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ef416fc2 | 1 | //======================================================================== |
2 | // | |
3 | // XRef.cc | |
4 | // | |
5 | // Copyright 1996-2003 Glyph & Cog, LLC | |
6 | // | |
7 | //======================================================================== | |
8 | ||
9 | #include <config.h> | |
10 | ||
11 | #ifdef USE_GCC_PRAGMAS | |
12 | #pragma implementation | |
13 | #endif | |
14 | ||
15 | #include <stdlib.h> | |
16 | #include <stddef.h> | |
17 | #include <string.h> | |
18 | #include <ctype.h> | |
19 | #include "gmem.h" | |
20 | #include "Object.h" | |
21 | #include "Stream.h" | |
22 | #include "Lexer.h" | |
23 | #include "Parser.h" | |
24 | #include "Dict.h" | |
25 | #include "Error.h" | |
26 | #include "ErrorCodes.h" | |
27 | #include "XRef.h" | |
28 | ||
29 | //------------------------------------------------------------------------ | |
30 | ||
31 | #define xrefSearchSize 1024 // read this many bytes at end of file | |
32 | // to look for 'startxref' | |
33 | ||
34 | //------------------------------------------------------------------------ | |
35 | // Permission bits | |
36 | //------------------------------------------------------------------------ | |
37 | ||
38 | #define permPrint (1<<2) | |
39 | #define permChange (1<<3) | |
40 | #define permCopy (1<<4) | |
41 | #define permNotes (1<<5) | |
42 | #define defPermFlags 0xfffc | |
43 | ||
44 | //------------------------------------------------------------------------ | |
45 | // ObjectStream | |
46 | //------------------------------------------------------------------------ | |
47 | ||
48 | class ObjectStream { | |
49 | public: | |
50 | ||
51 | // Create an object stream, using object number <objStrNum>, | |
52 | // generation 0. | |
53 | ObjectStream(XRef *xref, int objStrNumA); | |
54 | ||
55 | ~ObjectStream(); | |
56 | ||
57 | // Return the object number of this object stream. | |
58 | int getObjStrNum() { return objStrNum; } | |
59 | ||
60 | // Get the <objIdx>th object from this stream, which should be | |
61 | // object number <objNum>, generation 0. | |
62 | Object *getObject(int objIdx, int objNum, Object *obj); | |
63 | ||
64 | private: | |
65 | ||
66 | int objStrNum; // object number of the object stream | |
67 | int nObjects; // number of objects in the stream | |
68 | Object *objs; // the objects (length = nObjects) | |
69 | int *objNums; // the object numbers (length = nObjects) | |
70 | }; | |
71 | ||
72 | ObjectStream::ObjectStream(XRef *xref, int objStrNumA) { | |
73 | Stream *str; | |
74 | Parser *parser; | |
75 | int *offsets; | |
76 | Object objStr, obj1, obj2; | |
77 | int first, i; | |
78 | ||
79 | objStrNum = objStrNumA; | |
80 | nObjects = 0; | |
81 | objs = NULL; | |
82 | objNums = NULL; | |
83 | ||
84 | if (!xref->fetch(objStrNum, 0, &objStr)->isStream()) { | |
85 | goto err1; | |
86 | } | |
87 | ||
88 | if (!objStr.streamGetDict()->lookup("N", &obj1)->isInt()) { | |
89 | obj1.free(); | |
90 | goto err1; | |
91 | } | |
92 | nObjects = obj1.getInt(); | |
93 | obj1.free(); | |
94 | if (nObjects <= 0) { | |
95 | goto err1; | |
96 | } | |
97 | ||
98 | if (!objStr.streamGetDict()->lookup("First", &obj1)->isInt()) { | |
