Passed
Pull Request — master (#377)
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unknown
02:34
created

RawDataParser::__construct()   A

Complexity

Conditions 1
Paths 1

Size

Total Lines 6
Code Lines 2

Duplication

Lines 0
Ratio 0 %

Code Coverage

Tests 3
CRAP Score 1

Importance

Changes 1
Bugs 0 Features 1
Metric Value
cc 1
eloc 2
c 1
b 0
f 1
nc 1
nop 1
dl 0
loc 6
ccs 3
cts 3
cp 1
crap 1
rs 10
1
<?php
2
3
/**
4
 * This file is based on code of tecnickcom/TCPDF PDF library.
5
 *
6
 * Original author Nicola Asuni ([email protected]) and
7
 * contributors (https://github.com/tecnickcom/TCPDF/graphs/contributors).
8
 *
9
 * @see https://github.com/tecnickcom/TCPDF
10
 *
11
 * Original code was licensed on the terms of the LGPL v3.
12
 *
13
 * ------------------------------------------------------------------------------
14
 *
15
 * @file This file is part of the PdfParser library.
16
 *
17
 * @author  Konrad Abicht <[email protected]>
18
 * @date    2020-01-06
19
 *
20
 * @license LGPLv3
21
 * @url     <https://github.com/smalot/pdfparser>
22
 *
23
 *  PdfParser is a pdf library written in PHP, extraction oriented.
24
 *  Copyright (C) 2017 - Sébastien MALOT <[email protected]>
25
 *
26
 *  This program is free software: you can redistribute it and/or modify
27
 *  it under the terms of the GNU Lesser General Public License as published by
28
 *  the Free Software Foundation, either version 3 of the License, or
29
 *  (at your option) any later version.
30
 *
31
 *  This program is distributed in the hope that it will be useful,
32
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
33
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
34
 *  GNU Lesser General Public License for more details.
35
 *
36
 *  You should have received a copy of the GNU Lesser General Public License
37
 *  along with this program.
38
 *  If not, see <http://www.pdfparser.org/sites/default/LICENSE.txt>.
39
 */
40
41
namespace Smalot\PdfParser\RawData;
42
43
use Exception;
44
45
class RawDataParser
46
{
47
    /**
48
     * Configuration array.
49
     */
50
    protected $cfg = [
51
        // if `true` ignore filter decoding errors
52
        'ignore_filter_decoding_errors' => true,
53
        // if `true` ignore missing filter decoding errors
54
        'ignore_missing_filter_decoders' => true,
55
    ];
56
57
    protected $filterHelper;
58
    protected $objects;
59
60
    /**
61
     * @param array $cfg Configuration array, default is []
62
     */
63 26
    public function __construct($cfg = [])
64
    {
65
        // merge given array with default values
66 26
        $this->cfg = array_merge($this->cfg, $cfg);
67
68 26
        $this->filterHelper = new FilterHelper();
69 26
    }
70
71
    /**
72
     * Decode the specified stream.
73
     *
74
     * @param string $pdfData PDF data
75
     * @param array  $xref
76
     * @param array  $sdic    Stream's dictionary array
77
     * @param string $stream  Stream to decode
78
     *
79
     * @return array containing decoded stream data and remaining filters
80
     */
81 24
    protected function decodeStream($pdfData, $xref, $sdic, $stream)
82
    {
83
        // get stream length and filters
84 24
        $slength = \strlen($stream);
85 24
        if ($slength <= 0) {
86
            return ['', []];
87
        }
88 24
        $filters = [];
89 24
        foreach ($sdic as $k => $v) {
90 24
            if ('/' == $v[0]) {
91 24
                if (('Length' == $v[1]) && (isset($sdic[($k + 1)])) && ('numeric' == $sdic[($k + 1)][0])) {
92
                    // get declared stream length
93 24
                    $declength = (int) ($sdic[($k + 1)][1]);
94 24
                    if ($declength < $slength) {
95 24
                        $stream = substr($stream, 0, $declength);
96 24
                        $slength = $declength;
97
                    }
98 24
                } elseif (('Filter' == $v[1]) && (isset($sdic[($k + 1)]))) {
99
                    // resolve indirect object
100 24
                    $objval = $this->getObjectVal($pdfData, $xref, $sdic[($k + 1)]);
101 24
                    if ('/' == $objval[0]) {
102
                        // single filter
103 24
                        $filters[] = $objval[1];
104 1
                    } elseif ('[' == $objval[0]) {
105
                        // array of filters
106 1
                        foreach ($objval[1] as $flt) {
107 1
                            if ('/' == $flt[0]) {
108 1
                                $filters[] = $flt[1];
109
                            }
110
                        }
111
                    }
112
                }
113
            }
114
        }
115
116
        // decode the stream
117 24
        $remaining_filters = [];
118 24
        foreach ($filters as $filter) {
119 24
            if (\in_array($filter, $this->filterHelper->getAvailableFilters())) {
120
                try {
121 24
                    $stream = $this->filterHelper->decodeFilter($filter, $stream);
122 1
