From 6670c685ab9f929121c5498115b278c95574e461 Mon Sep 17 00:00:00 2001 From: m-holger Date: Tue, 16 Aug 2022 13:59:32 +0100 Subject: Move QPDFObjectHandle::parseInternal to new class QPDFParser Part of #729 --- libqpdf/QPDFObjectHandle.cc | 498 +------------------------------------------- 1 file changed, 5 insertions(+), 493 deletions(-) (limited to 'libqpdf/QPDFObjectHandle.cc') diff --git a/libqpdf/QPDFObjectHandle.cc b/libqpdf/QPDFObjectHandle.cc index 8a2d59e3..377a1cbb 100644 --- a/libqpdf/QPDFObjectHandle.cc +++ b/libqpdf/QPDFObjectHandle.cc @@ -8,6 +8,7 @@ #include #include #include +#include #include #include #include @@ -1879,8 +1880,8 @@ QPDFObjectHandle::parseContentStream_data( tokenizer.readToken(input, "content", true); qpdf_offset_t offset = input->getLastOffset(); input->seek(offset, SEEK_SET); - QPDFObjectHandle obj = parseInternal( - input, "content", tokenizer, empty, nullptr, context, true); + auto obj = QPDFParser(input, "content", tokenizer, nullptr, context) + .parse(empty, true); if (!obj.isInitialized()) { // EOF break; @@ -1943,497 +1944,8 @@ QPDFObjectHandle::parse( StringDecrypter* decrypter, QPDF* context) { - return parseInternal( - input, object_description, tokenizer, empty, decrypter, context, false); -} - -QPDFObjectHandle -QPDFObjectHandle::parseInternal( - std::shared_ptr input, - std::string const& object_description, - QPDFTokenizer& tokenizer, - bool& empty, - StringDecrypter* decrypter, - QPDF* context, - bool content_stream) -{ - // This method must take care not to resolve any objects. Don't - // check the type of any object without first ensuring that it is - // a direct object. Otherwise, doing so may have the side effect - // of reading the object and changing the file pointer. If you do - // this, it will cause a logic error to be thrown from - // QPDF::inParse(). - - QPDF::ParseGuard pg(context); - - empty = false; - - QPDFObjectHandle object; - bool set_offset = false; - - std::vector olist_stack; - olist_stack.push_back(SparseOHArray()); - std::vector state_stack; - state_stack.push_back(st_top); - std::vector offset_stack; - qpdf_offset_t offset = input->tell(); - offset_stack.push_back(offset); - bool done = false; - int bad_count = 0; - int good_count = 0; - bool b_contents = false; - std::vector contents_string_stack; - contents_string_stack.push_back(""); - std::vector contents_offset_stack; - contents_offset_stack.push_back(-1); - while (!done) { - bool bad = false; - SparseOHArray& olist = olist_stack.back(); - parser_state_e state = state_stack.back(); - offset = offset_stack.back(); - std::string& contents_string = contents_string_stack.back(); - qpdf_offset_t& contents_offset = contents_offset_stack.back(); - - object = QPDFObjectHandle(); - set_offset = false; - - QPDFTokenizer::Token token = - tokenizer.readToken(input, object_description, true); - std::string const& token_error_message = token.getErrorMessage(); - if (!token_error_message.empty()) { - // Tokens other than tt_bad can still generate warnings. - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - input->getLastOffset(), - token_error_message)); - } - - switch (token.getType()) { - case QPDFTokenizer::tt_eof: - if (!content_stream) { - QTC::TC("qpdf", "QPDFObjectHandle eof in parseInternal"); - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - input->getLastOffset(), - "unexpected EOF")); - } - bad = true; - state = st_eof; - break; - - case QPDFTokenizer::tt_bad: - QTC::TC("qpdf", "QPDFObjectHandle bad token in parse"); - bad = true; - object = newNull(); - break; - - case QPDFTokenizer::tt_brace_open: - case QPDFTokenizer::tt_brace_close: - QTC::TC("qpdf", "QPDFObjectHandle bad brace"); - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - input->getLastOffset(), - "treating unexpected brace token as null")); - bad = true; - object = newNull(); - break; - - case QPDFTokenizer::tt_array_close: - if (state == st_array) { - state = st_stop; - } else { - QTC::TC("qpdf", "QPDFObjectHandle bad array close"); - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - input->getLastOffset(), - "treating unexpected array close token as null")); - bad = true; - object = newNull(); - } - break; - - case QPDFTokenizer::tt_dict_close: - if (state == st_dictionary) { - state = st_stop; - } else { - QTC::TC("qpdf", "QPDFObjectHandle bad dictionary