#include // include first for large file support #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include std::string QPDF::qpdf_version = "8.0.2"; static char const* EMPTY_PDF = "%PDF-1.3\n" "1 0 obj\n" "<< /Type /Catalog /Pages 2 0 R >>\n" "endobj\n" "2 0 obj\n" "<< /Type /Pages /Kids [] /Count 0 >>\n" "endobj\n" "xref\n" "0 3\n" "0000000000 65535 f \n" "0000000009 00000 n \n" "0000000058 00000 n \n" "trailer << /Size 3 /Root 1 0 R >>\n" "startxref\n" "110\n" "%%EOF\n"; void QPDF::CopiedStreamDataProvider::provideStreamData( int objid, int generation, Pipeline* pipeline) { QPDFObjectHandle foreign_stream = this->foreign_streams[QPDFObjGen(objid, generation)]; foreign_stream.pipeStreamData(pipeline, 0, qpdf_dl_none); } void QPDF::CopiedStreamDataProvider::registerForeignStream( QPDFObjGen const& local_og, QPDFObjectHandle foreign_stream) { this->foreign_streams[local_og] = foreign_stream; } QPDF::StringDecrypter::StringDecrypter(QPDF* qpdf, int objid, int gen) : qpdf(qpdf), objid(objid), gen(gen) { } void QPDF::StringDecrypter::decryptString(std::string& val) { qpdf->decryptString(val, objid, gen); } std::string const& QPDF::QPDFVersion() { return QPDF::qpdf_version; } QPDF::Members::Members() : provided_password_is_hex_key(false), encrypted(false), encryption_initialized(false), ignore_xref_streams(false), suppress_warnings(false), out_stream(&std::cout), err_stream(&std::cerr), attempt_recovery(true), encryption_V(0), encryption_R(0), encrypt_metadata(true), cf_stream(e_none), cf_string(e_none), cf_file(e_none), cached_key_objid(0), cached_key_generation(0), pushed_inherited_attributes_to_pages(false), copied_stream_data_provider(0), reconstructed_xref(false), first_xref_item_offset(0), uncompressed_after_compressed(false) { } QPDF::Members::~Members() { } QPDF::QPDF() : m(new Members()) { m->tokenizer.allowEOF(); } QPDF::~QPDF() { // If two objects are mutually referential (through each object // having an array or dictionary that contains an indirect // reference to the other), the circular references in the // PointerHolder objects will prevent the objects from being // deleted. Walk through all objects in the object cache, which // is those objects that we read from the file, and break all // resolved references. At this point, obviously no one is still // using the QPDF object, but we'll explicitly clear the xref // table anyway just to prevent any possibility of resolve() // succeeding. Note that we can't break references like this at // any time when the QPDF object is active. If we do, the next // reference will reread the object from the file, which would // have the effect of undoing any modifications that may have been // made to any of the objects. this->m->xref_table.clear(); for (std::map::iterator iter = this->m->obj_cache.begin(); iter != this->m->obj_cache.end(); ++iter) { QPDFObject::ObjAccessor::releaseResolved( (*iter).second.object.getPointer()); } } void QPDF::processFile(char const* filename, char const* password) { FileInputSource* fi = new FileInputSource(); fi->setFilename(filename); processInputSource(fi, password); } void QPDF::processFile(char const* description, FILE* filep, bool close_file, char const* password) { FileInputSource* fi = new FileInputSource(); fi->setFile(description, filep, close_file); processInputSource(fi, password); } void QPDF::processMemoryFile(char const* description, char const* buf, size_t length, char const* password) { processInputSource( new BufferInputSource( description, new Buffer(QUtil::unsigned_char_pointer(buf), length), true), password); } void QPDF::processInputSource(PointerHolder source, char const* password) { this->m->file = source; parse(password); } void QPDF::setPasswordIsHexKey(bool val) { this->m->provided_password_is_hex_key = val; } void QPDF::emptyPDF() { processMemoryFile("empty PDF", EMPTY_PDF, strlen(EMPTY_PDF)); } void QPDF::setIgnoreXRefStreams(bool val) { this->m->ignore_xref_streams = val; } void QPDF::setOutputStreams(std::ostream* out, std::ostream* err) { this->m->out_stream = out ? out : &std::cout; this->m->err_stream = err ? err : &std::cerr; } void QPDF::setSuppressWarnings(bool val) { this->m->suppress_warnings = val; } void QPDF::setAttemptRecovery(bool val) { this->m->attempt_recovery = val; } std::vector QPDF::getWarnings() { std::vector result = this->m->warnings; this->m->warnings.clear(); return result; } bool QPDF::findHeader() { qpdf_offset_t global_offset = this->m->file->tell(); std::string line = this->m->file->readLine(1024); char const* p = line.c_str(); if (strncmp(p, "%PDF-", 5) != 0) { throw std::logic_error("findHeader is not looking at %PDF-"); } p += 5; std::string version; // Note: The string returned by line.c_str() is always // null-terminated. The code below never overruns the buffer // because a null character always short-circuits further // advancement. bool valid = QUtil::is_digit(*p); if (valid) { while (QUtil::is_digit(*p)) { version.append(1, *p++); } if ((*p == '.') && QUtil::is_digit(*(p+1))) { version.append(1, *p++); while (QUtil::is_digit(*p)) { version.append(1, *p++); } } else { valid = false; } } if (valid) { this->m->pdf_version = version; if (global_offset != 0) { // Empirical evidence strongly suggests that when there is // leading material prior to the PDF header, all explicit // offsets in the file are such that 0 points to the // beginning of the header. QTC::TC("qpdf", "QPDF global offset"); this->m->file = new OffsetInputSource(this->m->file, global_offset); } } return valid; } bool QPDF::findStartxref() { QPDFTokenizer::Token t = readToken(this->m->file); if (t == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "startxref")) { t = readToken(this->m->file); if (t.getType() == QPDFTokenizer::tt_integer) { // Position in front of offset token this->m->file->seek(this->m->file->getLastOffset(), SEEK_SET); return true; } } return false; } void QPDF::parse(char const* password) { if (password) { this->m->provided_password = password; } // Find the header anywhere in the first 1024 bytes of the file. PatternFinder hf(*this, &QPDF::findHeader); if (! this->m->file->findFirst("%PDF-", 0, 1024, hf)) { QTC::TC("qpdf", "QPDF not a pdf file"); warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", 0, "can't find PDF header")); // QPDFWriter writes files that usually require at least // version 1.2 for /FlateDecode this->m->pdf_version = "1.2"; } if (atof(this->m->pdf_version.c_str()) < 1.2) { this->m->tokenizer.allowPoundAnywhereInName(); } // PDF spec says %%EOF must be found within the last 1024 bytes of // the file. We add an extra 30 characters to leave room for the // startxref stuff. this->m->file->seek(0, SEEK_END); qpdf_offset_t end_offset = this->m->file->tell(); qpdf_offset_t start_offset = (end_offset > 1054 ? end_offset - 1054 : 0); PatternFinder sf(*this, &QPDF::findStartxref); qpdf_offset_t xref_offset = 0; if (this->m->file->findLast("startxref", start_offset, 0, sf)) { xref_offset = QUtil::string_to_ll( readToken(this->m->file).getValue().c_str()); } try { if (xref_offset == 0) { QTC::TC("qpdf", "QPDF can't find startxref"); throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", 0, "can't find startxref"); } read_xref(xref_offset); } catch (QPDFExc& e) { if (this->m->attempt_recovery) { reconstruct_xref(e); QTC::TC("qpdf", "QPDF