/htdocs/includes/fpdfi/pdf_parser.php
PHP | 719 lines | 411 code | 140 blank | 168 comment | 131 complexity | 7f2fcf98013f7830e1e8b3c1e26e6a95 MD5 | raw file
Possible License(s): LGPL-3.0, LGPL-2.1, GPL-3.0, MIT
- <?php
- //
- // FPDI - Version 1.4.2
- //
- // Copyright 2004-2011 Setasign - Jan Slabon
- //
- // Licensed under the Apache License, Version 2.0 (the "License");
- // you may not use this file except in compliance with the License.
- // You may obtain a copy of the License at
- //
- // http://www.apache.org/licenses/LICENSE-2.0
- //
- // Unless required by applicable law or agreed to in writing, software
- // distributed under the License is distributed on an "AS IS" BASIS,
- // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- // See the License for the specific language governing permissions and
- // limitations under the License.
- //
-
- if (!defined ('PDF_TYPE_NULL'))
- define ('PDF_TYPE_NULL', 0);
- if (!defined ('PDF_TYPE_NUMERIC'))
- define ('PDF_TYPE_NUMERIC', 1);
- if (!defined ('PDF_TYPE_TOKEN'))
- define ('PDF_TYPE_TOKEN', 2);
- if (!defined ('PDF_TYPE_HEX'))
- define ('PDF_TYPE_HEX', 3);
- if (!defined ('PDF_TYPE_STRING'))
- define ('PDF_TYPE_STRING', 4);
- if (!defined ('PDF_TYPE_DICTIONARY'))
- define ('PDF_TYPE_DICTIONARY', 5);
- if (!defined ('PDF_TYPE_ARRAY'))
- define ('PDF_TYPE_ARRAY', 6);
- if (!defined ('PDF_TYPE_OBJDEC'))
- define ('PDF_TYPE_OBJDEC', 7);
- if (!defined ('PDF_TYPE_OBJREF'))
- define ('PDF_TYPE_OBJREF', 8);
- if (!defined ('PDF_TYPE_OBJECT'))
- define ('PDF_TYPE_OBJECT', 9);
- if (!defined ('PDF_TYPE_STREAM'))
- define ('PDF_TYPE_STREAM', 10);
- if (!defined ('PDF_TYPE_BOOLEAN'))
- define ('PDF_TYPE_BOOLEAN', 11);
- if (!defined ('PDF_TYPE_REAL'))
- define ('PDF_TYPE_REAL', 12);
-
- require_once('pdf_context.php');
-
- if (!class_exists('pdf_parser', false)) {
-
- class pdf_parser {
-
- /**
- * Filename
- * @var string
- */
- var $filename;
-
- /**
- * File resource
- * @var resource
- */
- var $f;
-
- /**
- * PDF Context
- * @var object pdf_context-Instance
- */
- var $c;
-
- /**
- * xref-Data
- * @var array
- */
- var $xref;
-
- /**
- * root-Object
- * @var array
- */
- var $root;
-
- /**
- * PDF version of the loaded document
- * @var string
- */
- var $pdfVersion;
-
- /**
- * For reading encrypted documents and xref/objectstreams are in use
- *
- * @var boolean
- */
- var $readPlain = true;
-
- /**
- * Constructor
- *
- * @param string $filename Source-Filename
- */
- function pdf_parser($filename) {
- $this->filename = $filename;
-
- $this->f = @fopen($this->filename, 'rb');
-
- if (!$this->f)
- $this->error(sprintf('Cannot open %s !', $filename));
-
- $this->getPDFVersion();
-
- $this->c = new pdf_context($this->f);
-
- // Read xref-Data
- $this->xref = array();
- $this->pdf_read_xref($this->xref, $this->pdf_find_xref());
-
- // Check for Encryption
- $this->getEncryption();
-
- // Read root
- $this->pdf_read_root();
- }
-
- /**
- * Close the opened file
- */
- function closeFile() {
- if (isset($this->f) && is_resource($this->f)) {
- fclose($this->f);
