Hello Adam, Thanks for the reply. Unfortunately, we're not interested in encrypting the form; only in preventing further changes beyond a nominal "finished" point. I was only hoping for a "global" way of doing that.
I think you may have made an error when you said > Now, to answer your question, the AccessPermission class is not related > to encryption, Since org.apache.pdfbox.pdmodel.encryption.AccessPermission is part of the encryption package, and since it also used as a argument to the StandardProtectionPolicy and PublicKeyRecipient constructors, it is clearly "related" to encryption. Regards, Ken On Aug 25, 2011, at 12:21 AM, Adam Nichols wrote: > Hello. > > First, let me explain what the options are in terms of protecting a PDF. > There are three different types: > 1. No protection. There's no encryption, no passwords, and anyone with > the right software can read, modify, extract, print and whatever else > they desire. > 2. PDFs with an owner password. These can be opened and read by anyone, > however there are some flags which are set which say "please don't edit > this", "please don't print", and so forth. From a technical standpoint, > there's nothing stopping anyone from doing these prohibited actions, but > most software will respect these flags and only allow you to preform > prohibited actions if you enter the correct owner password. > 3. Then there are PDFs with a user password. These can not be opened, > read, or processed in any way without the user password. There is > encryption (RC4 or AES) which stops anyone from bypassing this, no > matter what software they use. Once the correct password is entered, > the file is decrypted and it treated like #1 or #2. > > Now, to answer your question, the AccessPermission class is not related > to encryption, however it is related to the owner password. You will > not need to enter a password to open protected files (as long as there's > no user password); you will only need the password to edit them. Just > keep in mind that it's only going to stop people who didn't REALLY want > to edit it. > > There's no way to use strong encryption to enforce the editability of > the file. As long as the program can process the file enough to know > what to render, then it has everything it needs to write out a copy and > modify the copy. > > Hope this helps you understand how PDFs work, and how the class works. > > --Adam > > On 08/24/2011 08:19 PM, Ken Bowen wrote: >> Hi Everyone, >> >> We have routines which create and fill out pdf forms using PDFBox. >> After creating and filling the fields, we need to make all of them read-only. >> Is there a global way to do this with PDFBox for a form? >> Or do I need to go through and apply PDField.setReadonly(true) to each field? >> >> I've observed that org.apache.pdfbox.pdmodel.encryption.AccessPermission has >> a bit for setting fields read-only, but it seems this class is only related >> to encyrpted PDFs -- is this true? >> >> Thanks in advance, >> -- Ken >>
