diff options
Diffstat (limited to 'libqpdf/QPDF.cc')
| -rw-r--r-- | libqpdf/QPDF.cc | 496 |
1 files changed, 157 insertions, 339 deletions
diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc index e1ce5fc4..bee2f3ee 100644 --- a/libqpdf/QPDF.cc +++ b/libqpdf/QPDF.cc @@ -68,6 +68,18 @@ QPDF::CopiedStreamDataProvider::registerForeignStream( 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() @@ -940,358 +952,164 @@ QPDF::readObject(PointerHolder<InputSource> input, { setLastObjectDescription(description, objid, generation); qpdf_offset_t offset = input->tell(); - QPDFObjectHandle object = readObjectInternal( - input, objid, generation, in_object_stream, false, false); - // Override last_offset so that it points to the beginning of the - // object we just read - input->setLastOffset(offset); - return object; -} - -QPDFObjectHandle -QPDF::readObjectInternal(PointerHolder<InputSource> input, - int objid, int generation, - bool in_object_stream, - bool in_array, bool in_dictionary) -{ - if (in_dictionary && in_array) - { - // Although dictionaries and arrays arbitrarily nest, these - // variables indicate what is at the top of the stack right - // now, so they can, by definition, never both be true. - throw std::logic_error( - "INTERNAL ERROR: readObjectInternal: in_dict && in_array"); - } - - QPDFObjectHandle object; - qpdf_offset_t offset = input->tell(); - std::vector<QPDFObjectHandle> olist; - bool done = false; - while (! done) + bool empty = false; + PointerHolder<StringDecrypter> decrypter_ph; + StringDecrypter* decrypter = 0; + if (this->encrypted && (! in_object_stream)) { - object = QPDFObjectHandle(); - - QPDFTokenizer::Token token = readToken(input); - - switch (token.getType()) - { - case QPDFTokenizer::tt_brace_open: - case QPDFTokenizer::tt_brace_close: - // Don't know what to do with these for now - QTC::TC("qpdf", "QPDF bad brace"); - throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), - this->last_object_description, - input->getLastOffset(), - "unexpected brace token"); - break; - - case QPDFTokenizer::tt_array_close: - if (in_array) - { - done = true; - } - else - { - QTC::TC("qpdf", "QPDF bad array close"); - throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), - this->last_object_description, - input->getLastOffset(), - "unexpected array close token"); - } - break; - - case QPDFTokenizer::tt_dict_close: - if (in_dictionary) - { - done = true; - } - else - { - QTC::TC("qpdf", "QPDF bad dictionary close"); - throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), - this->last_object_description, - input->getLastOffset(), - "unexpected dictionary close token"); - } - break; - - case QPDFTokenizer::tt_array_open: - object = readObjectInternal( - input, objid, generation, in_object_stream, true, false); - break; - - case QPDFTokenizer::tt_dict_open: - object = readObjectInternal( - input, objid, generation, in_object_stream, false, true); - break; - - case QPDFTokenizer::tt_bool: - object = QPDFObjectHandle::newBool( - (token.getValue() == "true")); - break; - - case QPDFTokenizer::tt_null: - object = QPDFObjectHandle::newNull(); - break; - - case QPDFTokenizer::tt_integer: - object = QPDFObjectHandle::newInteger( - QUtil::string_to_ll(token.getValue().c_str())); - break; - - case QPDFTokenizer::tt_real: - object = QPDFObjectHandle::newReal(token.getValue()); - break; - - case QPDFTokenizer::tt_name: - object = QPDFObjectHandle::newName(token.getValue()); - break; - - case QPDFTokenizer::tt_word: - { - std::string const& value = token.getValue(); - if ((value == "R") && (in_array || in_dictionary) && - (olist.size() >= 2) && - (olist[olist.size() - 1].isInteger()) && - (olist[olist.size() - 2].isInteger())) - { - // Try to resolve indirect objects - object = QPDFObjectHandle::Factory::newIndirect( - this, - olist[olist.size() - 2].getIntValue(), - olist[olist.size() - 1].getIntValue()); - olist.pop_back(); - olist.pop_back(); - } - else if ((value == "endobj") && - (! (in_array || in_dictionary))) - { - // 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->last_object_description, - input->getLastOffset(), - "empty object treated as null")); - object = QPDFObjectHandle::newNull(); - input->seek(input->getLastOffset(), SEEK_SET); - } - else - { - throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), - this->last_object_description, - input->getLastOffset(), - "unknown token while reading object (" + - value + ")"); - } - } - break; - - case QPDFTokenizer::tt_string: - { - std::string val = token.getValue(); - if (this->encrypted && (! in_object_stream)) - { - decryptString(val, objid, generation); - } - object = QPDFObjectHandle::newString(val); - } - break; - - default: - throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), - this->last_object_description, - input->getLastOffset(), - "unknown token type while reading object"); - break; - } - - if (in_dictionary || in_array) - { - if (! done) - { - olist.push_back(object); - } - } - else if (! object.isInitialized()) - { - throw std::logic_error( - "INTERNAL ERROR: uninitialized object (token = " + - QUtil::int_to_string(token.getType()) + - ", " + token.getValue() + ")"); - } - else - { - done = true; - } + decrypter_ph = new StringDecrypter(this, objid, generation); + decrypter = decrypter_ph.getPointer(); } - - if (in_array) + QPDFObjectHandle object = QPDFObjectHandle::parse( + input, description, this->tokenizer, empty, decrypter, this); + if (empty) { - object = QPDFObjectHandle::newArray(olist); + // 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->last_object_description, + input->getLastOffset(), + "empty object treated as null")); } - else if (in_dictionary) + else if (object.isDictionary() && (! in_object_stream)) { - // Convert list to map. Alternating elements are keys. - std::map<std::string, QPDFObjectHandle> dict; - if (olist.size() % 2) - { - QTC::TC("qpdf", "QPDF dictionary odd number of elements"); - throw QPDFExc( - qpdf_e_damaged_pdf, input->getName(), - this->last_object_description, input->getLastOffset(), - "dictionary ending here has an odd number of elements"); - } - for (unsigned int i = 0; i < olist.size(); i += 2) - { - QPDFObjectHandle key_obj = olist[i]; - QPDFObjectHandle val = olist[i + 1]; - if (! key_obj.isName()) - { - throw QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), this->last_object_description, offset, - std::string("dictionary key not name (") + - key_obj.unparse() + ")"); - } - dict[key_obj.getName()] = val; - } - object = QPDFObjectHandle::newDictionary(dict); + // 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->last_object_description, + input->tell(), + "stream keyword followed" + " by carriage return only")); + } + } + } + else + { + QTC::TC("qpdf", "QPDF stream without newline"); + warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(), + this->last_object_description, + input->tell(), + "stream keyword not followed" + " by proper line terminator")); + } + } - if (! 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->last_object_description, - input->tell(), - "stream keyword followed" - " by carriage return only")); - } - } - } - else - { - QTC::TC("qpdf", "QPDF stream without newline"); - warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(), - this->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; - // 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<std::string, QPDFObjectHandle> dict = + object.getDictAsMap(); - try - { - if (dict.count("/Length") == 0) - { - QTC::TC("qpdf", "QPDF stream without length"); - throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), - this->last_object_description, offset, - "stream dictionary lacks /Length key"); - } + if (dict.count("/Length") == 0) + { + QTC::TC("qpdf", "QPDF stream without length"); + throw QPDFExc(qpdf_e_damaged_pdf, input->getName(), + this->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->last_object_description, offset, - "/Length key in stream dictionary is not " - "an integer"); - } + 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->last_object_description, offset, + "/Length key in stream dictionary is not " + "an integer"); + } - length = length_obj.getIntValue(); - input->seek( - stream_offset + (qpdf_offset_t)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->last_object_description, - input->getLastOffset(), - "expected endstream"); - } - } - catch (QPDFExc& e) - { - if (this->attempt_recovery) - { - // may throw an exception - 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); - } - } + length = length_obj.getIntValue(); + input->seek( + stream_offset + (qpdf_offset_t)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->last_object_description, + input->getLastOffset(), + "expected endstream"); + } + } + catch (QPDFExc& e) + { + if (this->attempt_recovery) + { + // may throw an exception + 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; } |