- unset($this->f);
- }
- }
-
- /**
- * Print Error and die
- *
- * @param string $msg Error-Message
- */
- function error($msg) {
- die('<b>PDF-Parser Error:</b> ' . $msg);
- }
-
- /**
- * Check Trailer for Encryption
- */
- function getEncryption() {
- if (isset($this->xref['trailer'][1]['/Encrypt'])) {
- $this->error('File is encrypted!');
- }
- }
-
- /**
- * Find/Return /Root
- *
- * @return array
- */
- function pdf_find_root() {
- if ($this->xref['trailer'][1]['/Root'][0] != PDF_TYPE_OBJREF) {
- $this->error('Wrong Type of Root-Element! Must be an indirect reference');
- }
-
- return $this->xref['trailer'][1]['/Root'];
- }
-
- /**
- * Read the /Root
- */
- function pdf_read_root() {
- // read root
- $this->root = $this->pdf_resolve_object($this->c, $this->pdf_find_root());
- }
-
- /**
- * Get PDF-Version
- *
- * And reset the PDF Version used in FPDI if needed
- */
- function getPDFVersion() {
- fseek($this->f, 0);
- preg_match('/\d\.\d/',fread($this->f, 16), $m);
- if (isset($m[0]))
- $this->pdfVersion = $m[0];
- return $this->pdfVersion;
- }
-
- /**
- * Find the xref-Table
- */
- function pdf_find_xref() {
- $toRead = 1500;
-
- $stat = fseek ($this->f, -$toRead, SEEK_END);
- if ($stat === -1) {
- fseek ($this->f, 0);
- }
- $data = fread($this->f, $toRead);
-
- $pos = strlen($data) - strpos(strrev($data), strrev('startxref'));
- $data = substr($data, $pos);
-
- if (!preg_match('/\s*(\d+).*$/s', $data, $matches)) {
- $this->error('Unable to find pointer to xref table');
- }
-
- return (int) $matches[1];
- }
-
- /**
- * Read xref-table
- *
- * @param array $result Array of xref-table
- * @param integer $offset of xref-table
- */
- function pdf_read_xref(&$result, $offset) {
- $o_pos = $offset-min(20, $offset);
- fseek($this->f, $o_pos); // set some bytes backwards to fetch errorious docs
-
- $data = fread($this->f, 100);
-
- $xrefPos = strrpos($data, 'xref');
-
- if ($xrefPos === false) {
- fseek($this->f, $offset);
- $c = new pdf_context($this->f);
- $xrefStreamObjDec = $this->pdf_read_value($c);
-
- if (is_array($xrefStreamObjDec) && isset($xrefStreamObjDec[0]) && $xrefStreamObjDec[0] == PDF_TYPE_OBJDEC) {
- $this->error(sprintf('This document (%s) probably uses a compression technique which is not supported by the free parser shipped with FPDI.', $this->filename));
- } else {
- $this->error('Unable to find xref table.');
- }
- }
-
- if (!isset($result['xref_location'])) {
- $result['xref_location'] = $o_pos + $xrefPos;
- $result['max_object'] = 0;
- }
-
- $cylces = -1;
- $bytesPerCycle = 100;
-
- fseek($this->f, $o_pos = $o_pos + $xrefPos + 4); // set the handle directly after the "xref"-keyword
- $data = fread($this->f, $bytesPerCycle);
-
- while (($trailerPos = strpos($data, 'trailer', max($bytesPerCycle * $cylces++, 0))) === false && !feof($this->f)) {
- $data .= fread($this->f, $bytesPerCycle);
- }
-
- if ($trailerPos === false) {
- $this->error('Trailer keyword not found after xref table');
- }
-
- $data = substr($data, 0, $trailerPos);
-
- // get Line-Ending
