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mirror of https://github.com/qpdf/qpdf.git synced 2024-05-29 08:20:53 +00:00
qpdf/libqpdf/QPDF_Stream.cc
Jay Berkenbilt 9044a24097 PointerHolder: deprecate getPointer() and getRefcount()
Use get() and use_count() instead. Add #define
NO_POINTERHOLDER_DEPRECATION to remove deprecation markers for these
only.

This commit also removes all deprecated PointerHolder API calls from
qpdf's code except in PointerHolder's test suite, which must continue
to test the deprecated APIs.
2022-02-04 13:12:37 -05:00

690 lines
18 KiB
C++

#include <qpdf/QPDF_Stream.hh>
#include <qpdf/QUtil.hh>
#include <qpdf/Pipeline.hh>
#include <qpdf/Pl_Flate.hh>
#include <qpdf/Pl_Buffer.hh>
#include <qpdf/Pl_Count.hh>
#include <qpdf/ContentNormalizer.hh>
#include <qpdf/QTC.hh>
#include <qpdf/QPDF.hh>
#include <qpdf/QPDFExc.hh>
#include <qpdf/Pl_QPDFTokenizer.hh>
#include <qpdf/QIntC.hh>
#include <qpdf/SF_FlateLzwDecode.hh>
#include <qpdf/SF_DCTDecode.hh>
#include <qpdf/SF_RunLengthDecode.hh>
#include <qpdf/SF_ASCII85Decode.hh>
#include <qpdf/SF_ASCIIHexDecode.hh>
#include <stdexcept>
class SF_Crypt: public QPDFStreamFilter
{
public:
SF_Crypt() = default;
virtual ~SF_Crypt() = default;
virtual bool setDecodeParms(QPDFObjectHandle decode_parms)
{
if (decode_parms.isNull())
{
return true;
}
bool filterable = true;
for (auto const& key: decode_parms.getKeys())
{
if (((key == "/Type") || (key == "/Name")) &&
((! decode_parms.hasKey("/Type")) ||
decode_parms.isDictionaryOfType("/CryptFilterDecodeParms")))
{
// we handle this in decryptStream
}
else
{
filterable = false;
}
}
return filterable;
}
virtual Pipeline* getDecodePipeline(Pipeline*)
{
// Not used -- handled by pipeStreamData
return nullptr;
}
};
std::map<std::string, std::string> QPDF_Stream::filter_abbreviations = {
// The PDF specification provides these filter abbreviations for
// use in inline images, but according to table H.1 in the pre-ISO
// versions of the PDF specification, Adobe Reader also accepts
// them for stream filters.
{"/AHx", "/ASCIIHexDecode"},
{"/A85", "/ASCII85Decode"},
{"/LZW", "/LZWDecode"},
{"/Fl", "/FlateDecode"},
{"/RL", "/RunLengthDecode"},
{"/CCF", "/CCITTFaxDecode"},
{"/DCT", "/DCTDecode"},
};
std::map<
std::string,
std::function<std::shared_ptr<QPDFStreamFilter>()>>
QPDF_Stream::filter_factories = {
{"/Crypt", []() { return std::make_shared<SF_Crypt>(); }},
{"/FlateDecode", SF_FlateLzwDecode::flate_factory},
{"/LZWDecode", SF_FlateLzwDecode::lzw_factory},
{"/RunLengthDecode", SF_RunLengthDecode::factory},
{"/DCTDecode", SF_DCTDecode::factory},
{"/ASCII85Decode", SF_ASCII85Decode::factory},
{"/ASCIIHexDecode", SF_ASCIIHexDecode::factory},
};
QPDF_Stream::QPDF_Stream(QPDF* qpdf, int objid, int generation,
QPDFObjectHandle stream_dict,
qpdf_offset_t offset, size_t length) :
qpdf(qpdf),
objid(objid),
generation(generation),
filter_on_write(true),
stream_dict(stream_dict),
offset(offset),
length(length)
{
if (! stream_dict.isDictionary())
{
throw std::logic_error(
"stream object instantiated with non-dictionary "
"object for dictionary");
}
setStreamDescription();
}
QPDF_Stream::~QPDF_Stream()
{
}
void
QPDF_Stream::registerStreamFilter(
std::string const& filter_name,
std::function<std::shared_ptr<QPDFStreamFilter>()> factory)
{
filter_factories[filter_name] = factory;
}
void
QPDF_Stream::setFilterOnWrite(bool val)
{
this->filter_on_write = val;
}
bool
QPDF_Stream::getFilterOnWrite() const
{
return this->filter_on_write;
}
void
QPDF_Stream::releaseResolved()
{
this->stream_provider = 0;
QPDFObjectHandle::ReleaseResolver::releaseResolved(this->stream_dict);
}
void
QPDF_Stream::setObjGen(int objid, int generation)
{
if (! ((this->objid == 0) && (this->generation == 0)))
{
throw std::logic_error(
"attempt to set object ID and generation of a stream"
