Hi,
I'm sorry, that's my fault. I've your previous message still marked as
> "to-be-done", but I changed my mind, I think it is risky to make such
> change just before the release. I didn't bother to let you know, for
> which I apologize.
>
Apology accepted. I just thought (besides being disgruntled), if I don't
bring up the issue again it might get totally forgotten.
> I didn't look into your PDF, neither I'd find time any time soon, I'm
> afraid. But if nobody is quicker, I'll check it in time of review &
> test of your patch.
Looking into the PDF when reviewing the patch is fine, I guess.
Don't forget the other PDF I linked to in a previous mail, in contrast to
the last PDF this one is loadable with my patch.
> Whether certain key should or should not be
> encrypted declares the PDF standard. It's just about to find out it
> there.
>
I had a brief look into the standard and could find it now, the ID should
be unencrypted:
"(Optional, but strongly recommended; PDF 1.1) An array of two byte-strings
constituting a file identifier (see Section 10.3, “File Identifiers”) for
the file. *The two bytestrings should be direct objects and should be
unencrypted.* Although this entry is optional, its absence might prevent
the file from functioning in some workflows that depend on files being
uniquely identified."
So Podofo is definitely doing something wrong there, since the ID
bytestrings of a trailer are always decrypted, as far as I can see! With
AESv2 encrpyted documents this wrong decryption does not cause errors, with
AESv3 it does, it seems. Keep in mind that the latter document (with AESv3)
is still not loadable even after the decryption of the ID is circumvented,
there's might be something wrong in general with decrpytion of AESv3
encrypted documents.
Best regards
F.E.
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Podofo-users mailing list
Podofo-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/podofo-users
