capng_change_id(3) [centos man page]

CAPNG_CHANGE_ID(3)						   Libcap-ng API						CAPNG_CHANGE_ID(3)

NAME

       capng_change_id - change the credentials retaining capabilities

SYNOPSIS

       #include <cap-ng.h>

       int capng_change_id(int uid, int gid, capng_flags_t flag);

DESCRIPTION

       This  function  will  change uid and gid to the ones given while retaining the capabilities previously specified in capng_update. It is not
       necessary and perhaps better if capng_apply has not been called prior to this function so that all necessary privileges are  still  intact.
       The caller is required to have CAP_SETPCAP capability still active before calling this function.

       This  function  also takes a flag parameter that helps to tailor the exact actions performed by the function to secure the environment. The
       option may be or'ed together. The legal values are:

	      CAPNG_NO_FLAG
		     Simply change uid and retain specified capabilities and that's all.

	      CAPNG_DROP_SUPP_GRP
		     After changing id, remove and supplement groups that may come with the account.

	      CAPNG_CLEAR_BOUNDING
		     After changing the uid and gid, clear the bounding set regardless to the internal representation already setup.

RETURN VALUE

       This returns 0 on success and a negative number on failure. -1 means capng has not been initted properly, -2 means a failure requesting	to
       keep  capabilities  across  the	uid  change, -3 means that applying the intermediate capabilities failed, -4 means changing gid failed, -5
       means dropping supplemental groups failed, -6 means changing the uid failed, -7 means dropping the ability to  retain  caps  across  a  uid
       change failed, -8 means clearing the bounding set failed, -9 means dropping CAP_SETPCAP failed.

       Note: the only safe action to do upon failure of this function is to probably exit. This is because you are likely in a situation with par-
       tial permissions and not what you intended.

SEE ALSO

       capng_update(3), capng_apply(3), prctl(2), capabilities(7)

AUTHOR

       Steve Grubb

Red Hat 							     June 2009							CAPNG_CHANGE_ID(3)

Privileges::Drop(3pm)					User Contributed Perl Documentation				     Privileges::Drop(3pm)

NAME

       Privileges::Drop - A module to make it simple to drop all privileges, even POSIX groups.

DESCRIPTION

       This module tries to simplify the process of dropping privileges. This can be useful when your Perl program needs to bind to privileged
       ports, etc. This module is much like Proc::UID, except that it's implemented in pure Perl.  Special care has been taken to also drop saved
       uid on platforms that support this, currently only test on on Linux.

SYNOPSIS

	 use Privileges::Drop;

	 # Do privileged stuff

	 # Drops privileges and sets euid/uid to 1000 and egid/gid to 1000.
	 drop_uidgid(1000, 1000);

	 # Drop privileges to user nobody looking up gid and uid with getpwname
	 # This also set the environment variables USER, LOGNAME, HOME and SHELL.
	 drop_privileges('nobody');

METHODS

       drop_uidgid($uid, $gid, @groups)
	   Drops privileges and sets euid/uid to $uid and egid/gid to $gid.

	   Supplementary groups can be set in @groups.

       drop_privileges($user)
	   Drops privileges to the $user, looking up gid and uid with getpwname and calling drop_uidgid() with these arguments.

	   The environment variables USER, LOGNAME, HOME and SHELL are also set to the values returned by getpwname.

	   Returns the $uid and $gid on success and dies on error.

	   NOTE: If drop_privileges() is called when you don't have root privileges it will just return undef;

NOTES

       As this module only uses Perl's built-in functions, it relies on them to work correctly. That means setting $GID and $EGID should also call
       setgroups(), something that might not have been the case before Perl 5.004. So if you are running an older version, Proc::UID might be a
       better choice.

AUTHOR

       Troels Liebe Bentsen <tlb@rapanden.dk>

COPYRIGHT

       Copyright(C) 2007-2009 Troels Liebe Bentsen

       This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

perl v5.14.2							    2012-03-10						     Privileges::Drop(3pm)