close"); - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - input->getLastOffset(), - "unexpected dictionary close token")); - bad = true; - object = newNull(); - } - break; - - case QPDFTokenizer::tt_array_open: - case QPDFTokenizer::tt_dict_open: - if (olist_stack.size() > 500) { - QTC::TC("qpdf", "QPDFObjectHandle too deep"); - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - input->getLastOffset(), - "ignoring excessively deeply nested data structure")); - bad = true; - object = newNull(); - state = st_top; - } else { - olist_stack.push_back(SparseOHArray()); - state = st_start; - offset_stack.push_back(input->tell()); - state_stack.push_back( - (token.getType() == QPDFTokenizer::tt_array_open) - ? st_array - : st_dictionary); - b_contents = false; - contents_string_stack.push_back(""); - contents_offset_stack.push_back(-1); - } - break; - - case QPDFTokenizer::tt_bool: - object = newBool((token.getValue() == "true")); - break; - - case QPDFTokenizer::tt_null: - object = newNull(); - break; - - case QPDFTokenizer::tt_integer: - object = newInteger(QUtil::string_to_ll(token.getValue().c_str())); - break; - - case QPDFTokenizer::tt_real: - object = newReal(token.getValue()); - break; - - case QPDFTokenizer::tt_name: - { - std::string name = token.getValue(); - object = newName(name); - - if (name == "/Contents") { - b_contents = true; - } else { - b_contents = false; - } - } - break; - - case QPDFTokenizer::tt_word: - { - std::string const& value = token.getValue(); - if (content_stream) { - object = QPDFObjectHandle::newOperator(value); - } else if ( - (value == "R") && (state != st_top) && - (olist.size() >= 2) && - (!olist.at(olist.size() - 1).isIndirect()) && - (olist.at(olist.size() - 1).isInteger()) && - (!olist.at(olist.size() - 2).isIndirect()) && - (olist.at(olist.size() - 2).isInteger())) { - if (context == nullptr) { - QTC::TC( - "qpdf", - "QPDFObjectHandle indirect without context"); - throw std::logic_error( - "QPDFObjectHandle::parse called without context" - " on an object with indirect references"); - } - // Try to resolve indirect objects - object = newIndirect( - context, - QPDFObjGen( - olist.at(olist.size() - 2).getIntValueAsInt(), - olist.at(olist.size() - 1).getIntValueAsInt())); - olist.remove_last(); - olist.remove_last(); - } else if ((value == "endobj") && (state == st_top)) { - // We just saw endobj without having read - // anything. Treat this as a null and do not move - // the input source's offset. - object = newNull(); - input->seek(input->getLastOffset(), SEEK_SET); - empty = true; - } else { - QTC::TC("qpdf", "QPDFObjectHandle treat word as string"); - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - input->getLastOffset(), - "unknown token while reading object;" - " treating as string")); - bad = true; - object = newString(value); - } - } - break; - - case QPDFTokenizer::tt_string: - { - std::string val = token.getValue(); - if (decrypter) { - if (b_contents) { - contents_string = val; - contents_offset = input->getLastOffset(); - b_contents = false; - } - decrypter->decryptString(val); - } - object = QPDFObjectHandle::newString(val); - } - - break; - - default: - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - input->getLastOffset(), - "treating unknown token type as null while " - "reading object")); - bad = true; - object = newNull(); - break; - } - - if ((!object.isInitialized()) && - (!((state == st_start) || (state == st_stop) || - (state == st_eof)))) { - throw std::logic_error("QPDFObjectHandle::parseInternal: " - "unexpected uninitialized object"); - object = newNull(); - } - - if (bad) { - ++bad_count; - good_count = 0; - } else { - ++good_count; - if (good_count > 3) { - bad_count = 0; - } - } - if (bad_count > 5) { - // We had too many consecutive errors without enough - // intervening successful objects. Give up. - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - input->getLastOffset(), - "too many errors; giving up on reading object")); - state = st_top; - object = newNull(); - } - - switch (state) { - case st_eof: - if (state_stack.size() > 1) { - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - input->getLastOffset(), - "parse error while reading object")); - } - done = true; - // In content stream mode, leave object uninitialized to - // indicate EOF - if (!content_stream) { - object = newNull(); - } - break; - - case st_dictionary: - case