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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
     plugin-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 approval_plugin, audit_plugin, io_plugin,
     or	policy_plugin struct contained in the plugin.  If a plugin implements
     multiple plugin types, there must be a Plugin line	for each unique	symbol
     name.  The	path may be fully qualified or relative.  If not fully quali-
     fied, 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 be-
     ing 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, for I/O log-
     ging (if enabled by the policy) and for auditing.	This is	equivalent to
     the following:

	   Plugin sudoers_policy sudoers.so
	   Plugin sudoers_io sudoers.so
	   Plugin sudoers_audit	sudoers.so

     Starting with sudo	version	1.9.1, some of the logging functionality of
     the sudoers plugin	has been moved from the	policy plugin to an audit
     plugin.  To maintain compatibility	with sudo.conf files from older	sudo
     versions, if sudoers is configured	as the security	policy,	it will	be
     used as an	audit plugin as	well.  This guarantees that the	logging	behav-
     ior will be consistnet with that of sudo versions 1.9.0 and below.

     For more information on the sudo plugin architecture, see the
     sudo_plugin(5) 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.

     devsearch
	       An ordered, colon-separated search path of directories to look
	       in for device nodes.  This is used when mapping the process's
	       tty device number to a device name on systems that do not pro-
	       vide such a mechanism.  Sudo will not recurse into sub-directo-
	       ries.  If terminal devices may be located in a sub-directory of
	       /dev, that path must be explicitly listed in devsearch.	The
	       default value is
	       /dev/pts:/dev/vt:/dev/term:/dev/zcons:/dev/pty:/dev

	       This option is ignored on systems that support either the
	       devname() or _ttyname_dev() functions, for example BSD, macOS
	       and Solaris.

     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.

   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 set-user-ID	processes like sudo so this option can be en-
	       abled without compromising security.  To	actually get a sudo
	       core file you will likely need to enable	core dumps for set-
	       user-ID processes.  On BSD and Linux systems this is accom-
	       plished in the sysctl(8)	command.  On Solaris, the coreadm(1m)
	       command is used to configure core dump behavior.

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

     developer_mode
	       By default sudo refuses to load plugins which can be modified
	       by other	than the root user.  The plugin	should be owned	by
	       root and	write access permissions should	be disabled for
	       "group" and "other".  To	make development of a plugin easier,
	       you can disable that by setting "developer_mode"	option to true
	       in sudo.conf as follows:

		     Set developer_mode	true

	       Please note that	this creates a security	risk, so it is not
	       recommended on critical systems such as a desktop machine for
	       daily use, but is intended to be	used in	development environ-
	       ments (VM, container, etc).  Before enabling developer mode,
	       ensure you understand the implications.

	       This setting is only available in sudo version 1.9.0 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 re-
	       turned by the kernel for	the user.  Starting with sudo version
	       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 secu-
	       rity 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 database
			 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	consuming when
			 querying a network-based group	database.  Most	oper-
			 ating systems provide an efficient method of perform-
			 ing 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 de-
	       tect 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.

	       This setting is only available in sudo version 1.8.7 and
	       higher.	It should not be required in sudo versions 1.8.24 and
	       higher and may be removed in a later release.

     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 de-
     bug 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-terminal 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
     #
     # Sudo plugins:
     #	 Plugin	plugin_name plugin_path	plugin_options ...
     #
     # 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
     Plugin sudoers_audit sudoers.so

     #
     # Sudo askpass:
     #	 Path askpass /path/to/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 device search path:
     #	 Path devsearch	/dev/path1:/dev/path2:/dev
     #
     # A colon-separated list of paths to check	when searching for a user's
     # terminal	device.
     #
     #Path devsearch /dev/pts:/dev/vt:/dev/term:/dev/zcons:/dev/pty:/dev

     #
     # Sudo noexec:
     #	 Path noexec /path/to/sudo_noexec.so
     #
     # 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 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

     #
     # Sudo plugin directory:
     #	 Path plugin_dir /path/to/plugins
     #
     # The default directory to	use when searching for plugins that are
     # specified without a fully qualified path	name.
     #
     #Path plugin_dir /usr/local/libexec/sudo

     #
     # Sudo developer mode:
     #	 Set developer_mode true|false
     #
     # Allow loading of	plugins	that are owned by non-root or are writable
     # by "group" or "other".  Should only be used during plugin development.
     #Set developer_mode true

     #
     # Core dumps:
     #	 Set disable_coredump true|false
     #
     # 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:
     #	 Set group_source static|dynamic|adaptive
     #
     # 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

     #
     # Sudo interface probing:
     #	 Set probe_interfaces true|false
     #
     # By default, sudo	will probe the system's	network	interfaces and
     # pass the	IP address of each enabled interface to	the policy plugin.
     # On systems with a large number of virtual interfaces this may take
     # a noticeable amount of time.
     #
     #Set probe_interfaces false

     #
     # Sudo debug files:
     #	 Debug program /path/to/debug_log subsystem@priority[,subsyste@priority]
     #
     # Sudo and	related	programs support logging debug information to a	file.
     # The program is typically	sudo, sudoers.so, sudoreplay or	visudo.
     #
     # Subsystems vary based on	the program; "all" matches all subsystems.
     # Priority	may be crit, err, warn,	notice,	diag, info, trace or debug.
     # Multiple	subsystem@priority may be specified, separated by a comma.
     #
     #Debug sudo /var/log/sudo_debug all@debug
     #Debug sudoers.so /var/log/sudoers_debug all@debug

SEE ALSO
     sudo_plugin(5), sudoers(5), sudo(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 1.9.2			 June 1, 2020			    Sudo 1.9.2

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