POSIX1E(3)

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

LIBRARY
libposix1e

SYNOPSIS
#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 FreeBSD, 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 FreeBSD, 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, FreeBSD 4.0 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). FreeBSD currently provides documentation and APIs for fine-grained capability support, but implementation is currently not included in the base system. Documentation of these API calls is provided in cap(3). Additional patches supporting POSIX.1e features are provided by the TrustedBSD project: http://www.trustedbsd.org

IMPLEMENTATION NOTES
FreeBSD'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 FreeBSD 4.0 so as to discourage their use in the short term.

FILES

SEE ALSO
acl(3), acl(9), cap(3), cap(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.