.rn '' }` ''' $RCSfile: sudoers.5,v $$Revision: 1.6 $$Date: 2001/01/09 18:15:31 $ ''' ''' $Log: sudoers.5,v $ ''' Revision 1.6 2001/01/09 18:15:31 krw ''' Typos: 'eg.' -> 'e.g.' ''' ''' Revision 1.5 2000/03/27 03:44:39 millert ''' sudo 1.6.3; see http://www.courtesan.com/sudo/current.html for a list ''' of changes. ''' ''' Revision 1.5 2000/03/27 03:26:23 millert ''' Use 8 and 5 in the man page bodies as well. ''' ''' .de Sh .br .if t .Sp .ne 5 .PP \fB\\$1\fR .PP .. .de Sp .if t .sp .5v .if n .sp .. .de Ip .br .ie \\n(.$>=3 .ne \\$3 .el .ne 3 .IP "\\$1" \\$2 .. .de Vb .ft CW .nf .ne \\$1 .. .de Ve .ft R .fi .. ''' ''' ''' Set up \*(-- to give an unbreakable dash; ''' string Tr holds user defined translation string. ''' Bell System Logo is used as a dummy character. ''' .tr \(*W-|\(bv\*(Tr .ie n \{\ .ds -- \(*W- .ds PI pi .if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch .if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo 12 pitch .ds L" "" .ds R" "" ''' \*(M", \*(S", \*(N" and \*(T" are the equivalent of ''' \*(L" and \*(R", except that they are used on ".xx" lines, ''' such as .IP and .SH, which do another additional levels of ''' double-quote interpretation .ds M" """ .ds S" """ .ds N" """"" .ds T" """"" .ds L' ' .ds R' ' .ds M' ' .ds S' ' .ds N' ' .ds T' ' 'br\} .el\{\ .ds -- \(em\| .tr \*(Tr .ds L" `` .ds R" '' .ds M" `` .ds S" '' .ds N" `` .ds T" '' .ds L' ` .ds R' ' .ds M' ` .ds S' ' .ds N' ` .ds T' ' .ds PI \(*p 'br\} .\" If the F register is turned on, we'll generate .\" index entries out stderr for the following things: .\" TH Title .\" SH Header .\" Sh Subsection .\" Ip Item .\" X<> Xref (embedded .\" Of course, you have to process the output yourself .\" in some meaninful fashion. .if \nF \{ .de IX .tm Index:\\$1\t\\n%\t"\\$2" .. .nr % 0 .rr F .\} .TH sudoers 5 "1.6.3" "26/Mar/2000" "FILE FORMATS" .UC .if n .hy 0 .if n .na .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .de CQ \" put $1 in typewriter font .ft CW 'if n "\c 'if t \\&\\$1\c 'if n \\&\\$1\c 'if n \&" \\&\\$2 \\$3 \\$4 \\$5 \\$6 \\$7 '.ft R .. .\" @(#)ms.acc 1.5 88/02/08 SMI; from UCB 4.2 . \" AM - accent mark definitions .bd B 3 . \" fudge factors for nroff and troff .if n \{\ . ds #H 0 . ds #V .8m . ds #F .3m . ds #[ \f1 . ds #] \fP .\} .if t \{\ . ds #H ((1u-(\\\\n(.fu%2u))*.13m) . ds #V .6m . ds #F 0 . ds #[ \& . ds #] \& .\} . \" simple accents for nroff and troff .if n \{\ . ds ' \& . ds ` \& . ds ^ \& . ds , \& . ds ~ ~ . ds ? ? . ds ! ! . ds / . ds q .\} .if t \{\ . ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" . ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' . ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' . ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' . ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' . ds ? \s-2c\h'-\w'c'u*7/10'\u\h'\*(#H'\zi\d\s+2\h'\w'c'u*8/10' . ds ! \s-2\(or\s+2\h'-\w'\(or'u'\v'-.8m'.\v'.8m' . ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' . ds q o\h'-\w'o'u*8/10'\s-4\v'.4m'\z\(*i\v'-.4m'\s+4\h'\w'o'u*8/10' .\} . \" troff and (daisy-wheel) nroff accents .ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V' .ds 8 \h'\*(#H'\(*b\h'-\*(#H' .ds v \\k:\h'-(\\n(.wu*9/10-\*(#H)'\v'-\*(#V'\*(#[\s-4v\s0\v'\*(#V'\h'|\\n:u'\*(#] .ds _ \\k:\h'-(\\n(.wu*9/10-\*(#H+(\*(#F*2/3))'\v'-.4m'\z\(hy\v'.4m'\h'|\\n:u' .ds . \\k:\h'-(\\n(.wu*8/10)'\v'\*(#V*4/10'\z.