reconstructed xref table"); } else { throw e; } } initializeEncryption(); findAttachmentStreams(); } void QPDF::warn(QPDFExc const& e) { this->m->warnings.push_back(e); if (! this->m->suppress_warnings) { *this->m->err_stream << "WARNING: " << this->m->warnings.back().what() << std::endl; } } void QPDF::setTrailer(QPDFObjectHandle obj) { if (this->m->trailer.isInitialized()) { return; } this->m->trailer = obj; } void QPDF::reconstruct_xref(QPDFExc& e) { if (this->m->reconstructed_xref) { // Avoid xref reconstruction infinite loops. This is getting // very hard to reproduce because qpdf is throwing many fewer // exceptions while parsing. Most situations are warnings now. throw e; } this->m->reconstructed_xref = true; warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", 0, "file is damaged")); warn(e); warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", 0, "Attempting to reconstruct cross-reference table")); // Delete all references to type 1 (uncompressed) objects std::set to_delete; for (std::map::iterator iter = this->m->xref_table.begin(); iter != this->m->xref_table.end(); ++iter) { if (((*iter).second).getType() == 1) { to_delete.insert((*iter).first); } } for (std::set::iterator iter = to_delete.begin(); iter != to_delete.end(); ++iter) { this->m->xref_table.erase(*iter); } this->m->file->seek(0, SEEK_END); qpdf_offset_t eof = this->m->file->tell(); this->m->file->seek(0, SEEK_SET); bool in_obj = false; qpdf_offset_t line_start = 0; // Don't allow very long tokens here during recovery. static size_t const MAX_LEN = 100; while (this->m->file->tell() < eof) { this->m->file->findAndSkipNextEOL(); qpdf_offset_t next_line_start = this->m->file->tell(); this->m->file->seek(line_start, SEEK_SET); QPDFTokenizer::Token t1 = readToken(this->m->file, MAX_LEN); qpdf_offset_t token_start = this->m->file->tell() - t1.getValue().length(); if (token_start >= next_line_start) { // don't process yet } else if (in_obj) { if (t1 == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "endobj")) { in_obj = false; } } else { if (t1.getType() == QPDFTokenizer::tt_integer) { QPDFTokenizer::Token t2 = readToken(this->m->file, MAX_LEN); QPDFTokenizer::Token t3 = readToken(this->m->file, MAX_LEN); if ((t2.getType() == QPDFTokenizer::tt_integer) && (t3 == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "obj"))) { in_obj = true; int obj = QUtil::string_to_int(t1.getValue().c_str()); int gen = QUtil::string_to_int(t2.getValue().c_str()); insertXrefEntry(obj, 1, token_start, gen, true); } } else if ((! this->m->trailer.isInitialized()) && (t1 == QPDFTokenizer::Token( QPDFTokenizer::tt_word, "trailer"))) { QPDFObjectHandle t = readObject(this->m->file, "trailer", 0, 0, false); if (! t.isDictionary()) { // Oh well. It was worth a try. } else { setTrailer(t); } } } this->m->file->seek(next_line_start, SEEK_SET); line_start = next_line_start; } if (! this->m->trailer.isInitialized()) { // We could check the last encountered object to see if it was // an xref stream. If so, we could try to get the trailer // from there. This may make it possible to recover files // with bad startxref pointers even when they have object // streams. throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", 0, "unable to find trailer " "dictionary while recovering damaged file"); } // We could iterate through the objects looking for streams and // try to find objects inside of them, but it's probably not worth // the trouble. Acrobat can't recover files with any errors in an // xref stream, and this would be a real long shot anyway. If we // wanted to do anything that involved looking at stream contents, // we'd also have to call initializeEncryption() here. It's safe // to call it more than once. } void QPDF::read_xref(qpdf_offset_t xref_offset) { std::map free_table; std::set visited; while (xref_offset) { visited.insert(xref_offset); char buf[7]; memset(buf, 0, sizeof(buf)); this->m->file->seek(xref_offset, SEEK_SET); this->m->file->read(buf, sizeof(buf) - 1); // The PDF spec says xref must be followed by a line // terminator, but files exist in the wild where it is // terminated by arbitrary whitespace. if ((strncmp(buf, "xref", 4) == 0) && QUtil::is_space(buf[4])) { QTC::TC("qpdf", "QPDF xref space", ((buf[4] == '\n') ? 0 : (buf[4] == '\r') ? 1 : (buf[4] == ' ') ? 2 : 9999)); int skip = 4; // buf is null-terminated, and QUtil::is_space('\0') is // false, so this won't overrun. while (QUtil::is_space(buf[skip])) { ++skip; } xref_offset = read_xrefTable(xref_offset + skip); } else { xref_offset = read_xrefStream(xref_offset); } if (visited.count(xref_offset) != 0) { QTC::TC("qpdf", "QPDF xref loop"); throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", 0, "loop detected following xref tables"); } } if (! this->m->trailer.isInitialized()) { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", 0, "unable to find trailer while reading xref"); } int size = this->m->trailer.getKey("/Size").getIntValue(); int max_obj = 0; if (! this->m->xref_table.empty()) { max_obj = (*(this->m->xref_table.rbegin())).first.getObj(); } if (! this->m->deleted_objects.empty()) { max_obj = std::max(max_obj, *(this->m->deleted_objects.rbegin())); } if (size != max_obj + 1) { QTC::TC("qpdf", "QPDF xref size mismatch"); warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", 0, std::string("reported number of objects (") + QUtil::int_to_string(size) + ") inconsistent with actual number of objects (" + QUtil::int_to_string(max_obj + 1) + ")")); } // We no longer need the deleted_objects table, so go ahead and // clear it out to make sure we never depend on its being set. this->m->deleted_objects.clear(); } bool QPDF::parse_xrefFirst(std::string const& line, int& obj, int& num, int& bytes) { // is_space and is_digit both return false on '\0', so this will // not overrun the null-terminated buffer. char const* p = line.c_str(); char const* start = line.c_str(); // Skip zero or more spaces while (QUtil::is_space(*p)) { ++p; } // Require digit if (! QUtil::is_digit(*p)) { return false; } // Gather digits std::string obj_str; while (QUtil::is_digit(*p)) { obj_str.append(1, *p++); } // Require space if (! QUtil::is_space(*p)) { return false; } // Skip spaces while (QUtil::is_space(*p)) { ++p; } // Require digit if (! QUtil::is_digit(*p)) { return false; } // Gather digits std::string num_str; while (QUtil::is_digit(*p)) { num_str.append(1, *p++); } // Skip any space including line terminators while (QUtil::is_space(*p)) { ++p; } bytes = p - start; obj = QUtil::string_to_int(obj_str.c_str()); num = QUtil::string_to_int(num_str.c_str()); return true; } bool QPDF::parse_xrefEntry(std::string const& line, qpdf_offset_t& f1, int& f2, char& type) { // is_space and is_digit both return false on '\0', so this will // not overrun the null-terminated buffer. char const* p = line.c_str(); // Skip zero or more spaces. There aren't supposed to be any. bool invalid = false; while (QUtil::is_space(*p)) { ++p; QTC::TC("qpdf", "QPDF ignore first space in xref entry"); invalid = true; } // Require digit if (! QUtil::is_digit(*p)) { return false; } // Gather digits std::string f1_str; while (QUtil::is_digit(*p)) { f1_str.append(1, *p++); } // Require space if (! QUtil::is_space(*p)) { return false; } if (QUtil::is_space(*(p+1))) { QTC::TC("qpdf", "QPDF ignore first extra space in xref entry"); invalid = true; } // Skip spaces while (QUtil::is_space(*p)) { ++p; } // Require digit if (! QUtil::is_digit(*p)) { return false; } // Gather digits std::string f2_str; while (QUtil::is_digit(*p)) { f2_str.append(1, *p++); } // Require space if (! QUtil::is_space(*p)) { return false; } if (QUtil::is_space(*(p+1))) { QTC::TC("qpdf", "QPDF ignore second extra space in xref entry"); invalid = true; } // Skip spaces while (QUtil::is_space(*p)) { ++p; } if ((*p == 'f') || (*p == 'n')) { type = *p; } else { return false; } if ((f1_str.length() != 10) || (f2_str.length() != 5)) { QTC::TC("qpdf", "QPDF ignore length error xref entry"); invalid = true; } if (invalid) { warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "xref table", this->m->file->getLastOffset(), "accepting invalid xref table entry")); } f1 = QUtil::string_to_ll(f1_str.c_str()); f2 = QUtil::string_to_int(f2_str.c_str()); return true; } qpdf_offset_t QPDF::read_xrefTable(qpdf_offset_t xref_offset) { std::vector deleted_items; this->m->file->seek(xref_offset, SEEK_SET); bool done = false; while (! done) { char linebuf[51]; memset(linebuf, 0, sizeof(linebuf)); this->m->file->read(linebuf, sizeof(linebuf) - 1); std::string line = linebuf; int obj = 0; int num = 0; int bytes = 0; if (! parse_xrefFirst(line, obj, num, bytes)) { QTC::TC("qpdf", "QPDF invalid xref"); throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "xref table", this->m->file->getLastOffset(), "xref syntax invalid"); } this->m->file->seek(this->m->file->getLastOffset() + bytes, SEEK_SET); for (int i = obj; i < obj + num; ++i) { if (i == 0) { // This is needed by checkLinearization() this->m->first_xref_item_offset = this->m->file->tell(); } std::string xref_entry = this->m->file->readLine(30); // For xref_table, these will always be small enough to be ints qpdf_offset_t f1 = 0; int f2 = 0; char type = '\0'; if (! parse_xrefEntry(xref_entry, f1, f2, type)) { QTC::TC("qpdf", "QPDF invalid xref entry"); throw QPDFExc( qpdf_e_damaged_pdf, this->m->file->getName(), "xref table", this->m->file->getLastOffset(), "invalid xref entry (obj=" + QUtil::int_to_string(i) + ")"); } if (type == 'f') { // Save deleted items until after we've checked the // XRefStm, if any. deleted_items.push_back(QPDFObjGen(i, f2)); } else { insertXrefEntry(i, 1, f1, f2); } } qpdf_offset_t pos = this->m->file->tell(); QPDFTokenizer::Token t = readToken(this->m->file); if (t == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "trailer")) { done = true; } else { this->m->file->seek(pos, SEEK_SET); } } // Set offset to previous xref table if any QPDFObjectHandle cur_trailer = readObject(this->m->file, "trailer", 0, 0, false); if (! cur_trailer.isDictionary()) { QTC::TC("qpdf", "QPDF missing trailer"); throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", this->m->file->getLastOffset(), "expected trailer dictionary"); } if (! this->m->trailer.isInitialized()) { setTrailer(cur_trailer); if (! this->m->trailer.hasKey("/Size")) { QTC::TC("qpdf", "QPDF trailer lacks size"); throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "trailer", this->m->file->getLastOffset(), "trailer dictionary lacks /Size key"); } if (! this->m->trailer.getKey("/Size").isInteger()) { QTC::TC("qpdf", "QPDF trailer size not integer"); throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "trailer", this->m->file->getLastOffset(), "/Size key in trailer dictionary is not " "an integer"); } } if (cur_trailer.hasKey("/XRefStm")) { if (this->m->ignore_xref_streams) { QTC::TC("qpdf", "QPDF ignoring XRefStm in trailer"); } else { if (cur_trailer.getKey("/XRefStm").isInteger()) { // Read the xref stream but disregard any return value // -- we'll use our trailer's /Prev key instead of the // xref stream's. (void) read_xrefStream( cur_trailer.getKey("/XRefStm").getIntValue()); } else { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "xref stream", xref_offset, "invalid /XRefStm"); } } } // Handle any deleted items now that we've read the /XRefStm. for (std::vector::iterator iter = deleted_items.begin(); iter != deleted_items.end(); ++iter) { QPDFObjGen& og = *iter; insertXrefEntry(og.getObj(), 0, 0, og.getGen()); } if (cur_trailer.hasKey("/Prev")) { if (! cur_trailer.getKey("/Prev").isInteger()) { QTC::TC("qpdf", "QPDF trailer prev not integer"); throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "trailer", this->m->file->getLastOffset(), "/Prev key in trailer dictionary is not " "an integer"); } QTC::TC("qpdf", "QPDF prev key in trailer dictionary"); xref_offset = cur_trailer.getKey("/Prev").getIntValue(); } else { xref_offset = 0; } return xref_offset; } qpdf_offset_t QPDF::read_xrefStream(qpdf_offset_t xref_offset) { bool found = false; if (! this->m->ignore_xref_streams) { int xobj; int xgen; QPDFObjectHandle xref_obj; try { xref_obj = readObjectAtOffset( false, xref_offset, "xref stream", -1, 0, xobj, xgen); } catch (QPDFExc&) { // ignore -- report error below } if (xref_obj.isInitialized() && xref_obj.isStream() && xref_obj.getDict().getKey("/Type").isName() && xref_obj.getDict().getKey("/Type").getName() == "/XRef") { QTC::TC("qpdf", "QPDF found xref stream"); found = true; xref_offset = processXRefStream(xref_offset, xref_obj); } } if (! found) { QTC::TC("qpdf", "QPDF can't find xref"); throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", xref_offset, "xref not found"); } return xref_offset; } qpdf_offset_t QPDF::processXRefStream(qpdf_offset_t xref_offset, QPDFObjectHandle& xref_obj) { QPDFObjectHandle dict = xref_obj.getDict(); QPDFObjectHandle W_obj = dict.getKey("/W"); QPDFObjectHandle Index_obj = dict.getKey("/Index"); if (! (W_obj.isArray() && (W_obj.getArrayNItems() >= 3) && W_obj.getArrayItem(0).isInteger() && W_obj.getArrayItem(1).isInteger() && W_obj.getArrayItem(2).isInteger() && dict.getKey("/Size").isInteger() && (Index_obj.isArray() || Index_obj.isNull()))) { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "xref stream", xref_offset, "Cross-reference stream does not have" " proper /W and /Index keys"); } int W[3]; size_t entry_size = 0; int max_bytes = sizeof(qpdf_offset_t); for (int i = 0; i < 3; ++i) { W[i] = W_obj.getArrayItem(i).getIntValue(); if (W[i] > max_bytes) { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "xref stream", xref_offset, "Cross-reference stream's /W contains" " impossibly large values"); } entry_size += W[i]; } if (entry_size == 0) { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "xref stream", xref_offset, "Cross-reference stream's /W indicates" " entry size of 0"); } long long max_num_entries = static_cast(-1) / entry_size; std::vector indx; if (Index_obj.isArray()) { int n_index = Index_obj.getArrayNItems(); if ((n_index % 2) || (n_index < 2)) { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "xref stream", xref_offset, "Cross-reference stream's /Index has an" " invalid number of values"); } for (int i = 0; i < n_index; ++i) { if (Index_obj.getArrayItem(i).isInteger()) { indx.push_back(Index_obj.getArrayItem(i).getIntValue()); } else { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "xref stream", xref_offset, "Cross-reference stream's /Index's item " + QUtil::int_to_string(i) + " is not an integer"); } } QTC::TC("qpdf", "QPDF xref /Index is array", n_index == 2 ? 