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sudoers(4)

SUDOERS(4)                    File Formats Manual                   SUDOERS(4)



NAME
       sudoers - default sudo security policy plugin

DESCRIPTION
       The sudoers policy plugin determines a user's sudo privileges.  It is
       the default sudo policy plugin.  The policy is driven by the
       /etc/sudoers file or, optionally in LDAP.  The policy format is
       described in detail in the SUDOERS FILE FORMAT section.  For
       information on storing sudoers policy information in LDAP, please see
       sudoers.ldap(4).

   Configuring sudo.conf for sudoers
       sudo consults the sudo.conf(4) file to determine which policy and I/O
       logging plugins to load.  If no sudo.conf(4) file is present, or if it
       contains no Plugin lines, sudoers will be used for policy decisions and
       I/O logging.  To explicitly configure sudo.conf(4) to use the sudoers
       plugin, the following configuration can be used.

             Plugin sudoers_policy sudoers.so
             Plugin sudoers_io sudoers.so

       Starting with sudo 1.8.5, it is possible to specify optional arguments
       to the sudoers plugin in the sudo.conf(4) file.  These arguments, if
       present, should be listed after the path to the plugin (i.e., after
       sudoers.so).  Multiple arguments may be specified, separated by white
       space.  For example:

             Plugin sudoers_policy sudoers.so sudoers_mode=0400

       The following plugin arguments are supported:

       ldap_conf=pathname
                 The ldap_conf argument can be used to override the default
                 path to the ldap.conf file.

       ldap_secret=pathname
                 The ldap_secret argument can be used to override the default
                 path to the ldap.secret file.

       sudoers_file=pathname
                 The sudoers_file argument can be used to override the default
                 path to the sudoers file.

       sudoers_uid=uid
                 The sudoers_uid argument can be used to override the default
                 owner of the sudoers file.  It should be specified as a
                 numeric user-ID.

       sudoers_gid=gid
                 The sudoers_gid argument can be used to override the default
                 group of the sudoers file.  It must be specified as a numeric
                 group-ID (not a group name).

       sudoers_mode=mode
                 The sudoers_mode argument can be used to override the default
                 file mode for the sudoers file.  It should be specified as an
                 octal value.

       For more information on configuring sudo.conf(4), please refer to its
       manual.

   User Authentication
       The sudoers security policy requires that most users authenticate
       themselves before they can use sudo.  A password is not required if the
       invoking user is root, if the target user is the same as the invoking
       user, or if the policy has disabled authentication for the user or
       command.  Unlike su(1), when sudoers requires authentication, it
       validates the invoking user's credentials, not the target user's (or
       root's) credentials.  This can be changed via the rootpw, targetpw and
       runaspw flags, described later.

       If a user who is not listed in the policy tries to run a command via
       sudo, mail is sent to the proper authorities.  The address used for
       such mail is configurable via the mailto Defaults entry (described
       later) and defaults to root.

       Note that no mail will be sent if an unauthorized user tries to run
       sudo with the -l or -v option unless there is an authentication error
       and either the mail_always or mail_badpass flags are enabled.  This
       allows users to determine for themselves whether or not they are
       allowed to use sudo.  By default, all attempts to run sudo (successful
       or not) are logged, regardless of whether or not mail is sent.

       If sudo is run by root and the SUDO_USER environment variable is set,
       the sudoers policy will use this value to determine who the actual user
       is.  This can be used by a user to log commands through sudo even when
       a root shell has been invoked.  It also allows the -e option to remain
       useful even when invoked via a sudo-run script or program.  Note,
       however, that the sudoers file lookup is still done for root, not the
       user specified by SUDO_USER.

       sudoers uses per-user time stamp files for credential caching.  Once a
       user has been authenticated, a record is written containing the user-ID
       that was used to authenticate, the terminal session ID, the start time
       of the session leader (or parent process) and a time stamp (using a
       monotonic clock if one is available).  The user may then use sudo
       without a password for a short period of time (5 minutes unless
       overridden by the timestamp_timeout option) .  By default, sudoers uses
       a separate record for each terminal, which means that a user's login
       sessions are authenticated separately.  The timestamp_type option can
       be used to select the type of time stamp record sudoers will use.

   Logging
       By default, sudoers logs both successful and unsuccessful attempts (as
       well as errors).  The log_allowed and log_denied flags can be used to
       control this behavior.  Messages can be logged to syslog(3), a log
       file, or both.  The default is to log to syslog(3) but this is
       configurable via the syslog and logfile settings.  See LOG FORMAT for a
       description of the log file format.

       sudoers is also capable of running a command in a pseudo-terminal and
       logging all input and/or output.  The standard input, standard output
       and standard error can be logged even when not associated with a
       terminal.  I/O logging is not on by default but can be enabled using
       the log_input and log_output options as well as the LOG_INPUT and
       LOG_OUTPUT command tags.  See I/O LOG FILES for details on how I/O log
       files are stored.

   Command environment
       Since environment variables can influence program behavior, sudoers
       provides a means to restrict which variables from the user's
       environment are inherited by the command to be run.  There are two
       distinct ways sudoers can deal with environment variables.

       By default, the env_reset flag is enabled.  This causes commands to be
       executed with a new, minimal environment.  On AIX (and Linux systems
       without PAM), the environment is initialized with the contents of the
       /etc/environment file.  The HOME, MAIL, SHELL, LOGNAME and USER
       environment variables are initialized based on the target user and the
       SUDO_* variables are set based on the invoking user.  Additional
       variables, such as DISPLAY, PATH and TERM, are preserved from the
       invoking user's environment if permitted by the env_check or env_keep
       options.  This is effectively a whitelist for environment variables.  A
       few environment variables are treated specially.  If the PATH and TERM
       variables are not preserved from the user's environment, they will be
       set to default values.  The LOGNAME and USER are handled as a single
       entity.  If one of them is preserved (or removed) from the user's
       environment, the other will be as well.  If LOGNAME and USER are to be
       preserved but only one of them is present in the user's environment,
       the other will be set to the same value.  This avoids an inconsistent
       environment where one of the variables describing the user name is set
       to the invoking user and one is set to the target user.  Environment
       variables with a value beginning with () are removed unless both the
       name and value parts are matched by env_keep or env_check, as they may
       be interpreted as functions by the bash shell.  Prior to version
       1.8.11, such variables were always removed.

       If, however, the env_reset flag is disabled, any variables not
       explicitly denied by the env_check and env_delete options are allowed
       and their values are inherited from the invoking process.  Prior to
       version 1.8.21, environment variables with a value beginning with ()
       were always removed.  Beginning with version 1.8.21, a pattern in
       env_delete is used to match bash shell functions instead.  Since it is
       not possible to block all potentially dangerous environment variables,
       use of the default env_reset behavior is encouraged.

       Environment variables specified by env_check, env_delete, or env_keep
       may include one or more ‘*’ characters which will match zero or more
       characters.  No other wildcard characters are supported.

       By default, environment variables are matched by name.  However, if the
       pattern includes an equal sign (‘=’), both the variables name and value
       must match.  For example, a bash shell function could be matched as
       follows:

           env_keep += "BASH_FUNC_my_func%%=()*"

       Without the “=()*” suffix, this would not match, as bash shell
       functions are not preserved by default.

       The complete list of environment variables that are preserved or
       removed, as modified by global Defaults parameters in sudoers, is
       displayed when sudo is run by root with the -V option.  Please note
       that the list of environment variables to remove varies based on the
       operating system sudo is running on.

       Other sudoers options may influence the command environment, such as
       always_set_home, secure_path, set_logname, and set_home.

       On systems that support PAM where the pam_env module is enabled for
       sudo, variables in the PAM environment may be merged in to the
       environment.  If a variable in the PAM environment is already present
       in the user's environment, the value will only be overridden if the
       variable was not preserved by sudoers.  When env_reset is enabled,
       variables preserved from the invoking user's environment by the
       env_keep list take precedence over those in the PAM environment.  When
       env_reset is disabled, variables present the invoking user's
       environment take precedence over those in the PAM environment unless
       they match a pattern in the env_delete list.

       Note that the dynamic linker on most operating systems will remove
       variables that can control dynamic linking from the environment of set-
       user-ID executables, including sudo.  Depending on the operating system
       this may include _RLD*, DYLD_*, LD_*, LDR_*, LIBPATH, SHLIB_PATH, and
       others.  These type of variables are removed from the environment
       before sudo even begins execution and, as such, it is not possible for
       sudo to preserve them.

       As a special case, if the -i option (initial login) is specified,
       sudoers will initialize the environment regardless of the value of
       env_reset.  The DISPLAY, PATH and TERM variables remain unchanged;
       HOME, MAIL, SHELL, USER, and LOGNAME are set based on the target user.
       On AIX (and Linux systems without PAM), the contents of
       /etc/environment are also included.  All other environment variables
       are removed unless permitted by env_keep or env_check, described above.

       Finally, the restricted_env_file and env_file files are applied, if
       present.  The variables in restricted_env_file are applied first and
       are subject to the same restrictions as the invoking user's
       environment, as detailed above.  The variables in env_file are applied
       last and are not subject to these restrictions.  In both cases,
       variables present in the files will only be set to their specified
       values if they would not conflict with an existing environment
       variable.

SUDOERS FILE FORMAT
       The sudoers file is composed of two types of entries: aliases
       (basically variables) and user specifications (which specify who may
       run what).

       When multiple entries match for a user, they are applied in order.
       Where there are multiple matches, the last match is used (which is not
       necessarily the most specific match).

       The sudoers file grammar will be described below in Extended Backus-
       Naur Form (EBNF).  Don't despair if you are unfamiliar with EBNF; it is
       fairly simple, and the definitions below are annotated.

   Quick guide to EBNF
       EBNF is a concise and exact way of describing the grammar of a
       language.  Each EBNF definition is made up of production rules.  E.g.,

       symbol ::= definition | alternate1 | alternate2 ...

       Each production rule references others and thus makes up a grammar for
       the language.  EBNF also contains the following operators, which many
       readers will recognize from regular expressions.  Do not, however,
       confuse them with “wildcard” characters, which have different meanings.

       ?     Means that the preceding symbol (or group of symbols) is
             optional.  That is, it may appear once or not at all.

       *     Means that the preceding symbol (or group of symbols) may appear
             zero or more times.

       +     Means that the preceding symbol (or group of symbols) may appear
             one or more times.

       Parentheses may be used to group symbols together.  For clarity, we
       will use single quotes ('') to designate what is a verbatim character
       string (as opposed to a symbol name).

   Aliases
       There are four kinds of aliases: User_Alias, Runas_Alias, Host_Alias
       and Cmnd_Alias.  Beginning with sudo 1.9.0, Cmd_Alias may be used in
       place of Cmnd_Alias if desired.

       Alias ::= 'User_Alias'  User_Alias_Spec (':' User_Alias_Spec)* |
                 'Runas_Alias' Runas_Alias_Spec (':' Runas_Alias_Spec)* |
                 'Host_Alias'  Host_Alias_Spec (':' Host_Alias_Spec)* |
                 'Cmnd_Alias'  Cmnd_Alias_Spec (':' Cmnd_Alias_Spec)* |
                 'Cmd_Alias'   Cmnd_Alias_Spec (':' Cmnd_Alias_Spec)*

       User_Alias ::= NAME

       User_Alias_Spec ::= User_Alias '=' User_List

       Runas_Alias ::= NAME

       Runas_Alias_Spec ::= Runas_Alias '=' Runas_List

       Host_Alias ::= NAME

       Host_Alias_Spec ::= Host_Alias '=' Host_List

       Cmnd_Alias ::= NAME

       Cmnd_Alias_Spec ::= Cmnd_Alias '=' Cmnd_List

       NAME ::= [A-Z]([A-Z][0-9]_)*

       Each alias definition is of the form

       Alias_Type NAME = item1, item2, ...

       where Alias_Type is one of User_Alias, Runas_Alias, Host_Alias, or
       Cmnd_Alias.  A NAME is a string of uppercase letters, numbers, and
       underscore characters (‘_’).  A NAME must start with an uppercase
       letter.  It is possible to put several alias definitions of the same
       type on a single line, joined by a colon (‘:’).  E.g.,

       Alias_Type NAME = item1, item2, item3 : NAME = item4, item5

       It is a syntax error to redefine an existing alias.  It is possible to
       use the same name for aliases of different types, but this is not
       recommended.

       The definitions of what constitutes a valid alias member follow.

       User_List ::= User |
                     User ',' User_List

       User ::= '!'* user name |
                '!'* #uid |
                '!'* %group |
                '!'* %#gid |
                '!'* +netgroup |
                '!'* %:nonunix_group |
                '!'* %:#nonunix_gid |
                '!'* User_Alias

       A User_List is made up of one or more user names, user-IDs (prefixed
       with ‘#’), system group names and IDs (prefixed with ‘%’ and ‘%#’
       respectively), netgroups (prefixed with ‘+’), non-Unix group names and
       IDs (prefixed with ‘%:’ and ‘%:#’ respectively) and User_Aliases.  Each
       list item may be prefixed with zero or more ‘!’  operators.  An odd
       number of ‘!’  operators negate the value of the item; an even number
       just cancel each other out.  User netgroups are matched using the user
       and domain members only; the host member is not used when matching.

       A user name, uid, group, gid, netgroup, nonunix_group or nonunix_gid
       may be enclosed in double quotes to avoid the need for escaping special
       characters.  Alternately, special characters may be specified in
       escaped hex mode, e.g., \x20 for space.  When using double quotes, any
       prefix characters must be included inside the quotes.

       The actual nonunix_group and nonunix_gid syntax depends on the
       underlying group provider plugin.  For instance, the QAS AD plugin
       supports the following formats:

       ·  Group in the same domain: "%:Group Name"

       ·  Group in any domain: "%:Group Name@FULLY.QUALIFIED.DOMAIN"

       ·  Group SID: "%:S-1-2-34-5678901234-5678901234-5678901234-567"

       See GROUP PROVIDER PLUGINS for more information.

       Note that quotes around group names are optional.  Unquoted strings
       must use a backslash (‘\’) to escape spaces and special characters.
       See Other special characters and reserved words for a list of
       characters that need to be escaped.