99 | obj1.free(); | |
100 | goto err1; | |
101 | } | |
102 | first = obj1.getInt(); | |
103 | obj1.free(); | |
104 | if (first < 0) { | |
105 | goto err1; | |
106 | } | |
107 | ||
108 | objs = new Object[nObjects]; | |
109 | objNums = (int *)gmallocn(nObjects, sizeof(int)); | |
110 | offsets = (int *)gmallocn(nObjects, sizeof(int)); | |
111 | ||
112 | // parse the header: object numbers and offsets | |
113 | objStr.streamReset(); | |
114 | obj1.initNull(); | |
115 | str = new EmbedStream(objStr.getStream(), &obj1, gTrue, first); | |
116 | parser = new Parser(xref, new Lexer(xref, str)); | |
117 | for (i = 0; i < nObjects; ++i) { | |
118 | parser->getObj(&obj1); | |
119 | parser->getObj(&obj2); | |
120 | if (!obj1.isInt() || !obj2.isInt()) { | |
121 | obj1.free(); | |
122 | obj2.free(); | |
123 | delete parser; | |
124 | gfree(offsets); | |
125 | goto err1; | |
126 | } | |
127 | objNums[i] = obj1.getInt(); | |
128 | offsets[i] = obj2.getInt(); | |
129 | obj1.free(); | |
130 | obj2.free(); | |
131 | if (objNums[i] < 0 || offsets[i] < 0 || | |
132 | (i > 0 && offsets[i] < offsets[i-1])) { | |
133 | delete parser; | |
134 | gfree(offsets); | |
135 | goto err1; | |
136 | } | |
137 | } | |
138 | while (str->getChar() != EOF) ; | |
139 | delete parser; | |
140 | ||
141 | // skip to the first object - this shouldn't be necessary because | |
142 | // the First key is supposed to be equal to offsets[0], but just in | |
143 | // case... | |
144 | for (i = first; i < offsets[0]; ++i) { | |
145 | objStr.getStream()->getChar(); | |
146 | } | |
147 | ||
148 | // parse the objects | |
149 | for (i = 0; i < nObjects; ++i) { | |
150 | obj1.initNull(); | |
151 | if (i == nObjects - 1) { | |
152 | str = new EmbedStream(objStr.getStream(), &obj1, gFalse, 0); | |
153 | } else { | |
154 | str = new EmbedStream(objStr.getStream(), &obj1, gTrue, | |
155 | offsets[i+1] - offsets[i]); | |
156 | } | |
157 | parser = new Parser(xref, new Lexer(xref, str)); | |
158 | parser->getObj(&objs[i]); | |
159 | while (str->getChar() != EOF) ; | |
160 | delete parser; | |
161 | } | |
162 | ||
163 | gfree(offsets); | |
164 | ||
165 | err1: | |
166 | objStr.free(); | |
167 | return; | |
168 | } | |
169 | ||
170 | ObjectStream::~ObjectStream() { | |
171 | int i; | |
172 | ||
173 | if (objs) { | |
174 | for (i = 0; i < nObjects; ++i) { | |
175 | objs[i].free(); | |
176 | } | |
177 | delete[] objs; | |
178 | } | |
179 | gfree(objNums); | |
180 | } | |
181 | ||
182 | Object *ObjectStream::getObject(int objIdx, int objNum, Object *obj) { | |
183 | if (objIdx < 0 || objIdx >= nObjects || objNum != objNums[objIdx]) { | |
184 | return obj->initNull(); | |
185 | } | |
186 | return objs[objIdx].copy(obj); | |
187 | } | |
188 | ||
189 | //------------------------------------------------------------------------ | |
190 | // XRef | |
191 | //------------------------------------------------------------------------ | |
192 | ||
193 | XRef::XRef(BaseStream *strA) { | |
194 | Guint pos; | |
195 | Object obj; | |
196 | ||
197 | ok = gTrue; | |
198 | errCode = errNone; | |
199 | size = 0; | |
200 | entries = NULL; | |
201 | streamEnds = NULL; | |
202 | streamEndsLen = 0; | |
203 | objStr = NULL; | |
204 | ||
