Description
Is your feature request related to a problem? Please describe.
When trying to open pdf or epub protected with Adobe Adept DRM, a generic exception "opening a document caused Failed to open file" is thrown.
A epub protected with the CARE DRM can be opened.
The attribute "is_protected" is shown as FALSE.
But trying to get a page text causes exception "getting page text caused code=7: cannot find entry OEBPS/cover.xhtml"
Describe the solution you'd like
An exception text that states that the file is protected by a DRM (and ideally, which one)
If the file can be opened (as in the case of CARE), there should be an attribute "DRM" that either is empty or contains the name of the DRM used
Describe alternatives you've considered
TBH, I have not found any other Python libraries or CLI tools that handle this in a satisfactory way