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SUDO.CONF(5)		  FreeBSD File Formats Manual		  SUDO.CONF(5)

NAME
     sudo.conf -- configuration	for sudo front end

DESCRIPTION
     The sudo.conf file	is used	to configure the sudo front end.  It specifies
     the security policy and I/O logging plugins, debug	flags as well as plug-
     in-agnostic path names and	settings.

     The sudo.conf file	supports the following directives, described in	detail
     below.

     Plugin    a security policy or I/O	logging	plugin

     Path      a plugin-agnostic path

     Set       a front end setting, such as disable_coredump or	group_source

     Debug     debug flags to aid in debugging sudo, sudoreplay, visudo, and
	       the sudoers plugin.

     The pound sign (`#') is used to indicate a	comment.  Both the comment
     character and any text after it, up to the	end of the line, are ignored.

     Long lines	can be continued with a	backslash (`\')	as the last character
     on	the line.  Note	that leading white space is removed from the beginning
     of	lines even when	the continuation character is used.

     Non-comment lines that don't begin	with Plugin, Path, Debug, or Set are
     silently ignored.

     The sudo.conf file	is always parsed in the	``C'' locale.

   Plugin configuration
     sudo supports a plugin architecture for security policies and input/out-
     put logging.  Third parties can develop and distribute their own policy
     and I/O logging plugins to	work seamlessly	with the sudo front end.
     Plugins are dynamically loaded based on the contents of sudo.conf.

     A Plugin line consists of the Plugin keyword, followed by the symbol_name
     and the path to the dynamic shared	object that contains the plugin.  The
     symbol_name is the	name of	the struct policy_plugin or struct io_plugin
     symbol contained in the plugin.  The path may be fully qualified or rela-
     tive.  If not fully qualified, it is relative to the directory specified
     by	the plugin_dir Path setting, which defaults to
     /usr/local/libexec/sudo.  In other	words:

	   Plugin sudoers_policy sudoers.so

     is	equivalent to:

	   Plugin sudoers_policy /usr/local/libexec/sudo/sudoers.so

     If	the plugin was compiled	statically into	the sudo binary	instead	of
     being installed as	a dynamic shared object, the path should be specified
     without a leading directory, as it	does not actually exist	in the file
     system.  For example:

	   Plugin sudoers_policy sudoers.so

     Starting with sudo	1.8.5, any additional parameters after the path	are
     passed as arguments to the	plugin's open function.	 For example, to over-
     ride the compile-time default sudoers file	mode:

	   Plugin sudoers_policy sudoers.so sudoers_mode=0440

     See the sudoers(5)	manual for a list of supported arguments.

     The same dynamic shared object may	contain	multiple plugins, each with a
     different symbol name.  The file must be owned by uid 0 and only writable
     by	its owner.  Because of ambiguities that	arise from composite policies,
     only a single policy plugin may be	specified.  This limitation does not
     apply to I/O plugins.

     If	no sudo.conf file is present, or if it contains	no Plugin lines, the
     sudoers plugin will be used as the	default	security policy	and for	I/O
     logging (if enabled by the	policy).  This is equivalent to	the following:

	   Plugin sudoers_policy sudoers.so
	   Plugin sudoers_io sudoers.so

     For more information on the sudo plugin architecture, see the
     sudo_plugin(8) manual.

   Path	settings
     A Path line consists of the Path keyword, followed	by the name of the
     path to set and its value.	 For example:

	   Path	noexec /usr/local/libexec/sudo/sudo_noexec.so
	   Path	askpass	/usr/X11R6/bin/ssh-askpass

     If	no path	name is	specified, features relying on the specified setting
     will be disabled.	Disabling Path settings	is only	supported in sudo ver-
     sion 1.8.16 and higher.