205 | encrypted = gFalse; | |
206 | permFlags = defPermFlags; | |
207 | ownerPasswordOk = gFalse; | |
208 | ||
209 | // read the trailer | |
210 | str = strA; | |
211 | start = str->getStart(); | |
212 | pos = getStartXref(); | |
213 | ||
214 | // if there was a problem with the 'startxref' position, try to | |
215 | // reconstruct the xref table | |
216 | if (pos == 0) { | |
217 | if (!(ok = constructXRef())) { | |
218 | errCode = errDamaged; | |
219 | return; | |
220 | } | |
221 | ||
222 | // read the xref table | |
223 | } else { | |
224 | while (readXRef(&pos)) ; | |
225 | ||
226 | // if there was a problem with the xref table, | |
227 | // try to reconstruct it | |
228 | if (!ok) { | |
229 | if (!(ok = constructXRef())) { | |
230 | errCode = errDamaged; | |
231 | return; | |
232 | } | |
233 | } | |
234 | } | |
235 | ||
236 | // get the root dictionary (catalog) object | |
237 | trailerDict.dictLookupNF("Root", &obj); | |
238 | if (obj.isRef()) { | |
239 | rootNum = obj.getRefNum(); | |
240 | rootGen = obj.getRefGen(); | |
241 | obj.free(); | |
242 | } else { | |
243 | obj.free(); | |
244 | if (!(ok = constructXRef())) { | |
245 | errCode = errDamaged; | |
246 | return; | |
247 | } | |
248 | } | |
249 | ||
250 | // now set the trailer dictionary's xref pointer so we can fetch | |
251 | // indirect objects from it | |
252 | trailerDict.getDict()->setXRef(this); | |
253 | } | |
254 | ||
255 | XRef::~XRef() { | |
256 | gfree(entries); | |
257 | trailerDict.free(); | |
258 | if (streamEnds) { | |
259 | gfree(streamEnds); | |
260 | } | |
261 | if (objStr) { | |
262 | delete objStr; | |
263 | } | |
264 | } | |
265 | ||
266 | // Read the 'startxref' position. | |
267 | Guint XRef::getStartXref() { | |
268 | char buf[xrefSearchSize+1]; | |
269 | char *p; | |
270 | int c, n, i; | |
271 | ||
272 | // read last xrefSearchSize bytes | |
273 | str->setPos(xrefSearchSize, -1); | |
274 | for (n = 0; n < xrefSearchSize; ++n) { | |
275 | if ((c = str->getChar()) == EOF) { | |
276 | break; | |
277 | } | |
278 | buf[n] = c; | |
279 | } | |
280 | buf[n] = '\0'; | |
281 | ||
282 | // find startxref | |
283 | for (i = n - 9; i >= 0; --i) { | |
284 | if (!strncmp(&buf[i], "startxref", 9)) { | |
285 | break; | |
286 | } | |
287 | } | |
288 | if (i < 0) { | |
289 | return 0; | |
290 | } | |
291 | for (p = &buf[i+9]; isspace(*p); ++p) ; | |
292 | lastXRefPos = strToUnsigned(p); | |
293 | ||
294 | return lastXRefPos; | |
295 | } | |
296 | ||
297 | // Read one xref table section. Also reads the associated trailer | |
298 | // dictionary, and returns the prev pointer (if any). | |
299 | GBool XRef::readXRef(Guint *pos) { | |
300 | Parser *parser; | |
301 | Object obj; | |
302 | GBool more; | |
303 | ||
304 | // start up a parser, parse one token | |
305 | obj.initNull(); | |
306 | parser = new Parser(NULL, | |
307 | new Lexer(NULL, | |
308 | str->makeSubStream(start + *pos, gFalse, 0, &obj))); | |
309 | parser->getObj(&obj); | |
310 | ||
311 | // parse an old-style xref table | |
312 | if (obj.isCmd("xref")) { | |
313 | obj.free(); | |
314 | more = readXRefTable(parser, pos); | |
315 | ||
316 | // parse an xref stream | |
317 | } else if (obj.isInt()) { | |
318 | obj.free(); | |
