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tcpdf/tcpdf_parser.php
nicolaasuni 7929b6d32e 6.0.061 (2014-02-18) 
- Bug #893 "Parsing error on streamed xref for secured pdf" was fixed.
2014-02-18 19:39:15 +00:00

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<?php
//============================================================+
// File name : tcpdf_parser.php
// Version : 1.0.014
// Begin : 2011-05-23
// Last Update : 2014-02-18
// Author : Nicola Asuni - Tecnick.com LTD - www.tecnick.com - info@tecnick.com
// License : http://www.tecnick.com/pagefiles/tcpdf/LICENSE.TXT GNU-LGPLv3
// -------------------------------------------------------------------
// Copyright (C) 2011-2014 Nicola Asuni - Tecnick.com LTD
//
// This file is part of TCPDF software library.
//
// TCPDF is free software: you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// TCPDF is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
// See the GNU Lesser General Public License for more details.
//
// You should have received a copy of the License
// along with TCPDF. If not, see
// <http://www.tecnick.com/pagefiles/tcpdf/LICENSE.TXT>.
//
// See LICENSE.TXT file for more information.
// -------------------------------------------------------------------
//
// Description : This is a PHP class for parsing PDF documents.
//
//============================================================+
/**
* @file
* This is a PHP class for parsing PDF documents.<br>
* @package com.tecnick.tcpdf
* @author Nicola Asuni
* @version 1.0.014
*/
// include class for decoding filters
require_once(dirname(__FILE__).'/include/tcpdf_filters.php');
/**
* @class TCPDF_PARSER
* This is a PHP class for parsing PDF documents.<br>
* @package com.tecnick.tcpdf
* @brief This is a PHP class for parsing PDF documents..
* @version 1.0.010
* @author Nicola Asuni - info@tecnick.com
*/
class TCPDF_PARSER {
/**
* Raw content of the PDF document.
* @private
*/
private $pdfdata = '';
/**
* XREF data.
* @protected
*/
protected $xref = array();
/**
* Array of PDF objects.
* @protected
*/
protected $objects = array();
/**
* Class object for decoding filters.
* @private
*/
private $FilterDecoders;
/**
* Array of configuration parameters.
* @private
*/
private $cfg = array(
'die_for_errors' => false,
'ignore_filter_decoding_errors' => true,
'ignore_missing_filter_decoders' => true,
);
// -----------------------------------------------------------------------------
/**
* Parse a PDF document an return an array of objects.
* @param $data (string) PDF data to parse.
* @param $cfg (array) Array of configuration parameters:
* 'die_for_errors' : if true termitate the program execution in case of error, otherwise thows an exception;
* 'ignore_filter_decoding_errors' : if true ignore filter decoding errors;
* 'ignore_missing_filter_decoders' : if true ignore missing filter decoding errors.
* @public
* @since 1.0.000 (2011-05-24)
*/
public function __construct($data, $cfg=array()) {
if (empty($data)) {
$this->Error('Empty PDF data.');
}
// find the pdf header starting position
if (($trimpos = strpos($data, '%PDF-')) === FALSE) {
$this->Error('Invalid PDF data: missing %PDF header.');
}
// get PDF content string
$this->pdfdata = substr($data, $trimpos);
// get length
$pdflen = strlen($this->pdfdata);
// set configuration parameters
$this->setConfig($cfg);
// get xref and trailer data
$this->xref = $this->getXrefData();
// parse all document objects
$this->objects = array();
foreach ($this->xref['xref'] as $obj => $offset) {
if (!isset($this->objects[$obj]) AND ($offset > 0)) {
// decode objects with positive offset
$this->objects[$obj] = $this->getIndirectObject($obj, $offset, true);
}
}
// release some memory
unset($this->pdfdata);
$this->pdfdata = '';
}
/**
* Set the configuration parameters.