       Runas_List ::= Runas_Member |
                      Runas_Member ',' Runas_List

       Runas_Member ::= '!'* user name |
                        '!'* #uid |
                        '!'* %group |
                        '!'* %#gid |
                        '!'* %:nonunix_group |
                        '!'* %:#nonunix_gid |
                        '!'* +netgroup |
                        '!'* Runas_Alias

       A Runas_List is similar to a User_List except that instead of
       User_Aliases it can contain Runas_Aliases.  Note that user names and
       groups are matched as strings.  In other words, two users (groups) with
       the same user (group) ID are considered to be distinct.  If you wish to
       match all user names with the same user-ID (e.g., root and toor), you
       can use a user-ID instead of a name (#0 in the example given).  Note
       that the user-ID or group-ID specified in a Runas_Member need not be
       listed in the password or group database.

       Host_List ::= Host |
                     Host ',' Host_List

       Host ::= '!'* host name |
                '!'* ip_addr |
                '!'* network(/netmask)? |
                '!'* +netgroup |
                '!'* Host_Alias

       A Host_List is made up of one or more host names, IP addresses, network
       numbers, netgroups (prefixed with ‘+’) and other aliases.  Again, the
       value of an item may be negated with the ‘!’  operator.  Host netgroups
       are matched using the host (both qualified and unqualified) and domain
       members only; the user member is not used when matching.  If you
       specify a network number without a netmask, sudo will query each of the
       local host's network interfaces and, if the network number corresponds
       to one of the hosts's network interfaces, will use the netmask of that
       interface.  The netmask may be specified either in standard IP address
       notation (e.g., 255.255.255.0 or ffff:ffff:ffff:ffff::), or CIDR
       notation (number of bits, e.g., 24 or 64).  A host name may include
       shell-style wildcards (see the Wildcards section below), but unless the
       host name command on your machine returns the fully qualified host
       name, you'll need to use the fqdn flag for wildcards to be useful.
       Note that sudo only inspects actual network interfaces; this means that
       IP address 127.0.0.1 (localhost) will never match.  Also, the host name
       “localhost” will only match if that is the actual host name, which is
       usually only the case for non-networked systems.

       digest ::= [A-Fa-f0-9]+ |
               [A-Za-z0-9\+/=]+

       Digest_Spec ::= "sha224" ':' digest |
                 "sha256" ':' digest |
                 "sha384" ':' digest |
                 "sha512" ':' digest

       Digest_List ::= Digest_Spec |
                       Digest_Spec ',' Digest_List

       Cmnd_List ::= Cmnd |
                     Cmnd ',' Cmnd_List

       command name ::= file name |
                        file name args |
                        file name '""'

       Edit_Spec ::= "sudoedit" file name+

       Cmnd ::= Digest_List? '!'* command name |
                '!'* directory |
                '!'* Edit_Spec |
                '!'* Cmnd_Alias

       A Cmnd_List is a list of one or more command names, directories, and
       other aliases.  A command name is a fully qualified file name which may
       include shell-style wildcards (see the Wildcards section below).  A
       simple file name allows the user to run the command with any arguments
       they wish.  However, you may also specify command line arguments
       (including wildcards).  Alternately, you can specify "" to indicate
       that the command may only be run without command line arguments.  A
       directory is a fully qualified path name ending in a ‘/’.  When you
       specify a directory in a Cmnd_List, the user will be able to run any
       file within that directory (but not in any sub-directories therein).

       If a Cmnd has associated command line arguments, then the arguments in
       the Cmnd must match exactly those given by the user on the command line
       (or match the wildcards if there are any).  Note that the following
       characters must be escaped with a ‘\’ if they are used in command
       arguments: ‘,’, ‘:’, ‘=’, ‘\’.  The built-in command “sudoedit” is used
       to permit a user to run sudo with the -e option (or as sudoedit).  It
       may take command line arguments just as a normal command does.  Note
       that “sudoedit” is a command built into sudo itself and must be
       specified in the sudoers file without a leading path.  If a leading
       path is present, for example /usr/bin/sudoedit, the path name will be
       silently converted to “sudoedit”.  A fully-qualified path for sudoedit
       is treated as an error by visudo.

       A command name may be preceded by a Digest_List, a comma-separated list
       of one or more Digest_Spec entries.  If a Digest_List is present, the
       command will only match successfully if it can be verified using one of
       the SHA-2 digests in the list.  Starting with version 1.9.0, the ALL
       reserved word can be used in conjunction with a Digest_List.  The
       following digest formats are supported: sha224, sha256, sha384 and
       sha512.  The string may be specified in either hex or base64 format
       (base64 is more compact).  There are several utilities capable of
       generating SHA-2 digests in hex format such as openssl, shasum,
       sha224sum, sha256sum, sha384sum, sha512sum.

       For example, using openssl:

       $ openssl dgst -sha224 /bin/ls
       SHA224(/bin/ls)= 118187da8364d490b4a7debbf483004e8f3e053ec954309de2c41a25

       It is also possible to use openssl to generate base64 output:

       $ openssl dgst -binary -sha224 /bin/ls | openssl base64
       EYGH2oNk1JC0p9679IMATo8+BT7JVDCd4sQaJQ==

       Warning, if the user has write access to the command itself (directly
       or via a sudo command), it may be possible for the user to replace the
       command after the digest check has been performed but before the
       command is executed.  A similar race condition exists on systems that
       lack the fexecve(2) system call when the directory in which the command
       is located is writable by the user.  See the description of the fdexec
       setting for more information on how sudo executes commands that have an
       associated digest.

       Command digests are only supported by version 1.8.7 or higher.

   Defaults
       Certain configuration options may be changed from their default values
       at run-time via one or more Default_Entry lines.  These may affect all
       users on any host, all users on a specific host, a specific user, a
       specific command, or commands being run as a specific user.  Note that
       per-command entries may not include command line arguments.  If you
       need to specify arguments, define a Cmnd_Alias and reference that
       instead.

       Default_Type ::= 'Defaults' |
                        'Defaults' '@' Host_List |
                        'Defaults' ':' User_List |
                        'Defaults' '!' Cmnd_List |
                        'Defaults' '>' Runas_List

       Default_Entry ::= Default_Type Parameter_List

       Parameter_List ::= Parameter |
                          Parameter ',' Parameter_List

       Parameter ::= Parameter '=' Value |
                     Parameter '+=' Value |
                     Parameter '-=' Value |
                     '!'* Parameter

       Parameters may be flags, integer values, strings, or lists.  Flags are
       implicitly boolean and can be turned off via the ‘!’  operator.  Some
       integer, string and list parameters may also be used in a boolean
       context to disable them.  Values may be enclosed in double quotes ("")
       when they contain multiple words.  Special characters may be escaped
       with a backslash (‘\’).

       Lists have two additional assignment operators, += and -=.  These
       operators are used to add to and delete from a list respectively.  It
       is not an error to use the -= operator to remove an element that does
       not exist in a list.

       Defaults entries are parsed in the following order: generic, host, user
       and runas Defaults first, then command defaults.  If there are multiple
       Defaults settings of the same type, the last matching setting is used.
       The following Defaults settings are parsed before all others since they
       may affect subsequent entries: fqdn, group_plugin, runas_default,
       sudoers_locale.

       See SUDOERS OPTIONS for a list of supported Defaults parameters.

   User specification
       User_Spec ::= User_List Host_List '=' Cmnd_Spec_List \
                     (':' Host_List '=' Cmnd_Spec_List)*

       Cmnd_Spec_List ::= Cmnd_Spec |
                          Cmnd_Spec ',' Cmnd_Spec_List

       Cmnd_Spec ::= Runas_Spec? Option_Spec* Tag_Spec* Cmnd

       Runas_Spec ::= '(' Runas_List? (':' Runas_List)? ')'

       Option_Spec ::= (Solaris_Priv_Spec | Date_Spec | Timeout_Spec)

       Solaris_Priv_Spec ::= ('PRIVS=privset' | 'LIMITPRIVS=privset')

       Date_Spec ::= ('NOTBEFORE=timestamp' | 'NOTAFTER=timestamp')

       Timeout_Spec ::= 'TIMEOUT=timeout'

       Tag_Spec ::= ('EXEC:' | 'NOEXEC:' | 'FOLLOW:' | 'NOFOLLOW' |
                     'LOG_INPUT:' | 'NOLOG_INPUT:' | 'LOG_OUTPUT:' |
                     'NOLOG_OUTPUT:' | 'MAIL:' | 'NOMAIL:' | 'PASSWD:' |
                     'NOPASSWD:' | 'SETENV:' | 'NOSETENV:')

       A user specification determines which commands a user may run (and as
       what user) on specified hosts.  By default, commands are run as root,
       but this can be changed on a per-command basis.

       The basic structure of a user specification is “who where = (as_whom)
       what”.  Let's break that down into its constituent parts:

   Runas_Spec
       A Runas_Spec determines the user and/or the group that a command may be
       run as.  A fully-specified Runas_Spec consists of two Runas_Lists (as
       defined above) separated by a colon (‘:’) and enclosed in a set of
       parentheses.  The first Runas_List indicates which users the command
       may be run as via the -u option.  The second defines a list of groups
       that can be specified via the -g option in addition to any of the
       target user's groups.  If both Runas_Lists are specified, the command
       may be run with any combination of users and groups listed in their
       respective Runas_Lists.  If only the first is specified, the command
       may be run as any user in the list but no -g option may be specified.
       If the first Runas_List is empty but the second is specified, the
       command may be run as the invoking user with the group set to any
       listed in the Runas_List.  If both Runas_Lists are empty, the command
       may only be run as the invoking user.  If no Runas_Spec is specified
       the command may be run as root and no group may be specified.

       A Runas_Spec sets the default for the commands that follow it.  What
       this means is that for the entry:

       dgb  boulder = (operator) /bin/ls, /bin/kill, /usr/bin/lprm

       The user dgb may run /bin/ls, /bin/kill, and /usr/bin/lprm on the host
       boulder—but only as operator.  E.g.,

       $ sudo -u operator /bin/ls

       It is also possible to override a Runas_Spec later on in an entry.  If
       we modify the entry like so:

       dgb  boulder = (operator) /bin/ls, (root) /bin/kill, /usr/bin/lprm

       Then user dgb is now allowed to run /bin/ls as operator, but /bin/kill
       and /usr/bin/lprm as root.

       We can extend this to allow dgb to run /bin/ls with either the user or
       group set to operator:

       dgb  boulder = (operator : operator) /bin/ls, (root) /bin/kill,\
            /usr/bin/lprm

       Note that while the group portion of the Runas_Spec permits the user to
       run as command with that group, it does not force the user to do so.
       If no group is specified on the command line, the command will run with
       the group listed in the target user's password database entry.  The
       following would all be permitted by the sudoers entry above:

       $ sudo -u operator /bin/ls
       $ sudo -u operator -g operator /bin/ls
       $ sudo -g operator /bin/ls

       In the following example, user tcm may run commands that access a modem
       device file with the dialer group.

       tcm  boulder = (:dialer) /usr/bin/tip, /usr/bin/cu,\
            /usr/local/bin/minicom

       Note that in this example only the group will be set, the command still
       runs as user tcm.  E.g.

       $ sudo -g dialer /usr/bin/cu

       Multiple users and groups may be present in a Runas_Spec, in which case
       the user may select any combination of users and groups via the -u and
       -g options.  In this example:

       alan ALL = (root, bin : operator, system) ALL

       user alan may run any command as either user root or bin, optionally
       setting the group to operator or system.

   Option_Spec
       A Cmnd may have zero or more options associated with it.  Options may
       consist of Solaris privileges sets, start and/or end dates and command
       timeouts.  Once an option is set for a Cmnd, subsequent Cmnds in the
       Cmnd_Spec_List, inherit that option unless it is overridden by another
       option.

   Solaris_Priv_Spec
       On Solaris systems, sudoers file entries may optionally specify Solaris
       privilege set and/or limit privilege set associated with a command.  If
       privileges or limit privileges are specified with the command it will
       override any default values specified in sudoers.

       A privilege set is a comma-separated list of privilege names.  The
       ppriv(1) command can be used to list all privileges known to the
       system.  For example:

       $ ppriv -l

       In addition, there are several “special” privilege strings:

       none      the empty set

       all       the set of all privileges

       zone      the set of all privileges available in the current zone

       basic     the default set of privileges normal users are granted at
                 login time

       Privileges can be excluded from a set by prefixing the privilege name
       with either an ‘!’  or ‘-’ character.

   Date_Spec
       sudoers rules can be specified with a start and end date via the
       NOTBEFORE and NOTAFTER settings.  The time stamp must be specified in
       Generalized Time as defined by RFC 4517.  The format is effectively
       yyyymmddHHMMSSZ where the minutes and seconds are optional.  The ‘Z’
       suffix indicates that the time stamp is in Coordinated Universal Time
       (UTC).  It is also possible to specify a timezone offset from UTC in
       hours and minutes instead of a ‘Z’.  For example, ‘-0500’ would
       correspond to Eastern Standard time in the US.  As an extension, if no
       ‘Z’ or timezone offset is specified, local time will be used.

       The following are all valid time stamps:

           20170214083000Z
           2017021408Z
           20160315220000-0500
           20151201235900

   Timeout_Spec
       A command may have a timeout associated with it.  If the timeout
       expires before the command has exited, the command will be terminated.
       The timeout may be specified in combinations of days, hours, minutes
       and seconds with a single-letter case-insensitive suffix that indicates
       the unit of time.  For example, a timeout of 7 days, 8 hours, 30
       minutes and 10 seconds would be written as 7d8h30m10s.  If a number is
       specified without a unit, seconds are assumed.  Any of the days,
       minutes, hours or seconds may be omitted.  The order must be from
       largest to smallest unit and a unit may not be specified more than
       once.

       The following are all valid timeout values: 7d8h30m10s, 14d, 8h30m,
       600s, 3600.  The following are invalid timeout values: 12m2w1d,
       30s10m4h, 1d2d3h.

       This setting is only supported by version 1.8.20 or higher.

   Tag_Spec
       A command may have zero or more tags associated with it.  The following
       tag values are supported: EXEC, NOEXEC, FOLLOW, NOFOLLOW, LOG_INPUT,
       NOLOG_INPUT, LOG_OUTPUT, NOLOG_OUTPUT, MAIL, NOMAIL, PASSWD, NOPASSWD,
       SETENV, and NOSETENV.  Once a tag is set on a Cmnd, subsequent Cmnds in
       the Cmnd_Spec_List, inherit the tag unless it is overridden by the
       opposite tag (in other words, PASSWD overrides NOPASSWD and NOEXEC
       overrides EXEC).