319 | if (!parser->getObj(&obj)->isInt()) { | |
320 | goto err1; | |
321 | } | |
322 | obj.free(); | |
323 | if (!parser->getObj(&obj)->isCmd("obj")) { | |
324 | goto err1; | |
325 | } | |
326 | obj.free(); | |
327 | if (!parser->getObj(&obj)->isStream()) { | |
328 | goto err1; | |
329 | } | |
330 | more = readXRefStream(obj.getStream(), pos); | |
331 | obj.free(); | |
332 | ||
333 | } else { | |
334 | goto err1; | |
335 | } | |
336 | ||
337 | delete parser; | |
338 | return more; | |
339 | ||
340 | err1: | |
341 | obj.free(); | |
342 | delete parser; | |
343 | ok = gFalse; | |
344 | return gFalse; | |
345 | } | |
346 | ||
347 | GBool XRef::readXRefTable(Parser *parser, Guint *pos) { | |
348 | XRefEntry entry; | |
349 | GBool more; | |
350 | Object obj, obj2; | |
351 | Guint pos2; | |
352 | int first, n, newSize, i; | |
353 | ||
354 | while (1) { | |
355 | parser->getObj(&obj); | |
356 | if (obj.isCmd("trailer")) { | |
357 | obj.free(); | |
358 | break; | |
359 | } | |
360 | if (!obj.isInt()) { | |
361 | goto err1; | |
362 | } | |
363 | first = obj.getInt(); | |
364 | obj.free(); | |
365 | if (!parser->getObj(&obj)->isInt()) { | |
366 | goto err1; | |
367 | } | |
368 | n = obj.getInt(); | |
369 | obj.free(); | |
370 | if (first < 0 || n < 0 || first + n < 0) { | |
371 | goto err1; | |
372 | } | |
373 | if (first + n > size) { | |
374 | for (newSize = size ? 2 * size : 1024; | |
375 | first + n > newSize && newSize > 0; | |
376 | newSize <<= 1) ; | |
377 | if (newSize < 0) { | |
378 | goto err1; | |
379 | } | |
380 | entries = (XRefEntry *)greallocn(entries, newSize, sizeof(XRefEntry)); | |
381 | for (i = size; i < newSize; ++i) { | |
382 | entries[i].offset = 0xffffffff; | |
383 | entries[i].type = xrefEntryFree; | |
384 | } | |
385 | size = newSize; | |
386 | } | |
387 | for (i = first; i < first + n; ++i) { | |
388 | if (!parser->getObj(&obj)->isInt()) { | |
389 | goto err1; | |
390 | } | |
391 | entry.offset = (Guint)obj.getInt(); | |
392 | obj.free(); | |
393 | if (!parser->getObj(&obj)->isInt()) { | |
394 | goto err1; | |
395 | } | |
396 | entry.gen = obj.getInt(); | |
397 | obj.free(); | |
398 | parser->getObj(&obj); | |
399 | if (obj.isCmd("n")) { | |
400 | entry.type = xrefEntryUncompressed; | |
401 | } else if (obj.isCmd("f")) { | |
402 | entry.type = xrefEntryFree; | |
403 | } else { | |
404 | goto err1; | |
405 | } | |
406 | obj.free(); | |
407 | if (entries[i].offset == 0xffffffff) { | |
408 | entries[i] = entry; | |
409 | // PDF files of patents from the IBM Intellectual Property | |
410 | // Network have a bug: the xref table claims to start at 1 | |
411 | // instead of 0. | |
412 | if (i == 1 && first == 1 && | |
413 | entries[1].offset == 0 && entries[1].gen == 65535 && | |
414 | entries[1].type == xrefEntryFree) { | |
415 | i = first = 0; | |
416 | entries[0] = entries[1]; | |
417 | entries[1].offset = 0xffffffff; | |
418 | } | |
419 | } | |
420 | } | |
421 | } | |
422 | ||
423 | // read the trailer dictionary | |
424 | if (!parser->getObj(&obj)->isDict()) { | |
425 | goto err1; | |
426 | } | |
427 | ||
428 | // get the 'Prev' pointer | |
429 | obj.getDict()->lookupNF("Prev", &obj2); | |
430 | if (obj2.isInt()) { | |
431 | *pos = (Guint)obj2.getInt(); | |