                } catch (Exception $e) {
123 1
                    $emsg = $e->getMessage();
124 1
                    if ((('~' == $emsg[0]) && !$this->cfg['ignore_missing_filter_decoders'])
125 1
                        || (('~' != $emsg[0]) && !$this->cfg['ignore_filter_decoding_errors'])
126
                    ) {
127 24
                        throw new Exception($e->getMessage());
128
                    }
129
                }
130
            } else {
131
                // add missing filter to array
132 3
                $remaining_filters[] = $filter;
133
            }
134
        }
135
136 24
        return [$stream, $remaining_filters];
137
    }
138
139
    /**
140
     * Decode the Cross-Reference section
141
     *
142
     * @param string $pdfData   PDF data
143
     * @param int    $startxref Offset at which the xref section starts (position of the 'xref' keyword)
144
     * @param array  $xref      Previous xref array (if any)
145
     *
146
     * @return array containing xref and trailer data
147
     */
148 20
    protected function decodeXref($pdfData, $startxref, $xref = [])
149
    {
150 20
        $startxref += 4; // 4 is the length of the word 'xref'
151
        // 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)
152 20
        $offset = $startxref + strspn($pdfData, "\x00\x09\x0a\x0c\x0d\x20", $startxref);
153
        // initialize object number
154 20
        $obj_num = 0;
155
        // search for cross-reference entries or subsection
156 20
        while (preg_match('/([0-9]+)[\x20]([0-9]+)[\x20]?([nf]?)(\r\n|[\x20]?[\r\n])/', $pdfData, $matches, PREG_OFFSET_CAPTURE, $offset) > 0) {
157 20
            if ($matches[0][1] != $offset) {
158
                // we are on another section
159 5
                break;
160
            }
161 20
            $offset += \strlen($matches[0][0]);
162 20
            if ('n' == $matches[3][0]) {
163
                // create unique object index: [object number]_[generation number]
164 20
                $index = $obj_num.'_'.(int) ($matches[2][0]);
165
                // check if object already exist
166 20
                if (!isset($xref['xref'][$index])) {
167
                    // store object offset position
168 20
                    $xref['xref'][$index] = (int) ($matches[1][0]);
169
                }
170 20
                ++$obj_num;
171 20
            } elseif ('f' == $matches[3][0]) {
172 20
                ++$obj_num;
173
            } else {
174
                // object number (index)
175 20
                $obj_num = (int) ($matches[1][0]);
176
            }
177
        }
178
        // get trailer data
179 20
        if (preg_match('/trailer[\s]*<<(.*)>>/isU', $pdfData, $matches, PREG_OFFSET_CAPTURE, $offset) > 0) {
180 20
            $trailer_data = $matches[1][0];
181 20
            if (!isset($xref['trailer']) || empty($xref['trailer'])) {
182
                // get only the last updated version
183 20
                $xref['trailer'] = [];
184
                // parse trailer_data
185 20
                if (preg_match('/Size[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) {
186 20
                    $xref['trailer']['size'] = (int) ($matches[1]);
187
                }
188 20
                if (preg_match('/Root[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
189 20
                    $xref['trailer']['root'] = (int) ($matches[1]).'_'.(int) ($matches[2]);
190
                }
191 20
                if (preg_match('/Encrypt[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
192
                    $xref['trailer']['encrypt'] = (int) ($matches[1]).'_'.(int) ($matches[2]);
193
                }
194 20
                if (preg_match('/Info[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
195 20
                    $xref['trailer']['info'] = (int) ($matches[1]).'_'.(int) ($matches[2]);
196
                }
197 20
                if (preg_match('/ID[\s]*[\[][\s]*[<]([^>]*)[>][\s]*[<]([^>]*)[>]/i', $trailer_data, $matches) > 0) {
198 19
                    $xref['trailer']['id'] = [];
199 19
                    $xref['trailer']['id'][0] = $matches[1];
200 19
                    $xref['trailer']['id'][1] = $matches[2];
201
                }
202
            }
203 20
            if (preg_match('/Prev[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) {
204
                // get previous xref
205 20
                $xref = $this->getXrefData($pdfData, (int) ($matches[1]), $xref);
206
            }
207
        } else {
208
            throw new Exception('Unable to find trailer');
209
        }
210
211 20
        return $xref;
212
    }
213
214
    /**
215
     * Decode the Cross-Reference Stream section
216
     *
217
     * @param string $pdfData   PDF data
218
     * @param int    $startxref Offset at which the xref section starts
219
     * @param array  $xref      Previous xref array (if any)
220
     *
221
     * @return array containing xref and trailer data
222
     *
223
     * @throws Exception if unknown PNG predictor detected
224
     */