       EXEC and NOEXEC

         If sudo has been compiled with noexec support and the underlying
         operating system supports it, the NOEXEC tag can be used to prevent a
         dynamically-linked executable from running further commands itself.

         In the following example, user aaron may run /usr/bin/more and
         /usr/bin/vi but shell escapes will be disabled.

         aaron     shanty = NOEXEC: /usr/bin/more, /usr/bin/vi

         See the Preventing shell escapes section below for more details on
         how NOEXEC works and whether or not it will work on your system.

       FOLLOW and NOFOLLOW
         Starting with version 1.8.15, sudoedit will not open a file that is a
         symbolic link unless the sudoedit_follow flag is enabled.  The FOLLOW
         and NOFOLLOW tags override the value of sudoedit_follow and can be
         used to permit (or deny) the editing of symbolic links on a per-
         command basis.  These tags are only effective for the sudoedit
         command and are ignored for all other commands.

       LOG_INPUT and NOLOG_INPUT

         These tags override the value of the log_input flag on a per-command
         basis.  For more information, see the description of log_input in the
         SUDOERS OPTIONS section below.

       LOG_OUTPUT and NOLOG_OUTPUT

         These tags override the value of the log_output flag on a per-command
         basis.  For more information, see the description of log_output in
         the SUDOERS OPTIONS section below.

       MAIL and NOMAIL

         These tags provide fine-grained control over whether mail will be
         sent when a user runs a command by overriding the value of the
         mail_all_cmnds flag on a per-command basis.  They have no effect when
         sudo is run with the -l or -v options.  A NOMAIL tag will also
         override the mail_always and mail_no_perms options.  For more
         information, see the descriptions of mail_all_cmnds, mail_always, and
         mail_no_perms in the SUDOERS OPTIONS section below.

       PASSWD and NOPASSWD

         By default, sudo requires that a user authenticate him or herself
         before running a command.  This behavior can be modified via the
         NOPASSWD tag.  Like a Runas_Spec, the NOPASSWD tag sets a default for
         the commands that follow it in the Cmnd_Spec_List.  Conversely, the
         PASSWD tag can be used to reverse things.  For example:

         ray  rushmore = NOPASSWD: /bin/kill, /bin/ls, /usr/bin/lprm

         would allow the user ray to run /bin/kill, /bin/ls, and /usr/bin/lprm
         as root on the machine rushmore without authenticating himself.  If
         we only want ray to be able to run /bin/kill without a password the
         entry would be:

           ray  rushmore = NOPASSWD: /bin/kill, PASSWD: /bin/ls, /usr/bin/lprm

         Note, however, that the PASSWD tag has no effect on users who are in
         the group specified by the exempt_group setting.

         By default, if the NOPASSWD tag is applied to any of a user's entries
         for the current host, the user will be able to run “sudo -l” without
         a password.  Additionally, a user may only run “sudo -v” without a
         password if all of the user's entries for the current host have the
         NOPASSWD tag.  This behavior may be overridden via the verifypw and
         listpw options.

       SETENV and NOSETENV

         These tags override the value of the setenv flag on a per-command
         basis.  Note that if SETENV has been set for a command, the user may
         disable the env_reset flag from the command line via the -E option.
         Additionally, environment variables set on the command line are not
         subject to the restrictions imposed by env_check, env_delete, or
         env_keep.  As such, only trusted users should be allowed to set
         variables in this manner.  If the command matched is ALL, the SETENV
         tag is implied for that command; this default may be overridden by
         use of the NOSETENV tag.

   Wildcards
       sudo allows shell-style wildcards (aka meta or glob characters) to be
       used in host names, path names and command line arguments in the
       sudoers file.  Wildcard matching is done via the glob(3) and fnmatch(3)
       functions as specified by IEEE Std 1003.1 (“POSIX.1”).

       *         Matches any set of zero or more characters (including white
                 space).

       ?         Matches any single character (including white space).

       [...]     Matches any character in the specified range.

       [!...]    Matches any character not in the specified range.

       \x        For any character ‘x’, evaluates to ‘x’.  This is used to
                 escape special characters such as: ‘*’, ‘?’, ‘[’, and ‘]’.

       Note that these are not regular expressions.  Unlike a regular
       expression there is no way to match one or more characters within a
       range.

       Character classes may be used if your system's glob(3) and fnmatch(3)
       functions support them.  However, because the ‘:’ character has special
       meaning in sudoers, it must be escaped.  For example:

           /bin/ls [[\:alpha\:]]*

       Would match any file name beginning with a letter.

       Note that a forward slash (‘/’) will not be matched by wildcards used
       in the file name portion of the command.  This is to make a path like:

           /usr/bin/*

       match /usr/bin/who but not /usr/bin/X11/xterm.

       When matching the command line arguments, however, a slash does get
       matched by wildcards since command line arguments may contain arbitrary
       strings and not just path names.

       Wildcards in command line arguments should be used with care.
       Command line arguments are matched as a single, concatenated string.
       This mean a wildcard character such as ‘?’  or ‘*’ will match across
       word boundaries, which may be unexpected.  For example, while a sudoers
       entry like:

           %operator ALL = /bin/cat /var/log/messages*

       will allow command like:

           $ sudo cat /var/log/messages.1

       It will also allow:

           $ sudo cat /var/log/messages /etc/shadow

       which is probably not what was intended.  In most cases it is better to
       do command line processing outside of the sudoers file in a scripting
       language.

   Exceptions to wildcard rules
       The following exceptions apply to the above rules:

       ""        If the empty string "" is the only command line argument in
                 the sudoers file entry it means that command is not allowed
                 to be run with any arguments.

       sudoedit  Command line arguments to the sudoedit built-in command
                 should always be path names, so a forward slash (‘/’) will
                 not be matched by a wildcard.

   Including other files from within sudoers
       It is possible to include other sudoers files from within the sudoers
       file currently being parsed using the @include and @includedir
       directives.  For compatibility with sudo versions prior to 1.9.1,
       #include and #includedir are also accepted.

       An include file can be used, for example, to keep a site-wide sudoers
       file in addition to a local, per-machine file.  For the sake of this
       example the site-wide sudoers file will be /etc/sudoers and the per-
       machine one will be /etc/sudoers.local.  To include /etc/sudoers.local
       from within /etc/sudoers one would use the following line in
       /etc/sudoers:

           @include /etc/sudoers.local

       When sudo reaches this line it will suspend processing of the current
       file (/etc/sudoers) and switch to /etc/sudoers.local.  Upon reaching
       the end of /etc/sudoers.local, the rest of /etc/sudoers will be
       processed.  Files that are included may themselves include other files.
       A hard limit of 128 nested include files is enforced to prevent include
       file loops.

       The path to the include file may contain white space if it is escaped
       with a backslash (‘\’).  Alternately, the entire path may be enclosed
       in double quotes (""), in which case no escaping is necessary.  To
       include a literal backslash in the path, ‘\\’ should be used.

       If the path to the include file is not fully-qualified (does not begin
       with a ‘/’), it must be located in the same directory as the sudoers
       file it was included from.  For example, if /etc/sudoers contains the
       line:

           @include sudoers.local

       the file that will be included is /etc/sudoers.local.

       The file name may also include the %h escape, signifying the short form
       of the host name.  In other words, if the machine's host name is
       “xerxes”, then

           @include /etc/sudoers.%h

       will cause sudo to include the file /etc/sudoers.xerxes.

       The @includedir directive can be used to create a sudoers.d directory
       that the system package manager can drop sudoers file rules into as
       part of package installation.  For example, given:

           @includedir /etc/sudoers.d

       sudo will suspend processing of the current file and read each file in
       /etc/sudoers.d, skipping file names that end in ‘~’ or contain a ‘.’
       character to avoid causing problems with package manager or editor
       temporary/backup files.  Files are parsed in sorted lexical order.
       That is, /etc/sudoers.d/01_first will be parsed before
       /etc/sudoers.d/10_second.  Be aware that because the sorting is
       lexical, not numeric, /etc/sudoers.d/1_whoops would be loaded after
       /etc/sudoers.d/10_second.  Using a consistent number of leading zeroes
       in the file names can be used to avoid such problems.  After parsing
       the files in the directory, control returns to the file that contained
       the @includedir directive.

       Note that unlike files included via @include, visudo will not edit the
       files in a @includedir directory unless one of them contains a syntax
       error.  It is still possible to run visudo with the -f flag to edit the
       files directly, but this will not catch the redefinition of an alias
       that is also present in a different file.

   Other special characters and reserved words
       The pound sign (‘#’) is used to indicate a comment (unless it is part
       of a #include directive or unless it occurs in the context of a user
       name and is followed by one or more digits, in which case it is treated
       as a user-ID).  Both the comment character and any text after it, up to
       the end of the line, are ignored.

       The reserved word ALL is a built-in alias that always causes a match to
       succeed.  It can be used wherever one might otherwise use a Cmnd_Alias,
       User_Alias, Runas_Alias, or Host_Alias.  You should not try to define
       your own alias called ALL as the built-in alias will be used in
       preference to your own.  Please note that using ALL can be dangerous
       since in a command context, it allows the user to run any command on
       the system.

       An exclamation point (‘!’)  can be used as a logical not operator in a
       list or alias as well as in front of a Cmnd.  This allows one to
       exclude certain values.  For the ‘!’  operator to be effective, there
       must be something for it to exclude.  For example, to match all users
       except for root one would use:

           ALL,!root

       If the ALL, is omitted, as in:

           !root

       it would explicitly deny root but not match any other users.  This is
       different from a true “negation” operator.

       Note, however, that using a ‘!’  in conjunction with the built-in ALL
       alias to allow a user to run “all but a few” commands rarely works as
       intended (see SECURITY NOTES below).

       Long lines can be continued with a backslash (‘\’) as the last
       character on the line.

       White space between elements in a list as well as special syntactic
       characters in a User Specification (‘=’, ‘:’, ‘(’, ‘)’) is optional.

       The following characters must be escaped with a backslash (‘\’) when
       used as part of a word (e.g., a user name or host name): ‘!’, ‘=’, ‘:’,
       ‘,’, ‘(’, ‘)’, ‘\’.

SUDOERS OPTIONS
       sudo's behavior can be modified by Default_Entry lines, as explained
       earlier.  A list of all supported Defaults parameters, grouped by type,
       are listed below.

       Boolean Flags:

       always_query_group_plugin
                         If a group_plugin is configured, use it to resolve
                         groups of the form %group as long as there is not
                         also a system group of the same name.  Normally, only
                         groups of the form %:group are passed to the
                         group_plugin.  This flag is off by default.

       always_set_home   If enabled, sudo will set the HOME environment
                         variable to the home directory of the target user
                         (which is the root user unless the -u option is
                         used).  This flag is largely obsolete and has no
                         effect unless the env_reset flag has been disabled or
                         HOME is present in the env_keep list, both of which
                         are strongly discouraged.  This flag is off by
                         default.

       authenticate      If set, users must authenticate themselves via a
                         password (or other means of authentication) before
                         they may run commands.  This default may be
                         overridden via the PASSWD and NOPASSWD tags.  This
                         flag is on by default.

       case_insensitive_group
                         If enabled, group names in sudoers will be matched in
                         a case insensitive manner.  This may be necessary
                         when users are stored in LDAP or AD.  This flag is on
                         by default.

       case_insensitive_user
                         If enabled, user names in sudoers will be matched in
                         a case insensitive manner.  This may be necessary
                         when groups are stored in LDAP or AD.  This flag is
                         on by default.

       closefrom_override
                         If set, the user may use the -C option which
                         overrides the default starting point at which sudo
                         begins closing open file descriptors.  This flag is
                         off by default.

       compress_io       If set, and sudo is configured to log a command's
                         input or output, the I/O logs will be compressed
                         using zlib.  This flag is on by default when sudo is
                         compiled with zlib support.

       exec_background   By default, sudo runs a command as the foreground
                         process as long as sudo itself is running in the
                         foreground.  When the exec_background flag is enabled
                         and the command is being run in a pseudo-terminal
                         (due to I/O logging or the use_pty flag), the command
                         will be run as a background process.  Attempts to
                         read from the controlling terminal (or to change
                         terminal settings) will result in the command being
                         suspended with the SIGTTIN signal (or SIGTTOU in the
                         case of terminal settings).  If this happens when
                         sudo is a foreground process, the command will be
                         granted the controlling terminal and resumed in the
                         foreground with no user intervention required.  The
                         advantage of initially running the command in the
                         background is that sudo need not read from the
                         terminal unless the command explicitly requests it.
                         Otherwise, any terminal input must be passed to the
                         command, whether it has required it or not (the
                         kernel buffers terminals so it is not possible to
                         tell whether the command really wants the input).
                         This is different from historic sudo behavior or when
                         the command is not being run in a pseudo-terminal.

                         For this to work seamlessly, the operating system
                         must support the automatic restarting of system
                         calls.  Unfortunately, not all operating systems do
                         this by default, and even those that do may have
                         bugs.  For example, macOS fails to restart the
                         tcgetattr() and tcsetattr() system calls (this is a
                         bug in macOS).  Furthermore, because this behavior
                         depends on the command stopping with the SIGTTIN or
                         SIGTTOU signals, programs that catch these signals
                         and suspend themselves with a different signal
                         (usually SIGTOP) will not be automatically
                         foregrounded.  Some versions of the linux su(1)
                         command behave this way.  This flag is off by
                         default.

