	 $objval = 'null';
 621  	 	 	 	 } elseif (substr($this->pdfdata, $offset, 4) == 'true') {
 622  	 	 	 	 	 // boolean true object
 623  	 	 	 	 	 $objtype = 'boolean';
 624  	 	 	 	 	 $offset += 4;
 625  	 	 	 	 	 $objval = 'true';
 626  	 	 	 	 } elseif (substr($this->pdfdata, $offset, 5) == 'false') {
 627  	 	 	 	 	 // boolean false object
 628  	 	 	 	 	 $objtype = 'boolean';
 629  	 	 	 	 	 $offset += 5;
 630  	 	 	 	 	 $objval = 'false';
 631  	 	 	 	 } elseif (substr($this->pdfdata, $offset, 6) == 'stream') {
 632  	 	 	 	 	 // start stream object
 633  	 	 	 	 	 $objtype = 'stream';
 634  	 	 	 	 	 $offset += 6;
 635  	 	 	 	 	 if (preg_match('/^([\r]?[\n])/isU', substr($this->pdfdata, $offset), $matches) == 1) {
 636  	 	 	 	 	 	 $offset += strlen($matches[0]);
 637  	 	 	 	 	 	 if (preg_match('/(endstream)[\x09\x0a\x0c\x0d\x20]/isU', substr($this->pdfdata, $offset), $matches, PREG_OFFSET_CAPTURE) == 1) {
 638  	 	 	 	 	 	 	 $objval = substr($this->pdfdata, $offset, $matches[0][1]);
 639  	 	 	 	 	 	 	 $offset += $matches[1][1];
 640  	 	 	 	 	 	 }
 641  	 	 	 	 	 }
 642  	 	 	 	 } elseif (substr($this->pdfdata, $offset, 9) == 'endstream') {
 643  	 	 	 	 	 // end stream object
 644  	 	 	 	 	 $objtype = 'endstream';
 645  	 	 	 	 	 $offset += 9;
 646  	 	 	 	 } elseif (preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+R/iU', substr($this->pdfdata, $offset, 33), $matches) == 1) {
 647  	 	 	 	 	 // indirect object reference
 648  	 	 	 	 	 $objtype = 'objref';
 649  	 	 	 	 	 $offset += strlen($matches[0]);
 650  	 	 	 	 	 $objval = intval($matches[1]).'_'.intval($matches[2]);
 651  	 	 	 	 } elseif (preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+obj/iU', substr($this->pdfdata, $offset, 33), $matches) == 1) {
 652  	 	 	 	 	 // object start
 653  	 	 	 	 	 $objtype = 'obj';
 654  	 	 	 	 	 $objval = intval($matches[1]).'_'.intval($matches[2]);
 655  	 	 	 	 	 $offset += strlen ($matches[0]);
 656  	 	 	 	 } elseif (($numlen = strspn($this->pdfdata, '+-.0123456789', $offset)) > 0) {
 657  	 	 	 	 	 // numeric object
 658  	 	 	 	 	 $objtype = 'numeric';
 659  	 	 	 	 	 $objval = substr($this->pdfdata, $offset, $numlen);
 660  	 	 	 	 	 $offset += $numlen;
 661  	 	 	 	 }
 662  	 	 	 	 break;
 663  	 	 	 }
 664  	 	 }
 665  	 	 return array($objtype, $objval, $offset);
 666  	 }
 667  
 668  	 /**
 669  	  * Get content of indirect object.
 670  	  * @param string $obj_ref Object number and generation number separated by underscore character.
 671  	  * @param int $offset Object offset.
 672  	  * @param boolean $decoding If true decode streams.
 673  	  * @return array containing object data.
 674  	  * @protected
 675  	  * @since 1.0.000 (2011-05-24)
 676  	  */
 677  	protected function getIndirectObject($obj_ref, $offset=0, $decoding=true) {
 678  	 	 $obj = explode('_', $obj_ref);
 679  	 	 if (($obj === false) OR (count($obj) != 2)) {
 680  	 	 	 $this->Error('Invalid object reference: '.$obj);
 681  	 	 	 return;
 682  	 	 }
 683  	 	 $objref = $obj[0].' '.$obj[1].' obj';
 684  	 	 // ignore leading zeros
 685  	 	 $offset += strspn($this->pdfdata, '0', $offset);
 686  	 	 if (strpos($this->pdfdata, $objref, $offset) != $offset) {
 687  	 	 	 // an indirect reference to an undefined object shall be considered a reference to the null object
 688  	 	 	 return array('null', 'null', $offset);
 689  	 	 }
 690  	 	 // starting position of object content
 691  	 	 $offset += strlen($objref);
 692  	 	 // get array of object content
 693  	 	 $objdata = array();
 694  	 	 $i = 0; // object main index
 695  	 	 do {
 696  	 	 	 $oldoffset = $offset;
 697                          // get element
 698  	 	 	 $element = $this->getRawObject($offset);
 699  	 	 	 $offset = $element[2];
 700  	 	 	 // decode stream using stream's dictionary information
 701  	 	 	 if ($decoding AND ($element[0] == 'stream') AND (isset($objdata[($i - 1)][0])) AND ($objdata[($i - 1)][0] == '<<')) {
 702  	 	 	 	 $element[3] = $this->decodeStream($objdata[($i - 1)][1], $element[1]);
 703  	 	 	 }
 704  	 	 	 $objdata[$i] = $element;
 705  	 	 	 ++$i;
 706  	 	 } while (($element[0] != 'endobj') AND ($offset != $oldoffset));
 707  	 	 // remove closing delimiter
 708  	 	 array_pop($objdata);
 709  	 	 // return raw object content
 710  	 	 return $objdata;
 711  	 }
 712  
 713  	 /**
 714  	  * Get the content of object, resolving indect object reference if necessary.