- preg_match_all("/(\r\n|\n|\r)/", substr($data, 0, 100), $m); // check the first 100 bytes for linebreaks
-
- $differentLineEndings = count(array_unique($m[0]));
- if ($differentLineEndings > 1) {
- $lines = preg_split("/(\r\n|\n|\r)/", $data, -1, PREG_SPLIT_NO_EMPTY);
- } else {
- $lines = explode($m[0][1], $data);
- }
-
- $data = $differentLineEndings = $m = null;
- unset($data, $differentLineEndings, $m);
-
- $linesCount = count($lines);
-
- $start = 1;
-
- for ($i = 0; $i < $linesCount; $i++) {
- $line = trim($lines[$i]);
- if ($line) {
- $pieces = explode(' ', $line);
- $c = count($pieces);
- switch($c) {
- case 2:
- $start = (int)$pieces[0];
- $end = $start + (int)$pieces[1];
- if ($end > $result['max_object'])
- $result['max_object'] = $end;
- break;
- case 3:
- if (!isset($result['xref'][$start]))
- $result['xref'][$start] = array();
-
- if (!array_key_exists($gen = (int) $pieces[1], $result['xref'][$start])) {
- $result['xref'][$start][$gen] = $pieces[2] == 'n' ? (int) $pieces[0] : null;
- }
- $start++;
- break;
- default:
- $this->error('Unexpected data in xref table');
- }
- }
- }
-
- $lines = $pieces = $line = $start = $end = $gen = null;
- unset($lines, $pieces, $line, $start, $end, $gen);
-
- fseek($this->f, $o_pos + $trailerPos + 7);
-
- $c = new pdf_context($this->f);
- $trailer = $this->pdf_read_value($c);
-
- $c = null;
- unset($c);
-
- if (!isset($result['trailer'])) {
- $result['trailer'] = $trailer;
- }
-
- if (isset($trailer[1]['/Prev'])) {
- $this->pdf_read_xref($result, $trailer[1]['/Prev'][1]);
- }
-
- $trailer = null;
- unset($trailer);
-
- return true;
- }
-
- /**
- * Reads an Value
- *
- * @param object $c pdf_context
- * @param string $token a Token
- * @return mixed
- */
- function pdf_read_value(&$c, $token = null) {
- if (is_null($token)) {
- $token = $this->pdf_read_token($c);
- }
-
- if ($token === false) {
- return false;
- }
-
- switch ($token) {
- case '<':
- // This is a hex string.
- // Read the value, then the terminator
-
- $pos = $c->offset;
-
- while(1) {
-
- $match = strpos ($c->buffer, '>', $pos);
-
- // If you can't find it, try
- // reading more data from the stream
-
- if ($match === false) {
- if (!$c->increase_length()) {
- return false;
- } else {
- continue;
- }
- }
-
- $result = substr ($c->buffer, $c->offset, $match - $c->offset);
- $c->offset = $match + 1;
-
- return array (PDF_TYPE_HEX, $result);
- }
-
- break;
- case '<<':
- // This is a dictionary.
-
- $result = array();
-
- // Recurse into this function until we reach
- // the end of the dictionary.
- while (($key = $this->pdf_read_token($c)) !== '>>') {
- if ($key === false) {
- return false;
- }
-
- if (($value = $this->pdf_read_value($c)) === false) {
- return false;
- }
-
- // Catch missing value
- if ($value[0] == PDF_TYPE_TOKEN && $value[1] == '>>') {
- $result[$key] = array(PDF_TYPE_NULL);
- break;
- }
-
- $result[$key] = $value;
- }
-
- return array (PDF_TYPE_DICTIONARY, $result);
-
- case '[':
- // This is an array.
-
- $result = array();
-
- // Recurse into this function until we reach
- // the end of the array.