                         This setting is only supported by version 1.8.7 or
                         higher.  It has no effect unless I/O logging is
                         enabled or the use_pty flag is enabled.

       env_editor        If set, visudo will use the value of the SUDO_EDITOR,
                         VISUAL or EDITOR environment variables before falling
                         back on the default editor list.  Note that visudo is
                         typically run as root so this flag may allow a user
                         with visudo privileges to run arbitrary commands as
                         root without logging.  An alternative is to place a
                         colon-separated list of “safe” editors int the editor
                         variable.  visudo will then only use SUDO_EDITOR,
                         VISUAL or EDITOR if they match a value specified in
                         editor.  If the env_reset flag is enabled, the
                         SUDO_EDITOR, VISUAL and/or EDITOR environment
                         variables must be present in the env_keep list for
                         the env_editor flag to function when visudo is
                         invoked via sudo.  This flag is on by default.

       env_reset         If set, sudo will run the command in a minimal
                         environment containing the TERM, PATH, HOME, MAIL,
                         SHELL, LOGNAME, USER and SUDO_* variables.  Any
                         variables in the caller's environment or in the file
                         specified by the restricted_env_file setting that
                         match the env_keep and env_check lists are then
                         added, followed by any variables present in the file
                         specified by the env_file setting (if any).  The
                         contents of the env_keep and env_check lists, as
                         modified by global Defaults parameters in sudoers,
                         are displayed when sudo is run by root with the -V
                         option.  If the secure_path setting is enabled, its
                         value will be used for the PATH environment variable.
                         This flag is on by default.

       fast_glob         Normally, sudo uses the glob(3) function to do shell-
                         style globbing when matching path names.  However,
                         since it accesses the file system, glob(3) can take a
                         long time to complete for some patterns, especially
                         when the pattern references a network file system
                         that is mounted on demand (auto mounted).  The
                         fast_glob flag causes sudo to use the fnmatch(3)
                         function, which does not access the file system to do
                         its matching.  The disadvantage of fast_glob is that
                         it is unable to match relative path names such as
                         ./ls or ../bin/ls.  This has security implications
                         when path names that include globbing characters are
                         used with the negation operator, ‘!’, as such rules
                         can be trivially bypassed.  As such, this flag should
                         not be used when the sudoers file contains rules that
                         contain negated path names which include globbing
                         characters.  This flag is off by default.

       fqdn              Set this flag if you want to put fully qualified host
                         names in the sudoers file when the local host name
                         (as returned by the hostname command) does not
                         contain the domain name.  In other words, instead of
                         myhost you would use myhost.mydomain.edu.  You may
                         still use the short form if you wish (and even mix
                         the two).  This flag is only effective when the
                         “canonical” host name, as returned by the
                         getaddrinfo() or gethostbyname() function, is a
                         fully-qualified domain name.  This is usually the
                         case when the system is configured to use DNS for
                         host name resolution.

                         If the system is configured to use the /etc/hosts
                         file in preference to DNS, the “canonical” host name
                         may not be fully-qualified.  The order that sources
                         are queried for host name resolution is usually
                         specified in the /etc/nsswitch.conf,
                         /etc/netsvc.conf, /etc/host.conf, or, in some cases,
                         /etc/resolv.conf file.  In the /etc/hosts file, the
                         first host name of the entry is considered to be the
                         “canonical” name; subsequent names are aliases that
                         are not used by sudoers.  For example, the following
                         hosts file line for the machine “xyzzy” has the
                         fully-qualified domain name as the “canonical” host
                         name, and the short version as an alias.

                               192.168.1.1 xyzzy.sudo.ws xyzzy

                         If the machine's hosts file entry is not formatted
                         properly, the fqdn flag will not be effective if it
                         is queried before DNS.

                         Beware that when using DNS for host name resolution,
                         turning on fqdn requires sudoers to make DNS lookups
                         which renders sudo unusable if DNS stops working (for
                         example if the machine is disconnected from the
                         network).  Also note that just like with the hosts
                         file, you must use the “canonical” name as DNS knows
                         it.  That is, you may not use a host alias (CNAME
                         entry) due to performance issues and the fact that
                         there is no way to get all aliases from DNS.

                         This flag is off by default.

       ignore_audit_errors
                         Allow commands to be run even if sudoers cannot write
                         to the audit log.  If enabled, an audit log write
                         failure is not treated as a fatal error.  If
                         disabled, a command may only be run after the audit
                         event is successfully written.  This flag is only
                         effective on systems for which sudoers supports audit
                         logging, including FreeBSD, Linux, macOS and Solaris.
                         This flag is on by default.

       ignore_dot        If set, sudo will ignore "." or "" (both denoting
                         current directory) in the PATH environment variable;
                         the PATH itself is not modified.  This flag is off by
                         default.

       ignore_iolog_errors
                         Allow commands to be run even if sudoers cannot write
                         to the I/O log (local or remote).  If enabled, an I/O
                         log write failure is not treated as a fatal error.
                         If disabled, the command will be terminated if the
                         I/O log cannot be written to.  This flag is off by
                         default.

       ignore_logfile_errors
                         Allow commands to be run even if sudoers cannot write
                         to the log file.  If enabled, a log file write
                         failure is not treated as a fatal error.  If
                         disabled, a command may only be run after the log
                         file entry is successfully written.  This flag only
                         has an effect when sudoers is configured to use file-
                         based logging via the logfile setting.  This flag is
                         on by default.

       ignore_local_sudoers
                         If set via LDAP, parsing of /etc/sudoers will be
                         skipped.  This is intended for Enterprises that wish
                         to prevent the usage of local sudoers files so that
                         only LDAP is used.  This thwarts the efforts of rogue
                         operators who would attempt to add roles to
                         /etc/sudoers.  When this flag is enabled,
                         /etc/sudoers does not even need to exist.  Since this
                         flag tells sudo how to behave when no specific LDAP
                         entries have been matched, this sudoOption is only
                         meaningful for the cn=defaults section.  This flag is
                         off by default.

       ignore_unknown_defaults
                         If set, sudo will not produce a warning if it
                         encounters an unknown Defaults entry in the sudoers
                         file or an unknown sudoOption in LDAP.  This flag is
                         off by default.

       insults           If set, sudo will insult users when they enter an
                         incorrect password.  This flag is off by default.

       log_allowed       If set, sudoers will log commands allowed by the
                         policy to the system audit log (where supported) as
                         well as to syslog and/or a log file.  This flag is on
                         by default.

                         This setting is only supported by version 1.8.29 or
                         higher.

       log_denied        If set, sudoers will log commands denied by the
                         policy to the system audit log (where supported) as
                         well as to syslog and/or a log file.  This flag is on
                         by default.

                         This setting is only supported by version 1.8.29 or
                         higher.

       log_host          If set, the host name will be included in log entries
                         written to the file configured by the logfile
                         setting.  This flag is off by default.

       log_input         If set, sudo will run the command in a pseudo-
                         terminal and log all user input.  If the standard
                         input is not connected to the user's tty, due to I/O
                         redirection or because the command is part of a
                         pipeline, that input is also captured and stored in a
                         separate log file.  Anything sent to the standard
                         input will be consumed, regardless of whether or not
                         the command run via sudo is actually reading the
                         standard input.  This may have unexpected results
                         when using sudo in a shell script that expects to
                         process the standard input.  For more information
                         about I/O logging, see the I/O LOG FILES section.
                         This flag is off by default.

       log_output        If set, sudo will run the command in a pseudo-
                         terminal and log all output that is sent to the
                         screen, similar to the script(1) command.  For more
                         information about I/O logging, see the I/O LOG FILES
                         section.  This flag is off by default.

       log_server_keepalive
                         If set, sudo will enable the TCP keepalive socket
                         option on the connection to the log server.  This
                         enables the periodic transmission of keepalive
                         messages to the server.  If the server does not
                         respond to a message, the connection will be closed
                         and the running command will be killed unless the
                         ignore_iolog_errors flag is set.  This flag is on by
                         default.

       log_server_verify
                         If set, the server certificate received during the
                         TLS handshake must be valid and it must contain
                         either the server name (from log_servers) or its IP
                         address.  If either of these conditions is not met,
                         the TLS handshake will fail.  This flag is on by
                         default.  sudo

       log_year          If set, the four-digit year will be logged in the
                         (non-syslog) sudo log file.  This flag is off by
                         default.

       long_otp_prompt   When validating with a One Time Password (OTP) scheme
                         such as S/Key or OPIE, a two-line prompt is used to
                         make it easier to cut and paste the challenge to a
                         local window.  It's not as pretty as the default but
                         some people find it more convenient.  This flag is
                         off by default.

       mail_all_cmnds    Send mail to the mailto user every time a user
                         attempts to run a command via sudo (this includes
                         sudoedit).  No mail will be sent if the user runs
                         sudo with the -l or -v option unless there is an
                         authentication error and the mail_badpass flag is
                         also set.  This flag is off by default.

       mail_always       Send mail to the mailto user every time a user runs
                         sudo.  This flag is off by default.

       mail_badpass      Send mail to the mailto user if the user running sudo
                         does not enter the correct password.  If the command
                         the user is attempting to run is not permitted by
                         sudoers and one of the mail_all_cmnds, mail_always,
                         mail_no_host, mail_no_perms or mail_no_user flags are
                         set, this flag will have no effect.  This flag is off
                         by default.

       mail_no_host      If set, mail will be sent to the mailto user if the
                         invoking user exists in the sudoers file, but is not
                         allowed to run commands on the current host.  This
                         flag is off by default.

       mail_no_perms     If set, mail will be sent to the mailto user if the
                         invoking user is allowed to use sudo but the command
                         they are trying is not listed in their sudoers file
                         entry or is explicitly denied.  This flag is off by
                         default.

       mail_no_user      If set, mail will be sent to the mailto user if the
                         invoking user is not in the sudoers file.  This flag
                         is on by default.

       match_group_by_gid
                         By default, sudoers will look up each group the user
                         is a member of by group-ID to determine the group
                         name (this is only done once).  The resulting list of
                         the user's group names is used when matching groups
                         listed in the sudoers file.  This works well on
                         systems where the number of groups listed in the
                         sudoers file is larger than the number of groups a
                         typical user belongs to.  On systems where group
                         lookups are slow, where users may belong to a large
                         number of groups, and where the number of groups
                         listed in the sudoers file is relatively small, it
                         may be prohibitively expensive and running commands
                         via sudo may take longer than normal.  On such
                         systems it may be faster to use the
                         match_group_by_gid flag to avoid resolving the user's
                         group-IDs to group names.  In this case, sudoers must
                         look up any group name listed in the sudoers file and
                         use the group-ID instead of the group name when
                         determining whether the user is a member of the
                         group.

                         Note that if match_group_by_gid is enabled, group
                         database lookups performed by sudoers will be keyed
                         by group name as opposed to group-ID.  On systems
                         where there are multiple sources for the group
                         database, it is possible to have conflicting group
                         names or group-IDs in the local /etc/group file and
                         the remote group database.  On such systems, enabling
                         or disabling match_group_by_gid can be used to choose
                         whether group database queries are performed by name
                         (enabled) or ID (disabled), which may aid in working
                         around group entry conflicts.

                         The match_group_by_gid flag has no effect when
                         sudoers data is stored in LDAP.  This flag is off by
                         default.

                         This setting is only supported by version 1.8.18 or
                         higher.

       netgroup_tuple    If set, netgroup lookups will be performed using the
                         full netgroup tuple: host name, user name and domain
                         (if one is set).  Historically, sudo only matched the
                         user name and domain for netgroups used in a
                         User_List and only matched the host name and domain
                         for netgroups used in a Host_List.  This flag is off
                         by default.

       noexec            If set, all commands run via sudo will behave as if
                         the NOEXEC tag has been set, unless overridden by an
                         EXEC tag.  See the description of EXEC and NOEXEC
                         above as well as the Preventing shell escapes section
                         at the end of this manual.  This flag is off by
                         default.

       pam_acct_mgmt     On systems that use PAM for authentication, sudo will
                         perform PAM account validation for the invoking user
                         by default.  The actual checks performed depend on
                         which PAM modules are configured.  If enabled,
                         account validation will be performed regardless of
                         whether or not a password is required.  This flag is
                         on by default.

                         This setting is only supported by version 1.8.28 or
                         higher.

       pam_rhost         On systems that use PAM for authentication, sudo will
                         set the PAM remote host value to the name of the
                         local host when the pam_rhost flag is enabled.  On
                         Linux systems, enabling pam_rhost may result in DNS
                         lookups of the local host name when PAM is
                         initialized.  On Solaris versions prior to Solaris 8,
                         pam_rhost must be enabled if pam_ruser is also
                         enabled to avoid a crash in the Solaris PAM
                         implementation.

                         This flag is off by default on systems other than
                         Solaris.

                         This setting is only supported by version 1.9.0 or
                         higher.

       pam_ruser         On systems that use PAM for authentication, sudo will
                         set the PAM remote user value to the name of the user
                         that invoked sudo when the pam_ruser flag is enabled.
                         This flag is on by default.

                         This setting is only supported by version 1.9.0 or
                         higher.

       pam_session       On systems that use PAM for authentication, sudo will
                         create a new PAM session for the command to be run
                         in.  Unless sudo is given the -i or -s options, PAM
                         session modules are run with the “silent” flag
                         enabled.  This prevents last login information from
                         being displayed for every command on some systems.
                         Disabling pam_session may be needed on older PAM
                         implementations or on operating systems where opening
                         a PAM session changes the utmp or wtmp files.  If PAM
                         session support is disabled, resource limits may not
                         be updated for the command being run.  If
                         pam_session, pam_setcred, and use_pty are disabled
                         and I/O logging has not been configured, sudo will
                         execute the command directly instead of running it as
                         a child process.  This flag is on by default.

                         This setting is only supported by version 1.8.7 or
                         higher.

       pam_setcred       On systems that use PAM for authentication, sudo will
                         attempt to establish credentials for the target user
                         by default, if supported by the underlying
                         authentication system.  One example of a credential
                         is a Kerberos ticket.  If pam_session, pam_setcred,
                         and use_pty are disabled and I/O logging has not been
                         configured, sudo will execute the command directly
                         instead of running it as a child process.  This flag
                         is on by default.