0 : 1); } else { QTC::TC("qpdf", "QPDF xref /Index is null"); long long size = dict.getKey("/Size").getIntValue(); indx.push_back(0); indx.push_back(size); } long long num_entries = 0; for (unsigned int i = 1; i < indx.size(); i += 2) { if (indx.at(i) > max_num_entries - num_entries) { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "xref stream", xref_offset, "Cross-reference stream claims to contain" " too many entries: " + QUtil::int_to_string(indx.at(i)) + " " + QUtil::int_to_string(max_num_entries) + " " + QUtil::int_to_string(num_entries)); } num_entries += indx.at(i); } // entry_size and num_entries have both been validated to ensure // that this multiplication does not cause an overflow. size_t expected_size = entry_size * num_entries; PointerHolder bp = xref_obj.getStreamData(qpdf_dl_specialized); size_t actual_size = bp->getSize(); if (expected_size != actual_size) { QPDFExc x(qpdf_e_damaged_pdf, this->m->file->getName(), "xref stream", xref_offset, "Cross-reference stream data has the wrong size;" " expected = " + QUtil::int_to_string(expected_size) + "; actual = " + QUtil::int_to_string(actual_size)); if (expected_size > actual_size) { throw x; } else { warn(x); } } int cur_chunk = 0; int chunk_count = 0; bool saw_first_compressed_object = false; // Actual size vs. expected size check above ensures that we will // not overflow any buffers here. We know that entry_size * // num_entries is equal to the size of the buffer. unsigned char const* data = bp->getBuffer(); for (int i = 0; i < num_entries; ++i) { // Read this entry unsigned char const* entry = data + (entry_size * i); qpdf_offset_t fields[3]; unsigned char const* p = entry; for (int j = 0; j < 3; ++j) { fields[j] = 0; if ((j == 0) && (W[0] == 0)) { QTC::TC("qpdf", "QPDF default for xref stream field 0"); fields[0] = 1; } for (int k = 0; k < W[j]; ++k) { fields[j] <<= 8; fields[j] += static_cast(*p++); } } // Get the object and generation number. The object number is // based on /Index. The generation number is 0 unless this is // an uncompressed object record, in which case the generation // number appears as the third field. int obj = indx.at(cur_chunk) + chunk_count; ++chunk_count; if (chunk_count >= indx.at(cur_chunk + 1)) { cur_chunk += 2; chunk_count = 0; } if (saw_first_compressed_object) { if (fields[0] != 2) { this->m->uncompressed_after_compressed = true; } } else if (fields[0] == 2) { saw_first_compressed_object = true; } if (obj == 0) { // This is needed by checkLinearization() this->m->first_xref_item_offset = xref_offset; } insertXrefEntry(obj, static_cast(fields[0]), fields[1], static_cast(fields[2])); } if (! this->m->trailer.isInitialized()) { setTrailer(dict); } if (dict.hasKey("/Prev")) { if (! dict.getKey("/Prev").isInteger()) { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "xref stream", this->m->file->getLastOffset(), "/Prev key in xref stream dictionary is not " "an integer"); } QTC::TC("qpdf", "QPDF prev key in xref stream dictionary"); xref_offset = dict.getKey("/Prev").getIntValue(); } else { xref_offset = 0; } return xref_offset; } void QPDF::insertXrefEntry(int obj, int f0, qpdf_offset_t f1, int f2, bool overwrite) { // Populate the xref table in such a way that the first reference // to an object that we see, which is the one in the latest xref // table in which it appears, is the one that gets stored. This // works because we are reading more recent appends before older // ones. Exception: if overwrite is true, then replace any // existing object. This is used in xref recovery mode, which // reads the file from beginning to end. // If there is already an entry for this object and generation in // the table, it means that a later xref table has registered this // object. Disregard this one. { // private scope int gen = (f0 == 2 ? 0 : f2); QPDFObjGen og(obj, gen); if (this->m->xref_table.count(og)) { if (overwrite) { QTC::TC("qpdf", "QPDF xref overwrite object"); this->m->xref_table.erase(og); } else { QTC::TC("qpdf", "QPDF xref reused object"); return; } } if (this->m->deleted_objects.count(obj)) { QTC::TC("qpdf", "QPDF xref deleted object"); return; } } switch (f0) { case 0: this->m->deleted_objects.insert(obj); break; case 1: // f2 is generation QTC::TC("qpdf", "QPDF xref gen > 0", ((f2 > 0) ? 1 : 0)); this->m->xref_table[QPDFObjGen(obj, f2)] = QPDFXRefEntry(f0, f1, f2); break; case 2: this->m->xref_table[QPDFObjGen(obj, 0)] = QPDFXRefEntry(f0, f1, f2); break; default: throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "xref stream", this->m->file->getLastOffset(), "unknown xref stream entry type " + QUtil::int_to_string(f0)); break; } } void QPDF::showXRefTable() { for (std::map::iterator iter = this->m->xref_table.begin(); iter != this->m->xref_table.end(); ++iter) { QPDFObjGen const& og = (*iter).first; QPDFXRefEntry const& entry = (*iter).second; *this->m->out_stream << og.getObj() << "/" << og.getGen() << ": "; switch (entry.getType()) { case 1: *this->m->out_stream << "uncompressed; offset = " << entry.getOffset(); break; case 2: *this->m->out_stream << "compressed; stream = " << entry.getObjStreamNumber() << ", index = " << entry.getObjStreamIndex(); break; default: throw std::logic_error("unknown cross-reference table type while" " showing xref_table"); break; } *this->m->out_stream << std::endl; } } std::vector QPDF::getAllObjects() { std::vector result; for (std::map::iterator iter = this->m->xref_table.begin(); iter != this->m->xref_table.end(); ++iter) { QPDFObjGen const& og = (*iter).first; result.push_back(QPDFObjectHandle::Factory::newIndirect( this, og.getObj(), og.getGen())); } return result; } void QPDF::setLastObjectDescription(std::string const& description, int objid, int generation) { this->m->last_object_description.clear(); if (! description.empty()) { this->m->last_object_description += description; if (objid > 0) { this->m->last_object_description += ": "; } } if (objid > 0) { this->m->last_object_description += "object " + QUtil::int_to_string(objid) + " " + QUtil::int_to_string(generation); } } QPDFObjectHandle QPDF::readObject(PointerHolder input, std::string const& description, int objid, int generation, bool in_object_stream) { setLastObjectDescription(description, objid, generation); qpdf_offset_t offset = input->tell(); bool empty = false; PointerHolder decrypter_ph; StringDecrypter* decrypter = 0; if (this->m->encrypted && (! in_object_stream)) { decrypter_ph = new StringDecrypter(this, objid, generation); decrypter = decrypter_ph.getPointer(); } QPDFObjectHandle object = QPDFObjectHandle::parse( input, this->m->last_object_description, this->m->tokenizer, empty, decrypter, this); if (empty) { // Nothing in the PDF spec appears to allow empty objects, but // they have been encountered in actual PDF files and Adobe // Reader appears to ignore them. warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(), this->m->last_object_description, input->getLastOffset(), "empty object treated as null")); } else if (object.isDictionary() && (! in_object_stream)) { // check for stream qpdf_offset_t cur_offset = input->tell(); if (readToken(input) == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "stream")) { // The PDF specification states that the word "stream" // should be followed