An Adobe PDF can be protected from Printing and Copy-Paste by setting a password. For example shown below you can’t print (Print button greyed out) and copy (Copy option not seen in context menu). All these are restriction you can apply to your PDF using a password.

But if you have protected files inside SharePoint and you want to unprotected them, you have to first download them locally then remove the password using Acrobat Reader. After that you have to upload them again to the document library.

For that I have created a Custom Action that helps to automate this without downloading.

The Custom Action redirects you to a custom Application Page and asks for the password to the file.

Since most files in my SharePoint environment are version controller, my code does the check-in with comment as well.

I am making this little application available for download here. I will publish the source code later.