* @param $cfg (array) Array of configuration parameters:
* 'die_for_errors' : if true termitate the program execution in case of error, otherwise thows an exception;
* 'ignore_filter_decoding_errors' : if true ignore filter decoding errors;
* 'ignore_missing_filter_decoders' : if true ignore missing filter decoding errors.
* @public
*/
protected function setConfig($cfg) {
if (isset($cfg['die_for_errors'])) {
$this->cfg['die_for_errors'] = !!$cfg['die_for_errors'];
}
if (isset($cfg['ignore_filter_decoding_errors'])) {
$this->cfg['ignore_filter_decoding_errors'] = !!$cfg['ignore_filter_decoding_errors'];
}
if (isset($cfg['ignore_missing_filter_decoders'])) {
$this->cfg['ignore_missing_filter_decoders'] = !!$cfg['ignore_missing_filter_decoders'];
}
}
/**
* Return an array of parsed PDF document objects.
* @return (array) Array of parsed PDF document objects.
* @public
* @since 1.0.000 (2011-06-26)
*/
public function getParsedData() {
return array($this->xref, $this->objects);
}
/**
* Get Cross-Reference (xref) table and trailer data from PDF document data.
* @param $offset (int) xref offset (if know).
* @param $xref (array) previous xref array (if any).
* @return Array containing xref and trailer data.
* @protected
* @since 1.0.000 (2011-05-24)
*/
protected function getXrefData($offset=0, $xref=array()) {
if ($offset == 0) {
// find last startxref
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) {
$this->Error('Unable to find startxref');
}
$matches = array_pop($matches);
$startxref = $matches[1];
} elseif (strpos($this->pdfdata, 'xref', $offset) == $offset) {
// Already pointing at the xref table
$startxref = $offset;
} elseif (preg_match('/([0-9]+[\s][0-9]+[\s]obj)/i', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset)) {
// Cross-Reference Stream object
$startxref = $offset;
} elseif (preg_match('/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset)) {
// startxref found
$startxref = $matches[1][0];
} else {
$this->Error('Unable to find startxref');
}
// check xref position
if (strpos($this->pdfdata, 'xref', $startxref) == $startxref) {
// Cross-Reference
$xref = $this->decodeXref($startxref, $xref);
} else {
// Cross-Reference Stream
$xref = $this->decodeXrefStream($startxref, $xref);
}
if (empty($xref)) {
$this->Error('Unable to find xref');
}
return $xref;
}
/**
* Decode the Cross-Reference section
* @param $startxref (int) Offset at which the xref section starts (position of the 'xref' keyword).
* @param $xref (array) Previous xref array (if any).
* @return Array containing xref and trailer data.
* @protected
* @since 1.0.000 (2011-06-20)
*/
protected function decodeXref($startxref, $xref=array()) {
$startxref += 4; // 4 is the lenght of the word 'xref'
// 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)
$offset = $startxref + strspn($this->pdfdata, "\x00\x09\x0a\x0c\x0d\x20", $startxref);
// initialize object number
$obj_num = 0;
// search for cross-reference entries or subsection
while (preg_match('/([0-9]+)[\x20]([0-9]+)[\x20]?([nf]?)(\r\n|[\x20]?[\r\n])/', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset) > 0) {
if ($matches[0][1] != $offset) {
// we are on another section
break;
}
$offset += strlen($matches[0][0]);
if ($matches[3][0] == 'n') {
// create unique object index: [object number]_[generation number]