225 5
    protected function decodeXrefStream($pdfData, $startxref, $xref = [])
226
    {
227
        // try to read Cross-Reference Stream
228 5
        $xrefobj = $this->getRawObject($pdfData, $startxref);
229 5
        $xrefcrs = $this->getIndirectObject($pdfData, $xref, $xrefobj[1], $startxref, true);
230 5
        if (!isset($xref['trailer']) || empty($xref['trailer'])) {
231
            // get only the last updated version
232 5
            $xref['trailer'] = [];
233 5
            $filltrailer = true;
234
        } else {
235 4
            $filltrailer = false;
236
        }
237 5
        if (!isset($xref['xref'])) {
238 5
            $xref['xref'] = [];
239
        }
240 5
        $valid_crs = false;
241 5
        $columns = 0;
242 5
        $sarr = $xrefcrs[0][1];
243 5
        if (!\is_array($sarr)) {
244
            $sarr = [];
245
        }
246
247 5
        $wb = [];
248
249 5
        foreach ($sarr as $k => $v) {
250
            if (
251 5
                ('/' == $v[0])
252 5
                && ('Type' == $v[1])
253
                && (
254 5
                    isset($sarr[($k + 1)])
255 5
                    && '/' == $sarr[($k + 1)][0]
256 5
                    && 'XRef' == $sarr[($k + 1)][1]
257
                )
258
            ) {
259 5
                $valid_crs = true;
260 5
            } elseif (('/' == $v[0]) && ('Index' == $v[1]) && (isset($sarr[($k + 1)]))) {
261
                // first object number in the subsection
262 4
                $index_first = (int) ($sarr[($k + 1)][1][0][1]);
263 5
            } elseif (('/' == $v[0]) && ('Prev' == $v[1]) && (isset($sarr[($k + 1)]) && ('numeric' == $sarr[($k + 1)][0]))) {
264
                // get previous xref offset
265 4
                $prevxref = (int) ($sarr[($k + 1)][1]);
266 5
            } elseif (('/' == $v[0]) && ('W' == $v[1]) && (isset($sarr[($k + 1)]))) {
267
                // number of bytes (in the decoded stream) of the corresponding field
268 5
                $wb[0] = (int) ($sarr[($k + 1)][1][0][1]);
269 5
                $wb[1] = (int) ($sarr[($k + 1)][1][1][1]);
270 5
                $wb[2] = (int) ($sarr[($k + 1)][1][2][1]);
271 5
            } elseif (('/' == $v[0]) && ('DecodeParms' == $v[1]) && (isset($sarr[($k + 1)][1]))) {
272 5
                $decpar = $sarr[($k + 1)][1];
273 5
                foreach ($decpar as $kdc => $vdc) {
274
                    if (
275 5
                        '/' == $vdc[0]
276 5
                        && 'Columns' == $vdc[1]
277
                        && (
278 5
                            isset($decpar[($kdc + 1)])
279 5
                            && 'numeric' == $decpar[($kdc + 1)][0]
280
                        )
281
                    ) {
282 5
                        $columns = (int) ($decpar[($kdc + 1)][1]);
283
                    } elseif (
284 5
                        '/' == $vdc[0]
285 5
                        && 'Predictor' == $vdc[1]
286
                        && (
287 5
                            isset($decpar[($kdc + 1)])
288 5
                            && 'numeric' == $decpar[($kdc + 1)][0]
289
                        )
290
                    ) {
291 5
                        $predictor = (int) ($decpar[($kdc + 1)][1]);
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292
                    }
293
                }
294 5
            } elseif ($filltrailer) {
295 5
                if (('/' == $v[0]) && ('Size' == $v[1]) && (isset($sarr[($k + 1)]) && ('numeric' == $sarr[($k + 1)][0]))) {
296 5
                    $xref['trailer']['size'] = $sarr[($k + 1)][1];
297 5
                } elseif (('/' == $v[0]) && ('Root' == $v[1]) && (isset($sarr[($k + 1)]) && ('objref' == $sarr[($k + 1)][0]))) {
298 5
                    $xref['trailer']['root'] = $sarr[($k + 1)][1];
299 5
                } elseif (('/' == $v[0]) && ('Info' == $v[1]) && (isset($sarr[($k + 1)]) && ('objref' == $sarr[($k + 1)][0]))) {
300 5
                    $xref['trailer']['info'] = $sarr[($k + 1)][1];
301 5
                } elseif (('/' == $v[0]) && ('Encrypt' == $v[1]) && (isset($sarr[($k + 1)]) && ('objref' == $sarr[($k + 1)][0]))) {
302
                    $xref['trailer']['encrypt'] = $sarr[($k + 1)][1];
303 5
                } elseif (('/' == $v[0]) && ('ID' == $v[1]) && (isset($sarr[($k + 1)]))) {
304 5
                    $xref['trailer']['id'] = [];
305 5
                    $xref['trailer']['id'][0] = $sarr[($k + 1)][1][0][1];
306 5
                    $xref['trailer']['id'][1] = $sarr[($k + 1)][1][1][1];
307
                }
308
            }
309
        }
310
311
        // decode data
312 5
        if ($valid_crs && isset($xrefcrs[1][3][0])) {
313
            // number of bytes in a row
314 5
            $rowlen = ($columns + 1);
315
            // convert the stream into an array of integers
316 5
            $sdata = unpack('C*', $xrefcrs[1][3][0]);
317
            // split the rows
318 5
            $sdata = array_chunk($sdata, $rowlen);
0 ignored issues
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Bug introduced by
