Hello all I am writing crypt filter and it arises a doubt related to gnupdf's design. According to PDF Reference, encrpytion is defined (mostly) by a global dictionary. This dictionary holds a list of crypt filters will be used in the rest of the document.
I suppose crypt filter module will receive parameters from its filter dictionary. However, it is not enought, it is even optional. We must consider global data, I think. Nevertheless these parameters will be known by upper layers.
