elementary-dev-community team mailing list archive

[Cameron Norman <camerontnorman@xxxxxxxxx>]

Hello all,

I recently have taken an interest in some of the containment and 
security features being developed for Ubuntu touch, as well as Lennart 
Poettering's plans for containment on GNOME.

One of the recurring aspects that I see is a "Content Hub" (Ubuntu) or 
"application Portals" (GNOME) system. Both of these have remarkable 
similarity (in concept) to elementary's Contractor. Although many of 
you most likely did not foresee Contractor's role in security when it 
was created, it undoubtedly does have one. By delegating out 
responsibilities (such as, say, printing), Contractor allows for the 
removal of privileges from an application. If all applications are 
using the print contract, there is no need for those applications to 
have the capability to use the printer.

By extending Contractor's scope (or moving to another service) further 
containment, as well as better features, is possible. Specifically, 
returning data, instead of handing them off, will allow for increased 
consolidation of privileges.

The open and save GTK file dialogs are great example. If apps use 
contracts to perform these functions, they do not need to be given the 
privilege of directly reading or writing to the user's documents, 
pictures, emails, etc.

Another good example is retrieving a profile photo. Instead of having 
every social media app be able to directly access the webcam, they 
could ask Contractor for a photo, and contractor could give the webcam 
option.

These are the changes/additions that I think could make this possible:
* returning data instead of just handing it off
* ability to call a contract by name (e.g. "Print" or "OpenFile")
* passing / returning more types of data: not just files, but also 
strings, booleans, or URLs

Before I go into detail about how I have been thinking about exposing 
this functionality, I would like to hear all of your thoughts about the 
merit of these changes, and if any of you would like to develop these 
things with me (heads up: I suck at programming :).

Lennart Poettering's presentation of portals at GUADEC 2013, starting 
at 35:00.

Ubuntu Mobile's "Content Hub".

Thank you very much for reading,
--
Cameron Norman