 715  	  * @param string $obj Object value.
 716  	  * @return array containing object data.
 717  	  * @protected
 718  	  * @since 1.0.000 (2011-06-26)
 719  	  */
 720  	protected function getObjectVal($obj) {
 721  	 	 if ($obj[0] == 'objref') {
 722  	 	 	 // reference to indirect object
 723  	 	 	 if (isset($this->objects[$obj[1]])) {
 724  	 	 	 	 // this object has been already parsed
 725  	 	 	 	 return $this->objects[$obj[1]];
 726  	 	 	 } elseif (isset($this->xref[$obj[1]])) {
 727  	 	 	 	 // parse new object
 728  	 	 	 	 $this->objects[$obj[1]] = $this->getIndirectObject($obj[1], $this->xref[$obj[1]], false);
 729  	 	 	 	 return $this->objects[$obj[1]];
 730  	 	 	 }
 731  	 	 }
 732  	 	 return $obj;
 733  	 }
 734  
 735  	 /**
 736  	  * Decode the specified stream.
 737  	  * @param array $sdic Stream's dictionary array.
 738  	  * @param string $stream Stream to decode.
 739  	  * @return array containing decoded stream data and remaining filters.
 740  	  * @protected
 741  	  * @since 1.0.000 (2011-06-22)
 742  	  */
 743  	protected function decodeStream($sdic, $stream) {
 744  	 	 // get stream length and filters
 745  	 	 $slength = strlen($stream);
 746  	 	 if ($slength <= 0) {
 747  	 	 	 return array('', array());
 748  	 	 }
 749  	 	 $filters = array();
 750  	 	 foreach ($sdic as $k => $v) {
 751  	 	 	 if ($v[0] == '/') {
 752  	 	 	 	 if (($v[1] == 'Length') AND (isset($sdic[($k + 1)])) AND ($sdic[($k + 1)][0] == 'numeric')) {
 753  	 	 	 	 	 // get declared stream length
 754  	 	 	 	 	 $declength = intval($sdic[($k + 1)][1]);
 755  	 	 	 	 	 if ($declength < $slength) {
 756  	 	 	 	 	 	 $stream = substr($stream, 0, $declength);
 757  	 	 	 	 	 	 $slength = $declength;
 758  	 	 	 	 	 }
 759  	 	 	 	 } elseif (($v[1] == 'Filter') AND (isset($sdic[($k + 1)]))) {
 760  	 	 	 	 	 // resolve indirect object
 761  	 	 	 	 	 $objval = $this->getObjectVal($sdic[($k + 1)]);
 762  	 	 	 	 	 if ($objval[0] == '/') {
 763  	 	 	 	 	 	 // single filter
 764  	 	 	 	 	 	 $filters[] = $objval[1];
 765  	 	 	 	 	 } elseif ($objval[0] == '[') {
 766  	 	 	 	 	 	 // array of filters
 767  	 	 	 	 	 	 foreach ($objval[1] as $flt) {
 768  	 	 	 	 	 	 	 if ($flt[0] == '/') {
 769  	 	 	 	 	 	 	 	 $filters[] = $flt[1];
 770  	 	 	 	 	 	 	 }
 771  	 	 	 	 	 	 }
 772  	 	 	 	 	 }
 773  	 	 	 	 }
 774  	 	 	 }
 775  	 	 }
 776  	 	 // decode the stream
 777  	 	 $remaining_filters = array();
 778  	 	 foreach ($filters as $filter) {
 779  	 	 	 if (in_array($filter, TCPDF_FILTERS::getAvailableFilters())) {
 780  	 	 	 	 try {
 781  	 	 	 	 	 $stream = TCPDF_FILTERS::decodeFilter($filter, $stream);
 782  	 	 	 	 } catch (Exception $e) {
 783  	 	 	 	 	 $emsg = $e->getMessage();
 784  	 	 	 	 	 if ((($emsg[0] == '~') AND !$this->cfg['ignore_missing_filter_decoders'])
 785  	 	 	 	 	 	 OR (($emsg[0] != '~') AND !$this->cfg['ignore_filter_decoding_errors'])) {
 786  	 	 	 	 	 	 $this->Error($e->getMessage());
 787  	 	 	 	 	 }
 788  	 	 	 	 }
 789  	 	 	 } else {
 790  	 	 	 	 // add missing filter to array
 791  	 	 	 	 $remaining_filters[] = $filter;
 792  	 	 	 }
 793  	 	 }
 794  	 	 return array($stream, $remaining_filters);
 795  	 }
 796  
 797  	 /**
 798  	  * Throw an exception or print an error message and die if the K_TCPDF_PARSER_THROW_EXCEPTION_ERROR constant is set to true.
 799  	  * @param string $msg The error message
 800  	  * @public
 801  	  * @since 1.0.000 (2011-05-23)
 802  	  */
 803  	public function Error($msg) {
 804  	 	 if ($this->cfg['die_for_errors']) {
 805  	 	 	 die('<strong>TCPDF_PARSER ERROR: </strong>'.$msg);
 806  	 	 } else {
 807  	 	 	 throw new Exception('TCPDF_PARSER ERROR: '.$msg);
 808  	 	 }
 809  	 }
 810  
 811  } // END OF TCPDF_PARSER CLASS
 812  
 813  //============================================================+
 814  // END OF FILE
 815  //============================================================+