\v'-\*(#V*4/10'\h'|\\n:u' .ds 3 \*(#[\v'.2m'\s-2\&3\s0\v'-.2m'\*(#] .ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#] .ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H' .ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u' .ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#] .ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#] .ds ae a\h'-(\w'a'u*4/10)'e .ds Ae A\h'-(\w'A'u*4/10)'E .ds oe o\h'-(\w'o'u*4/10)'e .ds Oe O\h'-(\w'O'u*4/10)'E . \" corrections for vroff .if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u' .if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u' . \" for low resolution devices (crt and lpr) .if \n(.H>23 .if \n(.V>19 \ \{\ . ds : e . ds 8 ss . ds v \h'-1'\o'\(aa\(ga' . ds _ \h'-1'^ . ds . \h'-1'. . ds 3 3 . ds o a . ds d- d\h'-1'\(ga . ds D- D\h'-1'\(hy . ds th \o'bp' . ds Th \o'LP' . ds ae ae . ds Ae AE . ds oe oe . ds Oe OE .\} .rm #[ #] #H #V #F C .SH "NAME" sudoers \- list of which users may execute what .SH "DESCRIPTION" The \fIsudoers\fR file is composed two types of entries: aliases (basically variables) and user specifications (which specify who may run what). The grammar of \fIsudoers\fR will be described below in Extended Backus-Naur Form (EBNF). Don't despair if you don't know what EBNF is, it is fairly simple and the definitions below are annotated. .Sh "Quick guide to \s-1EBNF\s0" \s-1EBNF\s0 is a concise and exact way of describing the grammar of a language. Each \s-1EBNF\s0 definition is made up of \fIproduction rules\fR. Eg. .PP .Vb 1 \& symbol ::= definition | alternate1 | alternate2 ... .Ve Each \fIproduction rule\fR references others and thus makes up a grammar for the language. \s-1EBNF\s0 also contains the following operators, which many readers will recognize from regular expressions. Do not, however, confuse them with \*(L"wildcard\*(R" characters, which have different meanings. .Ip "\f(CW?\fR" 8 Means that the preceding symbol (or group of symbols) is optional. That is, it may appear once or not at all. .Ip "\f(CW*\fR" 8 Means that the preceding symbol (or group of symbols) may appear zero or more times. .Ip "\f(CW+\fR" 8 Means that the preceding symbol (or group of symbols) may appear one or more times. .PP 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). .Sh "Aliases" There are four kinds of aliases: the \f(CWUser_Alias\fR, \f(CWRunas_Alias\fR, \f(CWHost_Alias\fR and \f(CWCmnd_Alias\fR. .PP .Vb 4 \& Alias ::= 'User_Alias' = User_Alias (':' User_Alias)* | \& 'Runas_Alias' = Runas_Alias (':' Runas_Alias)* | \& 'Host_Alias' = Host_Alias (':' Host_Alias)* | \& 'Cmnd_Alias' = Cmnd_Alias (':' Cmnd_Alias)* .Ve .Vb 1 \& User_Alias ::= NAME '=' User_List .Ve .Vb 1 \& Runas_Alias ::= NAME '=' Runas_User_List .Ve .Vb 1 \& Host_Alias ::= NAME '=' Host_List .Ve .Vb 1 \& Cmnd_Alias ::= NAME '=' Cmnd_List .Ve .Vb 1 \& NAME ::= [A-Z]([A-Z][0-9]_)* .Ve Each \fIalias\fR definition is of the form .PP .Vb 1 \& Alias_Type NAME = item1, item2, ... .Ve where \fIAlias_Type\fR is one of \f(CWUser_Alias\fR, \f(CWRunas_Alias\fR, \f(CWHost_Alias\fR, or \f(CWCmnd_Alias\fR. A \f(CWNAME\fR is a string of upper case letters, numbers, and the underscore characters ('_'). A \f(CWNAME\fR \fBmust\fR start with an upper case letter. It is possible to put several alias definitions of the same type on a single line, joined by a semicolon (':'). Eg. .PP .Vb 1 \& Alias_Type NAME = item1, item2, item3 : NAME = item4, item5 .Ve The definitions of what constitutes a valid \fIalias\fR member follow. .PP .Vb 2 \& User_List ::= User | \& User ',' User_List .Ve .Vb 5 \& User ::= '!'* username | \& '!'* '#'uid | \& '!'* '%'group | \& '!'* '+'netgroup | \& '!'* User_Alias .Ve A \f(CWUser_List\fR is made up of one or more usernames, uids (prefixed with \*(L'#'), System groups (prefixed with \*(L'%'), netgroups (prefixed with \*(L'+') and other aliases. Each list item may be prefixed with one or more \*(L'!\*(R' operators. An odd number of \*(L'!\*(R' operators negates the value of the item; an even number just cancel each other out. .PP .Vb 2 \& Runas_List ::= Runas_User | \& Runas_User ',' Runas_List .Ve .Vb 5 \& Runas_User ::= '!'* username | \& '!'* '#'uid | \& '!'* '%'group | \& '!'* +netgroup | \& '!'* Runas_Alias .Ve Likewise, a \f(CWRunas_List\fR has the same possible elements as a \f(CWUser_List\fR, except that it can include a \f(CWRunas_Alias\fR, instead of a \f(CWUser_Alias\fR. .PP .Vb 2 \& Host_List ::= Host | \& Host ',' Host_List .Ve .Vb 5 \& Host ::= '!'* hostname | \& '!'* ip_addr | \& '!'* network(/netmask)? | \& '!'* '+'netgroup | \& '!'* Host_Alias .Ve A \f(CWHost_List\fR is made up of one or more hostnames, \s-1IP\s0 addresses, network numbers, netgroups (prefixed with \*(L'+') and other aliases. Again, the value of an item may be negated with the \*(L'!\*(R' operator. If you do not specify a netmask with a network number, the netmask of the host's ethernet \fIinterface\fR\|(s) will be used when matching. The netmask may be specified either in dotted quad notation (e.g. 255.255.255.0) or \s-1CIDR\s0 notation (number of bits, e.g. 24). A hostname may include shell-style wildcards (see `Wildcards\*(R' section below), but unless the \f(CWhostname\fR command on your machine returns the fully qualified hostname, you'll need to use the \fIfqdn\fR option for wildcards to be useful. .PP .Vb 2 \& Cmnd_List ::= Cmnd | \& Cmnd ',' Cmnd_List .Ve .Vb 3 \& commandname ::= filename | \& filename args | \& filename '""' .Ve .Vb 3 \& Cmnd ::= '!'* commandname | \& '!'* directory | \& '!'* Cmnd_Alias .Ve A \f(CWCmnd_List\fR is a list of one or more commandnames, directories, and other aliases. A commandname is a fully qualified filename which may include shell-style wildcards (see `Wildcards\*(R' section below). A simple filename allows the user to run the command with any arguments he/she wishes. However, you may also command line arguments (including wildcards). Alternately, you can specify \f(CW""\fR to indicate that the command may only be run \fBwithout\fR command line arguments. A directory is a fully qualified pathname ending in a \*(L'/\*(R'. When you specify a directory in a \f(CWCmnd_List\fR, the user will be able to run any file within that directory (but not in any subdirectories therein). .PP If a \f(CWCmnd\fR has associated command line arguments, then the