2.1 === * Update documentation to reflect new command line flags and any other relevant changes. Should read through ChangeLog and the manual before releasing 2.1. * Update release documentation to remember not to include debugging in the Windows release and to strip the DLL and executables. Consider making the "install" target do something useful for Windows. Update README.windows in this case including taking out the mention of strip since it should be handled by the install step. Determine whether -g with strip is different from not -g with strip. * Add comments for the security functions that map them back to the items in Adobe's products. * Have force version at least turn off object streams and maybe change security settings? * Add error codes to QPDFException. Change the error interface so that warnings and errors are pointers that can be queried using more C API functions. We need a way to get a full string as well as an error code, file name, offset, and message. We should go through all error messages to try to include all these fields as appropriate. Make sure invalid password is specifically detectable. I/O errors and so forth should also be distinguishable. Make sure all errors include information about the most recent read location including byte offset and object/generation number. * It might be nice to be able to trap I/O errors separately from other errors; especially be able to separate errors that the user can fix (like permission errors) from errors that they probably can't fix like corrupted PDF files, unsupported filters, or internal errors. However, only QPDF::processFile(), which does the initial read, and QPDFWriter::QPDFWriter(), which does the initial write, are at all likely to generate such errors for a case other than a catastrophic failure. * "Delphi wrapper unit 'qpdf.pas' created by Zarko Gajic (http://delphi.about.com). .. use at your own risk and for whatever the purpose you want .. no support provided. Sample code provided." * Test cases for metadata: make sure we get uncompressed metadata for all --stream-data modes unless encrypted. Have check_metadata function in the test suite that should report whether the metadata is compressed (by looking at the /Filter key in the stream dictionary) and tries to extract it filtered to make sure encryption/decryption works. We should also grep for some string for encrypted files where it's not supposed to be encrypted to make sure it's also not compressed. * R = 4, V = 4 encryption. - Update C API for R4 encryption - When we write encrypted files, we must remember to omit any encryption filter settings from original streams. - test various combinations with and without cleartext-metadata and aes in compression tests - figure out a way to test crypt filters defined on a stream - test extraction of metadata with and without encrypted metadata - would be nice to test strings and streams with different encryption types, but without sample data, we'd have to write them ourselves which is not that useful - figure out how to look at the metadata so I can tell whether /EncryptMetadata is working the way it's supposed to - Do something with embedded files, but what and how? - General notes: /CF - keys are crypt filter names, values are are crypt dictionaries Individual streams may also have crypt filters. Filter type /Crypt; /DecodeParms must contain a Crypt filter decode parameters dictionary whose /Name entry specifies the particular filter to be used. If /Name is missing, use /Identity. /DecodeParms << /Crypt << /Name /XYZ >> >> where /XYZ is /Identity or a key in /CF. /Identity means not to encrypt. Crypt Dictionaries /Type (optional) /CryptFilter /CFM: /V2 - use rc4 /AESV2 - use aes /Length - supposed to be key length, but the one file I have has a bogus value for it, so I'm ignoring it. We will ignore remaining fields and values. 2.2 === * Add ability to create new streams or replace stream data. Consider stream data sources to include a file and offset, a buffer, or a some kind of callback mechanism. Find messages exchanged with Stefan Heinsen in August, 2009. He seems to like to send encrypted mail. (key 01FCC336) * Look at page splitting. General ======= * The second xref stream for linearized files has to be padded only because we need file_size as computed in pass 1 to be accurate. If we were not allowing writing to a pipe, we could seek back to the beginning and fill in the value of /L in the linearization dictionary as an optimization to alleviate the need for this padding. Doing so would require us to pad the /L value individually and also to save the file descriptor and determine whether it's seekable. This is probably not worth bothering with. * The whole xref handling code in the QPDF object allows the same object with more than one generation to coexist, but a lot of logic assumes this isn't the case. Anything that creates mappings only with the object number and not the generation is this way, including most of the interaction between QPDFWriter and QPDF. If we wanted to allow the same object with more than one generation to coexist, which I'm not sure is allowed, we could fix this by changing xref_table. Alternatively, we could detect and disallow that case. In fact, it appears that Adobe reader and other PDF viewing software silently ignores objects of this type, so this is probably not a big deal. * Pl_PNGFilter is only partially implemented. If we ever decoded images, we'd have to finish implementing it along with the other filter decode parameters and types. For just handling xref streams, there's really no need as it wouldn't make sense to use any kind of predictor other than 12 (PNG UP filter). * If we ever want to have check mode check the integrity of the free list, this can be done by looking at the code from prior to the object stream support of 4/5/2008. It's in an if (0) block and there's a comment about it. There's also something about it in qpdf.test -- search for "free table". On the other hand, the value of doing this seems very low since no viewer seems to care, so it's probably not worth it. * Embedded file streams: figure out why running qpdf over the pdf 1.7 spec results in a file that crashes acrobat reader when you try to save nested documents. * QPDFObjectHandle::getPageImages() doesn't notice images in inherited resource dictionaries. See comments in that function. * Based on an idea suggested by user "Atom Smasher", consider providing some mechanism to recover earlier versions of a file embedded prior to appended sections. Splitting by Pages ================== Although qpdf does not currently support splitting a file into pages, the work done for linearization covers almost all the work. To do page splitting. If this functionality is needed, study obj_user_to_objects and object_to_obj_users created in QPDF_optimization for ideas. It's quite possible that the information computed by calculateLinearizationData is actually sufficient to do page splitting in many circumstances. That code knows which objects are used by which pages, though it doesn't do anything page-specific with outlines, thumbnails, page labels, or anything else. Another approach would be to traverse only pages that are being output taking care not to traverse into the pages tree, and then to fabricate a new pages tree. Either way, care must be taken to handle other things such as outlines, page labels, thumbnails, threads, zones, etc. in a sensible way. This may include simply omitting information other than page content.