$index = $obj_num.'_'.intval($matches[2][0]);
// check if object already exist
if (!isset($xref['xref'][$index])) {
// store object offset position
$xref['xref'][$index] = intval($matches[1][0]);
}
++$obj_num;
} elseif ($matches[3][0] == 'f') {
++$obj_num;
} else {
// object number (index)
$obj_num = intval($matches[1][0]);
}
}
// get trailer data
if (preg_match('/trailer[\s]*<<(.*)>>/isU', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset) > 0) {
$trailer_data = $matches[1][0];
if (!isset($xref['trailer']) OR empty($xref['trailer'])) {
// get only the last updated version
$xref['trailer'] = array();
// parse trailer_data
if (preg_match('/Size[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) {
$xref['trailer']['size'] = intval($matches[1]);
}
if (preg_match('/Root[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
$xref['trailer']['root'] = intval($matches[1]).'_'.intval($matches[2]);
}
if (preg_match('/Encrypt[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
$xref['trailer']['encrypt'] = intval($matches[1]).'_'.intval($matches[2]);
}
if (preg_match('/Info[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
$xref['trailer']['info'] = intval($matches[1]).'_'.intval($matches[2]);
}
if (preg_match('/ID[\s]*[\[][\s]*[<]([^>]*)[>][\s]*[<]([^>]*)[>]/i', $trailer_data, $matches) > 0) {
$xref['trailer']['id'] = array();
$xref['trailer']['id'][0] = $matches[1];
$xref['trailer']['id'][1] = $matches[2];
}
}
if (preg_match('/Prev[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) {
// get previous xref
$xref = $this->getXrefData(intval($matches[1]), $xref);
}
} else {
$this->Error('Unable to find trailer');
}
return $xref;
}
/**
* Decode the Cross-Reference Stream section
* @param $startxref (int) Offset at which the xref section starts.
* @param $xref (array) Previous xref array (if any).
* @return Array containing xref and trailer data.
* @protected
* @since 1.0.003 (2013-03-16)
*/
protected function decodeXrefStream($startxref, $xref=array()) {
// try to read Cross-Reference Stream
$xrefobj = $this->getRawObject($startxref);
$xrefcrs = $this->getIndirectObject($xrefobj[1], $startxref, true);
if (!isset($xref['trailer']) OR empty($xref['trailer'])) {
// get only the last updated version
$xref['trailer'] = array();
$filltrailer = true;
} else {
$filltrailer = false;
}
if (!isset($xref['xref'])) {
$xref['xref'] = array();
}
$valid_crs = false;
$columns = 0;
$sarr = $xrefcrs[0][1];
foreach ($sarr as $k => $v) {
if (($v[0] == '/') AND ($v[1] == 'Type') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == '/') AND ($sarr[($k +1)][1] == 'XRef'))) {
$valid_crs = true;
} elseif (($v[0] == '/') AND ($v[1] == 'Index') AND (isset($sarr[($k +1)]))) {
// first object number in the subsection
$index_first = intval($sarr[($k +1)][1][0][1]);
// number of entries in the subsection
$index_entries = intval($sarr[($k +1)][1][1][1]);
} elseif (($v[0] == '/') AND ($v[1] == 'Prev') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'numeric'))) {
// get previous xref offset
$prevxref = intval($sarr[($k +1)][1]);
} elseif (($v[0] == '/') AND ($v[1] == 'W') AND (isset($sarr[($k +1)]))) {
// number of bytes (in the decoded stream) of the corresponding field
$wb = array();
$wb[0] = intval($sarr[($k +1)][1][0][1]);
