# man > SUDO.CONF(5) [_SUDO.CONF_(5)](https://www.chedong.com/phpMan.php/man/SUDO.CONF/5/markdown) File Formats Manual [_SUDO.CONF_(5)](https://www.chedong.com/phpMan.php/man/SUDO.CONF/5/markdown) ## NAME sudo.conf — configuration for sudo front-end ## DESCRIPTION The **sudo.conf **file is used to configure the **sudo **front-end. It is used to configure sudo plugins, plugin-agnostic path names, debug flags, and other settings. The **sudo.conf **file supports the following directives, described in detail below. Plugin an approval, audit, I/O logging, or security policy 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. Lead‐ ing white space is removed from the beginning of lines even when a 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/output logging. Third parties can develop and distribute their own policy and I/O logging plugins to work seam‐ lessly 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_ _approval_plugin_, _struct_ _audit_plugin_, _struct_ _io_plugin_, or _struct_ _policy_plugin_ defined by 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 de‐ faults to _/usr/libexec/sudo_. In other words: Plugin sudoers_policy sudoers.so is equivalent to: Plugin sudoers_policy /usr/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 On AIX systems, the plugin may be either a shared object ending in ‘.so’ or an archive file containing a shared object ending in ‘.a’ with the name of the shared object in parentheses at the end. 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 override the compile-time default sudoers file mode: Plugin sudoers_policy sudoers.so sudoers_mode=0440 See the [_sudoers_(5)](https://www.chedong.com/phpMan.php/man/sudoers/5/markdown) 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 user-ID 0 and only writable by its owner. Because of ambi‐ guities 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 logging (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 behavior will be consistent with that of **sudo **versions 1.9.0 and below. For more information on the **sudo **plugin architecture, see the [_sudo_plugin_(5)](https://www.chedong.com/phpMan.php/man/sudoplugin/5/markdown) 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 intercept /usr/libexec/sudo/sudo_intercept.so Path noexec /usr/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 **version 1.8.16 and higher. The following plugin-agnostic paths may be set in the _/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 provide such a mechanism. Sudo will _not_ recurse into sub-directories. If terminal devices may be located in a sub-directory of _/dev_, that path must be explic‐ itly 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. intercept The path to a shared library containing a wrappers for the [_execve_(2)](https://www.chedong.com/phpMan.php/man/execve/2/markdown), [_execl_(3)](https://www.chedong.com/phpMan.php/man/execl/3/markdown), [_execle_(3)](https://www.chedong.com/phpMan.php/man/execle/3/markdown), [_execlp_(3)](https://www.chedong.com/phpMan.php/man/execlp/3/markdown), [_execv_(3)](https://www.chedong.com/phpMan.php/man/execv/3/markdown), [_execvp_(3)](https://www.chedong.com/phpMan.php/man/execvp/3/markdown), [_execvpe_(3)](https://www.chedong.com/phpMan.php/man/execvpe/3/markdown), and [_system_(3)](https://www.chedong.com/phpMan.php/man/system/3/markdown) library functions that intercepts attempts to run further commands and performs a policy check before al‐ lowing them to be executed. This is used to implement the _intercept_ and _log_subcmds_ functionality on systems that support LD_PRELOAD or the equivalent. The _intercept_ path may be set to either a single fully-qualified path, or, for systems that support separate LD_PRELOAD environment variables for 32-bit and 64-bit executa‐ bles, it may optionally be set to two fully-qualified paths separated by a colon (‘:’). The first path should be the 32-bit version and the second the 64-bit version. This two-path form is currently only supported on AIX and Solaris systems. The default value is _/usr/libexec/sudo/sudo_intercept.so_. noexec The path to a shared library containing wrappers for the [_execve_(2)](https://www.chedong.com/phpMan.php/man/execve/2/markdown), [_execl_(3)](https://www.chedong.com/phpMan.php/man/execl/3/markdown), [_execle_(3)](https://www.chedong.com/phpMan.php/man/execle/3/markdown), [_execlp_(3)](https://www.chedong.com/phpMan.php/man/execlp/3/markdown), [_exect_(3)](https://www.chedong.com/phpMan.php/man/exect/3/markdown), [_execv_(3)](https://www.chedong.com/phpMan.php/man/execv/3/markdown), [_execveat_(3)](https://www.chedong.com/phpMan.php/man/execveat/3/markdown), [_execvP_(3)](https://www.chedong.com/phpMan.php/man/execvP/3/markdown), [_execvp_(3)](https://www.chedong.com/phpMan.php/man/execvp/3/markdown), [_execvpe_(3)](https://www.chedong.com/phpMan.php/man/execvpe/3/markdown), [_fexecve_(3)](https://www.chedong.com/phpMan.php/man/fexecve/3/markdown), [_popen_(3)](https://www.chedong.com/phpMan.php/man/popen/3/markdown), [_posix_spawn_(3)](https://www.chedong.com/phpMan.php/man/posixspawn/3/markdown), [_posix_spawnp_(3)](https://www.chedong.com/phpMan.php/man/posixspawnp/3/markdown), [_system_(3)](https://www.chedong.com/phpMan.php/man/system/3/markdown), and [_wordexp_(3)](https://www.chedong.com/phpMan.php/man/wordexp/3/markdown) library functions that prevent the execution of further commands. This is used to implement the _noexec_ functionality on systems that support LD_PRELOAD or the equivalent. The _noexec_ path may be set to either a single fully-qualified path, or, for systems that support separate LD_PRELOAD environment variables for 32-bit and 64-bit executa‐ bles, it may optionally be set to two fully-qualified paths separated by a colon (‘:’). The first path should be the 32-bit version and the second the 64-bit version. This two-path