by either a carriage return and // a newline or by a newline alone. It specifically // disallowed following it by a carriage return alone // since, in that case, there would be no way to tell // whether the NL in a CR NL sequence was part of the // stream data. However, some readers, including // Adobe reader, accept a carriage return by itself // when followed by a non-newline character, so that's // what we do here. { char ch; if (input->read(&ch, 1) == 0) { // A premature EOF here will result in some // other problem that will get reported at // another time. } else if (ch == '\n') { // ready to read stream data QTC::TC("qpdf", "QPDF stream with NL only"); } else if (ch == '\r') { // Read another character if (input->read(&ch, 1) != 0) { if (ch == '\n') { // Ready to read stream data QTC::TC("qpdf", "QPDF stream with CRNL"); } else { // Treat the \r by itself as the // whitespace after endstream and // start reading stream data in spite // of not having seen a newline. QTC::TC("qpdf", "QPDF stream with CR only"); input->unreadCh(ch); warn(QPDFExc( qpdf_e_damaged_pdf, input->getName(), this->m->last_object_description, input->tell(), "stream keyword followed" " by carriage return only")); } } } else { QTC::TC("qpdf", "QPDF stream without newline"); if (! QUtil::is_space(ch)) { QTC::TC("qpdf", "QPDF stream with non-space"); input->unreadCh(ch); } warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(), this->m->last_object_description, input->tell(), "stream keyword not followed" " by proper line terminator")); } } // Must get offset before accessing any additional // objects since resolving a previously unresolved // indirect object will change file position. qpdf_offset_t stream_offset = input->tell(); size_t length = 0; try { std::map dict = object.getDictAsMap(); if (dict.count("/Length") == 0) { QTC::TC("qpdf", "QPDF stream without length"); throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), this->m->last_object_description, offset, "stream dictionary lacks /Length key"); } QPDFObjectHandle length_obj = dict["/Length"]; if (! length_obj.isInteger()) { QTC::TC("qpdf", "QPDF stream length not integer"); throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), this->m->last_object_description, offset, "/Length key in stream dictionary is not " "an integer"); } length = length_obj.getIntValue(); input->seek(stream_offset + length, SEEK_SET); if (! (readToken(input) == QPDFTokenizer::Token( QPDFTokenizer::tt_word, "endstream"))) { QTC::TC("qpdf", "QPDF missing endstream"); throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), this->m->last_object_description, input->getLastOffset(), "expected endstream"); } } catch (QPDFExc& e) { if (this->m->attempt_recovery) { warn(e); length = recoverStreamLength( input, objid, generation, stream_offset); } else { throw e; } } object = QPDFObjectHandle::Factory::newStream( this, objid, generation, object, stream_offset, length); } else { input->seek(cur_offset, SEEK_SET); } } // Override last_offset so that it points to the beginning of the // object we just read input->setLastOffset(offset); return object; } bool QPDF::findEndstream() { // Find endstream or endobj. Position the input at that token. QPDFTokenizer::Token t = readToken(this->m->file, 20); if ((t.getType() == QPDFTokenizer::tt_word) && ((t.getValue() == "endobj") || (t.getValue() == "endstream"))) { this->m->file->seek(this->m->file->getLastOffset(), SEEK_SET); return true; } return false; } size_t QPDF::recoverStreamLength(PointerHolder input, int objid, int generation, qpdf_offset_t stream_offset) { // Try to reconstruct stream length by looking for // endstream or endobj warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(), this->m->last_object_description, stream_offset, "attempting to recover stream length")); PatternFinder ef(*this, &QPDF::findEndstream); size_t length = 0; if (this->m->file->findFirst("end", stream_offset, 0, ef)) { length = this->m->file->tell() - stream_offset; // Reread endstream but, if it was endobj, don't skip that. QPDFTokenizer::Token t = readToken(this->m->file); if (t.getValue() == "endobj") { this->m->file->seek(this->m->file->getLastOffset(), SEEK_SET); } } if (length) { int this_obj_offset = 0; QPDFObjGen this_obj(0, 0); // Make sure this is inside this object for (std::map::iterator iter = this->m->xref_table.begin(); iter != this->m->xref_table.end(); ++iter) { QPDFObjGen const& og = (*iter).first; QPDFXRefEntry const& entry = (*iter).second; if (entry.getType() == 1) { qpdf_offset_t obj_offset = entry.getOffset(); if ((obj_offset > stream_offset) && ((this_obj_offset == 0) || (this_obj_offset > obj_offset))) { this_obj_offset = obj_offset; this_obj = og; } } } if (this_obj_offset && (this_obj.getObj() == objid) && (this_obj.getGen() == generation)) { // Well, we found endstream\nendobj within the space // allowed for this object, so we're probably in good // shape. } else { QTC::TC("qpdf", "QPDF found wrong endstream in recovery"); } } if (length == 0) { warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(), this->m->last_object_description, stream_offset, "unable to recover stream data;" " treating stream as empty")); } else { warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(), this->m->last_object_description, stream_offset, "recovered stream length: " + QUtil::int_to_string(length))); } QTC::TC("qpdf", "QPDF recovered stream length"); return length; } QPDFTokenizer::Token QPDF::readToken(PointerHolder input, size_t max_len) { return this->m->tokenizer.readToken( input, this->m->last_object_description, true, max_len); } QPDFObjectHandle QPDF::readObjectAtOffset(bool try_recovery, qpdf_offset_t offset, std::string const& description, int exp_objid, int exp_generation, int& objid, int& generation) { if (! this->m->attempt_recovery) { try_recovery = false; } setLastObjectDescription(description, exp_objid, exp_generation); // Special case: if offset is 0, just return null. Some PDF // writers, in particular "Mac OS X 10.7.5 Quartz PDFContext", may // store deleted objects in the xref table as "0000000000 00000 // n", which is not correct, but it won't hurt anything for to // ignore these. if (offset == 0) { QTC::TC("qpdf", "QPDF bogus 0 offset", 0); warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), this->m->last_object_description, 0, "object has offset 0")); return QPDFObjectHandle::newNull(); } this->m->file->seek(offset, SEEK_SET); QPDFTokenizer::Token tobjid = readToken(this->m->file); QPDFTokenizer::Token tgen = readToken(this->m->file); QPDFTokenizer::Token tobj = readToken(this->m->file); bool objidok = (tobjid.getType() == QPDFTokenizer::tt_integer); int genok = (tgen.getType() == QPDFTokenizer::tt_integer); int objok = (tobj == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "obj")); QTC::TC("qpdf", "QPDF check objid", objidok ? 1 : 0); QTC::TC("qpdf", "QPDF check generation", genok ? 1 : 0); QTC::TC("qpdf", "QPDF check obj", objok ? 