- while (($token = $this->pdf_read_token($c)) !== ']') {
- if ($token === false) {
- return false;
- }
-
- if (($value = $this->pdf_read_value($c, $token)) === false) {
- return false;
- }
-
- $result[] = $value;
- }
-
- return array (PDF_TYPE_ARRAY, $result);
-
- case '(' :
- // This is a string
- $pos = $c->offset;
-
- $openBrackets = 1;
- do {
- for (; $openBrackets != 0 && $pos < $c->length; $pos++) {
- switch (ord($c->buffer[$pos])) {
- case 0x28: // '('
- $openBrackets++;
- break;
- case 0x29: // ')'
- $openBrackets--;
- break;
- case 0x5C: // backslash
- $pos++;
- }
- }
- } while($openBrackets != 0 && $c->increase_length());
-
- $result = substr($c->buffer, $c->offset, $pos - $c->offset - 1);
- $c->offset = $pos;
-
- return array (PDF_TYPE_STRING, $result);
-
- case 'stream':
- $o_pos = ftell($c->file)-strlen($c->buffer);
- $o_offset = $c->offset;
-
- $c->reset($startpos = $o_pos + $o_offset);
-
- $e = 0; // ensure line breaks in front of the stream
- if ($c->buffer[0] == chr(10) || $c->buffer[0] == chr(13))
- $e++;
- if ($c->buffer[1] == chr(10) && $c->buffer[0] != chr(10))
- $e++;
-
- if ($this->actual_obj[1][1]['/Length'][0] == PDF_TYPE_OBJREF) {
- $tmp_c = new pdf_context($this->f);
- $tmp_length = $this->pdf_resolve_object($tmp_c, $this->actual_obj[1][1]['/Length']);
- $length = $tmp_length[1][1];
- } else {
- $length = $this->actual_obj[1][1]['/Length'][1];
- }
-
- if ($length > 0) {
- $c->reset($startpos + $e,$length);
- $v = $c->buffer;
- } else {
- $v = '';
- }
- $c->reset($startpos + $e + $length + 9); // 9 = strlen("endstream")
-
- return array(PDF_TYPE_STREAM, $v);
-
- default :
- if (is_numeric ($token)) {
- // A numeric token. Make sure that
- // it is not part of something else.
- if (($tok2 = $this->pdf_read_token ($c)) !== false) {
- if (is_numeric ($tok2)) {
-
- // Two numeric tokens in a row.
- // In this case, we're probably in
- // front of either an object reference
- // or an object specification.
- // Determine the case and return the data
- if (($tok3 = $this->pdf_read_token ($c)) !== false) {
- switch ($tok3) {
- case 'obj':
- return array (PDF_TYPE_OBJDEC, (int) $token, (int) $tok2);
- case 'R':
- return array (PDF_TYPE_OBJREF, (int) $token, (int) $tok2);
- }
- // If we get to this point, that numeric value up
- // there was just a numeric value. Push the extra
- // tokens back into the stack and return the value.
- array_push ($c->stack, $tok3);
- }
- }
-
- array_push ($c->stack, $tok2);
- }
-
- if ($token === (string)((int)$token))
- return array (PDF_TYPE_NUMERIC, (int)$token);
- else
- return array (PDF_TYPE_REAL, (float)$token);
- } else if ($token == 'true' || $token == 'false') {
- return array (PDF_TYPE_BOOLEAN, $token == 'true');
- } else if ($token == 'null') {
- return array (PDF_TYPE_NULL);
- } else {
- // Just a token. Return it.
- return array (PDF_TYPE_TOKEN, $token);
- }
- }
- }
-
- /**
- * Resolve an object
- *
- * @param object $c pdf_context
- * @param array $obj_spec The object-data
- * @param boolean $encapsulate Must set to true, cause the parsing and fpdi use this method only without this para
- */
- function pdf_resolve_object(&$c, $obj_spec, $encapsulate = true) {
- // Exit if we get invalid data
- if (!is_array($obj_spec)) {
- $ret = false;
- return $ret;
- }
-
- if ($obj_spec[0] == PDF_TYPE_OBJREF) {
-
- // This is a reference, resolve it
- if (isset($this->xref['xref'][$obj_spec[1]][$obj_spec[2]])) {
-
- // Save current file position
- // This is needed if you want to resolve
- // references while you're reading another object
- // (e.g.: if you need to determine the length
- // of a stream)
-
- $old_pos = ftell($c->file);
-
- // Reposition the file pointer and
- // load the object header.
