Ensure that TrustStorePermissionManager is not subject to PID races

[Thomas Voß]

Based on sarnold's review comment https://code.launchpad.net/~thomas-voss/location-service/fix-1219164/+merge/228861/comments/556132, the TrustStorePermissionManager implementation should:

  (1.) Query pid*, uid*, apparmor* profile from dbus daemon
  (2.) Query agent
  (3.) Query pid, uid, apparmor and compare to pid*, uid*, apparmor*

[Tyler Hicks (tyhicks)]

Hi Thomas - I'm trying to understand this a little more.

In step #1, the TrustStorePermissionManager is querying the pid*, uid*, apparmor_profile* of what, exactly? The agent?

In step #2, how does it query the agent? Over D-Bus?

In step #3, what is being queried for the pid, uid, and apparmor_profile? Is it the dbus-daemon again?

Thanks!

[Thomas Voß (thomas-voss)]

Hi Tyler,

 For (1.) pid, uid and apparmor-profile would be those of the application trying to access the trusted helper.
 For (2.) yes, via dbus
 For (3.) exactly, the dbus daemon is queried again.