" that already has them");
}
this->objid = objid;
this->generation = generation;
}
std::string
QPDF_Stream::unparse()
{
// Unparse stream objects as indirect references
return QUtil::int_to_string(this->objid) + " " +
QUtil::int_to_string(this->generation) + " R";
}
JSON
QPDF_Stream::getJSON()
{
return this->stream_dict.getJSON();
}
QPDFObject::object_type_e
QPDF_Stream::getTypeCode() const
{
return QPDFObject::ot_stream;
}
char const*
QPDF_Stream::getTypeName() const
{
return "stream";
}
void
QPDF_Stream::setDescription(QPDF* qpdf, std::string const& description)
{
this->QPDFObject::setDescription(qpdf, description);
setDictDescription();
}
void
QPDF_Stream::setStreamDescription()
{
setDescription(
this->qpdf,
this->qpdf->getFilename() +
", stream object " + QUtil::int_to_string(this->objid) + " " +
QUtil::int_to_string(this->generation));
}
void
QPDF_Stream::setDictDescription()
{
QPDF* qpdf = 0;
std::string description;
if ((! this->stream_dict.hasObjectDescription()) &&
getDescription(qpdf, description))
{
this->stream_dict.setObjectDescription(
qpdf, description + " -> stream dictionary");
}
}
QPDFObjectHandle
QPDF_Stream::getDict() const
{
return this->stream_dict;
}
bool
QPDF_Stream::isDataModified() const
{
return (! this->token_filters.empty());
}
qpdf_offset_t
QPDF_Stream::getOffset() const
{
return this->offset;
}
size_t
QPDF_Stream::getLength() const
{
return this->length;
}
PointerHolder<Buffer>
QPDF_Stream::getStreamDataBuffer() const
{
return this->stream_data;
}
PointerHolder<QPDFObjectHandle::StreamDataProvider>
QPDF_Stream::getStreamDataProvider() const
{
return this->stream_provider;
}
PointerHolder<Buffer>
QPDF_Stream::getStreamData(qpdf_stream_decode_level_e decode_level)
{
Pl_Buffer buf("stream data buffer");
bool filtered;
pipeStreamData(&buf, &filtered, 0, decode_level, false, false);
if (! filtered)
{
throw QPDFExc(qpdf_e_unsupported, qpdf->getFilename(),
"", this->offset,
"getStreamData called on unfilterable stream");
}
QTC::TC("qpdf", "QPDF_Stream getStreamData");
return buf.getBuffer();
}
PointerHolder<Buffer>
QPDF_Stream::getRawStreamData()
{
Pl_Buffer buf("stream data buffer");
if (! pipeStreamData(&buf, nullptr, 0, qpdf_dl_none, false, false))
{
throw QPDFExc(qpdf_e_unsupported, qpdf->getFilename(),
"", this->offset,
"error getting raw stream data");
}
QTC::TC("qpdf", "QPDF_Stream getRawStreamData");
return buf.getBuffer();
}
bool
QPDF_Stream::filterable(
std::vector<std::shared_ptr<QPDFStreamFilter>>& filters,
bool& specialized_compression,
bool& lossy_compression)
{
// Check filters
QPDFObjectHandle filter_obj = this->stream_dict.getKey("/Filter");
bool filters_okay = true;
std::vector<std::string> filter_names;
if (filter_obj.isNull())
{
// No filters
}
else if (filter_obj.isName())
{
// One filter
filter_names.push_back(filter_obj.getName());
}
else if (filter_obj.isArray())
{
// Potentially multiple filters
int n = filter_obj.getArrayNItems();
for (int i = 0; i < n; ++i)
{
QPDFObjectHandle item = filter_obj.getArrayItem(i);
if (item.isName())
{
filter_names.push_back(item.getName());
}
else
{
filters_okay = false;
}
}
}
else
{
filters_okay = false;
}
if (! filters_okay)
{
QTC::TC("qpdf", "QPDF_Stream invalid filter");
warn(QPDFExc(qpdf_e_damaged_pdf, qpdf->getFilename(),
"", this->offset,
"stream filter type is not name or array"));
return false;
}
bool filterable = true;
for (auto& filter_name: filter_names)
{
if (filter_abbreviations.count(filter_name))
{
QTC::TC("qpdf", "QPDF_Stream expand filter abbreviation");
filter_name = filter_abbreviations[filter_name];
}
auto ff = filter_factories.find(filter_name);
if (ff == filter_factories.end())
{
filterable = false;
}
else
{
filters.push_back((ff->second)());
}
}
if (! filterable)
{
return false;
}
// filters now contains a list of filters to be applied in order.