                         This setting is only supported by version 1.8.8 or
                         higher.

       passprompt_override
                         If set, the prompt specified by passprompt or the
                         SUDO_PROMPT environment variable will always be used
                         and will replace the prompt provided by a PAM module
                         or other authentication method.  This flag is off by
                         default.

       path_info         Normally, sudo will tell the user when a command
                         could not be found in their PATH environment
                         variable.  Some sites may wish to disable this as it
                         could be used to gather information on the location
                         of executables that the normal user does not have
                         access to.  The disadvantage is that if the
                         executable is simply not in the user's PATH, sudo
                         will tell the user that they are not allowed to run
                         it, which can be confusing.  This flag is on by
                         default.

       preserve_groups   By default, sudo will initialize the group vector to
                         the list of groups the target user is in.  When
                         preserve_groups is set, the user's existing group
                         vector is left unaltered.  The real and effective
                         group-IDs, however, are still set to match the target
                         user.  This flag is off by default.

       pwfeedback        By default, sudo reads the password like most other
                         Unix programs, by turning off echo until the user
                         hits the return (or enter) key.  Some users become
                         confused by this as it appears to them that sudo has
                         hung at this point.  When pwfeedback is set, sudo
                         will provide visual feedback when the user presses a
                         key.  Note that this does have a security impact as
                         an onlooker may be able to determine the length of
                         the password being entered.  This flag is off by
                         default.

       requiretty        If set, sudo will only run when the user is logged in
                         to a real tty.  When this flag is set, sudo can only
                         be run from a login session and not via other means
                         such as cron(1m) or cgi-bin scripts.  This flag is
                         off by default.

       root_sudo         If set, root is allowed to run sudo too.  Disabling
                         this prevents users from “chaining” sudo commands to
                         get a root shell by doing something like “sudo sudo
                         /bin/sh”.  Note, however, that turning off root_sudo
                         will also prevent root from running sudoedit.
                         Disabling root_sudo provides no real additional
                         security; it exists purely for historical reasons.
                         This flag is on by default.

       rootpw            If set, sudo will prompt for the root password
                         instead of the password of the invoking user when
                         running a command or editing a file.  This flag is
                         off by default.

       runas_allow_unknown_id
                         If enabled, allow matching of runas user and group
                         IDs that are not present in the password or group
                         databases.  In addition to explicitly matching
                         unknown user or group IDs in a Runas_List, this
                         option also allows the ALL alias to match unknown
                         IDs.  This flag is off by default.

                         This setting is only supported by version 1.8.30 or
                         higher.  Older versions of sudo always allowed
                         matching of unknown user and group IDs.

       runas_check_shell
                         If enabled, sudo will only run commands as a user
                         whose shell appears in the /etc/shells file, even if
                         the invoking user's Runas_List would otherwise permit
                         it.  If no /etc/shells file is present, a system-
                         dependent list of built-in default shells is used.
                         On many operating systems, system users such as
                         “bin”, do not have a valid shell and this flag can be
                         used to prevent commands from being run as those
                         users.  This flag is off by default.

                         This setting is only supported by version 1.8.30 or
                         higher.

       runaspw           If set, sudo will prompt for the password of the user
                         defined by the runas_default option (defaults to
                         root) instead of the password of the invoking user
                         when running a command or editing a file.  This flag
                         is off by default.

       set_home          If enabled and sudo is invoked with the -s option,
                         the HOME environment variable will be set to the home
                         directory of the target user (which is the root user
                         unless the -u option is used).  This flag is largely
                         obsolete and has no effect unless the env_reset flag
                         has been disabled or HOME is present in the env_keep
                         list, both of which are strongly discouraged.  This
                         flag is off by default.

       set_logname       Normally, sudo will set the LOGNAME and USER
                         environment variables to the name of the target user
                         (usually root unless the -u option is given).
                         However, since some programs (including the RCS
                         revision control system) use LOGNAME to determine the
                         real identity of the user, it may be desirable to
                         change this behavior.  This can be done by negating
                         the set_logname option.  Note that set_logname will
                         have no effect if the env_reset option has not been
                         disabled and the env_keep list contains LOGNAME or
                         USER.  This flag is on by default.

       set_utmp          When enabled, sudo will create an entry in the utmp
                         (or utmpx) file when a pseudo-terminal is allocated.
                         A pseudo-terminal is allocated by sudo when it is
                         running in a terminal and one or more of the
                         log_input, log_output or use_pty flags is enabled.
                         By default, the new entry will be a copy of the
                         user's existing utmp entry (if any), with the tty,
                         time, type and pid fields updated.  This flag is on
                         by default.

       setenv            Allow the user to disable the env_reset option from
                         the command line via the -E option.  Additionally,
                         environment variables set via the command line are
                         not subject to the restrictions imposed by env_check,
                         env_delete, or env_keep.  As such, only trusted users
                         should be allowed to set variables in this manner.
                         This flag is off by default.

       shell_noargs      If set and sudo is invoked with no arguments it acts
                         as if the -s option had been given.  That is, it runs
                         a shell as root (the shell is determined by the SHELL
                         environment variable if it is set, falling back on
                         the shell listed in the invoking user's /etc/passwd
                         entry if not).  This flag is off by default.

       stay_setuid       Normally, when sudo executes a command the real and
                         effective UIDs are set to the target user (root by
                         default).  This option changes that behavior such
                         that the real UID is left as the invoking user's UID.
                         In other words, this makes sudo act as a set-user-ID
                         wrapper.  This can be useful on systems that disable
                         some potentially dangerous functionality when a
                         program is run set-user-ID.  This option is only
                         effective on systems that support either the
                         setreuid(2) or setresuid(2) system call.  This flag
                         is off by default.

       sudoedit_checkdir
                         If set, sudoedit will check all directory components
                         of the path to be edited for writability by the
                         invoking user.  Symbolic links will not be followed
                         in writable directories and sudoedit will refuse to
                         edit a file located in a writable directory.  These
                         restrictions are not enforced when sudoedit is run by
                         root.  On some systems, if all directory components
                         of the path to be edited are not readable by the
                         target user, sudoedit will be unable to edit the
                         file.  This flag is on by default.

                         This setting was first introduced in version 1.8.15
                         but initially suffered from a race condition.  The
                         check for symbolic links in writable intermediate
                         directories was added in version 1.8.16.

       sudoedit_follow   By default, sudoedit will not follow symbolic links
                         when opening files.  The sudoedit_follow option can
                         be enabled to allow sudoedit to open symbolic links.
                         It may be overridden on a per-command basis by the
                         FOLLOW and NOFOLLOW tags.  This flag is off by
                         default.

                         This setting is only supported by version 1.8.15 or
                         higher.

       syslog_pid        When logging via syslog(3), include the process ID in
                         the log entry.  This flag is off by default.

                         This setting is only supported by version 1.8.21 or
                         higher.

       targetpw          If set, sudo will prompt for the password of the user
                         specified by the -u option (defaults to root) instead
                         of the password of the invoking user when running a
                         command or editing a file.  Note that this flag
                         precludes the use of a user-ID not listed in the
                         passwd database as an argument to the -u option.
                         This flag is off by default.

       tty_tickets       If set, users must authenticate on a per-tty basis.
                         With this flag enabled, sudo will use a separate
                         record in the time stamp file for each terminal.  If
                         disabled, a single record is used for all login
                         sessions.

                         This option has been superseded by the timestamp_type
                         option.

       umask_override    If set, sudo will set the umask as specified in the
                         sudoers file without modification.  This makes it
                         possible to specify a umask in the sudoers file that
                         is more permissive than the user's own umask and
                         matches historical behavior.  If umask_override is
                         not set, sudo will set the umask to be the union of
                         the user's umask and what is specified in sudoers.
                         This flag is off by default.

       use_netgroups     If set, netgroups (prefixed with ‘+’), may be used in
                         place of a user or host.  For LDAP-based sudoers,
                         netgroup support requires an expensive sub-string
                         match on the server unless the NETGROUP_BASE
                         directive is present in the /etc/ldap.conf file.  If
                         netgroups are not needed, this option can be disabled
                         to reduce the load on the LDAP server.  This flag is
                         on by default.

       use_pty           If set, and sudo is running in a terminal, the
                         command will be run in a pseudo-terminal (even if no
                         I/O logging is being done).  If the sudo process is
                         not attached to a terminal, use_pty has no effect.

                         A malicious program run under sudo may be capable of
                         injecting commands into the user's terminal or
                         running a background process that retains access to
                         the user's terminal device even after the main
                         program has finished executing.  By running the
                         command in a separate pseudo-terminal, this attack is
                         no longer possible.  This flag is off by default.

       user_command_timeouts
                         If set, the user may specify a timeout on the command
                         line.  If the timeout expires before the command has
                         exited, the command will be terminated.  If a timeout
                         is specified both in the sudoers file and on the
                         command line, the smaller of the two timeouts will be
                         used.  See the Timeout_Spec section for a description
                         of the timeout syntax.  This flag is off by default.

                         This setting is only supported by version 1.8.20 or
                         higher.

       utmp_runas        If set, sudo will store the name of the runas user
                         when updating the utmp (or utmpx) file.  By default,
                         sudo stores the name of the invoking user.  This flag
                         is off by default.

       visiblepw         By default, sudo will refuse to run if the user must
                         enter a password but it is not possible to disable
                         echo on the terminal.  If the visiblepw flag is set,
                         sudo will prompt for a password even when it would be
                         visible on the screen.  This makes it possible to run
                         things like “ssh somehost sudo ls” since by default,
                         ssh(1) does not allocate a tty when running a
                         command.  This flag is off by default.

       Integers:

       closefrom         Before it executes a command, sudo will close all
                         open file descriptors other than standard input,
                         standard output and standard error (ie: file
                         descriptors 0-2).  The closefrom option can be used
                         to specify a different file descriptor at which to
                         start closing.  The default is 3.

       command_timeout   The maximum amount of time a command is allowed to
                         run before it is terminated.  See the Timeout_Spec
                         section for a description of the timeout syntax.

                         This setting is only supported by version 1.8.20 or
                         higher.

       log_server_timeout
                         The maximum amount of time to wait when connecting to
                         a log server or waiting for a server response.  See
                         the Timeout_Spec section for a description of the
                         timeout syntax.  The default value is 30 seconds.

                         This setting is only supported by version 1.9.0 or
                         higher.

       maxseq            The maximum sequence number that will be substituted
                         for the “%{seq}” escape in the I/O log file (see the
                         iolog_dir description below for more information).
                         While the value substituted for “%{seq}” is in base
                         36, maxseq itself should be expressed in decimal.
                         Values larger than 2176782336 (which corresponds to
                         the base 36 sequence number “ZZZZZZ”) will be
                         silently truncated to 2176782336.  The default value
                         is 2176782336.

                         Once the local sequence number reaches the value of
                         maxseq, it will “roll over” to zero, after which
                         sudoers will truncate and re-use any existing I/O log
                         path names.

                         This setting is only supported by version 1.8.7 or
                         higher.

       passwd_tries      The number of tries a user gets to enter his/her
                         password before sudo logs the failure and exits.  The
                         default is 3.

       syslog_maxlen     On many systems, syslog(3) has a relatively small log
                         buffer.  IETF RFC 5424 states that syslog servers
                         must support messages of at least 480 bytes and
                         should support messages up to 2048 bytes.  By
                         default, sudoers creates log messages up to 980 bytes
                         which corresponds to the historic BSD syslog
                         implementation which used a 1024 byte buffer to store
                         the message, date, hostname and program name.  To
                         prevent syslog messages from being truncated, sudoers
                         will split up log messages that are larger than
                         syslog_maxlen bytes.  When a message is split,
                         additional parts will include the string “(command
                         continued)” after the user name and before the
                         continued command line arguments.

                         This setting is only supported by version 1.8.19 or
                         higher.

       Integers that can be used in a boolean context:

       loglinelen        Number of characters per line for the file log.  This
                         value is used to decide when to wrap lines for nicer
                         log files.  This has no effect on the syslog log
                         file, only the file log.  The default is 80 (use 0 or
                         negate the option to disable word wrap).

       passwd_timeout    Number of minutes before the sudo password prompt
                         times out, or 0 for no timeout.  The timeout may
                         include a fractional component if minute granularity
                         is insufficient, for example 2.5.  The default is 5.

       timestamp_timeout
                         Number of minutes that can elapse before sudo will
                         ask for a passwd again.  The timeout may include a
                         fractional component if minute granularity is
                         insufficient, for example 2.5.  The default is 5.
                         Set this to 0 to always prompt for a password.  If
                         set to a value less than 0 the user's time stamp will
                         not expire until the system is rebooted.  This can be
                         used to allow users to create or delete their own
                         time stamps via “sudo -v” and “sudo -k” respectively.

       umask             File mode creation mask to use when running the
                         command.  Negate this option or set it to 0777 to
                         prevent sudoers from changing the umask.  Unless the
                         umask_override flag is set, the actual umask will be
                         the union of the user's umask and the value of the
                         umask setting, which defaults to 0022.  This
                         guarantees that sudo never lowers the umask when
                         running a command.

                         If umask is explicitly set in sudoers, it will
                         override any umask setting in PAM or login.conf.  If
                         umask is not set in sudoers, the umask specified by
                         PAM or login.conf will take precedence.  The umask
                         setting in PAM is not used for sudoedit, which does
                         not create a new PAM session.

       Strings:

       authfail_message  Message that is displayed after a user fails to
                         authenticate.  The message may include the ‘%d’
                         escape which will expand to the number of failed
                         password attempts.  If set, it overrides the default
                         message, %d incorrect password attempt(s).

       badpass_message   Message that is displayed if a user enters an
                         incorrect password.  The default is Sorry, try again.
                         unless insults are enabled.

       editor            A colon (‘:’) separated list of editors path names
                         used by sudoedit and visudo.  For sudoedit, this list
                         is used to find an editor when none of the
                         SUDO_EDITOR, VISUAL or EDITOR environment variables
                         are set to an editor that exists and is executable.
                         For visudo, it is used as a white list of allowed
                         editors; visudo will choose the editor that matches
                         the user's SUDO_EDITOR, VISUAL or EDITOR environment
                         variable if possible, or the first editor in the list
                         that exists and is executable if not.  Unless invoked
                         as sudoedit, sudo does not preserve the SUDO_EDITOR,
                         VISUAL or EDITOR environment variables unless they
                         are present in the env_keep list or the env_reset
                         option is disabled.  The default is vi.

       iolog_dir         The top-level directory to use when constructing the
                         path name for the input/output log directory.  Only
                         used if the log_input or log_output options are
                         enabled or when the LOG_INPUT or LOG_OUTPUT tags are
                         present for a command.  The session sequence number,
                         if any, is stored in the directory.  The default is
                         /var/log/sudo-io.