432 | more = gTrue; | |
433 | } else if (obj2.isRef()) { | |
434 | // certain buggy PDF generators generate "/Prev NNN 0 R" instead | |
435 | // of "/Prev NNN" | |
436 | *pos = (Guint)obj2.getRefNum(); | |
437 | more = gTrue; | |
438 | } else { | |
439 | more = gFalse; | |
440 | } | |
441 | obj2.free(); | |
442 | ||
443 | // save the first trailer dictionary | |
444 | if (trailerDict.isNone()) { | |
445 | obj.copy(&trailerDict); | |
446 | } | |
447 | ||
448 | // check for an 'XRefStm' key | |
449 | if (obj.getDict()->lookup("XRefStm", &obj2)->isInt()) { | |
450 | pos2 = (Guint)obj2.getInt(); | |
451 | readXRef(&pos2); | |
452 | if (!ok) { | |
453 | obj2.free(); | |
454 | goto err1; | |
455 | } | |
456 | } | |
457 | obj2.free(); | |
458 | ||
459 | obj.free(); | |
460 | return more; | |
461 | ||
462 | err1: | |
463 | obj.free(); | |
464 | ok = gFalse; | |
465 | return gFalse; | |
466 | } | |
467 | ||
468 | GBool XRef::readXRefStream(Stream *xrefStr, Guint *pos) { | |
469 | Dict *dict; | |
470 | int w[3]; | |
471 | GBool more; | |
472 | Object obj, obj2, idx; | |
473 | int newSize, first, n, i; | |
474 | ||
475 | dict = xrefStr->getDict(); | |
476 | ||
477 | if (!dict->lookupNF("Size", &obj)->isInt()) { | |
478 | goto err1; | |
479 | } | |
480 | newSize = obj.getInt(); | |
481 | obj.free(); | |
482 | if (newSize < 0) { | |
483 | goto err1; | |
484 | } | |
485 | if (newSize > size) { | |
486 | entries = (XRefEntry *)greallocn(entries, newSize, sizeof(XRefEntry)); | |
487 | for (i = size; i < newSize; ++i) { | |
488 | entries[i].offset = 0xffffffff; | |
489 | entries[i].type = xrefEntryFree; | |
490 | } | |
491 | size = newSize; | |
492 | } | |
493 | ||
494 | if (!dict->lookupNF("W", &obj)->isArray() || | |
495 | obj.arrayGetLength() < 3) { | |
496 | goto err1; | |
497 | } | |
498 | for (i = 0; i < 3; ++i) { | |
499 | if (!obj.arrayGet(i, &obj2)->isInt()) { | |
500 | obj2.free(); | |
501 | goto err1; | |
502 | } | |
503 | w[i] = obj2.getInt(); | |
504 | obj2.free(); | |
505 | if (w[i] < 0 || w[i] > 4) { | |
506 | goto err1; | |
507 | } | |
508 | } | |
509 | obj.free(); | |
510 | ||
511 | xrefStr->reset(); | |
512 | dict->lookupNF("Index", &idx); | |
513 | if (idx.isArray()) { | |
514 | for (i = 0; i+1 < idx.arrayGetLength(); i += 2) { | |
515 | if (!idx.arrayGet(i, &obj)->isInt()) { | |
516 | idx.free(); | |
517 | goto err1; | |
518 | } | |
519 | first = obj.getInt(); | |
520 | obj.free(); | |
521 | if (!idx.arrayGet(i+1, &obj)->isInt()) { | |
522 | idx.free(); | |
523 | goto err1; | |
524 | } | |
525 | n = obj.getInt(); | |
526 | obj.free(); | |
527 | if (first < 0 || n < 0 || | |
528 | !readXRefStreamSection(xrefStr, w, first, n)) { | |
529 | idx.free(); | |
530 | goto err0; | |
531 | } | |
532 | } | |
533 | } else { | |
534 | if (!readXRefStreamSection(xrefStr, w, 0, newSize)) { | |
535 | idx.free(); | |
536 | goto err0; | |
537 | } | |
538 | } | |
539 | idx.free(); | |
540 | ||
541 | dict->lookupNF("Prev", &obj); | |
542 | if (obj.isInt()) { | |
543 | *pos = (Guint)obj.getInt(); | |
544 | more = gTrue; | |
545 | } else { | |
546 | more = gFalse; | |
547 | } | |
548 | obj.free(); | |
549 | if (trailerDict.isNone()) { | |
550 | trailerDict.initDict(dict); | |