It seems like $sdata can also be of type false; however, parameter $input of array_chunk() does only seem to accept array, maybe add an additional type check? ( Ignorable by Annotation )

If this is a false-positive, you can also ignore this issue in your code via the ignore-type  annotation

318
            $sdata = array_chunk(/** @scrutinizer ignore-type */ $sdata, $rowlen);
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319
            // initialize decoded array
320 5
            $ddata = [];
321
            // initialize first row with zeros
322 5
            $prev_row = array_fill(0, $rowlen, 0);
323
            // for each row apply PNG unpredictor
324 5
            foreach ($sdata as $k => $row) {
325
                // initialize new row
326 5
                $ddata[$k] = [];
327
                // get PNG predictor value
328 5
                $predictor = (10 + $row[0]);
329
                // for each byte on the row
330 5
                for ($i = 1; $i <= $columns; ++$i) {
331
                    // new index
332 5
                    $j = ($i - 1);
333 5
                    $row_up = $prev_row[$j];
334 5
                    if (1 == $i) {
335 5
                        $row_left = 0;
336 5
                        $row_upleft = 0;
337
                    } else {
338 5
                        $row_left = $row[($i - 1)];
339 5
                        $row_upleft = $prev_row[($j - 1)];
340
                    }
341 5
                    switch ($predictor) {
342 5
                        case 10:  // PNG prediction (on encoding, PNG None on all rows)
343
                            $ddata[$k][$j] = $row[$i];
344
                            break;
345
346 5
                        case 11:  // PNG prediction (on encoding, PNG Sub on all rows)
347
                            $ddata[$k][$j] = (($row[$i] + $row_left) & 0xff);
348
                            break;
349
350 5
                        case 12:  // PNG prediction (on encoding, PNG Up on all rows)
351 5
                            $ddata[$k][$j] = (($row[$i] + $row_up) & 0xff);
352 5
                            break;
353
354
                        case 13:  // PNG prediction (on encoding, PNG Average on all rows)
355
                            $ddata[$k][$j] = (($row[$i] + (($row_left + $row_up) / 2)) & 0xff);
356
                            break;
357
358
                        case 14:  // PNG prediction (on encoding, PNG Paeth on all rows)
359
                            // initial estimate
360
                            $p = ($row_left + $row_up - $row_upleft);
361
                            // distances
362
                            $pa = abs($p - $row_left);
363
                            $pb = abs($p - $row_up);
364
                            $pc = abs($p - $row_upleft);
365
                            $pmin = min($pa, $pb, $pc);
366
                            // return minimum distance
367
                            switch ($pmin) {
368
                                case $pa:
369
                                    $ddata[$k][$j] = (($row[$i] + $row_left) & 0xff);
370
                                    break;
371
372
                                case $pb:
373
                                    $ddata[$k][$j] = (($row[$i] + $row_up) & 0xff);
374
                                    break;
375
376
                                case $pc:
377
                                    $ddata[$k][$j] = (($row[$i] + $row_upleft) & 0xff);
378
                                    break;
379
                            }
380
                            break;
381
382
                        default:  // PNG prediction (on encoding, PNG optimum)
383
                            throw new Exception('Unknown PNG predictor');
384
                    }
385
                }
386 5
                $prev_row = $ddata[$k];
387
            } // end for each row
388
            // complete decoding
389 5
            $sdata = [];
390
            // for every row
391 5
            foreach ($ddata as $k => $row) {
392
                // initialize new row
393 5
                $sdata[$k] = [0, 0, 0];
394 5
                if (0 == $wb[0]) {
395
                    // default type field
396
                    $sdata[$k][0] = 1;
397
                }
398 5
                $i = 0; // count bytes in the row
399
                // for every column
400 5
                for ($c = 0; $c < 3; ++$c) {
401
                    // for every byte on the column
402 5
                    for ($b = 0; $b < $wb[$c]; ++$b) {
403 5
                        if (isset($row[$i])) {
404 5
                            $sdata[$k][$c] += ($row[$i] << (($wb[$c] - 1 - $b) * 8));
405
                        }
406 5
                        ++$i;
407
                    }
408
                }
409
            }
410 5
            $ddata = [];
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Unused Code introduced by
The assignment to $ddata is dead and can be removed.
