POSIX1E(3)

NAME
posix1e - introduction to the POSIX.1e security API

LIBRARY
libposix1e

SYNOPSIS
#include <sys/types.h>
#include <sys/acl.h>
#include <sys/audit.h>
#include <sys/capability.h>
#include <sys/mac.h>

DESCRIPTION
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 DragonFly, 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. Of these, the ACL interfaces are currently included with DragonFly, Auditing, Capabilities, and Mandatory Access Control are in the wings, and Information Flow Labels are not on the calendar.

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, DragonFly permits file systems to export Access Control Lists via the VFS, and provides a library for userland access to and manipulation of these ACLs, but support for ACLs is not provided by any file systems shipped in the base operating system. Available API calls relating to ACLs are described in detail in acl(3).

The patches supporting other POSIX.1e features are not available in the base operating system at this time--however, more information on them may be found on the FreeBSD POSIX.1e implementation web page:

http://www.watson.org/fbsd-hardening/posix1e/

IMPLEMENTATION NOTES
DragonFly's support for POSIX.1e interfaces and features is still under development at this time.

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. These userland utilities are not bundled with DragonFly so as to discourage their use in the short term.

SEE ALSO
acl(3), acl(9), extattr(9)

STANDARDS
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 FreeBSD POSIX.1e implementation page for more information.

HISTORY
POSIX.1e support was introduced in FreeBSD 4.0, and development continues.

AUTHORS
Robert N M Watson, Ilmar S Habibulin

BUGS
These features are not yet fully implemented. In particular, the shipped version of UFS/FFS does not support storage of additional security labels, and so is unable to (easily) provide support for most of these features.