                         The following percent (‘%’) escape sequences are
                         supported:

                         %{seq}
                               expanded to a monotonically increasing base-36
                               sequence number, such as 0100A5, where every
                               two digits are used to form a new directory,
                               e.g., 01/00/A5

                         %{user}
                               expanded to the invoking user's login name

                         %{group}
                               expanded to the name of the invoking user's
                               real group-ID

                         %{runas_user}
                               expanded to the login name of the user the
                               command will be run as (e.g., root)

                         %{runas_group}
                               expanded to the group name of the user the
                               command will be run as (e.g., wheel)

                         %{hostname}
                               expanded to the local host name without the
                               domain name

                         %{command}
                               expanded to the base name of the command being
                               run

                         In addition, any escape sequences supported by the
                         system's strftime(3) function will be expanded.

                         To include a literal ‘%’ character, the string ‘%%’
                         should be used.

       iolog_file        The path name, relative to iolog_dir, in which to
                         store input/output logs when the log_input or
                         log_output options are enabled or when the LOG_INPUT
                         or LOG_OUTPUT tags are present for a command.  Note
                         that iolog_file may contain directory components.
                         The default is “%{seq}”.

                         See the iolog_dir option above for a list of
                         supported percent (‘%’) escape sequences.

                         In addition to the escape sequences, path names that
                         end in six or more Xs will have the Xs replaced with
                         a unique combination of digits and letters, similar
                         to the mktemp(3) function.

                         If the path created by concatenating iolog_dir and
                         iolog_file already exists, the existing I/O log file
                         will be truncated and overwritten unless iolog_file
                         ends in six or more Xs.

       iolog_flush       If set, sudo will flush I/O log data to disk after
                         each write instead of buffering it.  This makes it
                         possible to view the logs in real-time as the program
                         is executing but may significantly reduce the
                         effectiveness of I/O log compression.  This flag is
                         off by default.

                         This setting is only supported by version 1.8.20 or
                         higher.

       iolog_group       The group name to look up when setting the group-ID
                         on new I/O log files and directories.  If iolog_group
                         is not set, the primary group-ID of the user
                         specified by iolog_user is used.  If neither
                         iolog_group nor iolog_user are set, I/O log files and
                         directories are created with group-ID 0.

                         This setting is only supported by version 1.8.19 or
                         higher.

       iolog_mode        The file mode to use when creating I/O log files.
                         Mode bits for read and write permissions for owner,
                         group or other are honored, everything else is
                         ignored.  The file permissions will always include
                         the owner read and write bits, even if they are not
                         present in the specified mode.  When creating I/O log
                         directories, search (execute) bits are added to match
                         the read and write bits specified by iolog_mode.
                         Defaults to 0600 (read and write by user only).

                         This setting is only supported by version 1.8.19 or
                         higher.

       iolog_user        The user name to look up when setting the user and
                         group-IDs on new I/O log files and directories.  If
                         iolog_group is set, it will be used instead of the
                         user's primary group-ID.  By default, I/O log files
                         and directories are created with user and group-ID 0.

                         This setting can be useful when the I/O logs are
                         stored on a Network File System (NFS) share.  Having
                         a dedicated user own the I/O log files means that
                         sudoers does not write to the log files as user-ID 0,
                         which is usually not permitted by NFS.

                         This setting is only supported by version 1.8.19 or
                         higher.

       lecture_status_dir
                         The directory in which sudo stores per-user lecture
                         status files.  Once a user has received the lecture,
                         a zero-length file is created in this directory so
                         that sudo will not lecture the user again.  This
                         directory should not be cleared when the system
                         reboots.  The default is /var/db/sudo/lectured.

       limitprivs        The default Solaris limit privileges to use when
                         constructing a new privilege set for a command.  This
                         bounds all privileges of the executing process.  The
                         default limit privileges may be overridden on a per-
                         command basis in sudoers.  This option is only
                         available if sudoers is built on Solaris 10 or
                         higher.

       log_server_cabundle
                         The path to a certificate authority bundle file, in
                         PEM format, to use instead of the system's default
                         certificate authority database when authenticating
                         the log server.  The default is to use the system's
                         default certificate authority database.  This setting
                         has no effect unless the log_server flag is enabled
                         and the remote log server is secured with TLS.

       log_server_peer_cert
                         The path to the client's certificate file, in PEM
                         format.  This setting is required when the log_server
                         flag is enabled and the remote log server is secured
                         with TLS.

       log_server_peer_key
                         The path to the client's private key file, in PEM
                         format.  This setting is required when the log_server
                         flag is enabled and the remote log server is secured
                         with TLS.

       mailsub           Subject of the mail sent to the mailto user.  The
                         escape %h will expand to the host name of the
                         machine.  Default is “*** SECURITY information for %h
                         ***”.

       noexec_file       As of sudo version 1.8.1 this option is no longer
                         supported.  The path to the noexec file should now be
                         set in the sudo.conf(4) file.

       pam_login_service
                         On systems that use PAM for authentication, this is
                         the service name used when the -i option is
                         specified.  The default value is “sudo”.  See the
                         description of pam_service for more information.

                         This setting is only supported by version 1.8.8 or
                         higher.

       pam_service       On systems that use PAM for authentication, the
                         service name specifies the PAM policy to apply.  This
                         usually corresponds to an entry in the pam.conf file
                         or a file in the /etc/pam.d directory.  The default
                         value is “sudo”.

                         This setting is only supported by version 1.8.8 or
                         higher.

       passprompt        The default prompt to use when asking for a password;
                         can be overridden via the -p option or the
                         SUDO_PROMPT environment variable.  The following
                         percent (‘%’) escape sequences are supported:

                         %H    expanded to the local host name including the
                               domain name (only if the machine's host name is
                               fully qualified or the fqdn option is set)

                         %h    expanded to the local host name without the
                               domain name

                         %p    expanded to the user whose password is being
                               asked for (respects the rootpw, targetpw and
                               runaspw flags in sudoers)

                         %U    expanded to the login name of the user the
                               command will be run as (defaults to root)

                         %u    expanded to the invoking user's login name

                         %%    two consecutive % characters are collapsed into
                               a single % character

                         On systems that use PAM for authentication,
                         passprompt will only be used if the prompt provided
                         by the PAM module matches the string “Password: ” or
                         “username's Password: ”.  This ensures that the
                         passprompt setting does not interfere with challenge-
                         response style authentication.  The
                         passprompt_override flag can be used to change this
                         behavior.

                         The default value is “Password: ”.

       privs             The default Solaris privileges to use when
                         constructing a new privilege set for a command.  This
                         is passed to the executing process via the inherited
                         privilege set, but is bounded by the limit
                         privileges.  If the privs option is specified but the
                         limitprivs option is not, the limit privileges of the
                         executing process is set to privs.  The default
                         privileges may be overridden on a per-command basis
                         in sudoers.  This option is only available if sudoers
                         is built on Solaris 10 or higher.

       runas_default     The default user to run commands as if the -u option
                         is not specified on the command line.  This defaults
                         to root.

       sudoers_locale    Locale to use when parsing the sudoers file, logging
                         commands, and sending email.  Note that changing the
                         locale may affect how sudoers is interpreted.
                         Defaults to “C”.

       timestamp_type    sudoers uses per-user time stamp files for credential
                         caching.  The timestamp_type option can be used to
                         specify the type of time stamp record used.  It has
                         the following possible values:

                         global  A single time stamp record is used for all of
                                 a user's login sessions, regardless of the
                                 terminal or parent process ID.  An additional
                                 record is used to serialize password prompts
                                 when sudo is used multiple times in a
                                 pipeline, but this does not affect
                                 authentication.

                         ppid    A single time stamp record is used for all
                                 processes with the same parent process ID
                                 (usually the shell).  Commands run from the
                                 same shell (or other common parent process)
                                 will not require a password for
                                 timestamp_timeout minutes (5 by default) .
                                 Commands run via sudo with a different parent
                                 process ID, for example from a shell script,
                                 will be authenticated separately.

                         tty     One time stamp record is used for each
                                 terminal, which means that a user's login
                                 sessions are authenticated separately.  If no
                                 terminal is present, the behavior is the same
                                 as ppid.  Commands run from the same terminal
                                 will not require a password for
                                 timestamp_timeout minutes (5 by default) .

                         kernel  The time stamp is stored in the kernel as an
                                 attribute of the terminal device.  If no
                                 terminal is present, the behavior is the same
                                 as ppid.  Negative timestamp_timeout values
                                 are not supported and positive values are
                                 limited to a maximum of 60 minutes.  This is
                                 currently only supported on OpenBSD.

                         The default value is tty.

                         This setting is only supported by version 1.8.21 or
                         higher.

       timestampdir      The directory in which sudo stores its time stamp
                         files.  This directory should be cleared when the
                         system reboots.  The default is /var/run/sudo/ts.

       timestampowner    The owner of the lecture status directory, time stamp
                         directory and all files stored therein.  The default
                         is root.

       env_check         Environment variables to be removed from the user's
                         environment unless they are considered “safe”.  For
                         all variables except TZ, “safe” means that the
                         variable's value does not contain any ‘%’ or ‘/’
                         characters.  This can be used to guard against
                         printf-style format vulnerabilities in poorly-written
                         programs.  The TZ variable is considered unsafe if
                         any of the following are true:

                         ·  It consists of a fully-qualified path name,
                            optionally prefixed with a colon (‘:’), that does
                            not match the location of the zoneinfo directory.

                         ·  It contains a ..  path element.

                         ·  It contains white space or non-printable
                            characters.

                         ·  It is longer than the value of PATH_MAX.

                         The argument may be a double-quoted, space-separated
                         list or a single value without double-quotes.  The
                         list can be replaced, added to, deleted from, or
                         disabled by using the =, +=, -=, and !  operators
                         respectively.  Regardless of whether the env_reset
                         option is enabled or disabled, variables specified by
                         env_check will be preserved in the environment if
                         they pass the aforementioned check.  The global list
                         of environment variables to check is displayed when
                         sudo is run by root with the -V option.

       env_delete        Environment variables to be removed from the user's
                         environment when the env_reset option is not in
                         effect.  The argument may be a double-quoted, space-
                         separated list or a single value without double-
                         quotes.  The list can be replaced, added to, deleted
                         from, or disabled by using the =, +=, -=, and !
                         operators respectively.  The global list of
                         environment variables to remove is displayed when
                         sudo is run by root with the -V option.  Note that
                         many operating systems will remove potentially
                         dangerous variables from the environment of any set-
                         user-ID process (such as sudo).

       env_keep          Environment variables to be preserved in the user's
                         environment when the env_reset option is in effect.
                         This allows fine-grained control over the environment
                         sudo-spawned processes will receive.  The argument
                         may be a double-quoted, space-separated list or a
                         single value without double-quotes.  The list can be
                         replaced, added to, deleted from, or disabled by
                         using the =, +=, -=, and !  operators respectively.
                         The global list of variables to keep is displayed
                         when sudo is run by root with the -V option.

                         Preserving the HOME environment variable has security
                         implications since many programs use it when
                         searching for configuration or data files.  Adding
                         HOME to env_keep may enable a user to run
                         unrestricted commands via sudo and is strongly
                         discouraged.  Users wishing to edit files with sudo
                         should run sudoedit (or sudo -e) to get their
                         accustomed editor configuration instead of invoking
                         the editor directly.

       log_servers       A list of one or more remote servers to use for I/O
                         log storage, separated by white space.  Starting with
                         sudo 1.9, it is possible to send I/O logs to a remote
                         server instead of logging them locally.  Log servers
                         must be running sudo_logsrvd or another service that
                         implements the protocol described by
                         sudo_logsrv.proto(4).

                         Server addresses should be of the form
                         “host[:port][(tls)]”.  The host portion may be a host
                         name, an IPv4 address, or an IPv6 address in square
                         brackets.

                         If the optional tls flag is present, the connection
                         will be secured with Transport Layer Security (TLS)
                         version 1.2 or 1.3.  Versions of TLS prior to 1.2 are
                         not supported.

                         If a port is specified, it may either be a port
                         number or a known service name as defined by the
                         system service name database.  If no port is
                         specified, port 30343 will be used for plaintext
                         connections and port 30344 will be used for TLS
                         connections.

                         When log_servers is enabled, I/O logs will not be
                         logged locally.  If multiple hosts are specified,
                         sudoers will try them in reverse order until it
                         connects successfully.  If no log servers are
                         reachable, the user will not be able to run a command
                         unless the ignore_iolog_errors flag is set.  If the
                         connection to the log server is interrupted while the
                         command is running, the command will be killed unless
                         ignore_iolog_errors is set.

GROUP PROVIDER PLUGINS
       The sudoers plugin supports its own plugin interface to allow non-Unix
       group lookups which can query a group source other than the standard
       Unix group database.  This can be used to implement support for the
       nonunix_group syntax described earlier.

       Group provider plugins are specified via the group_plugin setting.  The
       argument to group_plugin should consist of the plugin path, either
       fully-qualified or relative to the /usr/local/libexec/sudo directory,
       followed by any configuration options the plugin requires.  These
       options (if specified) will be passed to the plugin's initialization
       function.  If options are present, the string must be enclosed in
       double quotes ("").

       The following group provider plugins are installed by default:

       group_file
                 The group_file plugin supports an alternate group file that
                 uses the same syntax as the /etc/group file.  The path to the
                 group file should be specified as an option to the plugin.
                 For example, if the group file to be used is /etc/sudo-group:

                 Defaults group_plugin="group_file.so /etc/sudo-group"

       system_group
                 The system_group plugin supports group lookups via the
                 standard C library functions getgrnam() and getgrid().  This
                 plugin can be used in instances where the user belongs to
                 groups not present in the user's supplemental group vector.
                 This plugin takes no options:

                 Defaults group_plugin=system_group.so

       The group provider plugin API is described in detail in sudo_plugin(4).

LOG FORMAT
       sudoers can log events using either syslog(3) or a simple log file.
       The log format is almost identical in both cases.