551 | } | |
552 | ||
553 | return more; | |
554 | ||
555 | err1: | |
556 | obj.free(); | |
557 | err0: | |
558 | ok = gFalse; | |
559 | return gFalse; | |
560 | } | |
561 | ||
562 | GBool XRef::readXRefStreamSection(Stream *xrefStr, int *w, int first, int n) { | |
563 | Guint offset; | |
564 | int type, gen, c, newSize, i, j; | |
565 | ||
566 | if (first + n < 0) { | |
567 | return gFalse; | |
568 | } | |
569 | if (first + n > size) { | |
570 | for (newSize = size ? 2 * size : 1024; | |
571 | first + n > newSize && newSize > 0; | |
572 | newSize <<= 1) ; | |
573 | if (newSize < 0) { | |
574 | return gFalse; | |
575 | } | |
576 | entries = (XRefEntry *)greallocn(entries, newSize, sizeof(XRefEntry)); | |
577 | for (i = size; i < newSize; ++i) { | |
578 | entries[i].offset = 0xffffffff; | |
579 | entries[i].type = xrefEntryFree; | |
580 | } | |
581 | size = newSize; | |
582 | } | |
583 | for (i = first; i < first + n; ++i) { | |
584 | if (w[0] == 0) { | |
585 | type = 1; | |
586 | } else { | |
587 | for (type = 0, j = 0; j < w[0]; ++j) { | |
588 | if ((c = xrefStr->getChar()) == EOF) { | |
589 | return gFalse; | |
590 | } | |
591 | type = (type << 8) + c; | |
592 | } | |
593 | } | |
594 | for (offset = 0, j = 0; j < w[1]; ++j) { | |
595 | if ((c = xrefStr->getChar()) == EOF) { | |
596 | return gFalse; | |
597 | } | |
598 | offset = (offset << 8) + c; | |
599 | } | |
600 | for (gen = 0, j = 0; j < w[2]; ++j) { | |
601 | if ((c = xrefStr->getChar()) == EOF) { | |
602 | return gFalse; | |
603 | } | |
604 | gen = (gen << 8) + c; | |
605 | } | |
606 | if (entries[i].offset == 0xffffffff) { | |
607 | switch (type) { | |
608 | case 0: | |
609 | entries[i].offset = offset; | |
610 | entries[i].gen = gen; | |
611 | entries[i].type = xrefEntryFree; | |
612 | break; | |
613 | case 1: | |
614 | entries[i].offset = offset; | |
615 | entries[i].gen = gen; | |
616 | entries[i].type = xrefEntryUncompressed; | |
617 | break; | |
618 | case 2: | |
619 | entries[i].offset = offset; | |
620 | entries[i].gen = gen; | |
621 | entries[i].type = xrefEntryCompressed; | |
622 | break; | |
623 | default: | |
624 | return gFalse; | |
625 | } | |
626 | } | |
627 | } | |
628 | ||
629 | return gTrue; | |
630 | } | |
631 | ||
632 | // Attempt to construct an xref table for a damaged file. | |
633 | GBool XRef::constructXRef() { | |
634 | Parser *parser; | |
635 | Object newTrailerDict, obj; | |
636 | char buf[256]; | |
637 | Guint pos; | |
638 | int num, gen; | |
639 | int newSize; | |
640 | int streamEndsSize; | |
641 | char *p; | |
642 | int i; | |
643 | GBool gotRoot; | |
644 | ||
645 | gfree(entries); | |
646 | size = 0; | |
647 | entries = NULL; | |
648 | ||
649 | error(0, "PDF file is damaged - attempting to reconstruct xref table..."); | |
650 | gotRoot = gFalse; | |
651 | streamEndsLen = streamEndsSize = 0; | |
652 | ||
653 | str->reset(); | |
654 | while (1) { | |
655 | pos = str->getPos(); | |
656 | if (!str->getLine(buf, 256)) { | |
657 | break; | |
658 | } | |
659 | p = buf; | |
660 | ||
661 | // got trailer dictionary | |
662 | if (!strncmp(p, "trailer", 7)) { | |
663 | obj.initNull(); | |
664 | parser = new Parser(NULL, | |
665 | new Lexer(NULL, | |
