This results in a performance penalty of 1% to 2% when replaceObject
and swapObjects are never called and a somewhat larger penalty if they
are called, but it's worth it to avoid very confusing behavior as
discussed in depth in qpdf#507.
I thought /EFF was supposed to be used as a default for decrypting
embedded file streams, but actually it's supposed to be advice to a
conforming writer about handling new ones. This makes sense since the
findAttachmentStreams code, which is not actually needed, was never
right.
Keep a std::pair internal to the iterators so that operator* can
return a reference and operator-> can work, and each can work without
copying pairs of objects around.
If we ever had an encrypted file with different filters for
attachments and either the /EmbeddedFiles name tree was deep or some
of the file specs didn't have /Type, we would have overlooked those as
attachment streams. The code now properly handles /EmbeddedFiles as a
name tree.
This reverts an incorrect fix to #449 and codes it properly. The real
problem was that we were looking at the local dictionaries rather than
the foreign dictionaries when saving the foreign stream data. In the
case of direct objects, these happened to be the same, but in the case
of indirect objects, the object references could be pointing anywhere
since object numbers don't match up between the old and new files.
Specifically, if a stream had its stream data replaced and had
indirect /Filter or /DecodeParms, it would result in non-silent loss
of data and/or internal error.
It seems better not to compress signature dictionaries. Various PDF
digital signing tools, including Adobe Acrobat Reader DC, do not
compress signature dictionaries.
Table 8.93 "Entries in a signature dictionary" in PDF 1.5 reference
describes that /ByteRange in the signature dictionary shall be used to
describe a digest that does not include the signature value
(/Contents) itself.
The byte ranges cannot be determined if the dictionary is compressed.
When seeing to a position based on a value read from the input, we are
prone to integer overflow (fuzz issue 15442). Seek in two stages to
move the overflow check into the input source code.
This makes all integer type conversions that have potential data loss
explicit with calls that do range checks and raise an exception. After
this commit, qpdf builds with no warnings when -Wsign-conversion
-Wconversion is used with gcc or clang or when -W3 -Wd4800 is used
with MSVC. This significantly reduces the likelihood of potential
crashes from bogus integer values.
There are some parts of the code that take int when they should take
size_t or an offset. Such places would make qpdf not support files
with more than 2^31 of something that usually wouldn't be so large. In
the event that such a file shows up and is valid, at least qpdf would
raise an error in the right spot so the issue could be legitimately
addressed rather than failing in some weird way because of a silent
overflow condition.
* [bcc32 Error] QPDF.cc(375): E2268 Call to undefined function 'atof'
Full parser context
QPDF.cc(358): parsing: void QPDF::parse(const char *)
* [bcc32 Error] QPDFTokenizer.cc(183): E2268 Call to undefined function 'strtol'
Full parser context
QPDFTokenizer.cc(163): parsing: void QPDFTokenizer::resolveLiteral()
* [bcc32 Error] pdf-split-pages.cc(52): E2268 Call to undefined function 'exit'
Full parser context
pdf-split-pages.cc(50): parsing: void usage()
* PR #295: Including "cstdlib" should be replaced with "stdlib.h" to be more consistent. At the same time I changed the order of the surrounding includes to reflect alphabetical order, because at some files this already have been the case.
The original QPDF is only required now when the source
QPDFObjectHandle is a stream that gets its stream data from a
QPDFObjectHandle::StreamDataProvider.
Instead of calling assert for problems found during checking
linearization data, throw an exception which is later caught and
issued as an error. Ideally we would handle errors more robustly, but
this is still a significant improvement.
On certain operations, such as iterating through all objects and
adding new indirect objects, walk through the entire object structure
and explicitly resolve any indirect references to non-existent
objects. That prevents new objects from springing into existence and
causing the previously dangling references to point to them.
Prior to this fix, if there was a loop detected in following /Prev
pointers in xref streams/tables, it would cause qpdf to lose data.
Note that this condition causes many PDF readers to hang or fail.
Bump to an alpha release. This version is not being widely released
but is being used to push the new shared library version through the
debian packaging system and to test out github releases.
Add options to enable the raw encryption key to be directly shown or
specified. Thanks to Didier Stevens <didier.stevens@gmail.com> for the
idea and contribution of one implementation of this idea.
While scanning the file looking for objects, limit the length of
tokens we allow. This prevents us from getting caught up in reading a
file character by character while digging through large streams.