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411
            // fill xref
412 5
            if (isset($index_first)) {
413 4
                $obj_num = $index_first;
414
            } else {
415 5
                $obj_num = 0;
416
            }
417 5
            foreach ($sdata as $k => $row) {
418 5
                switch ($row[0]) {
419 5
                    case 0:  // (f) linked list of free objects
420 5
                            break;
421
422 5
                    case 1:  // (n) objects that are in use but are not compressed
423
                            // create unique object index: [object number]_[generation number]
424 5
                            $index = $obj_num.'_'.$row[2];
425
                            // check if object already exist
426 5
                            if (!isset($xref['xref'][$index])) {
427
                                // store object offset position
428 5
                                $xref['xref'][$index] = $row[1];
429
                            }
430 5
                            break;
431
432 5
                    case 2:  // compressed objects
433
                            // $row[1] = object number of the object stream in which this object is stored
434
                            // $row[2] = index of this object within the object stream
435 5
                            $index = $row[1].'_0_'.$row[2];
436 5
                            $xref['xref'][$index] = -1;
437 5
                            break;
438
439
                    default:  // null objects
440
                            break;
441
                }
442 5
                ++$obj_num;
443
            }
444
        } // end decoding data
445 5
        if (isset($prevxref)) {
446
            // get previous xref
447 4
            $xref = $this->getXrefData($pdfData, $prevxref, $xref);
448
        }
449
450 5
        return $xref;
451
    }
452
453
    /**
454
     * Get content of indirect object.
455
     *
456
     * @param string $pdfData  PDF data
457
     * @param array  $xref
458
     * @param string $objRef   Object number and generation number separated by underscore character
459
     * @param int    $offset   Object offset
460
     * @param bool   $decoding If true decode streams
461
     *
462
     * @return array containing object data
463
     *
464
     * @throws Exception if invalid object reference found
465
     */
466 24
    protected function getIndirectObject($pdfData, $xref, $objRef, $offset = 0, $decoding = true)
467
    {
468
        /*
469
         * build indirect object header
470
         */
471
        // $objHeader = "[object number] [generation number] obj"
472 24
        $objRefArr = explode('_', $objRef);
473 24
        if (2 !== \count($objRefArr)) {
474
            throw new Exception('Invalid object reference for $obj.');
475
        }
476 24
        $objHeader = $objRefArr[0].' '.$objRefArr[1].' obj';
477
478
        /*
479
         * check if we are in position
480
         */
481
        // ignore whitespace characters at offset (NUL, HT, LF, FF, CR, SP)
482 24
        $offset += strspn($pdfData, "\0\t\n\f\r ", $offset);
483
        // ignore leading zeros for object number
484 24
        $offset += strspn($pdfData, '0', $offset);
485 24
        if (substr($pdfData, $offset, \strlen($objHeader)) !== $objHeader) {
486
            // an indirect reference to an undefined object shall be considered a reference to the null object
487 2
            return ['null', 'null', $offset];
488
        }
489
490
        /*
491
         * get content
492
         */
493
        // starting position of object content
494 24
        $offset += \strlen($objHeader);
495 24
        $objContentArr = [];
496 24
        $i = 0; // object main index
497
        do {
498 24
            $oldOffset = $offset;
499
            // get element
500 24
            $element = $this->getRawObject($pdfData, $offset);
501 24
            $offset = $element[2];
502
            // decode stream using stream's dictionary information
503 24
            if ($decoding && ('stream' === $element[0]) && (isset($objContentArr[($i - 1)][0])) && ('<<' === $objContentArr[($i - 1)][0])) {
504 24
                $element[3] = $this->decodeStream($pdfData, $xref, $objContentArr[($i - 1)][1], $element[1]);
505
            }
506 24
            $objContentArr[$i] = $element;
507 24
            ++$i;
508 24
        } while (('endobj' !== $element[0]) && ($offset !== $oldOffset));
509
        // remove closing delimiter
510 24
        array_pop($objContentArr);
511
512
        /*
513
         * return raw object content
514
         */
515 24
        return $objContentArr;
516
    }
517
518
    /**
519
     * Get the content of object, resolving indirect object reference if necessary.