666 | str->makeSubStream(pos + 7, gFalse, 0, &obj))); | |
667 | parser->getObj(&newTrailerDict); | |
668 | if (newTrailerDict.isDict()) { | |
669 | newTrailerDict.dictLookupNF("Root", &obj); | |
670 | if (obj.isRef()) { | |
671 | rootNum = obj.getRefNum(); | |
672 | rootGen = obj.getRefGen(); | |
673 | if (!trailerDict.isNone()) { | |
674 | trailerDict.free(); | |
675 | } | |
676 | newTrailerDict.copy(&trailerDict); | |
677 | gotRoot = gTrue; | |
678 | } | |
679 | obj.free(); | |
680 | } | |
681 | newTrailerDict.free(); | |
682 | delete parser; | |
683 | ||
684 | // look for object | |
685 | } else if (isdigit(*p)) { | |
686 | num = atoi(p); | |
687 | if (num > 0) { | |
688 | do { | |
689 | ++p; | |
690 | } while (*p && isdigit(*p)); | |
691 | if (isspace(*p)) { | |
692 | do { | |
693 | ++p; | |
694 | } while (*p && isspace(*p)); | |
695 | if (isdigit(*p)) { | |
696 | gen = atoi(p); | |
697 | do { | |
698 | ++p; | |
699 | } while (*p && isdigit(*p)); | |
700 | if (isspace(*p)) { | |
701 | do { | |
702 | ++p; | |
703 | } while (*p && isspace(*p)); | |
704 | if (!strncmp(p, "obj", 3)) { | |
705 | if (num >= size) { | |
706 | newSize = (num + 1 + 255) & ~255; | |
707 | if (newSize < 0) { | |
708 | error(-1, "Bad object number"); | |
709 | return gFalse; | |
710 | } | |
711 | entries = (XRefEntry *) | |
712 | greallocn(entries, newSize, sizeof(XRefEntry)); | |
713 | for (i = size; i < newSize; ++i) { | |
714 | entries[i].offset = 0xffffffff; | |
715 | entries[i].type = xrefEntryFree; | |
716 | } | |
717 | size = newSize; | |
718 | } | |
719 | if (entries[num].type == xrefEntryFree || | |
720 | gen >= entries[num].gen) { | |
721 | entries[num].offset = pos - start; | |
722 | entries[num].gen = gen; | |
723 | entries[num].type = xrefEntryUncompressed; | |
724 | } | |
725 | } | |
726 | } | |
727 | } | |
728 | } | |
729 | } | |
730 | ||
731 | } else if (!strncmp(p, "endstream", 9)) { | |
732 | if (streamEndsLen == streamEndsSize) { | |
733 | streamEndsSize += 64; | |
734 | streamEnds = (Guint *)greallocn(streamEnds, | |
735 | streamEndsSize, sizeof(int)); | |
736 | } | |
737 | streamEnds[streamEndsLen++] = pos; | |
738 | } | |
739 | } | |
740 | ||
741 | if (gotRoot) | |
742 | return gTrue; | |
743 | ||
744 | error(-1, "Couldn't find trailer dictionary"); | |
745 | return gFalse; | |
746 | } | |
747 | ||
748 | void XRef::setEncryption(int permFlagsA, GBool ownerPasswordOkA, | |
749 | Guchar *fileKeyA, int keyLengthA, int encVersionA) { | |
750 | int i; | |
751 | ||
752 | encrypted = gTrue; | |
753 | permFlags = permFlagsA; | |
754 | ownerPasswordOk = ownerPasswordOkA; | |
755 | if (keyLengthA <= 16) { | |
756 | keyLength = keyLengthA; | |
757 | } else { | |
758 | keyLength = 16; | |
759 | } | |
760 | for (i = 0; i < keyLength; ++i) { | |
761 | fileKey[i] = fileKeyA[i]; | |
762 | } | |
763 | encVersion = encVersionA; | |
764 | } | |
765 | ||
766 | GBool XRef::okToPrint(GBool ignoreOwnerPW) { | |
767 | return (!ignoreOwnerPW && ownerPasswordOk) || (permFlags & permPrint); | |
768 | } | |
769 | ||
770 | GBool XRef::okToChange(GBool ignoreOwnerPW) { | |
771 | return (!ignoreOwnerPW && ownerPasswordOk) || (permFlags & permChange); | |
772 | } | |
773 | ||
774 | GBool XRef::okToCopy(GBool ignoreOwnerPW) { | |