$wb[1] = intval($sarr[($k +1)][1][1][1]);
$wb[2] = intval($sarr[($k +1)][1][2][1]);
} elseif (($v[0] == '/') AND ($v[1] == 'DecodeParms') AND (isset($sarr[($k +1)][1]))) {
$decpar = $sarr[($k +1)][1];
foreach ($decpar as $kdc => $vdc) {
if (($vdc[0] == '/') AND ($vdc[1] == 'Columns') AND (isset($decpar[($kdc +1)]) AND ($decpar[($kdc +1)][0] == 'numeric'))) {
$columns = intval($decpar[($kdc +1)][1]);
} elseif (($vdc[0] == '/') AND ($vdc[1] == 'Predictor') AND (isset($decpar[($kdc +1)]) AND ($decpar[($kdc +1)][0] == 'numeric'))) {
$predictor = intval($decpar[($kdc +1)][1]);
}
}
} elseif ($filltrailer) {
if (($v[0] == '/') AND ($v[1] == 'Size') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'numeric'))) {
$xref['trailer']['size'] = $sarr[($k +1)][1];
} elseif (($v[0] == '/') AND ($v[1] == 'Root') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'objref'))) {
$xref['trailer']['root'] = $sarr[($k +1)][1];
} elseif (($v[0] == '/') AND ($v[1] == 'Info') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'objref'))) {
$xref['trailer']['info'] = $sarr[($k +1)][1];
} elseif (($v[0] == '/') AND ($v[1] == 'Encrypt') AND (isset($sarr[($k +1)]) AND ($sarr[($k +1)][0] == 'objref'))) {
$xref['trailer']['encrypt'] = $sarr[($k +1)][1];
} elseif (($v[0] == '/') AND ($v[1] == 'ID') AND (isset($sarr[($k +1)]))) {
$xref['trailer']['id'] = array();
$xref['trailer']['id'][0] = $sarr[($k +1)][1][0][1];
$xref['trailer']['id'][1] = $sarr[($k +1)][1][1][1];
}
}
}
// decode data
if ($valid_crs AND isset($xrefcrs[1][3][0])) {
// number of bytes in a row
$rowlen = ($columns + 1);
// convert the stream into an array of integers
$sdata = unpack('C*', $xrefcrs[1][3][0]);
// split the rows
$sdata = array_chunk($sdata, $rowlen);
// initialize decoded array
$ddata = array();
// initialize first row with zeros
$prev_row = array_fill (0, $rowlen, 0);
// for each row apply PNG unpredictor
foreach ($sdata as $k => $row) {
// initialize new row
$ddata[$k] = array();
// get PNG predictor value
$predictor = (10 + $row[0]);
// for each byte on the row
for ($i=1; $i<=$columns; ++$i) {
// new index
$j = ($i - 1);
$row_up = $prev_row[$j];
if ($i == 1) {
$row_left = 0;
$row_upleft = 0;
} else {
$row_left = $row[($i - 1)];
$row_upleft = $prev_row[($j - 1)];
}
switch ($predictor) {
case 10: { // PNG prediction (on encoding, PNG None on all rows)
$ddata[$k][$j] = $row[$i];
break;
}
case 11: { // PNG prediction (on encoding, PNG Sub on all rows)
$ddata[$k][$j] = (($row[$i] + $row_left) & 0xff);
break;
}
case 12: { // PNG prediction (on encoding, PNG Up on all rows)
$ddata[$k][$j] = (($row[$i] + $row_up) & 0xff);
break;
}
case 13: { // PNG prediction (on encoding, PNG Average on all rows)
$ddata[$k][$j] = (($row[$i] + (($row_left + $row_up) / 2)) & 0xff);
break;
}
case 14: { // PNG prediction (on encoding, PNG Paeth on all rows)
// initial estimate
$p = ($row_left + $row_up - $row_upleft);
// distances
$pa = abs($p - $row_left);
$pb = abs($p - $row_up);
$pc = abs($p - $row_upleft);
$pmin = min($pa, $pb, $pc);
// return minumum distance
switch ($pmin) {
case $pa: {
$ddata[$k][$j] = (($row[$i] + $row_left) & 0xff);
break;
}
case $pb: {
$ddata[$k][$j] = (($row[$i] + $row_up) & 0xff);
break;
}
case $pc: {
$ddata[$k][$j] = (($row[$i] + $row_upleft) & 0xff);
break;
}
}
break;
}
