Information Technology Reference
In-Depth Information
AC is the set of algorithms of access control of subjects S to resources R. AC =
{AC
F
, AC
L
}, where AC
F
is the algorithm of access control to resources R
F
of the
secure Fenix OS, and AC
L
— the algorithm of access control to resources R
L
of the
Linux OS.
The algorithms of access control in Linux over Fenix, in dependence of the types
of objects and resources are shown in Fig 4.
R
F
Ro
L
Ri
L
S
F
AC
F
AC
F
Λ AC
L
-
S
L
AC
F
AC
L
AC
L
Fig. 4.
The Algorithms of Access Control in the Secure Hybrid Linux over Fenix OS in
Dependence of the Types of Subjects and Resources
Op is the set of operations of the system. Op = {Op
F
, Op
L
}, where Op
F
are multiple
operations which can be performed by the subjects of the secure Fenix system S
F
over
the resources of the secure Fenix system R
F
and the resources of the Linux operating
system Ro
L
, and Op
L
—
multiple operations which can be performed by the subjects
of the Linux operating system S
L
over the resources of the secure Fenix system R
F
and the resources of the Linux operating system R
L
. The set of operations Op
F
=
{deallocation, reading, writing, acquisition of security attributes, setup of security
attributes, generation, deletion}. The set of operations Op
L
= {deallocation, reading,
writing, acquisition of security attributes, setup of security attributes, generation,
deletion}.
P is the set of permissions. P = {P
F
, P
L
}, where P
F
are multiple permissions which
the subjects of the secure Fenix system S
F
may have in regard to the resources of the
secure Fenix system R
F
and in regard to the resources of the Linux operating system
Ro
L
, while P
L
are multiple permissions which the subjects of the Linux operating
system S
L
may have in regard to the resources of the secure Fenix system R
F
and in
regard to the resources of the Linux operating system R
L
. P
F
= Pd
F
∩ Pm
F
, where Pd
F
are discretionary permissions, and Pm
F
— mandatory permissions. Pd
F
= {reading,
writing, addition, execution}, Pm
F
= {reading, writing}. P
L
= {reading, writing,
execution}.
CR is the resource container. All resources R
F
and Ro
L
are aggregated in resource
containers. During authorization the access control algorithm interacts not with the
resource directly, but with the container CR
R
, where the resource R is aggregated.
Access control algorithms are abstracted from both the types of resources aggregated
in the containers and from the client requesting access to the resources. This makes it
possible to ensure isomorphism of access control both from the client requesting
access (secure Fenix OS application, or Linux OS application) and from the resources
(resources of the secure Fenix OS or resources of the Linux OS).
This way the actions of the Linux VM are transformed into uniform requests to the
resource containers controlled by the Fenix security features. All calls of the subjects
S
L
of the Linux VM for resources R
F
of the secure Fenix OS, with no exception, are
controlled by the access control algorithm AC
F
of the secure Fenix OS. Linux OS
operates under control of the secure Fenix OS security pattern and cannot bypass it.