     The following plugin-agnostic paths may be	set in the
     /usr/local/etc/sudo.conf file:

     askpass   The fully qualified path	to a helper program used to read the
	       user's password when no terminal	is available.  This may	be the
	       case when sudo is executed from a graphical (as opposed to
	       text-based) application.	 The program specified by askpass
	       should display the argument passed to it	as the prompt and
	       write the user's	password to the	standard output.  The value of
	       askpass may be overridden by the	SUDO_ASKPASS environment vari-
	       able.

     noexec    The fully-qualified path	to a shared library containing wrap-
	       pers for	the execl(), execle(), execlp(), exect(), execv(),
	       execve(), execvP(), execvp(), execvpe(),	fexecve(), popen(),
	       posix_spawn(), posix_spawnp(), system(),	and wordexp() library
	       functions that prevent the execution of further commands.  This
	       is used to implement the	noexec functionality on	systems	that
	       support LD_PRELOAD or its equivalent.  The default value	is:
	       /usr/local/libexec/sudo/sudo_noexec.so.

     plugin_dir
	       The default directory to	use when searching for plugins that
	       are specified without a fully qualified path name.  The default
	       value is	/usr/local/libexec/sudo.

     sesh      The fully-qualified path	to the sesh binary.  This setting is
	       only used when sudo is built with SELinux support.  The default
	       value is	/usr/local/libexec/sudo/sesh.

   Other settings
     The sudo.conf file	also supports the following front end settings:

     disable_coredump
	       Core dumps of sudo itself are disabled by default to prevent
	       the disclosure of potentially sensitive information.  To	aid in
	       debugging sudo crashes, you may wish to re-enable core dumps by
	       setting ``disable_coredump'' to false in	sudo.conf as follows:

		     Set disable_coredump false

	       All modern operating systems place restrictions on core dumps
	       from setuid processes like sudo so this option can be enabled
	       without compromising security.  To actually get a sudo core
	       file you	will likely need to enable core	dumps for setuid pro-
	       cesses.	On BSD and Linux systems this is accomplished in the
	       sysctl command.	On Solaris, the	coreadm	command	is used	to
	       configure core dump behavior.

	       This setting is only available in sudo version 1.8.4 and
	       higher.

     group_source
	       sudo passes the invoking	user's group list to the policy	and
	       I/O plugins.  On	most systems, there is an upper	limit to the
	       number of groups	that a user may	belong to simultaneously (typ-
	       ically 16 for compatibility with	NFS).  On systems with the
	       getconf(1) utility, running:
		     getconf NGROUPS_MAX
	       will return the maximum number of groups.

	       However,	it is still possible to	be a member of a larger	number
	       of groups--they simply won't be included	in the group list
	       returned	by the kernel for the user.  Starting with sudo	ver-
	       sion 1.8.7, if the user's kernel	group list has the maximum
	       number of entries, sudo will consult the	group database
	       directly	to determine the group list.  This makes it possible
	       for the security	policy to perform matching by group name even
	       when the	user is	a member of more than the maximum number of
	       groups.

	       The group_source	setting	allows the administrator to change
	       this default behavior.  Supported values	for group_source are:

	       static	 Use the static	group list that	the kernel returns.
			 Retrieving the	group list this	way is very fast but
			 it is subject to an upper limit as described above.
			 It is ``static'' in that it does not reflect changes
			 to the	group database made after the user logs	in.
			 This was the default behavior prior to	sudo 1.8.7.

	       dynamic	 Always	query the group	database directly.  It is
			 ``dynamic'' in	that changes made to the group data-
			 base after the	user logs in will be reflected in the
			 group list.  On some systems, querying	the group
			 database for all of a user's groups can be time con-
			 suming	when querying a	network-based group database.
			 Most operating	systems	provide	an efficient method of
			 performing such queries.  Currently, sudo supports
			 efficient group queries on AIX, BSD, HP-UX, Linux and
			 Solaris.

	       adaptive	 Only query the	group database if the static group
			 list returned by the kernel has the maximum number of
			 entries.  This	is the default behavior	in sudo	1.8.7
			 and higher.