   Accepted command log entries
       Commands that sudo runs are logged using the following format (split
       into multiple lines for readability):

           date hostname progname: username : TTY=ttyname ; PWD=cwd ; \
               USER=runasuser ; GROUP=runasgroup ; TSID=logid ; \
               ENV=env_vars COMMAND=command

       Where the fields are as follows:

       date          The date the command was run.  Typically, this is in the
                     format “MMM, DD, HH:MM:SS”.  If logging via syslog(3),
                     the actual date format is controlled by the syslog
                     daemon.  If logging to a file and the log_year option is
                     enabled, the date will also include the year.

       hostname      The name of the host sudo was run on.  This field is only
                     present when logging via syslog(3).

       progname      The name of the program, usually sudo or sudoedit.  This
                     field is only present when logging via syslog(3).

       username      The login name of the user who ran sudo.

       ttyname       The short name of the terminal (e.g., “console”, “tty01”,
                     or “pts/0”) sudo was run on, or “unknown” if there was no
                     terminal present.

       cwd           The current working directory that sudo was run in.

       runasuser     The user the command was run as.

       runasgroup    The group the command was run as if one was specified on
                     the command line.

       logid         An I/O log identifier that can be used to replay the
                     command's output.  This is only present when the
                     log_input or log_output option is enabled.

       env_vars      A list of environment variables specified on the command
                     line, if specified.

       command       The actual command that was executed.

       Messages are logged using the locale specified by sudoers_locale, which
       defaults to the “C” locale.

   Denied command log entries
       If the user is not allowed to run the command, the reason for the
       denial will follow the user name.  Possible reasons include:

       user NOT in sudoers
          The user is not listed in the sudoers file.

       user NOT authorized on host
          The user is listed in the sudoers file but is not allowed to run
          commands on the host.

       command not allowed
          The user is listed in the sudoers file for the host but they are not
          allowed to run the specified command.

       3 incorrect password attempts
          The user failed to enter their password after 3 tries.  The actual
          number of tries will vary based on the number of failed attempts and
          the value of the passwd_tries option.

       a password is required
          The -n option was specified but a password was required.

       sorry, you are not allowed to set the following environment variables
          The user specified environment variables on the command line that
          were not allowed by sudoers.

   Error log entries
       If an error occurs, sudoers will log a message and, in most cases, send
       a message to the administrator via email.  Possible errors include:

       parse error in /etc/sudoers near line N
          sudoers encountered an error when parsing the specified file.  In
          some cases, the actual error may be one line above or below the line
          number listed, depending on the type of error.

       problem with defaults entries
          The sudoers file contains one or more unknown Defaults settings.
          This does not prevent sudo from running, but the sudoers file should
          be checked using visudo.

       timestamp owner (username): No such user
          The time stamp directory owner, as specified by the timestampowner
          setting, could not be found in the password database.

       unable to open/read /etc/sudoers
          The sudoers file could not be opened for reading.  This can happen
          when the sudoers file is located on a remote file system that maps
          user-ID 0 to a different value.  Normally, sudoers tries to open the
          sudoers file using group permissions to avoid this problem.
          Consider either changing the ownership of /etc/sudoers or adding an
          argument like “sudoers_uid=N” (where ‘N’ is the user-ID that owns
          the sudoers file) to the end of the sudoers Plugin line in the
          sudo.conf(4) file.

       unable to stat /etc/sudoers
          The /etc/sudoers file is missing.

       /etc/sudoers is not a regular file
          The /etc/sudoers file exists but is not a regular file or symbolic
          link.

       /etc/sudoers is owned by uid N, should be 0
          The sudoers file has the wrong owner.  If you wish to change the
          sudoers file owner, please add “sudoers_uid=N” (where ‘N’ is the
          user-ID that owns the sudoers file) to the sudoers Plugin line in
          the sudo.conf(4) file.

       /etc/sudoers is world writable
          The permissions on the sudoers file allow all users to write to it.
          The sudoers file must not be world-writable, the default file mode
          is 0440 (readable by owner and group, writable by none).  The
          default mode may be changed via the “sudoers_mode” option to the
          sudoers Plugin line in the sudo.conf(4) file.

       /etc/sudoers is owned by gid N, should be 1
          The sudoers file has the wrong group ownership.  If you wish to
          change the sudoers file group ownership, please add “sudoers_gid=N”
          (where ‘N’ is the group-ID that owns the sudoers file) to the
          sudoers Plugin line in the sudo.conf(4) file.

       unable to open /var/run/sudo/ts/username
          sudoers was unable to read or create the user's time stamp file.
          This can happen when timestampowner is set to a user other than root
          and the mode on /var/run/sudo is not searchable by group or other.
          The default mode for /var/run/sudo is 0711.

       unable to write to /var/run/sudo/ts/username
          sudoers was unable to write to the user's time stamp file.

       /var/run/sudo/ts is owned by uid X, should be Y
          The time stamp directory is owned by a user other than
          timestampowner.  This can occur when the value of timestampowner has
          been changed.  sudoers will ignore the time stamp directory until
          the owner is corrected.

       /var/run/sudo/ts is group writable
          The time stamp directory is group-writable; it should be writable
          only by timestampowner.  The default mode for the time stamp
          directory is 0700.  sudoers will ignore the time stamp directory
          until the mode is corrected.

   Notes on logging via syslog
       By default, sudoers logs messages via syslog(3).  The date, hostname,
       and progname fields are added by the system's syslog() function, not
       sudoers itself.  As such, they may vary in format on different systems.

       The maximum size of syslog messages varies from system to system.  The
       syslog_maxlen setting can be used to change the maximum syslog message
       size from the default value of 980 bytes.  For more information, see
       the description of syslog_maxlen.

   Notes on logging to a file
       If the logfile option is set, sudoers will log to a local file, such as
       /var/log/sudo.  When logging to a file, sudoers uses a format similar
       to syslog(3), with a few important differences:

       1.   The progname and hostname fields are not present.

       2.   If the log_year option is enabled, the date will also include the
            year.

       3.   Lines that are longer than loglinelen characters (80 by default)
            are word-wrapped and continued on the next line with a four
            character indent.  This makes entries easier to read for a human
            being, but makes it more difficult to use grep(1) on the log
            files.  If the loglinelen option is set to 0 (or negated with a
            ‘!’), word wrap will be disabled.

I/O LOG FILES
       When I/O logging is enabled, sudo will run the command in a pseudo-
       terminal and log all user input and/or output, depending on which
       options are enabled.  I/O can be logged either to the local machine or
       to a remote log server.  For local logs, I/O is logged to the directory
       specified by the iolog_dir option (/var/log/sudo-io by default) using a
       unique session ID that is included in the sudo log line, prefixed with
       “TSID=”.  The iolog_file option may be used to control the format of
       the session ID.  For remote logs, the log_servers setting is used to
       specify one or more log servers running sudo_logsrvd or another server
       that implements the protocol described by sudo_logsrv.proto(4).

       For both local and remote I/O logs, each log is stored in a separate
       directory that contains the following files:

       log       A text file containing information about the command.  The
                 first line consists of the following colon-delimited fields:
                 the time the command was run, the name of the user who ran
                 sudo, the name of the target user, the name of the target
                 group (optional), the terminal that sudo was run from, and
                 the number of lines and columns of the terminal.  The second
                 and third lines contain the working directory the command was
                 run from and the path name of the command itself (with
                 arguments if present).

       log.json  A JSON-formatted file containing information about the
                 command.  This is similar to the log file but contains
                 additional information and is easily extensible.  The
                 log.json file will be used by sudoreplay(1m) in preference to
                 the log file if it exists.  The file may contain the
                 following elements:

                 timestamp
                           A JSON object containing time the command was run.
                           It consists of two values, seconds and nanoseconds.

                 columns   The number of columns of the terminal the command
                           ran on, or zero if no terminal was present.

                 command   The fully-qualified path of the command that was
                           run.

                 lines     The number of lines of the terminal the command ran
                           on, or zero if no terminal was present.

                 runargv   A JSON array representing the command's argument
                           vector as passed to the execve(2) system call.

                 runenv    A JSON array representing the command's environment
                           as passed to the execve(2) system call.

                 rungid    The group ID the command ran as.  This element is
                           only present when the user specifies a group on the
                           command line.

                 rungroup  The name of the group the command ran as.  This
                           element is only present when the user specifies a
                           group on the command line.

                 runuid    The user ID the command ran as.

                 runuser   The name of the user the command ran as.

                 submitcwd
                           The current working directory at the time sudo was
                           run.

                 submithost
                           The name of the host the command was run on.

                 submituser
                           The name of the user who ran the command via sudo.

                 ttyname   The path name of the terminal the user invoked sudo
                           from.  If the command was run in a pseudo-terminal,
                           ttyname will be different from the terminal the
                           command actually ran in.
       timing    Timing information used to replay the session.  Each line
                 consists of the I/O log entry type and amount of time since
                 the last entry, followed by type-specific data.  The I/O log
                 entry types and their corresponding type-specific data are:

                 0     standard input, number of bytes in the entry
                 1     standard output, number of bytes in the entry
                 2     standard error, number of bytes in the entry
                 3     terminal input, number of bytes in the entry
                 4     terminal output, number of bytes in the entry
                 5     window change, new number lines and columns
                 6     bug compatibility for sudo 1.8.7 terminal output
                 7     command suspend or resume, signal received
       ttyin     Raw input from the user's terminal, exactly as it was
                 received.  No post-processing is performed.  For manual
                 viewing, you may wish to convert carriage return characters
                 in the log to line feeds.  For example: ‘gunzip -c ttyin | tr
                 "\r" "\n"’

       stdin     The standard input when no terminal is present, or input
                 redirected from a pipe or file.

       ttyout    Output from the pseudo-terminal (what the command writes to
                 the screen).  Note that terminal-specific post-processing is
                 performed before the data is logged.  This means that, for
                 example, line feeds are usually converted to line
                 feed/carriage return pairs and tabs may be expanded to
                 spaces.

       stdout    The standard output when no terminal is present, or output
                 redirected to a pipe or file.

       stderr    The standard error redirected to a pipe or file.

       All files other than log are compressed in gzip format unless the
       compress_io flag has been disabled.  Due to buffering, it is not
       normally possible to display the I/O logs in real-time as the program
       is executing.  The I/O log data will not be complete until the program
       run by sudo has exited or has been terminated by a signal.  The
       iolog_flush flag can be used to disable buffering, in which case I/O
       log data is written to disk as soon as it is available.  The output
       portion of an I/O log file can be viewed with the sudoreplay(1m)
       utility, which can also be used to list or search the available logs.

       Note that user input may contain sensitive information such as
       passwords (even if they are not echoed to the screen), which will be
       stored in the log file unencrypted.  In most cases, logging the command
       output via log_output or LOG_OUTPUT is all that is required.

       Since each session's I/O logs are stored in a separate directory,
       traditional log rotation utilities cannot be used to limit the number
       of I/O logs.  The simplest way to limit the number of I/O is by setting
       the maxseq option to the maximum number of logs you wish to store.
       Once the I/O log sequence number reaches maxseq, it will be reset to
       zero and sudoers will truncate and re-use any existing I/O logs.

FILES
       /etc/sudo.conf            Sudo front end configuration

       /etc/sudoers              List of who can run what

       /etc/group                Local groups file

       /etc/netgroup             List of network groups

       /var/log/sudo-io          I/O log files

       /var/run/sudo/ts          Directory containing time stamps for the
                                 sudoers security policy

       /var/db/sudo/lectured     Directory containing lecture status files for
                                 the sudoers security policy

       /etc/environment          Initial environment for -i mode on AIX and
                                 Linux systems

EXAMPLES
       Below are example sudoers file entries.  Admittedly, some of these are
       a bit contrived.  First, we allow a few environment variables to pass
       and then define our aliases:

       # Run X applications through sudo; HOME is used to find the
       # .Xauthority file.  Note that other programs use HOME to find
       # configuration files and this may lead to privilege escalation!
       Defaults env_keep += "DISPLAY HOME"

       # User alias specification
       User_Alias     FULLTIMERS = millert, mikef, dowdy
       User_Alias     PARTTIMERS = bostley, jwfox, crawl
       User_Alias     WEBADMIN = will, wendy, wim

       # Runas alias specification
       Runas_Alias    OP = root, operator
       Runas_Alias    DB = oracle, sybase
       Runas_Alias    ADMINGRP = adm, oper

       # Host alias specification
       Host_Alias     SPARC = bigtime, eclipse, moet, anchor :\
                 SGI = grolsch, dandelion, black :\
                 ALPHA = widget, thalamus, foobar :\
                 HPPA = boa, nag, python
       Host_Alias     CUNETS = 128.138.0.0/255.255.0.0
       Host_Alias     CSNETS = 128.138.243.0, 128.138.204.0/24, 128.138.242.0
       Host_Alias     SERVERS = primary, mail, www, ns
       Host_Alias     CDROM = orion, perseus, hercules

       # Cmnd alias specification
       Cmnd_Alias     DUMPS = /usr/bin/mt, /usr/sbin/dump, /usr/sbin/rdump,\
                      /usr/sbin/restore, /usr/sbin/rrestore,\
                      sha224:0GomF8mNN3wlDt1HD9XldjJ3SNgpFdbjO1+NsQ== \
                      /home/operator/bin/start_backups
       Cmnd_Alias     KILL = /usr/bin/kill
       Cmnd_Alias     PRINTING = /usr/sbin/lpc, /usr/bin/lprm
       Cmnd_Alias     SHUTDOWN = /usr/sbin/shutdown
       Cmnd_Alias     HALT = /usr/sbin/halt
       Cmnd_Alias     REBOOT = /usr/sbin/reboot
       Cmnd_Alias     SHELLS = /usr/bin/sh, /usr/bin/csh, /usr/bin/ksh,\
                       /usr/local/bin/tcsh, /usr/bin/rsh,\
                       /usr/local/bin/zsh
       Cmnd_Alias     SU = /usr/bin/su
       Cmnd_Alias     PAGERS = /usr/bin/more, /usr/bin/pg, /usr/bin/less

       Here we override some of the compiled in default values.  We want sudo
       to log via syslog(3) using the auth facility in all cases.  We don't
       want to subject the full time staff to the sudo lecture, user millert
       need not give a password, and we don't want to reset the LOGNAME or
       USER environment variables when running commands as root.
       Additionally, on the machines in the SERVERS Host_Alias, we keep an
       additional local log file and make sure we log the year in each log
       line since the log entries will be kept around for several years.
       Lastly, we disable shell escapes for the commands in the PAGERS
       Cmnd_Alias (/usr/bin/more, /usr/bin/pg and /usr/bin/less) .  Note that
       this will not effectively constrain users with sudo ALL privileges.