form is currently only supported on AIX and Solaris systems. The default value is _/usr/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/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/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 poten‐ tially sensitive information. To aid in debugging **sudo **crashes, you may wish to re-en‐ able 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 enabled 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 accomplished in the [_sysctl_(8)](https://www.chedong.com/phpMan.php/man/sysctl/8/markdown) command. On Solaris, the [_coreadm_(1m)](https://www.chedong.com/phpMan.php/man/coreadm/1m/markdown) 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 sys‐ tems, there is an upper limit to the number of groups that a user may belong to simul‐ taneously (typically 16 for compatibility with NFS). On systems with the [_getconf_(1)](https://www.chedong.com/phpMan.php/man/getconf/1/markdown) 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 **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 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 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 operating sys‐ tems provide an efficient method of performing such queries. Currently, **sudo** supports efficient group queries on AIX, BSD, Linux, macOS, and Solaris. This is the default behavior on macOS in **sudo **1.9.6 and higher. 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 on systems other than macOS 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 or larger than 1024 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 pos‐ sible 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. This setting is only available in **sudo **version 1.8.7 and higher. It should not be re‐ quired 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 settings **sudo **versions 1.8.4 and higher support a flexible debugging framework that can log 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, plugin, or shared object to debug, the debug file name, and a comma-separated list of debug flags. The debug flag syntax used by **sudo**, the **sudoers **plugin along with its associated programs and shared objects is _subsystem_@_priority_ but a third-party plugin is free to use a different for‐ mat so long as it does not include a comma (‘,’). On AIX systems, a _Debug_ line will match a plugin specified as either the name of an SVR4-style shared object file ending in ‘.so’, an archive file ending in ‘.a’, or an archive file ending in ‘.a’ with the name of the shared object in parentheses. Examples: Debug sudo /var/log/sudo_debug all@warn,plugin@info would log all debugging statements at the _warn_ level and higher in addition to those at the _info_ level for the plugin subsystem. Debug sudo_intercept.so /var/log/intercept_debug all@debug would log all debugging statements, regardless of level, for the _sudo_intercept.so_ shared li‐ brary that implements **sudo**'s intercept functionality on some systems. Debug sudoers.so /var/log/sudoers_debug all@debug would log all debugging statements, regardless of level, for the **sudoers **plugin. See [_sudoers_(5)](https://www.chedong.com/phpMan.php/man/sudoers/5/markdown) for the full list of subsystems supported by the **sudoers **plugin. 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. Pre‐ viously, 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 pri‐ orities higher than it. For example, 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 program, process ID, func‐ tion, source file, and line number are logged. When the function returns, indicated by a left arrow ‘<-’, the same information 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)](https://www.chedong.com/phpMan.php/man/sudoers/5/markdown) plugin includes support for additional subsystems. ## FILES _/etc/sudo.conf_ **sudo **front-end configuration ## EXAMPLES # # Default /etc/sudo.conf file # # Sudo plugins: # Plugin plugin_name plugin_path plugin_options ... # # The plugin_path is relative to /usr/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 command interception: # Path intercept /path/to/sudo_intercept.so # # Path to a shared library containing replacements for the execv() # and execve() library functions that perform a policy check to verify # the command is allowed and simply return an error if not. This is # used to implement the "intercept" 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_intercept.so file. # #Path intercept /usr/libexec/sudo/sudo_intercept.so # # Sudo noexec: # Path noexec /path/to/sudo_noexec.so # # Path to a shared library containing replacements for the execv() # family of 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/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/libexec/sudo # # 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)](https://www.chedong.com/phpMan.php/man/sudoplugin/5/markdown), [_sudoers_(5)](https://www.chedong.com/phpMan.php/man/sudoers/5/markdown), [_sudo_(8)](https://www.chedong.com/phpMan.php/man/sudo/8/markdown) ## AUTHORS Many people have worked on **sudo **over the years; this version consists of code written primar‐ ily by: Todd C. Miller See the CONTRIBUTORS.md file in the **sudo **distribution (‐ tors/) for an exhaustive list of people who have contributed to **sudo**. ## BUGS If you believe you have found a bug in **sudo**, you can submit a bug report at ## SUPPORT Limited free support is available via the sudo-users mailing list, see to subscribe or search the archives. ## DISCLAIMER **sudo **is provided “AS IS” and any express or implied warranties, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose are dis‐ claimed. See the LICENSE.md file distributed with **sudo **or for complete details. Sudo 1.9.15p5 November 6, 2023 [_SUDO.CONF_(5)](https://www.chedong.com/phpMan.php/man/SUDO.CONF/5/markdown)