1 : 0); try { if (! (objidok && genok && objok)) { QTC::TC("qpdf", "QPDF expected n n obj"); throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), this->m->last_object_description, offset, "expected n n obj"); } objid = QUtil::string_to_int(tobjid.getValue().c_str()); generation = QUtil::string_to_int(tgen.getValue().c_str()); if (objid == 0) { QTC::TC("qpdf", "QPDF object id 0"); throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), this->m->last_object_description, offset, "object with ID 0"); } if ((exp_objid >= 0) && (! ((objid == exp_objid) && (generation == exp_generation)))) { QTC::TC("qpdf", "QPDF err wrong objid/generation"); QPDFExc e(qpdf_e_damaged_pdf, this->m->file->getName(), this->m->last_object_description, offset, std::string("expected ") + QUtil::int_to_string(exp_objid) + " " + QUtil::int_to_string(exp_generation) + " obj"); if (try_recovery) { // Will be retried below throw e; } else { // We can try reading the object anyway even if the ID // doesn't match. warn(e); } } } catch (QPDFExc& e) { if ((exp_objid >= 0) && try_recovery) { // Try again after reconstructing xref table reconstruct_xref(e); QPDFObjGen og(exp_objid, exp_generation); if (this->m->xref_table.count(og) && (this->m->xref_table[og].getType() == 1)) { qpdf_offset_t new_offset = this->m->xref_table[og].getOffset(); QPDFObjectHandle result = readObjectAtOffset( false, new_offset, description, exp_objid, exp_generation, objid, generation); QTC::TC("qpdf", "QPDF recovered in readObjectAtOffset"); return result; } else { QTC::TC("qpdf", "QPDF object gone after xref reconstruction"); warn(QPDFExc( qpdf_e_damaged_pdf, this->m->file->getName(), "", 0, std::string( "object " + QUtil::int_to_string(exp_objid) + " " + QUtil::int_to_string(exp_generation) + " not found in file after regenerating" " cross reference table"))); return QPDFObjectHandle::newNull(); } } else { throw e; } } QPDFObjectHandle oh = readObject( this->m->file, description, objid, generation, false); if (! (readToken(this->m->file) == QPDFTokenizer::Token(QPDFTokenizer::tt_word, "endobj"))) { QTC::TC("qpdf", "QPDF err expected endobj"); warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), this->m->last_object_description, this->m->file->getLastOffset(), "expected endobj")); } QPDFObjGen og(objid, generation); if (! this->m->obj_cache.count(og)) { // Store the object in the cache here so it gets cached // whether we first know the offset or whether we first know // the object ID and generation (in which we case we would get // here through resolve). // Determine the end offset of this object before and after // white space. We use these numbers to validate // linearization hint tables. Offsets and lengths of objects // may imply the end of an object to be anywhere between these // values. qpdf_offset_t end_before_space = this->m->file->tell(); // skip over spaces while (true) { char ch; if (this->m->file->read(&ch, 1)) { if (! isspace(static_cast(ch))) { this->m->file->seek(-1, SEEK_CUR); break; } } else { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), this->m->last_object_description, this->m->file->tell(), "EOF after endobj"); } } qpdf_offset_t end_after_space = this->m->file->tell(); this->m->obj_cache[og] = ObjCache(QPDFObjectHandle::ObjAccessor::getObject(oh), end_before_space, end_after_space); } return oh; } PointerHolder QPDF::resolve(int objid, int generation) { // Check object cache before checking xref table. This allows us // to insert things into the object cache that don't actually // exist in the file. QPDFObjGen og(objid, generation); if (this->m->resolving.count(og)) { // This can happen if an object references itself directly or // indirectly in some key that has to be resolved during // object parsing, such as stream length. QTC::TC("qpdf", "QPDF recursion loop in resolve"); warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", this->m->file->getLastOffset(), "loop detected resolving object " + QUtil::int_to_string(objid) + " " + QUtil::int_to_string(generation))); return new QPDF_Null; } ResolveRecorder rr(this, og); // PDF spec says unknown objects resolve to the null object. if ((! this->m->obj_cache.count(og)) && this->m->xref_table.count(og)) { QPDFXRefEntry const& entry = this->m->xref_table[og]; try { switch (entry.getType()) { case 1: { qpdf_offset_t offset = entry.getOffset(); // Object stored in cache by readObjectAtOffset int aobjid; int ageneration; QPDFObjectHandle oh = readObjectAtOffset(true, offset, "", objid, generation, aobjid, ageneration); } break; case 2: resolveObjectsInStream(entry.getObjStreamNumber()); break; default: throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", 0, "object " + QUtil::int_to_string(objid) + "/" + QUtil::int_to_string(generation) + " has unexpected xref entry type"); } } catch (QPDFExc& e) { warn(e); } catch (std::exception& e) { warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", 0, "object " + QUtil::int_to_string(objid) + "/" + QUtil::int_to_string(generation) + ": error reading object: " + e.what())); } } if (this->m->obj_cache.count(og) == 0) { QTC::TC("qpdf", "QPDF resolve failure to null"); QPDFObjectHandle oh = QPDFObjectHandle::newNull(); this->m->obj_cache[og] = ObjCache(QPDFObjectHandle::ObjAccessor::getObject(oh), -1, -1); } PointerHolder result(this->m->obj_cache[og].object); if (! result->hasDescription()) { result->setDescription( this, "object " + QUtil::int_to_string(objid) + " " + QUtil::int_to_string(generation)); } return result; } void QPDF::resolveObjectsInStream(int obj_stream_number) { // Force resolution of object stream QPDFObjectHandle obj_stream = getObjectByID(obj_stream_number, 0); if (! obj_stream.isStream()) { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), this->m->last_object_description, this->m->file->getLastOffset(), "supposed object stream " + QUtil::int_to_string(obj_stream_number) + " is not a stream"); } // For linearization data in the object, use the data from the // object stream for the objects in the stream. QPDFObjGen stream_og(obj_stream_number, 0); qpdf_offset_t end_before_space = this->m->obj_cache[stream_og].end_before_space; qpdf_offset_t end_after_space = this->m->obj_cache[stream_og].end_after_space; QPDFObjectHandle dict = obj_stream.getDict(); if (! (dict.getKey("/Type").isName() && dict.getKey("/Type").getName() == "/ObjStm")) { QTC::TC("qpdf", "QPDF ERR object stream with wrong type"); throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), this->m->last_object_description, this->m->file->getLastOffset(), "supposed object stream " + QUtil::int_to_string(obj_stream_number) + " has wrong type"); } if (! (dict.getKey("/N").isInteger() && dict.getKey("/First").isInteger())) { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), this->m->last_object_description, this->m->file->getLastOffset(), "object stream " + QUtil::int_to_string(obj_stream_number) + " has incorrect keys"); } int n = dict.getKey("/N").getIntValue(); int first = dict.getKey("/First").getIntValue(); std::map offsets; PointerHolder bp = obj_stream.getStreamData(qpdf_dl_specialized); PointerHolder input = new BufferInputSource( this->m->file->getName() + " object stream " + QUtil::int_to_string(obj_stream_number), bp.getPointer()); for (int i = 0; i < n; ++i) { QPDFTokenizer::Token tnum = readToken(input); QPDFTokenizer::Token toffset = readToken(input); if (! ((tnum.getType() == QPDFTokenizer::tt_integer) && (toffset.getType() == QPDFTokenizer::tt_integer))) { throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), this->m->last_object_description, input->getLastOffset(), "expected integer in object