       # Override built-in defaults
       Defaults       syslog=auth
       Defaults>root       !set_logname
       Defaults:FULLTIMERS !lecture
       Defaults:millert    !authenticate
       Defaults@SERVERS    log_year, logfile=/var/log/sudo.log
       Defaults!PAGERS          noexec

       The User specification is the part that actually determines who may run
       what.

       root      ALL = (ALL) ALL
       %wheel         ALL = (ALL) ALL

       We let root and any user in group wheel run any command on any host as
       any user.

       FULLTIMERS     ALL = NOPASSWD: ALL

       Full time sysadmins (millert, mikef, and dowdy) may run any command on
       any host without authenticating themselves.

       PARTTIMERS     ALL = ALL

       Part time sysadmins bostley, jwfox, and crawl) may run any command on
       any host but they must authenticate themselves first (since the entry
       lacks the NOPASSWD tag).

       jack      CSNETS = ALL

       The user jack may run any command on the machines in the CSNETS alias
       (the networks 128.138.243.0, 128.138.204.0, and 128.138.242.0).  Of
       those networks, only 128.138.204.0 has an explicit netmask (in CIDR
       notation) indicating it is a class C network.  For the other networks
       in CSNETS, the local machine's netmask will be used during matching.

       lisa      CUNETS = ALL

       The user lisa may run any command on any host in the CUNETS alias (the
       class B network 128.138.0.0).

       operator  ALL = DUMPS, KILL, SHUTDOWN, HALT, REBOOT, PRINTING,\
                 sudoedit /etc/printcap, /usr/oper/bin/

       The operator user may run commands limited to simple maintenance.
       Here, those are commands related to backups, killing processes, the
       printing system, shutting down the system, and any commands in the
       directory /usr/oper/bin/.  Note that one command in the DUMPS
       Cmnd_Alias includes a sha224 digest, /home/operator/bin/start_backups.
       This is because the directory containing the script is writable by the
       operator user.  If the script is modified (resulting in a digest
       mismatch) it will no longer be possible to run it via sudo.

       joe       ALL = /usr/bin/su operator

       The user joe may only su(1) to operator.

       pete      HPPA = /usr/bin/passwd [A-Za-z]*, !/usr/bin/passwd *root*

       %opers         ALL = (: ADMINGRP) /usr/sbin/

       Users in the opers group may run commands in /usr/sbin/ as themselves
       with any group in the ADMINGRP Runas_Alias (the adm and oper groups).

       The user pete is allowed to change anyone's password except for root on
       the HPPA machines.  Because command line arguments are matched as a
       single, concatenated string, the ‘*’ wildcard will match multiple
       words.  This example assumes that passwd(1) does not take multiple user
       names on the command line.  Note that on GNU systems, options to
       passwd(1) may be specified after the user argument.  As a result, this
       rule will also allow:

           passwd username --expire

       which may not be desirable.

       bob       SPARC = (OP) ALL : SGI = (OP) ALL

       The user bob may run anything on the SPARC and SGI machines as any user
       listed in the OP Runas_Alias (root and operator.)

       jim       +biglab = ALL

       The user jim may run any command on machines in the biglab netgroup.
       sudo knows that “biglab” is a netgroup due to the ‘+’ prefix.

       +secretaries   ALL = PRINTING, /usr/bin/adduser, /usr/bin/rmuser

       Users in the secretaries netgroup need to help manage the printers as
       well as add and remove users, so they are allowed to run those commands
       on all machines.

       fred      ALL = (DB) NOPASSWD: ALL

       The user fred can run commands as any user in the DB Runas_Alias
       (oracle or sybase) without giving a password.

       john      ALPHA = /usr/bin/su [!-]*, !/usr/bin/su *root*

       On the ALPHA machines, user john may su to anyone except root but he is
       not allowed to specify any options to the su(1) command.

       jen       ALL, !SERVERS = ALL

       The user jen may run any command on any machine except for those in the
       SERVERS Host_Alias (primary, mail, www and ns).

       jill      SERVERS = /usr/bin/, !SU, !SHELLS

       For any machine in the SERVERS Host_Alias, jill may run any commands in
       the directory /usr/bin/ except for those commands belonging to the SU
       and SHELLS Cmnd_Aliases.  While not specifically mentioned in the rule,
       the commands in the PAGERS Cmnd_Alias all reside in /usr/bin and have
       the noexec option set.

       steve          CSNETS = (operator) /usr/local/op_commands/

       The user steve may run any command in the directory
       /usr/local/op_commands/ but only as user operator.

       matt      valkyrie = KILL

       On his personal workstation, valkyrie, matt needs to be able to kill
       hung processes.

       WEBADMIN  www = (www) ALL, (root) /usr/bin/su www

       On the host www, any user in the WEBADMIN User_Alias (will, wendy, and
       wim), may run any command as user www (which owns the web pages) or
       simply su(1) to www.

       ALL       CDROM = NOPASSWD: /sbin/umount /CDROM,\
                 /sbin/mount -o nosuid\,nodev /dev/cd0a /CDROM

       Any user may mount or unmount a CD-ROM on the machines in the CDROM
       Host_Alias (orion, perseus, hercules) without entering a password.
       This is a bit tedious for users to type, so it is a prime candidate for
       encapsulating in a shell script.

SECURITY NOTES
   Limitations of the ‘!’ operator
       It is generally not effective to “subtract” commands from ALL using the
       ‘!’ operator.  A user can trivially circumvent this by copying the
       desired command to a different name and then executing that.  For
       example:

       bill ALL = ALL, !SU, !SHELLS

       Doesn't really prevent bill from running the commands listed in SU or
       SHELLS since he can simply copy those commands to a different name, or
       use a shell escape from an editor or other program.  Therefore, these
       kind of restrictions should be considered advisory at best (and
       reinforced by policy).

       In general, if a user has sudo ALL there is nothing to prevent them
       from creating their own program that gives them a root shell (or making
       their own copy of a shell) regardless of any ‘!’ elements in the user
       specification.

   Security implications of fast_glob
       If the fast_glob option is in use, it is not possible to reliably
       negate commands where the path name includes globbing (aka wildcard)
       characters.  This is because the C library's fnmatch(3) function cannot
       resolve relative paths.  While this is typically only an inconvenience
       for rules that grant privileges, it can result in a security issue for
       rules that subtract or revoke privileges.

       For example, given the following sudoers file entry:

       john ALL = /usr/bin/passwd [a-zA-Z0-9]*, /usr/bin/chsh [a-zA-Z0-9]*,\
                     /usr/bin/chfn [a-zA-Z0-9]*, !/usr/bin/* root

       User john can still run /usr/bin/passwd root if fast_glob is enabled by
       changing to /usr/bin and running ./passwd root instead.

   Preventing shell escapes
       Once sudo executes a program, that program is free to do whatever it
       pleases, including run other programs.  This can be a security issue
       since it is not uncommon for a program to allow shell escapes, which
       lets a user bypass sudo's access control and logging.  Common programs
       that permit shell escapes include shells (obviously), editors,
       paginators, mail and terminal programs.

       There are two basic approaches to this problem:

       restrict  Avoid giving users access to commands that allow the user to
                 run arbitrary commands.  Many editors have a restricted mode
                 where shell escapes are disabled, though sudoedit is a better
                 solution to running editors via sudo.  Due to the large
                 number of programs that offer shell escapes, restricting
                 users to the set of programs that do not is often unworkable.

       noexec    Many systems that support shared libraries have the ability
                 to override default library functions by pointing an
                 environment variable (usually LD_PRELOAD) to an alternate
                 shared library.  On such systems, sudo's noexec functionality
                 can be used to prevent a program run by sudo from executing
                 any other programs.  Note, however, that this applies only to
                 native dynamically-linked executables.  Statically-linked
                 executables and foreign executables running under binary
                 emulation are not affected.

                 The noexec feature is known to work on SunOS, Solaris, *BSD,
                 Linux, IRIX, Tru64 UNIX, macOS, HP-UX 11.x and AIX 5.3 and
                 above.  It should be supported on most operating systems that
                 support the LD_PRELOAD environment variable.  Check your
                 operating system's manual pages for the dynamic linker
                 (usually ld.so, ld.so.1, dyld, dld.sl, rld, or loader) to see
                 if LD_PRELOAD is supported.

                 On Solaris 10 and higher, noexec uses Solaris privileges
                 instead of the LD_PRELOAD environment variable.

                 To enable noexec for a command, use the NOEXEC tag as
                 documented in the User Specification section above.  Here is
                 that example again:

                 aaron     shanty = NOEXEC: /usr/bin/more, /usr/bin/vi

                 This allows user aaron to run /usr/bin/more and /usr/bin/vi
                 with noexec enabled.  This will prevent those two commands
                 from executing other commands (such as a shell).  If you are
                 unsure whether or not your system is capable of supporting
                 noexec you can always just try it out and check whether shell
                 escapes work when noexec is enabled.

       Note that restricting shell escapes is not a panacea.  Programs running
       as root are still capable of many potentially hazardous operations
       (such as changing or overwriting files) that could lead to unintended
       privilege escalation.  In the specific case of an editor, a safer
       approach is to give the user permission to run sudoedit (see below).

   Secure editing
       The sudoers plugin includes sudoedit support which allows users to
       securely edit files with the editor of their choice.  As sudoedit is a
       built-in command, it must be specified in the sudoers file without a
       leading path.  However, it may take command line arguments just as a
       normal command does.  Wildcards used in sudoedit command line arguments
       are expected to be path names, so a forward slash (‘/’) will not be
       matched by a wildcard.

       Unlike other sudo commands, the editor is run with the permissions of
       the invoking user and with the environment unmodified.  More
       information may be found in the description of the -e option in
       sudo(1m).

       For example, to allow user operator to edit the “message of the day”
       file:

             operator  sudoedit /etc/motd

       The operator user then runs sudoedit as follows:

             $ sudoedit /etc/motd

       The editor will run as the operator user, not root, on a temporary copy
       of /etc/motd.  After the file has been edited, /etc/motd will be
       updated with the contents of the temporary copy.

       Users should never be granted sudoedit permission to edit a file that
       resides in a directory the user has write access to, either directly or
       via a wildcard.  If the user has write access to the directory it is
       possible to replace the legitimate file with a link to another file,
       allowing the editing of arbitrary files.  To prevent this, starting
       with version 1.8.16, symbolic links will not be followed in writable
       directories and sudoedit will refuse to edit a file located in a
       writable directory unless the sudoedit_checkdir option has been
       disabled or the invoking user is root.  Additionally, in version 1.8.15
       and higher, sudoedit will refuse to open a symbolic link unless either
       the sudoedit_follow option is enabled or the sudoedit command is
       prefixed with the FOLLOW tag in the sudoers file.

   Time stamp file checks
       sudoers will check the ownership of its time stamp directory
       (/var/run/sudo/ts by default) and ignore the directory's contents if it
       is not owned by root or if it is writable by a user other than root.
       Older versions of sudo stored time stamp files in /tmp; this is no
       longer recommended as it may be possible for a user to create the time
       stamp themselves on systems that allow unprivileged users to change the
       ownership of files they create.

       While the time stamp directory should be cleared at reboot time, not
       all systems contain a /run or /var/run directory.  To avoid potential
       problems, sudoers will ignore time stamp files that date from before
       the machine booted on systems where the boot time is available.

       Some systems with graphical desktop environments allow unprivileged
       users to change the system clock.  Since sudoers relies on the system
       clock for time stamp validation, it may be possible on such systems for
       a user to run sudo for longer than timestamp_timeout by setting the
       clock back.  To combat this, sudoers uses a monotonic clock (which
       never moves backwards) for its time stamps if the system supports it.

       sudoers will not honor time stamps set far in the future.  Time stamps
       with a date greater than current_time + 2 * TIMEOUT will be ignored and
       sudoers will log and complain.

       If the timestamp_type option is set to “tty”, the time stamp record
       includes the device number of the terminal the user authenticated with.
       This provides per-terminal granularity but time stamp records may still
       outlive the user's session.

       Unless the timestamp_type option is set to “global”, the time stamp
       record also includes the session ID of the process that last
       authenticated.  This prevents processes in different terminal sessions
       from using the same time stamp record.  On systems where a process's
       start time can be queried, the start time of the session leader is
       recorded in the time stamp record.  If no terminal is present or the
       timestamp_type option is set to “ppid”, the start time of the parent
       process is used instead.  In most cases this will prevent a time stamp
       record from being re-used without the user entering a password when
       logging out and back in again.

DEBUGGING
       Versions 1.8.4 and higher of the sudoers plugin support a flexible
       debugging framework that can help track down what the plugin is doing
       internally if there is a problem.  This can be configured in the
       sudo.conf(4) file.

       The sudoers plugin uses the same debug flag format as the sudo front-
       end: subsystem@priority.

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

       The following subsystems are used by the sudoers plugin:

       alias     User_Alias, Runas_Alias, Host_Alias and Cmnd_Alias processing

       all       matches every subsystem

       audit     BSM and Linux audit code

       auth      user authentication

       defaults  sudoers file Defaults settings

       env       environment handling

       ldap      LDAP-based sudoers

       logging   logging support

       match     matching of users, groups, hosts and netgroups in the sudoers
                 file

       netif     network interface handling

       nss       network service switch handling in sudoers

       parser    sudoers file parsing

       perms     permission setting

       plugin    The equivalent of main for the plugin.

       pty       pseudo-terminal related code

       rbtree    redblack tree internals

       sssd      SSSD-based sudoers

       util      utility functions
       For example:

       Debug sudo /var/log/sudo_debug match@info,nss@info

       For more information, see the sudo.conf(4) manual.

SEE ALSO
       ssh(1), su(1), fnmatch(3), glob(3), mktemp(3), strftime(3),
       sudo.conf(4), sudo_plugin(4), sudoers.ldap(4), sudoers_timestamp(4),
       sudo(1m), visudo(1m)

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.

CAVEATS
       The sudoers file should always be edited by the visudo command which
       locks the file and does grammatical checking.  It is imperative that
       the sudoers file be free of syntax errors since sudo will not run with
       a syntactically incorrect sudoers file.

       When using netgroups of machines (as opposed to users), if you store
       fully qualified host name in the netgroup (as is usually the case), you
       either need to have the machine's host name be fully qualified as
       returned by the hostname command or use the fqdn option in sudoers.

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,
       including, 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                       July 5, 2020                       SUDOERS(4)
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