address@hidden writes:
> A good task to start would be to take a look to the PDF 1.7 reference,
> chapter syntax, section encryption filters, and determine what
> encryption stream filters we need to write and if we have support for
> all of them in GNU libcrypt. Would you like to do it?
>
Well, after taking a look to the overview chapter from PDF Reference I
read section you comment. I tell you: the standard defines only two
algorithms in order to decrypt pdf streams and strings.
On the one hand we must implement the AES algorithm, just like it
already is in the pdf knowledge database [1]. On the other hand, the
second algorithm is known as RC4, which unfortunately is, according to
the reference, a proprietary algorithm copyrighted by RSA Security,
Inf. I hope it doesn't arise any legal impediment.
Finally we will need md5 message-digest functions too.
I am not sure but I think libcrypt doesn't provide this. Have we work
to do here?
> In any case, welcome on board! :)
Thanks :)
Footnotes:
[1] http:/
gnupdf.org/Crypt_Filter