Xorg Developer's Conference - Security Talk

Rough outline of talk/discussion follows:

Security Advisories/Response

  • Not covered

X Authentication/Transport

  • Loadable module support for authentication methods. Could be done: provide registration function, call callback list passing connection setup information plus file descriptor; callback performs authentication entirely before returning decision to server.
  • Xtrans improvements. XCB doesn't use it. Could make it an actual library. Is a filehandle a sufficient abstraction?

Fine-Grained Access Control

  • Have a research paper; will post link.
  • Improved resource lookup functions: still thinking about the prototype for dixLookupResource. Not sure if the DixReadAccess/DixWriteAccess flags are useful or necessary.
  • Use the resource system to store your module's objects.
  • Don't multiplex different operations through the same protocol request.

Other Security Work of Note

  • Security error handling. Right now, the Security extension "hides" denials from the user by returning false information. I would like to see the server begin returning actual errors, preferably BadAccess.
  • devPrivates rework. Currently have separate functions for each supported structure. Could standardize this into one set of functions.
  • Need to add devPrivates to additional structures: PropertyRec.
  • Window labeling: currently exporting properties to window manager. Feature request: need secure area for showing labels.
  • Secure handling of input events. Secure attention key support.


  • Shared Display Wall