520
     *
521
     * @param string $pdfData PDF data
522
     * @param array  $obj     Object value
523
     *
524
     * @return array containing object data
525
     *
526
     * @throws Exception
527
     */
528 24
    protected function getObjectVal($pdfData, $xref, $obj)
529
    {
530 24
        if ('objref' == $obj[0]) {
531
            // reference to indirect object
532
            if (isset($this->objects[$obj[1]])) {
533
                // this object has been already parsed
534
                return $this->objects[$obj[1]];
535
            } elseif (isset($xref[$obj[1]])) {
536
                // parse new object
537
                $this->objects[$obj[1]] = $this->getIndirectObject($pdfData, $xref, $obj[1], $xref[$obj[1]], false);
538
539
                return $this->objects[$obj[1]];
540
            }
541
        }
542
543 24
        return $obj;
544
    }
545
546
    /**
547
     * Get object type, raw value and offset to next object
548
     *
549
     * @param int $offset Object offset
550
     *
551
     * @return array containing object type, raw value and offset to next object
552
     */
553 24
    protected function getRawObject($pdfData, $offset = 0)
554
    {
555 24
        $objtype = ''; // object type to be returned
556 24
        $objval = ''; // object value to be returned
557
558
        /*
559
         * skip initial white space chars:
560
         *      \x00 null (NUL)
561
         *      \x09 horizontal tab (HT)
562
         *      \x0A line feed (LF)
563
         *      \x0C form feed (FF)
564
         *      \x0D carriage return (CR)
565
         *      \x20 space (SP)
566
         */
567 24
        $offset += strspn($pdfData, "\x00\x09\x0a\x0c\x0d\x20", $offset);
568
569
        // get first char
570 24
        $char = $pdfData[$offset];
571
        // get object type
572 24
        switch ($char) {
573 24
            case '%':  // \x25 PERCENT SIGN
574
                    // skip comment and search for next token
575
                    $next = strcspn($pdfData, "\r\n", $offset);
576
                    if ($next > 0) {
577
                        $offset += $next;
578
579
                        return $this->getRawObject($pdfData, $offset);
580
                    }
581
                    break;
582
583 24
            case '/':  // \x2F SOLIDUS
584
                    // name object
585 24
                    $objtype = $char;
586 24
                    ++$offset;
587 24
                    $pregResult = preg_match(
588 24
                        '/^([^\x00\x09\x0a\x0c\x0d\x20\s\x28\x29\x3c\x3e\x5b\x5d\x7b\x7d\x2f\x25]+)/',
589 24
                        substr($pdfData, $offset, 256),
590
                        $matches
591
                    );
592 24
                    if (1 == $pregResult) {
593 24
                        $objval = $matches[1]; // unescaped value
594 24
                        $offset += \strlen($objval);
595
                    }
596 24
                    break;
597
598 24
            case '(':   // \x28 LEFT PARENTHESIS
599 24
            case ')':  // \x29 RIGHT PARENTHESIS
600
                    // literal string object
601 22
                    $objtype = $char;
602 22
                    ++$offset;
603 22
                    $strpos = $offset;
604 22
                    if ('(' == $char) {
605 22
                        $open_bracket = 1;
606 22
                        while ($open_bracket > 0) {
607 22
                            if (!isset($pdfData[$strpos])) {
608
                                break;
609
                            }
610 22
                            $ch = $pdfData[$strpos];
611 22
                            switch ($ch) {
612 22
                                case '\\':  // REVERSE SOLIDUS (5Ch) (Backslash)
613
                                        // skip next character
614 15
                                        ++$strpos;
615 15
                                        break;
616
617 22
                                case '(':  // LEFT PARENHESIS (28h)
618
                                        ++$open_bracket;
619
                                        break;
620
621 22
                                case ')':  // RIGHT PARENTHESIS (29h)
622 22
                                        --$open_bracket;
623 22
                                        break;
624
                            }
625 22
                            ++$strpos;
626
                        }
627 22
                        $objval = substr($pdfData, $offset, ($strpos - $offset - 1));
628 22
                        $offset = $strpos;
629
                    }
630 22
                    break;
631
632 24
            case '[':   // \x5B LEFT SQUARE BRACKET
633 24
            case ']':  // \x5D RIGHT SQUARE BRACKET
634
                // array object
635 24
                $objtype = $char;
636 24
                ++$offset;
637 24
                if ('[' == $char) {
638
                    // get array content
639 24
                    $objval = [];
640
                    do {
641 24
                        $oldOffset = $offset;
642
                        // get element
643 24
                        $element = $this->getRawObject($pdfData, $offset);
644 24
                        $offset = $element[2];
645 24
                        $objval[] = $element;
646 24
                    } while ((']' != $element[0]) && ($offset != $oldOffset));
647
                    // remove closing delimiter
648 24
                    array_pop($objval);
649
                }
650 24
                break;
651
652 24
            case '<':  // \x3C LESS-THAN SIGN
