Tuesday, June 1, 2010

micro(nano?) Auth

just thinking now... not yet completed memo.

For mobile (or whatever computers which run modern OS) device, every "Native-application" call for kernel would better be under MAC(Mandatory Access Control).
In this case, request-token can be used.
Request tokens are issued by OS while the application is certified. The token is checked for Revokation. MAC on each kernel call realizes "real-time Revokation".

Of course, periodical check would be available, and with less load; such a s "on app booting only" or "on OS rebooting only" type.

I'd better make a survey on SELinux case...

For virtualization Hypervisors, MAC can be useful, because application ACL is almost compatible for various guest OS.
But it should not degrade performance drastically.
Anyway, every kernel call is trapped by Hypervisor (CPU may help passing thru for most of the cases). And there, MAC can be done.

How to check?
Full Certification is heavy process. Just check matching of fingerprint? Or, just booting/loaded to memory as DLL case? I guess short-handed check shall be done on each load of executable objects.
But, "on writable-memory exec" would be the path to jail-breaking of executable loading check although some CPU architectures inhibit such operation(Stack area corruption and jump to anywhere hacker'd like is the very familier opration.)