	       For example, to cause sudo to only use the kernel's static list
	       of groups for the user:

		     Set group_source static

	       This setting is only available in sudo version 1.8.7 and
	       higher.

     max_groups
	       The maximum number of user groups to retrieve from the group
	       database.  Values less than one will be ignored.	 This setting
	       is only used when querying the group database directly.	It is
	       intended	to be used on systems where it is not possible to
	       detect when the array to	be populated with group	entries	is not
	       sufficiently large.  By default,	sudo will allocate four	times
	       the system's maximum number of groups (see above) and retry
	       with double that	number if the group database query fails.
	       However,	some systems just return as many entries as will fit
	       and do not indicate an error when there is a lack of space.

	       This setting is only available in sudo version 1.8.7 and
	       higher.

     probe_interfaces
	       By default, sudo	will probe the system's	network	interfaces and
	       pass the	IP address of each enabled interface to	the policy
	       plugin.	This makes it possible for the plugin to match rules
	       based on	the IP address without having to query DNS.  On	Linux
	       systems with a large number of virtual interfaces, this may
	       take a non-negligible amount of time.  If IP-based matching is
	       not required, network interface probing can be disabled as fol-
	       lows:

		     Set probe_interfaces false

	       This setting is only available in sudo version 1.8.10 and
	       higher.

   Debug flags
     sudo versions 1.8.4 and higher support a flexible debugging framework
     that can help track down what sudo	is doing internally if there is	a
     problem.

     A Debug line consists of the Debug	keyword, followed by the name of the
     program (or plugin) to debug (sudo, visudo, sudoreplay, sudoers), the
     debug file	name and a comma-separated list	of debug flags.	 The debug
     flag syntax used by sudo and the sudoers plugin is	subsystem@priority but
     a plugin is free to use a different format	so long	as it does not include
     a comma (`,').

     For example:

	   Debug sudo /var/log/sudo_debug all@warn,plugin@info

     would log all debugging statements	at the warn level and higher in	addi-
     tion to those at the info level for the plugin subsystem.

     As	of sudo	1.8.12,	multiple Debug entries may be specified	per program.
     Older versions of sudo only support a single Debug	entry per program.
     Plugin-specific Debug entries are also supported starting with sudo
     1.8.12 and	are matched by either the base name of the plugin that was
     loaded (for example sudoers.so) or	by the plugin's	fully-qualified	path
     name.  Previously,	the sudoers plugin shared the same Debug entry as the
     sudo front	end and	could not be configured	separately.

     The following priorities are supported, in	order of decreasing severity:
     crit, err,	warn, notice, diag, info, trace	and debug.  Each priority,
     when specified, also includes all priorities higher than it.  For exam-
     ple, a priority of	notice would include debug messages logged at notice
     and higher.

     The priorities trace and debug also include function call tracing which
     logs when a function is entered and when it returns.  For example,	the
     following trace is	for the	get_user_groups() function located in
     src/sudo.c:

	   sudo[123] ->	get_user_groups	@ src/sudo.c:385
	   sudo[123] <-	get_user_groups	@ src/sudo.c:429 := groups=10,0,5

     When the function is entered, indicated by	a right	arrow `->', the	pro-
     gram, process ID, function, source	file and line number are logged.  When
     the function returns, indicated by	a left arrow `<-', the same informa-
     tion is logged along with the return value.  In this case,	the return
     value is a	string.

     The following subsystems are used by the sudo front-end:

     all	 matches every subsystem

     args	 command line argument processing

     conv	 user conversation

     edit	 sudoedit

     event	 event subsystem

     exec	 command execution

     main	 sudo main function

     netif	 network interface handling

     pcomm	 communication with the	plugin

     plugin	 plugin	configuration

     pty	 pseudo-tty related code

     selinux	 SELinux-specific handling

     util	 utility functions

     utmp	 utmp handling

     The sudoers(5) plugin includes support for	additional subsystems.