default: { // PNG prediction (on encoding, PNG optimum)
$this->Error('Unknown PNG predictor');
break;
}
}
}
$prev_row = $ddata[$k];
} // end for each row
// complete decoding
$sdata = array();
// for every row
foreach ($ddata as $k => $row) {
// initialize new row
$sdata[$k] = array(0, 0, 0);
if ($wb[0] == 0) {
// default type field
$sdata[$k][0] = 1;
}
$i = 0; // count bytes in the row
// for every column
for ($c = 0; $c < 3; ++$c) {
// for every byte on the column
for ($b = 0; $b < $wb[$c]; ++$b) {
if (isset($row[$i])) {
$sdata[$k][$c] += ($row[$i] << (($wb[$c] - 1 - $b) * 8));
}
++$i;
}
}
}
$ddata = array();
// fill xref
if (isset($index_first)) {
$obj_num = $index_first;
} else {
$obj_num = 0;
}
foreach ($sdata as $k => $row) {
switch ($row[0]) {
case 0: { // (f) linked list of free objects
break;
}
case 1: { // (n) objects that are in use but are not compressed
// create unique object index: [object number]_[generation number]
$index = $obj_num.'_'.$row[2];
// check if object already exist
if (!isset($xref['xref'][$index])) {
// store object offset position
$xref['xref'][$index] = $row[1];
}
break;
}
case 2: { // compressed objects
// $row[1] = object number of the object stream in which this object is stored
// $row[2] = index of this object within the object stream
$index = $row[1].'_0_'.$row[2];
$xref['xref'][$index] = -1;
break;
}
default: { // null objects
break;
}
}
++$obj_num;
}
} // end decoding data
if (isset($prevxref)) {
// get previous xref
$xref = $this->getXrefData($prevxref, $xref);
}
return $xref;
}
/**
* Get object type, raw value and offset to next object
* @param $offset (int) Object offset.
* @return array containing object type, raw value and offset to next object
* @protected
* @since 1.0.000 (2011-06-20)
*/
protected function getRawObject($offset=0) {
$objtype = ''; // object type to be returned
$objval = ''; // object value to be returned
// 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)
$offset += strspn($this->pdfdata, "\x00\x09\x0a\x0c\x0d\x20", $offset);
// get first char
$char = $this->pdfdata[$offset];
// get object type
switch ($char) {
case '%': { // \x25 PERCENT SIGN
// skip comment and search for next token
$next = strcspn($this->pdfdata, "\r\n", $offset);
if ($next > 0) {
$offset += $next;
return $this->getRawObject($offset);
}
break;
}
case '/': { // \x2F SOLIDUS
// name object
$objtype = $char;
++$offset;
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) {
$objval = $matches[1]; // unescaped value
$offset += strlen($objval);
}
break;
}
case '(': // \x28 LEFT PARENTHESIS
case ')': { // \x29 RIGHT PARENTHESIS
// literal string object
$objtype = $char;
++$offset;
$strpos = $offset;
if ($char == '(') {
$open_bracket = 1;
while ($open_bracket > 0) {
if (!isset($this->pdfdata{$strpos})) {
break;
}
$ch = $this->pdfdata{$strpos};
switch ($ch) {
case '\\': { // REVERSE SOLIDUS (5Ch) (Backslash)
// skip next character
++$strpos;
break;
}
case '(': { // LEFT PARENHESIS (28h)
++$open_bracket;
break;
}
case ')': { // RIGHT PARENTHESIS (29h)
--$open_bracket;
break;
}
}
++$strpos;
}
$objval = substr($this->pdfdata, $offset, ($strpos - $offset - 1));
$offset = $strpos;
}
break;
}
case '[': // \x5B LEFT SQUARE BRACKET
case ']': { // \x5D RIGHT SQUARE BRACKET
// array object
$objtype = $char;