775 | return (!ignoreOwnerPW && ownerPasswordOk) || (permFlags & permCopy); | |
776 | } | |
777 | ||
778 | GBool XRef::okToAddNotes(GBool ignoreOwnerPW) { | |
779 | return (!ignoreOwnerPW && ownerPasswordOk) || (permFlags & permNotes); | |
780 | } | |
781 | ||
782 | Object *XRef::fetch(int num, int gen, Object *obj) { | |
783 | XRefEntry *e; | |
784 | Parser *parser; | |
785 | Object obj1, obj2, obj3; | |
786 | ||
787 | // check for bogus ref - this can happen in corrupted PDF files | |
788 | if (num < 0 || num >= size) { | |
789 | goto err; | |
790 | } | |
791 | ||
792 | e = &entries[num]; | |
793 | switch (e->type) { | |
794 | ||
795 | case xrefEntryUncompressed: | |
796 | if (e->gen != gen) { | |
797 | goto err; | |
798 | } | |
799 | obj1.initNull(); | |
800 | parser = new Parser(this, | |
801 | new Lexer(this, | |
802 | str->makeSubStream(start + e->offset, gFalse, 0, &obj1))); | |
803 | parser->getObj(&obj1); | |
804 | parser->getObj(&obj2); | |
805 | parser->getObj(&obj3); | |
806 | if (!obj1.isInt() || obj1.getInt() != num || | |
807 | !obj2.isInt() || obj2.getInt() != gen || | |
808 | !obj3.isCmd("obj")) { | |
809 | obj1.free(); | |
810 | obj2.free(); | |
811 | obj3.free(); | |
812 | delete parser; | |
813 | goto err; | |
814 | } | |
815 | parser->getObj(obj, encrypted ? fileKey : (Guchar *)NULL, keyLength, | |
816 | num, gen); | |
817 | obj1.free(); | |
818 | obj2.free(); | |
819 | obj3.free(); | |
820 | delete parser; | |
821 | break; | |
822 | ||
823 | case xrefEntryCompressed: | |
824 | if (gen != 0) { | |
825 | goto err; | |
826 | } | |
827 | if (!objStr || objStr->getObjStrNum() != (int)e->offset) { | |
828 | if (objStr) { | |
829 | delete objStr; | |
830 | } | |
831 | objStr = new ObjectStream(this, e->offset); | |
832 | } | |
833 | objStr->getObject(e->gen, num, obj); | |
834 | break; | |
835 | ||
836 | default: | |
837 | goto err; | |
838 | } | |
839 | ||
840 | return obj; | |
841 | ||
842 | err: | |
843 | return obj->initNull(); | |
844 | } | |
845 | ||
846 | Object *XRef::getDocInfo(Object *obj) { | |
847 | return trailerDict.dictLookup("Info", obj); | |
848 | } | |
849 | ||
850 | // Added for the pdftex project. | |
851 | Object *XRef::getDocInfoNF(Object *obj) { | |
852 | return trailerDict.dictLookupNF("Info", obj); | |
853 | } | |
854 | ||
855 | GBool XRef::getStreamEnd(Guint streamStart, Guint *streamEnd) { | |
856 | int a, b, m; | |
857 | ||
858 | if (streamEndsLen == 0 || | |
859 | streamStart > streamEnds[streamEndsLen - 1]) { | |
860 | return gFalse; | |
861 | } | |
862 | ||
863 | a = -1; | |
864 | b = streamEndsLen - 1; | |
865 | // invariant: streamEnds[a] < streamStart <= streamEnds[b] | |
866 | while (b - a > 1) { | |
867 | m = (a + b) / 2; | |
868 | if (streamStart <= streamEnds[m]) { | |
869 | b = m; | |
870 | } else { | |
871 | a = m; | |
872 | } | |
873 | } | |
874 | *streamEnd = streamEnds[b]; | |
875 | return gTrue; | |
876 | } | |
877 | ||
878 | Guint XRef::strToUnsigned(char *s) { | |
879 | Guint x; | |
880 | char *p; | |
881 | int i; | |
882 | ||
883 | x = 0; | |
884 | for (p = s, i = 0; *p && isdigit(*p) && i < 10; ++p, ++i) { | |
885 | x = 10 * x + (*p - '0'); | |
886 | } | |
887 | return x; | |
888 | } |