st_array: - setObjectDescriptionFromInput( - object, - context, - object_description, - input, - input->getLastOffset()); - object.setParsedOffset(input->getLastOffset()); - set_offset = true; - olist.append(object); - break; - - case st_top: - done = true; - break; - - case st_start: - break; - - case st_stop: - if ((state_stack.size() < 2) || (olist_stack.size() < 2)) { - throw std::logic_error( - "QPDFObjectHandle::parseInternal: st_stop encountered" - " with insufficient elements in stack"); - } - parser_state_e old_state = state_stack.back(); - state_stack.pop_back(); - if (old_state == st_array) { - // There's no newArray(SparseOHArray) since - // SparseOHArray is not part of the public API. - object = QPDFObjectHandle(QPDF_Array::create(olist)); - setObjectDescriptionFromInput( - object, context, object_description, input, offset); - // The `offset` points to the next of "[". Set the - // rewind offset to point to the beginning of "[". - // This has been explicitly tested with whitespace - // surrounding the array start delimiter. - // getLastOffset points to the array end token and - // therefore can't be used here. - object.setParsedOffset(offset - 1); - set_offset = true; - } else if (old_state == st_dictionary) { - // Convert list to map. Alternating elements are keys. - // Attempt to recover more or less gracefully from - // invalid dictionaries. - std::set names; - size_t n_elements = olist.size(); - for (size_t i = 0; i < n_elements; ++i) { - QPDFObjectHandle oh = olist.at(i); - if ((!oh.isIndirect()) && oh.isName()) { - names.insert(oh.getName()); - } - } - - std::map dict; - int next_fake_key = 1; - for (unsigned int i = 0; i < olist.size(); ++i) { - QPDFObjectHandle key_obj = olist.at(i); - QPDFObjectHandle val; - if (key_obj.isIndirect() || (!key_obj.isName())) { - bool found_fake = false; - std::string candidate; - while (!found_fake) { - candidate = "/QPDFFake" + - QUtil::int_to_string(next_fake_key++); - found_fake = (names.count(candidate) == 0); - QTC::TC( - "qpdf", - "QPDFObjectHandle found fake", - (found_fake ? 0 : 1)); - } - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - offset, - "expected dictionary key but found" - " non-name object; inserting key " + - candidate)); - val = key_obj; - key_obj = newName(candidate); - } else if (i + 1 >= olist.size()) { - QTC::TC("qpdf", "QPDFObjectHandle no val for last key"); - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - offset, - "dictionary ended prematurely; " - "using null as value for last key")); - val = newNull(); - setObjectDescriptionFromInput( - val, context, object_description, input, offset); - } else { - val = olist.at(++i); - } - std::string key = key_obj.getName(); - if (dict.count(key) > 0) { - QTC::TC("qpdf", "QPDFObjectHandle duplicate dict key"); - warn( - context, - QPDFExc( - qpdf_e_damaged_pdf, - input->getName(), - object_description, - offset, - "dictionary has duplicated key " + key + - "; last occurrence overrides earlier " - "ones")); - } - dict[key] = val; - } - if (!contents_string.empty() && dict.count("/Type") && - dict["/Type"].isNameAndEquals("/Sig") && - dict.count("/ByteRange") && dict.count("/Contents") && - dict["/Contents"].isString()) { - dict["/Contents"] = - QPDFObjectHandle::newString(contents_string); - dict["/Contents"].setParsedOffset(contents_offset); - } - object = newDictionary(dict); - setObjectDescriptionFromInput( - object, context, object_description, input, offset); - // The `offset` points to the next of "<<". Set the - // rewind offset to point to the beginning of "<<". - // This has been explicitly tested with whitespace - // surrounding the dictionary start delimiter. - // getLastOffset points to the dictionary end token - // and therefore can't be used here. - object.setParsedOffset(offset - 2); - set_offset = true; - } - olist_stack.pop_back(); - offset_stack.pop_back(); - if (state_stack.back() == st_top) { - done = true; - } else { - olist_stack.back().append(object); - } - contents_string_stack.pop_back(); - contents_offset_stack.pop_back(); - } - } - - if (!set_offset) { - setObjectDescriptionFromInput( - object, context, object_description, input, offset); - object.setParsedOffset(offset); - } - return object; + return QPDFParser(input, object_description, tokenizer, decrypter, context) + .parse(empty, false); } qpdf_offset_t -- cgit v1.2.3-54-g00ecf