++$offset;
if ($char == '[') {
// get array content
$objval = array();
do {
// get element
$element = $this->getRawObject($offset);
$offset = $element[2];
$objval[] = $element;
} while ($element[0] != ']');
// remove closing delimiter
array_pop($objval);
}
break;
}
case '<': // \x3C LESS-THAN SIGN
case '>': { // \x3E GREATER-THAN SIGN
if (isset($this->pdfdata{($offset + 1)}) AND ($this->pdfdata{($offset + 1)} == $char)) {
// dictionary object
$objtype = $char.$char;
$offset += 2;
if ($char == '<') {
// get array content
$objval = array();
do {
// get element
$element = $this->getRawObject($offset);
$offset = $element[2];
$objval[] = $element;
} while ($element[0] != '>>');
// remove closing delimiter
array_pop($objval);
}
} else {
// hexadecimal string object
$objtype = $char;
++$offset;
if (($char == '<') AND (preg_match('/^([0-9A-Fa-f\x09\x0a\x0c\x0d\x20]+)>/iU', substr($this->pdfdata, $offset), $matches) == 1)) {
// remove white space characters
$objval = strtr($matches[1], "\x09\x0a\x0c\x0d\x20", '');
$offset += strlen($matches[0]);
} elseif (($endpos = strpos($this->pdfdata, '>', $offset)) !== FALSE) {
$offset = $endpos + 1;
}
}
break;
}
default: {
if (substr($this->pdfdata, $offset, 6) == 'endobj') {
// indirect object
$objtype = 'endobj';
$offset += 6;
} elseif (substr($this->pdfdata, $offset, 4) == 'null') {
// null object
$objtype = 'null';
$offset += 4;
$objval = 'null';
} elseif (substr($this->pdfdata, $offset, 4) == 'true') {
// boolean true object
$objtype = 'boolean';
$offset += 4;
$objval = 'true';
} elseif (substr($this->pdfdata, $offset, 5) == 'false') {
// boolean false object
$objtype = 'boolean';
$offset += 5;
$objval = 'false';
} elseif (substr($this->pdfdata, $offset, 6) == 'stream') {
// start stream object
$objtype = 'stream';
$offset += 6;
if (preg_match('/^([\r]?[\n])/isU', substr($this->pdfdata, $offset), $matches) == 1) {
$offset += strlen($matches[0]);
if (preg_match('/(endstream)[\x09\x0a\x0c\x0d\x20]/isU', substr($this->pdfdata, $offset), $matches, PREG_OFFSET_CAPTURE) == 1) {
$objval = substr($this->pdfdata, $offset, $matches[0][1]);
$offset += $matches[1][1];
}
}
} elseif (substr($this->pdfdata, $offset, 9) == 'endstream') {
// end stream object
$objtype = 'endstream';
$offset += 9;
} elseif (preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+R/iU', substr($this->pdfdata, $offset, 33), $matches) == 1) {
// indirect object reference
$objtype = 'objref';
$offset += strlen($matches[0]);
$objval = intval($matches[1]).'_'.intval($matches[2]);
} elseif (preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+obj/iU', substr($this->pdfdata, $offset, 33), $matches) == 1) {
// object start
$objtype = 'obj';
$objval = intval($matches[1]).'_'.intval($matches[2]);
$offset += strlen ($matches[0]);
} elseif (($numlen = strspn($this->pdfdata, '+-.0123456789', $offset)) > 0) {
// numeric object
$objtype = 'numeric';
$objval = substr($this->pdfdata, $offset, $numlen);
$offset += $numlen;
}
break;
}
}
return array($objtype, $objval, $offset);
}
/**
* Get content of indirect object.
* @param $obj_ref (string) Object number and generation number separated by underscore character.
* @param $offset (int) Object offset.
* @param $decoding (boolean) If true decode streams.
* @return array containing object data.