653 24
            case '>':  // \x3E GREATER-THAN SIGN
654 24
                if (isset($pdfData[($offset + 1)]) && ($pdfData[($offset + 1)] == $char)) {
655
                    // dictionary object
656 24
                    $objtype = $char.$char;
657 24
                    $offset += 2;
658 24
                    if ('<' == $char) {
659
                        // get array content
660 24
                        $objval = [];
661
                        do {
662 24
                            $oldOffset = $offset;
663
                            // get element
664 24
                            $element = $this->getRawObject($pdfData, $offset);
665 24
                            $offset = $element[2];
666 24
                            $objval[] = $element;
667 24
                        } while (('>>' != $element[0]) && ($offset != $oldOffset));
668
                        // remove closing delimiter
669 24
                        array_pop($objval);
670
                    }
671
                } else {
672
                    // hexadecimal string object
673 8
                    $objtype = $char;
674 8
                    ++$offset;
675 8
                    $pregResult = preg_match(
676 8
                            '/^([0-9A-Fa-f\x09\x0a\x0c\x0d\x20]+)>/iU',
677 8
                            substr($pdfData, $offset),
678
                            $matches
679
                        );
680 8
                    if (('<' == $char) && 1 == $pregResult) {
681
                        // remove white space characters
682 8
                        $objval = strtr($matches[1], "\x09\x0a\x0c\x0d\x20", '');
683 8
                        $offset += \strlen($matches[0]);
684
                    } elseif (false !== ($endpos = strpos($pdfData, '>', $offset))) {
685
                        $offset = $endpos + 1;
686
                    }
687
                }
688 24
                    break;
689
690
            default:
691 24
                    if ('endobj' == substr($pdfData, $offset, 6)) {
692
                        // indirect object
693 24
                        $objtype = 'endobj';
694 24
                        $offset += 6;
695 24
                    } elseif ('null' == substr($pdfData, $offset, 4)) {
696
                        // null object
697 3
                        $objtype = 'null';
698 3
                        $offset += 4;
699 3
                        $objval = 'null';
700 24
                    } elseif ('true' == substr($pdfData, $offset, 4)) {
701
                        // boolean true object
702 7
                        $objtype = 'boolean';
703 7
                        $offset += 4;
704 7
                        $objval = 'true';
705 24
                    } elseif ('false' == substr($pdfData, $offset, 5)) {
706
                        // boolean false object
707 2
                        $objtype = 'boolean';
708 2
                        $offset += 5;
709 2
                        $objval = 'false';
710 24
                    } elseif ('stream' == substr($pdfData, $offset, 6)) {
711
                        // start stream object
712 24
                        $objtype = 'stream';
713 24
                        $offset += 6;
714 24
                        if (1 == preg_match('/^([\r]?[\n])/isU', substr($pdfData, $offset), $matches)) {
715 24
                            $offset += \strlen($matches[0]);
716 24
                            $pregResult = preg_match(
717 24
                                '/(endstream)[\x09\x0a\x0c\x0d\x20]/isU',
718 24
                                substr($pdfData, $offset),
719
                                $matches,
720 24
                                PREG_OFFSET_CAPTURE
721
                            );
722 24
                            if (1 == $pregResult) {
723 24
                                $objval = substr($pdfData, $offset, $matches[0][1]);
724 24
                                $offset += $matches[1][1];
725
                            }
726
                        }
727 24
                    } elseif ('endstream' == substr($pdfData, $offset, 9)) {
728
                        // end stream object
729 24
                        $objtype = 'endstream';
730 24
                        $offset += 9;
731 24
                    } elseif (1 == preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+R/iU', substr($pdfData, $offset, 33), $matches)) {
732
                        // indirect object reference
733 24
                        $objtype = 'objref';
734 24
                        $offset += \strlen($matches[0]);
735 24
                        $objval = (int) ($matches[1]).'_'.(int) ($matches[2]);
736 24
                    } elseif (1 == preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+obj/iU', substr($pdfData, $offset, 33), $matches)) {
737
                        // object start
738 5
                        $objtype = 'obj';
739 5
                        $objval = (int) ($matches[1]).'_'.(int) ($matches[2]);
740 5
                        $offset += \strlen($matches[0]);
741 24
                    } elseif (($numlen = strspn($pdfData, '+-.0123456789', $offset)) > 0) {
742
                        // numeric object
743 24
                        $objtype = 'numeric';
744 24
                        $objval = substr($pdfData, $offset, $numlen);
745 24
                        $offset += $numlen;
746
                    }
747 24
                    break;
748
        }
749
750 24
        return [$objtype, $objval, $offset];
751
    }
752
753
    /**
754
     * Get Cross-Reference (xref) table and trailer data from PDF document data.