// See which ones we can support.
// See if we can support any decode parameters that are specified.
QPDFObjectHandle decode_obj = this->stream_dict.getKey("/DecodeParms");
std::vector<QPDFObjectHandle> decode_parms;
if (decode_obj.isArray() && (decode_obj.getArrayNItems() == 0))
{
decode_obj = QPDFObjectHandle::newNull();
}
if (decode_obj.isArray())
{
for (int i = 0; i < decode_obj.getArrayNItems(); ++i)
{
decode_parms.push_back(decode_obj.getArrayItem(i));
}
}
else
{
for (unsigned int i = 0; i < filter_names.size(); ++i)
{
decode_parms.push_back(decode_obj);
}
}
// Ignore /DecodeParms entirely if /Filters is empty. At least
// one case of a file whose /DecodeParms was [ << >> ] when
// /Filters was empty has been seen in the wild.
if ((filters.size() != 0) && (decode_parms.size() != filters.size()))
{
warn(QPDFExc(qpdf_e_damaged_pdf, qpdf->getFilename(),
"", this->offset,
"stream /DecodeParms length is"
" inconsistent with filters"));
filterable = false;
}
if (! filterable)
{
return false;
}
for (size_t i = 0; i < filters.size(); ++i)
{
auto filter = filters.at(i);
auto decode_item = decode_parms.at(i);
if (filter->setDecodeParms(decode_item))
{
if (filter->isSpecializedCompression())
{
specialized_compression = true;
}
if (filter->isLossyCompression())
{
specialized_compression = true;
lossy_compression = true;
}
}
else
{
filterable = false;
}
}
return filterable;
}
bool
QPDF_Stream::pipeStreamData(Pipeline* pipeline, bool* filterp,
int encode_flags,
qpdf_stream_decode_level_e decode_level,
bool suppress_warnings, bool will_retry)
{
std::vector<std::shared_ptr<QPDFStreamFilter>> filters;
bool specialized_compression = false;
bool lossy_compression = false;
bool ignored;
if (filterp == nullptr)
{
filterp = &ignored;
}
bool& filter = *filterp;
filter = (! ((encode_flags == 0) && (decode_level == qpdf_dl_none)));
bool success = true;
if (filter)
{
filter = filterable(
filters, specialized_compression, lossy_compression);
if ((decode_level < qpdf_dl_all) && lossy_compression)
{
filter = false;
}
if ((decode_level < qpdf_dl_specialized) && specialized_compression)
{
filter = false;
}
QTC::TC("qpdf", "QPDF_Stream special filters",
(! filter) ? 0 :
lossy_compression ? 1 :
specialized_compression ? 2 :
3);
}
if (pipeline == 0)
{
QTC::TC("qpdf", "QPDF_Stream pipeStreamData with null pipeline");
// Return value is whether we can filter in this case.
return filter;
}
// Construct the pipeline in reverse order. Force pipelines we
// create to be deleted when this function finishes. Pipelines
// created by QPDFStreamFilter objects will be deleted by those
// objects.
std::vector<PointerHolder<Pipeline>> to_delete;
PointerHolder<ContentNormalizer> normalizer;
if (filter)
{
if (encode_flags & qpdf_ef_compress)
{
pipeline = new Pl_Flate("compress stream", pipeline,
Pl_Flate::a_deflate);
to_delete.push_back(pipeline);
}
if (encode_flags & qpdf_ef_normalize)
{
normalizer = new ContentNormalizer();
pipeline = new Pl_QPDFTokenizer(
"normalizer", normalizer.get(), pipeline);
to_delete.push_back(pipeline);
}
for (std::vector<PointerHolder<
QPDFObjectHandle::TokenFilter> >::reverse_iterator iter =
this->token_filters.rbegin();
iter != this->token_filters.rend(); ++iter)
{
pipeline = new Pl_QPDFTokenizer(
"token filter", (*iter).get(), pipeline);
to_delete.push_back(pipeline);
}
for (auto f_iter = filters.rbegin();
f_iter != filters.rend(); ++f_iter)
{
auto decode_pipeline = (*f_iter)->getDecodePipeline(pipeline);
if (decode_pipeline)
{
pipeline = decode_pipeline;
}
Pl_Flate* flate = dynamic_cast<Pl_Flate*>(pipeline);
if (flate != nullptr)
{
flate->setWarnCallback([this](char const* msg, int code) {
warn(QPDFExc(qpdf_e_damaged_pdf, qpdf->getFilename(),
"", this->offset, msg));
});
}
}
}
if (this->stream_data.get())
{
QTC::TC("qpdf", "QPDF_Stream pipe replaced stream data");
pipeline->write(this->stream_data->getBuffer(),
this->stream_data->getSize());
pipeline->finish();
}
else if (this->stream_provider.get())
{
Pl_Count count("stream provider count", pipeline);
if (this->stream_provider->supportsRetry())
{
if (! this->stream_provider->provideStreamData(
this->objid, this->generation, &count,
suppress_warnings, will_retry))
{
filter = false;
success = false;
}
}
else
{
this->stream_provider->provideStreamData(
this->objid, this->generation, &count);
}
qpdf_offset_t actual_length = count.getCount();
qpdf_offset_t desired_length = 0;
if (success && this->stream_dict.hasKey("/Length"))
{
desired_length = this->stream_dict.getKey("/Length").getIntValue();
if (actual_length == desired_length)
{
QTC::TC("qpdf", "QPDF_Stream pipe use stream provider");
}
else
{
QTC::TC("qpdf", "QPDF_Stream provider length mismatch");
// This would be caused by programmer error on the
// part of a library user, not by invalid input data.