stream header"); } int num = QUtil::string_to_int(tnum.getValue().c_str()); int offset = QUtil::string_to_ll(toffset.getValue().c_str()); offsets[num] = offset + first; } // To avoid having to read the object stream multiple times, store // all objects that would be found here in the cache. Remember // that some objects stored here might have been overridden by new // objects appended to the file, so it is necessary to recheck the // xref table and only cache what would actually be resolved here. for (std::map::iterator iter = offsets.begin(); iter != offsets.end(); ++iter) { int obj = (*iter).first; QPDFObjGen og(obj, 0); QPDFXRefEntry const& entry = this->m->xref_table[og]; if ((entry.getType() == 2) && (entry.getObjStreamNumber() == obj_stream_number)) { int offset = (*iter).second; input->seek(offset, SEEK_SET); QPDFObjectHandle oh = readObject(input, "", obj, 0, true); this->m->obj_cache[og] = ObjCache(QPDFObjectHandle::ObjAccessor::getObject(oh), end_before_space, end_after_space); } else { QTC::TC("qpdf", "QPDF not caching overridden objstm object"); } } } QPDFObjectHandle QPDF::makeIndirectObject(QPDFObjectHandle oh) { QPDFObjGen o1(0, 0); if (! this->m->obj_cache.empty()) { o1 = (*(this->m->obj_cache.rbegin())).first; } QPDFObjGen o2 = (*(this->m->xref_table.rbegin())).first; QTC::TC("qpdf", "QPDF indirect last obj from xref", (o2.getObj() > o1.getObj()) ? 1 : 0); int max_objid = std::max(o1.getObj(), o2.getObj()); QPDFObjGen next(max_objid + 1, 0); this->m->obj_cache[next] = ObjCache(QPDFObjectHandle::ObjAccessor::getObject(oh), -1, -1); return QPDFObjectHandle::Factory::newIndirect( this, next.getObj(), next.getGen()); } QPDFObjectHandle QPDF::getObjectByObjGen(QPDFObjGen const& og) { return getObjectByID(og.getObj(), og.getGen()); } QPDFObjectHandle QPDF::getObjectByID(int objid, int generation) { return QPDFObjectHandle::Factory::newIndirect(this, objid, generation); } void QPDF::replaceObject(QPDFObjGen const& og, QPDFObjectHandle oh) { replaceObject(og.getObj(), og.getGen(), oh); } void QPDF::replaceObject(int objid, int generation, QPDFObjectHandle oh) { if (oh.isIndirect()) { QTC::TC("qpdf", "QPDF replaceObject called with indirect object"); throw std::logic_error( "QPDF::replaceObject called with indirect object handle"); } // Force new object to appear in the cache resolve(objid, generation); // Replace the object in the object cache QPDFObjGen og(objid, generation); this->m->obj_cache[og] = ObjCache(QPDFObjectHandle::ObjAccessor::getObject(oh), -1, -1); } void QPDF::replaceReserved(QPDFObjectHandle reserved, QPDFObjectHandle replacement) { QTC::TC("qpdf", "QPDF replaceReserved"); reserved.assertReserved(); replaceObject(reserved.getObjGen(), replacement); } QPDFObjectHandle QPDF::copyForeignObject(QPDFObjectHandle foreign) { return copyForeignObject(foreign, false); } QPDFObjectHandle QPDF::copyForeignObject(QPDFObjectHandle foreign, bool allow_page) { if (! foreign.isIndirect()) { QTC::TC("qpdf", "QPDF copyForeign direct"); throw std::logic_error( "QPDF::copyForeign called with direct object handle"); } QPDF* other = foreign.getOwningQPDF(); if (other == this) { QTC::TC("qpdf", "QPDF copyForeign not foreign"); throw std::logic_error( "QPDF::copyForeign called with object from this QPDF"); } ObjCopier& obj_copier = this->m->object_copiers[other]; if (! obj_copier.visiting.empty()) { throw std::logic_error("obj_copier.visiting is not empty" " at the beginning of copyForeignObject"); } // Make sure we have an object in this file for every referenced // object in the old file. obj_copier.object_map maps foreign // QPDFObjGen to local objects. For everything new that we have // to copy, the local object will be a reservation, unless it is a // stream, in which case the local object will already be a // stream. reserveObjects(foreign, obj_copier, true); if (! obj_copier.visiting.empty()) { throw std::logic_error("obj_copier.visiting is not empty" " after reserving objects"); } // Copy any new objects and replace the reservations. for (std::vector::iterator iter = obj_copier.to_copy.begin(); iter != obj_copier.to_copy.end(); ++iter) { QPDFObjectHandle& to_copy = *iter; QPDFObjectHandle copy = replaceForeignIndirectObjects(to_copy, obj_copier, true); if (! to_copy.isStream()) { QPDFObjGen og(to_copy.getObjGen()); replaceReserved(obj_copier.object_map[og], copy); } } obj_copier.to_copy.clear(); return obj_copier.object_map[foreign.getObjGen()]; } void QPDF::reserveObjects(QPDFObjectHandle foreign, ObjCopier& obj_copier, bool top) { if (foreign.isReserved()) { throw std::logic_error( "QPDF: attempting to copy a foreign reserved object"); } if (foreign.isPagesObject()) { QTC::TC("qpdf", "QPDF not copying pages object"); return; } if ((! top) && foreign.isPageObject()) { QTC::TC("qpdf", "QPDF not crossing page boundary"); return; } if (foreign.isIndirect()) { QPDFObjGen foreign_og(foreign.getObjGen()); if (obj_copier.visiting.find(foreign_og) != obj_copier.visiting.end()) { QTC::TC("qpdf", "QPDF loop reserving objects"); return; } if (obj_copier.object_map.find(foreign_og) != obj_copier.object_map.end()) { QTC::TC("qpdf", "QPDF already reserved object"); return; } QTC::TC("qpdf", "QPDF copy indirect"); obj_copier.visiting.insert(foreign_og); std::map::iterator mapping = obj_copier.object_map.find(foreign_og); if (mapping == obj_copier.object_map.end()) { obj_copier.to_copy.push_back(foreign); QPDFObjectHandle reservation; if (foreign.isStream()) { reservation = QPDFObjectHandle::newStream(this); } else { reservation = QPDFObjectHandle::newReserved(this); } obj_copier.object_map[foreign_og] = reservation; } } if (foreign.isArray()) { QTC::TC("qpdf", "QPDF reserve array"); int n = foreign.getArrayNItems(); for (int i = 0; i < n; ++i) { reserveObjects(foreign.getArrayItem(i), obj_copier, false); } } else if (foreign.isDictionary()) { QTC::TC("qpdf", "QPDF reserve dictionary"); std::set keys = foreign.getKeys(); for (std::set::iterator iter = keys.begin(); iter != keys.end(); ++iter) { reserveObjects(foreign.getKey(*iter), obj_copier, false); } } else if (foreign.isStream()) { QTC::TC("qpdf", "QPDF reserve stream"); reserveObjects(foreign.getDict(), obj_copier, false); } if (foreign.isIndirect()) { QPDFObjGen foreign_og(foreign.getObjGen()); obj_copier.visiting.erase(foreign_og); } } QPDFObjectHandle QPDF::replaceForeignIndirectObjects( QPDFObjectHandle foreign, ObjCopier& obj_copier, bool top) { QPDFObjectHandle result; if ((! top) && foreign.isIndirect()) { QTC::TC("qpdf", "QPDF replace indirect"); QPDFObjGen foreign_og(foreign.getObjGen()); std::map::iterator mapping = obj_copier.object_map.find(foreign_og); if (mapping == obj_copier.object_map.end()) { // This case would occur if this is a reference to a Page // or Pages object that we didn't traverse into. QTC::TC("qpdf", "QPDF replace foreign indirect with null"); result = QPDFObjectHandle::newNull(); } else { result = obj_copier.object_map[foreign_og]; } } else if (foreign.isArray()) { QTC::TC("qpdf", "QPDF replace array"); result = QPDFObjectHandle::newArray(); int n = foreign.getArrayNItems(); for (int i = 0; i < n; ++i) { result.appendItem( replaceForeignIndirectObjects( foreign.getArrayItem(i), obj_copier, false)); } } else if (foreign.isDictionary()) { QTC::TC("qpdf", "QPDF replace dictionary"); result = QPDFObjectHandle::newDictionary(); std::set keys = foreign.getKeys(); for (std::set::iterator iter = keys.begin(); iter != keys.end(); ++iter) { result.replaceKey( *iter, replaceForeignIndirectObjects( foreign.getKey(*iter), obj_copier, false)); } } else if (foreign.isStream()) { QTC::TC("qpdf", "QPDF replace stream"); QPDFObjGen foreign_og(foreign.getObjGen()); result = obj_copier.object_map[foreign_og]; result.assertStream(); QPDFObjectHandle dict = result.getDict(); QPDFObjectHandle old_dict = foreign.getDict(); std::set keys = old_dict.getKeys(); for (std::set::iterator iter = keys.begin(); iter != keys.end(); ++iter) { dict.replaceKey( *iter, replaceForeignIndirectObjects( old_dict.getKey(*iter), obj_copier, false)); } if (this->m->copied_stream_data_provider == 0) { this->m->copied_stream_data_provider = new CopiedStreamDataProvider(); this->m->copied_streams = this->m->copied_stream_data_provider; } QPDFObjGen local_og(result.getObjGen()); this->m->copied_stream_data_provider->registerForeignStream( local_og, foreign); result.replaceStreamData(this->m->copied_streams, dict.getKey("/Filter"), dict.getKey("/DecodeParms")); } else { foreign.assertScalar(); result = foreign; result.makeDirect(); } if (top && (! result.isStream()) && result.isIndirect()) { throw std::logic_error("replacement for foreign object is indirect"); } return result; } void QPDF::swapObjects(QPDFObjGen const& og1, QPDFObjGen const& og2) { swapObjects(og1.getObj(), og1.getGen(), og2.getObj(), og2.getGen()); } void QPDF::swapObjects(int objid1, int generation1, int objid2, int generation2) { // Force objects to be loaded into cache; then swap them in the // cache. resolve(objid1, generation1); resolve(objid2, generation2); QPDFObjGen og1(objid1, generation1); QPDFObjGen og2(objid2, generation2); ObjCache t = this->m->obj_cache[og1]; this->m->obj_cache[og1] = this->m->obj_cache[og2]; this->m->obj_cache[og2] = t; } std::string QPDF::getFilename() const { return this->m->file->getName(); } std::string QPDF::getPDFVersion() const { return this->m->pdf_version; } int QPDF::getExtensionLevel() { int result = 0; QPDFObjectHandle obj = getRoot(); if (obj.hasKey("/Extensions")) { obj = obj.getKey("/Extensions"); if (obj.isDictionary() && obj.hasKey("/ADBE")) { obj = obj.getKey("/ADBE"); if (obj.isDictionary() && obj.hasKey("/ExtensionLevel")) { obj = obj.getKey("/ExtensionLevel"); if (obj.isInteger()) { result = obj.getIntValue(); } } } } return result; } QPDFObjectHandle QPDF::getTrailer() { return this->m->trailer; } QPDFObjectHandle QPDF::getRoot() { QPDFObjectHandle root = this->m->trailer.getKey("/Root"); if (! root.isDictionary()) { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", this->m->file->getLastOffset(), "unable to find /Root dictionary"); } return root; } void QPDF::getObjectStreamData(std::map& omap) { for (std::map::iterator iter = this->m->xref_table.begin(); iter != this->m->xref_table.end(); ++iter) { QPDFObjGen const& og = (*iter).first; QPDFXRefEntry const& entry = (*iter).second; if (entry.getType() == 2) { omap[og.getObj()] = entry.getObjStreamNumber(); } } } std::vector QPDF::getCompressibleObjGens() { // Return a list of objects that are allowed to be in object // streams. Walk through the objects by traversing the document // from the root, including a traversal of the pages tree. This // makes that objects that are on the same page are more likely to // be in the same object stream, which is slightly more efficient, // particularly with linearized files. This is better than // iterating through the xref table since it avoids preserving // orphaned items. // Exclude encryption dictionary, if any QPDFObjectHandle encryption_dict = this->m->trailer.getKey("/Encrypt"); QPDFObjGen encryption_dict_og = encryption_dict.getObjGen(); std::set visited; std::list queue; queue.push_front(this->m->trailer); std::vector result; while (! queue.empty()) { QPDFObjectHandle obj = queue.front(); queue.pop_front(); if (obj.isIndirect()) { QPDFObjGen og = obj.getObjGen(); if (visited.count(og)) { QTC::TC("qpdf", "QPDF loop detected traversing objects"); continue; } if (og == encryption_dict_og) { QTC::TC("qpdf", "QPDF exclude encryption dictionary"); } else if (! obj.isStream()) { result.push_back(og); } visited.insert(og); } if (obj.isStream()) { QPDFObjectHandle dict = obj.getDict(); std::set keys = dict.getKeys(); for (std::set::reverse_iterator iter = keys.rbegin(); iter != keys.rend(); ++iter) { std::string const& key = *iter; QPDFObjectHandle value = dict.getKey(key); if (key == "/Length") { // omit stream lengths if (value.isIndirect()) { QTC::TC("qpdf", "QPDF exclude indirect length"); } } else { queue.push_front(value); } } } else if (obj.isDictionary()) { std::set keys = obj.getKeys(); for (std::set::reverse_iterator iter = keys.rbegin(); iter != keys.rend(); ++iter) { queue.push_front(obj.getKey(*iter)); } } else if (obj.isArray()) { int n = obj.getArrayNItems(); for (int i = 1; i <= n; ++i) { queue.push_front(obj.getArrayItem(n - i)); } } } return result; } bool QPDF::pipeStreamData(int objid, int generation, qpdf_offset_t offset, size_t length, QPDFObjectHandle stream_dict, Pipeline* pipeline, bool suppress_warnings, bool will_retry) { bool success = false; std::vector > to_delete; if (this->m->encrypted) { decryptStream(pipeline, objid, generation, stream_dict, to_delete); } try { this->m->file->seek(offset, SEEK_SET); char buf[10240]; while (length > 0) { size_t to_read = (sizeof(buf) < length ? sizeof(buf) : length); size_t len = this->m->file->read(buf, to_read); if (len == 0) { throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), this->m->last_object_description, this->m->file->getLastOffset(), "unexpected EOF reading stream data"); } length -= len; pipeline->write(QUtil::unsigned_char_pointer(buf), len); } pipeline->finish(); success = true; } catch (QPDFExc& e) { if (! suppress_warnings) { warn(e); } } catch (std::exception& e) { if (! suppress_warnings) { QTC::TC("qpdf", "QPDF decoding error warning"); warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", this->m->file->getLastOffset(), "error decoding stream data for object " + QUtil::int_to_string(objid) + " " + QUtil::int_to_string(generation) + ": " + e.what())); if (will_retry) { warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", this->m->file->getLastOffset(), "stream will be re-processed without" " filtering to avoid data loss")); } } } if (! success) { try { pipeline->finish(); } catch (std::exception&) { // ignore } } return success; } void QPDF::findAttachmentStreams() { QPDFObjectHandle root = getRoot(); QPDFObjectHandle names = root.getKey("/Names"); if (! names.isDictionary()) { return; } QPDFObjectHandle embeddedFiles = names.getKey("/EmbeddedFiles"); if (! embeddedFiles.isDictionary()) { return; } names = embeddedFiles.getKey("/Names"); if (! names.isArray()) { return; } for (int i = 0; i < names.getArrayNItems(); ++i) { QPDFObjectHandle item = names.getArrayItem(i); if (item.isDictionary() && item.getKey("/Type").isName() && (item.getKey("/Type").getName() == "/Filespec") && item.getKey("/EF").isDictionary() && item.getKey("/EF").getKey("/F").isStream()) { QPDFObjectHandle stream = item.getKey("/EF").getKey("/F"); this->m->attachment_streams.insert(stream.getObjGen()); } } }