755
     *
756
     * @param string $pdfData
757
     * @param int    $offset  xref offset (if know)
758
     * @param array  $xref    previous xref array (if any)
759
     *
760
     * @return array containing xref and trailer data
761
     *
762
     * @throws Exception if it was unable to find startxref
763
     * @throws Exception if it was unable to find xref
764
     */
765 25
    protected function getXrefData($pdfData, $offset = 0, $xref = [])
766
    {
767 25
        $startxrefPreg = preg_match(
768 25
            '/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i',
769
            $pdfData,
770
            $matches,
771 25
            PREG_OFFSET_CAPTURE,
772
            $offset
773
        );
774
775 25
        if (0 == $offset) {
776
            // find last startxref
777 25
            $pregResult = preg_match_all(
778 25
                '/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i',
779
                $pdfData, $matches,
780 25
                PREG_SET_ORDER,
781
                $offset
782
            );
783 25
            if (0 == $pregResult) {
784
                throw new Exception('Unable to find startxref');
785
            }
786 25
            $matches = array_pop($matches);
787 25
            $startxref = $matches[1];
788 8
        } elseif (strpos($pdfData, 'xref', $offset) == $offset) {
789
            // Already pointing at the xref table
790 5
            $startxref = $offset;
791 4
        } elseif (preg_match('/([0-9]+[\s][0-9]+[\s]obj)/i', $pdfData, $matches, PREG_OFFSET_CAPTURE, $offset)) {
792
            // Cross-Reference Stream object
793 4
            $startxref = $offset;
794
        } elseif ($startxrefPreg) {
795
            // startxref found
796
            $startxref = $matches[1][0];
797
        } else {
798
            throw new Exception('Unable to find startxref');
799
        }
800
801 25
        if ($startxref > \strlen($pdfData)) {
802 1
            throw new Exception('Unable to find xref (PDF corrupted?)');
803
        }
804
805
        // check xref position
806 24
        if (strpos($pdfData, 'xref', $startxref) == $startxref) {
807
            // Cross-Reference
808 20
            $xref = $this->decodeXref($pdfData, $startxref, $xref);
809
        } else {
810
            // Cross-Reference Stream
811 5
            $xref = $this->decodeXrefStream($pdfData, $startxref, $xref);
812
        }
813 24
        if (empty($xref)) {
814
            throw new Exception('Unable to find xref');
815
        }
816
817 24
        return $xref;
818
    }
819
820
    /**
821
     * Parses PDF data and returns extracted data as array.
822
     *
823
     * @param string $data PDF data to parse
824
     *
825
     * @return array array of parsed PDF document objects
826
     *
827
     * @throws Exception if empty PDF data given
828
     * @throws Exception if PDF data missing %PDF header
829
     */
830 25
    public function parseData($data)
831
    {
832 25
        if (empty($data)) {
833
            throw new Exception('Empty PDF data given.');
834
        }
835
        // find the pdf header starting position
836 25
        if (false === ($trimpos = strpos($data, '%PDF-'))) {
837
            throw new Exception('Invalid PDF data: missing %PDF header.');
838
        }
839
840
        // get PDF content string
841 25
        $pdfData = substr($data, $trimpos);
842
843
        // get xref and trailer data
844 25
        $xref = $this->getXrefData($pdfData);
845
846
        // parse all document objects
847 24
        $objects = [];
848 24
        foreach ($xref['xref'] as $obj => $offset) {
849 24
            if (!isset($objects[$obj]) && ($offset > 0)) {
850
                // decode objects with positive offset
851 24
                $objects[$obj] = $this->getIndirectObject($pdfData, $xref, $obj, $offset, true);
852
            }
853
        }
854
855 24
        return [$xref, $objects];
856
    }
857
}
858