-
- $c->reset($this->xref['xref'][$obj_spec[1]][$obj_spec[2]]);
-
- $header = $this->pdf_read_value($c);
-
- if ($header[0] != PDF_TYPE_OBJDEC || $header[1] != $obj_spec[1] || $header[2] != $obj_spec[2]) {
- $toSearchFor = $obj_spec[1] . ' ' . $obj_spec[2] . ' obj';
- if (preg_match('/' . $toSearchFor . '/', $c->buffer)) {
- $c->offset = strpos($c->buffer, $toSearchFor) + strlen($toSearchFor);
- // reset stack
- $c->stack = array();
- } else {
- $this->error("Unable to find object ({$obj_spec[1]}, {$obj_spec[2]}) at expected location");
- }
- }
-
- // If we're being asked to store all the information
- // about the object, we add the object ID and generation
- // number for later use
- $result = array();
- $this->actual_obj =& $result;
- if ($encapsulate) {
- $result = array (
- PDF_TYPE_OBJECT,
- 'obj' => $obj_spec[1],
- 'gen' => $obj_spec[2]
- );
- }
-
- // Now simply read the object data until
- // we encounter an end-of-object marker
- while(1) {
- $value = $this->pdf_read_value($c);
- if ($value === false || count($result) > 4) {
- // in this case the parser coudn't find an endobj so we break here
- break;
- }
-
- if ($value[0] == PDF_TYPE_TOKEN && $value[1] === 'endobj') {
- break;
- }
-
- $result[] = $value;
- }
-
- $c->reset($old_pos);
-
- if (isset($result[2][0]) && $result[2][0] == PDF_TYPE_STREAM) {
- $result[0] = PDF_TYPE_STREAM;
- }
-
- return $result;
- }
- } else {
- return $obj_spec;
- }
- }
-
-
-
- /**
- * Reads a token from the file
- *
- * @param object $c pdf_context
- * @return mixed
- */
- function pdf_read_token(&$c)
- {
- // If there is a token available
- // on the stack, pop it out and
- // return it.
-
- if (count($c->stack)) {
- return array_pop($c->stack);
- }
-
- // Strip away any whitespace
-
- do {
- if (!$c->ensure_content()) {
- return false;
- }
- $c->offset += strspn($c->buffer, " \n\r\t", $c->offset);
- } while ($c->offset >= $c->length - 1);
-
- // Get the first character in the stream
-
- $char = $c->buffer[$c->offset++];
-
- switch ($char) {
-
- case '[':
- case ']':
- case '(':
- case ')':
-
- // This is either an array or literal string
- // delimiter, Return it
-
- return $char;
-
- case '<':
- case '>':
-
- // This could either be a hex string or
- // dictionary delimiter. Determine the
- // appropriate case and return the token
-
- if ($c->buffer[$c->offset] == $char) {
- if (!$c->ensure_content()) {
- return false;
- }
- $c->offset++;
- return $char . $char;
- } else {
- return $char;
- }
-
- case '%':
-
- // This is a comment - jump over it!
-
- $pos = $c->offset;
- while(1) {
- $match = preg_match("/(\r\n|\r|\n)/", $c->buffer, $m, PREG_OFFSET_CAPTURE, $pos);
- if ($match === 0) {
- if (!$c->increase_length()) {
- return false;
- } else {
- continue;
- }
- }
-
- $c->offset = $m[0][1]+strlen($m[0][0]);
-
- return $this->pdf_read_token($c);
- }
-
- default:
-
- // This is "another" type of token (probably
- // a dictionary entry or a numeric value)
- // Find the end and return it.
-
- if (!$c->ensure_content()) {
- return false;
- }
-
- while(1) {
-
- // Determine the length of the token
-
- $pos = strcspn($c->buffer, " %[]<>()\r\n\t/", $c->offset);
-
- if ($c->offset + $pos <= $c->length - 1) {
- break;
- } else {
- // If the script reaches this point,
- // the token may span beyond the end
- // of the current buffer. Therefore,
- // we increase the size of the buffer
- // and try again--just to be safe.
-
- $c->increase_length();
- }
- }
-
- $result = substr($c->buffer, $c->offset - 1, $pos + 1);
-
- $c->offset += $pos;
- return $result;
- }
- }
- }
- }