The IEEE POSIX.1e specification never left draft form, but the interfaces
it describes are now widely used despite inherent limitations.
Currently, only a few of the interfaces and features are implemented in
Fx ,
although efforts are underway to complete the integration at this time.
POSIX.1e describes five security extensions to the base POSIX.1 API:
Access Control Lists (ACLs), Auditing, Capabilities, Mandatory Access
Control, and Information Flow Labels.
Fx supports POSIX.1e ACL interfaces, as well as POSIX.1e-like MAC
interfaces.
The TrustedBSD Project has produced but not integrated an implementation
of POSIX.1e Capabilities.
POSIX.1e defines both syntax and semantics for these features, but fairly
substantial changes are required to implement these features in the
operating system.
As shipped,
Fx 4.0
provides API and VFS support for ACLs, but not an implementation on any
native file system.
Fx 5.0
includes support for ACLs as part of UFS1 and UFS2, as well as necessary
VFS support for additional file systems to export ACLs as appropriate.
Available API calls relating to ACLs are described in detail in
acl(3).
As shipped,
Fx 5.0
includes support for Mandatory Access Control as well as POSIX.1e-like
APIs for label management.
More information on API calls relating to MAC is available in
mac(3).
Additional patches supporting POSIX.1e features are provided by the
TrustedBSD project:
Fx Ns 's
support for POSIX.1e interfaces and features is still under
development at this time, and many of these features are considered new
or experimental.
ENVIRONMENT
POSIX.1e assigns security labels to all objects, extending the security
functionality described in POSIX.1.
These additional labels provide
fine-grained discretionary access control, fine-grained capabilities,
and labels necessary for mandatory access control.
POSIX.2c describes
a set of userland utilities for manipulating these labels.
Many of these services are supported by extended attributes, documented
in
extattr(2)
and
extattr(9).
While these APIs are not documented in POSIX.1e, they are similar in
structure.
POSIX.1e is described in IEEE POSIX.1e draft 17.
Discussion of the draft continues
on the cross-platform POSIX.1e implementation
mailing list.
To join this list, see the
Fx POSIX.1e implementation
page for more information.
HISTORY
POSIX.1e support was introduced in
Fx 4.0 ;
most of the features are available as of
Fx 5.0 .
Development continues.
AUTHORS
An Robert N M Watson
An Chris D. Faulhaber
An Thomas Moestl
An Ilmar S Habibulin
BUGS
Many of these features are considered new or experimental in
Fx 5.0
and should be deployed with appropriate caution.