FILES
     /usr/local/etc/sudo.conf  sudo front end configuration

EXAMPLES
     #
     # Default /usr/local/etc/sudo.conf	file
     #
     # Format:
     #	 Plugin	plugin_name plugin_path	plugin_options ...
     #	 Path askpass /path/to/askpass
     #	 Path noexec /path/to/sudo_noexec.so
     #	 Debug sudo /var/log/sudo_debug	all@warn
     #	 Set disable_coredump true
     #
     # The plugin_path is relative to /usr/local/libexec/sudo unless
     #	 fully qualified.
     # The plugin_name corresponds to a	global symbol in the plugin
     #	 that contains the plugin interface structure.
     # The plugin_options are optional.
     #
     # The sudoers plugin is used by default if	no Plugin lines	are
     # present.
     Plugin sudoers_policy sudoers.so
     Plugin sudoers_io sudoers.so

     #
     # Sudo askpass:
     #
     # An askpass helper program may be	specified to provide a graphical
     # password	prompt for "sudo -A" support.  Sudo does not ship with
     # its own askpass program but can use the OpenSSH askpass.
     #
     # Use the OpenSSH askpass
     #Path askpass /usr/X11R6/bin/ssh-askpass
     #
     # Use the Gnome OpenSSH askpass
     #Path askpass /usr/libexec/openssh/gnome-ssh-askpass

     #
     # Sudo noexec:
     #
     # Path to a shared	library	containing dummy versions of the execv(),
     # execve()	and fexecve() library functions	that just return an error.
     # This is used to implement the "noexec" functionality on systems that
     # support C<LD_PRELOAD> or	its equivalent.
     # The compiled-in value is	usually	sufficient and should only be
     # changed if you rename or	move the sudo_noexec.so	file.
     #
     #Path noexec /usr/local/libexec/sudo/sudo_noexec.so

     #
     # Core dumps:
     #
     # By default, sudo	disables core dumps while it is	executing
     # (they are re-enabled for	the command that is run).
     # To aid in debugging sudo	problems, you may wish to enable core
     # dumps by	setting	"disable_coredump" to false.
     #
     #Set disable_coredump false

     #
     # User groups:
     #
     # Sudo passes the user's group list to the	policy plugin.
     # If the user is a	member of the maximum number of	groups (usually	16),
     # sudo will query the group database directly to be sure to include
     # the full	list of	groups.
     #
     # On some systems,	this can be expensive so the behavior is configurable.
     # The "group_source" setting has three possible values:
     #	 static	  - use	the user's list	of groups returned by the kernel.
     #	 dynamic  - query the group database to	find the list of groups.
     #	 adaptive - if user is in less than the	maximum	number of groups.
     #		    use	the kernel list, else query the	group database.
     #
     #Set group_source static

SEE ALSO
     sudoers(5), sudo(8), sudo_plugin(8)

HISTORY
     See the HISTORY file in the sudo distribution (https://www.sudo.ws/his-
     tory.html)	for a brief history of sudo.

AUTHORS
     Many people have worked on	sudo over the years; this version consists of
     code written primarily by:

	   Todd	C. Miller

     See the CONTRIBUTORS file in the sudo distribution
     (https://www.sudo.ws/contributors.html) for an exhaustive list of people
     who have contributed to sudo.

BUGS
     If	you feel you have found	a bug in sudo, please submit a bug report at
     https://bugzilla.sudo.ws/

SUPPORT
     Limited free support is available via the sudo-users mailing list,	see
     https://www.sudo.ws/mailman/listinfo/sudo-users to	subscribe or search
     the archives.

DISCLAIMER
     sudo is provided ``AS IS''	and any	express	or implied warranties, includ-
     ing, but not limited to, the implied warranties of	merchantability	and
     fitness for a particular purpose are disclaimed.  See the LICENSE file
     distributed with sudo or https://www.sudo.ws/license.html for complete
     details.

Sudo 1.8.20p2		       October 15, 2016			 Sudo 1.8.20p2

NAME | DESCRIPTION | FILES | EXAMPLES | SEE ALSO | HISTORY | AUTHORS | BUGS | SUPPORT | DISCLAIMER

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