* @protected
* @since 1.0.000 (2011-05-24)
*/
protected function getIndirectObject($obj_ref, $offset=0, $decoding=true) {
$obj = explode('_', $obj_ref);
if (($obj === false) OR (count($obj) != 2)) {
$this->Error('Invalid object reference: '.$obj);
return;
}
$objref = $obj[0].' '.$obj[1].' obj';
// ignore leading zeros
$offset += strspn($this->pdfdata, '0', $offset);
if (strpos($this->pdfdata, $objref, $offset) != $offset) {
// an indirect reference to an undefined object shall be considered a reference to the null object
return array('null', 'null', $offset);
}
// starting position of object content
$offset += strlen($objref);
// get array of object content
$objdata = array();
$i = 0; // object main index
do {
// get element
$element = $this->getRawObject($offset);
$offset = $element[2];
// decode stream using stream's dictionary information
if ($decoding AND ($element[0] == 'stream') AND (isset($objdata[($i - 1)][0])) AND ($objdata[($i - 1)][0] == '<<')) {
$element[3] = $this->decodeStream($objdata[($i - 1)][1], $element[1]);
}
$objdata[$i] = $element;
++$i;
} while ($element[0] != 'endobj');
// remove closing delimiter
array_pop($objdata);
// return raw object content
return $objdata;
}
/**
* Get the content of object, resolving indect object reference if necessary.
* @param $obj (string) Object value.
* @return array containing object data.
* @protected
* @since 1.0.000 (2011-06-26)
*/
protected function getObjectVal($obj) {
if ($obj[0] == 'objref') {
// reference to indirect object
if (isset($this->objects[$obj[1]])) {
// this object has been already parsed
return $this->objects[$obj[1]];
} elseif (isset($this->xref[$obj[1]])) {
// parse new object
$this->objects[$obj[1]] = $this->getIndirectObject($obj[1], $this->xref[$obj[1]], false);
return $this->objects[$obj[1]];
}
}
return $obj;
}
/**
* Decode the specified stream.
* @param $sdic (array) Stream's dictionary array.
* @param $stream (string) Stream to decode.
* @return array containing decoded stream data and remaining filters.
* @protected
* @since 1.0.000 (2011-06-22)
*/
protected function decodeStream($sdic, $stream) {
// get stream lenght and filters
$slength = strlen($stream);
if ($slength <= 0) {
return array('', array());
}
$filters = array();
foreach ($sdic as $k => $v) {
if ($v[0] == '/') {
if (($v[1] == 'Length') AND (isset($sdic[($k + 1)])) AND ($sdic[($k + 1)][0] == 'numeric')) {
// get declared stream lenght
$declength = intval($sdic[($k + 1)][1]);
if ($declength < $slength) {
$stream = substr($stream, 0, $declength);
$slength = $declength;
}
} elseif (($v[1] == 'Filter') AND (isset($sdic[($k + 1)]))) {
// resolve indirect object
$objval = $this->getObjectVal($sdic[($k + 1)]);
if ($objval[0] == '/') {
// single filter
$filters[] = $objval[1];
} elseif ($objval[0] == '[') {
// array of filters
foreach ($objval[1] as $flt) {
if ($flt[0] == '/') {
$filters[] = $flt[1];
}
}
}
}
}
}
// decode the stream
$remaining_filters = array();
foreach ($filters as $filter) {
if (in_array($filter, TCPDF_FILTERS::getAvailableFilters())) {
try {
$stream = TCPDF_FILTERS::decodeFilter($filter, $stream);
} catch (Exception $e) {
$emsg = $e->getMessage();
if ((($emsg[0] == '~') AND !$this->cfg['ignore_missing_filter_decoders'])
OR (($emsg[0] != '~') AND !$this->cfg['ignore_filter_decoding_errors'])) {
$this->Error($e->getMessage());
}
}
} else {
// add missing filter to array
$remaining_filters[] = $filter;
}
}
return array($stream, $remaining_filters);
}
/**
* Throw an exception or print an error message and die if the K_TCPDF_PARSER_THROW_EXCEPTION_ERROR constant is set to true.
* @param $msg (string) The error message
* @public
* @since 1.0.000 (2011-05-23)
*/
public function Error($msg) {
if ($this->cfg['die_for_errors']) {
die('<strong>TCPDF_PARSER ERROR: </strong>'.$msg);
} else {
throw new Exception('TCPDF_PARSER ERROR: '.$msg);
}
}
} // END OF TCPDF_PARSER CLASS
//============================================================+
// END OF FILE
//============================================================+
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