throw std::runtime_error(
"stream data provider for " +
QUtil::int_to_string(this->objid) + " " +
QUtil::int_to_string(this->generation) +
" provided " +
QUtil::int_to_string(actual_length) +
" bytes instead of expected " +
QUtil::int_to_string(desired_length) + " bytes");
}
}
else if (success)
{
QTC::TC("qpdf", "QPDF_Stream provider length not provided");
this->stream_dict.replaceKey(
"/Length", QPDFObjectHandle::newInteger(actual_length));
}
}
else if (this->offset == 0)
{
QTC::TC("qpdf", "QPDF_Stream pipe no stream data");
throw std::logic_error(
"pipeStreamData called for stream with no data");
}
else
{
QTC::TC("qpdf", "QPDF_Stream pipe original stream data");
if (! QPDF::Pipe::pipeStreamData(this->qpdf, this->objid, this->generation,
this->offset, this->length,
this->stream_dict, pipeline,
suppress_warnings,
will_retry))
{
filter = false;
success = false;
}
}
if (filter &&
(! suppress_warnings) &&
normalizer.get() &&
normalizer->anyBadTokens())
{
warn(QPDFExc(qpdf_e_damaged_pdf, qpdf->getFilename(),
"", this->offset,
"content normalization encountered bad tokens"));
if (normalizer->lastTokenWasBad())
{
QTC::TC("qpdf", "QPDF_Stream bad token at end during normalize");
warn(QPDFExc(qpdf_e_damaged_pdf, qpdf->getFilename(),
"", this->offset,
"normalized content ended with a bad token;"
" you may be able to resolve this by"
" coalescing content streams in combination"
" with normalizing content. From the command"
" line, specify --coalesce-contents"));
}
warn(QPDFExc(qpdf_e_damaged_pdf, qpdf->getFilename(),
"", this->offset,
"Resulting stream data may be corrupted but is"
" may still useful for manual inspection."
" For more information on this warning, search"
" for content normalization in the manual."));
}
return success;
}
void
QPDF_Stream::replaceStreamData(PointerHolder<Buffer> data,
QPDFObjectHandle const& filter,
QPDFObjectHandle const& decode_parms)
{
this->stream_data = data;
this->stream_provider = 0;
replaceFilterData(filter, decode_parms, data->getSize());
}
void
QPDF_Stream::replaceStreamData(
PointerHolder<QPDFObjectHandle::StreamDataProvider> provider,
QPDFObjectHandle const& filter,
QPDFObjectHandle const& decode_parms)
{
this->stream_provider = provider;
this->stream_data = 0;
replaceFilterData(filter, decode_parms, 0);
}
void
QPDF_Stream::addTokenFilter(
PointerHolder<QPDFObjectHandle::TokenFilter> token_filter)
{
this->token_filters.push_back(token_filter);
}
void
QPDF_Stream::replaceFilterData(QPDFObjectHandle const& filter,
QPDFObjectHandle const& decode_parms,
size_t length)
{
this->stream_dict.replaceOrRemoveKey("/Filter", filter);
this->stream_dict.replaceOrRemoveKey("/DecodeParms", decode_parms);
if (length == 0)
{
QTC::TC("qpdf", "QPDF_Stream unknown stream length");
this->stream_dict.removeKey("/Length");
}
else
{
this->stream_dict.replaceKey(
"/Length", QPDFObjectHandle::newInteger(
QIntC::to_longlong(length)));
}
}
void
QPDF_Stream::replaceDict(QPDFObjectHandle new_dict)
{
this->stream_dict = new_dict;
setDictDescription();
QPDFObjectHandle length_obj = new_dict.getKey("/Length");
if (length_obj.isInteger())
{
this->length = QIntC::to_size(length_obj.getUIntValue());
}
else
{
this->length = 0;
}
}
void
QPDF_Stream::warn(QPDFExc const& e)
{
this->qpdf->warn(e);
}