arguments in the \f(CWCmnd\fR 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 \*(L'\e\*(R' if they are used in command arguments: \*(L',\*(R', \*(L':\*(R', \*(L'=\*(R', \*(L'\e\*(R'. .Sh "Defaults" Certain configuration options may be changed from their default values at runtime via one or more \f(CWDefault_Entry\fR lines. These may affect all users on any host, all users on a specific host, or just a specific user. When multiple entries match, they are applied in order. Where there are conflicting values, the last value on a matching line takes effect. .PP .Vb 3 \& Default_Type ::= 'Defaults' || \& 'Defaults' ':' User || \& 'Defaults' '@' Host .Ve .Vb 1 \& Default_Entry ::= Default_Type Parameter_List .Ve .Vb 2 \& Parameter ::= Parameter '=' Value || \& '!'* Parameter || .Ve Parameters may be \fBflags\fR, \fBinteger\fR values, or \fBstrings\fR. Flags are implicitly boolean and can be turned off via the \*(L'!\*(R' operator. Some integer and string parameters may also be used in a boolean context to disable them. Values may be enclosed in double quotes (\f(CW"\fR) when they contain multiple words. Special characters may be escaped with a backslash (\f(CW\e\fR). .PP \fBFlags\fR: .Ip "long_otp_prompt" 12 When validating with a One Time Password scheme (\fBS/Key\fR or \fB\s-1OPIE\s0\fR), 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. .Ip "ignore_dot" 12 If set, \fBsudo\fR will ignore \*(L'.\*(R' or \*(L'\*(R' (current dir) in \f(CW$PATH\fR; the \f(CW$PATH\fR itself is not modified. This flag is off by default. .Ip "mail_always" 12 Send mail to the \fImailto\fR user every time a users runs \fBsudo\fR. This flag is off by default. .Ip "mail_no_user" 12 If set, mail will be sent to the \fImailto\fR user if the invoking user is not in the \fIsudoers\fR file. This flag is on by default. .Ip "mail_no_host" 12 If set, mail will be sent to the \fImailto\fR user if the invoking user exists in the \fIsudoers\fR file, but is not allowed to run commands on the current host. This flag is off by default. .Ip "mail_no_perms" 12 If set, mail will be sent to the \fImailto\fR user if the invoking user allowed to use \fBsudo\fR but the command they are trying is not listed in their \fIsudoers\fR file entry. This flag is off by default. .Ip "tty_tickets" 12 If set, users must authenticate on a per-tty basis. Normally, \fBsudo\fR uses a directory in the ticket dir with the same name as the user running it. With this flag enabled, \fBsudo\fR will use a file named for the tty the user is logged in on in that directory. This flag is off by default. .Ip "lecture" 12 If set, a user will receive a short lecture the first time he/she runs \fBsudo\fR. This flag is on by default. .Ip "authenticate" 12 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 \f(CWPASSWD\fR and \f(CWNOPASSWD\fR tags. This flag is on by default. .Ip "root_sudo" 12 If set, root is allowed to run \fBsudo\fR too. Disabling this prevents users from \*(L"chaining\*(R" \fBsudo\fR commands to get a root shell by doing something like \f(CW"sudo sudo /bin/sh"\fR. This flag is on by default. .Ip "log_host" 12 If set, the hostname will be logged in the (non-syslog) \fBsudo\fR log file. This flag is off by default. .Ip "log_year" 12 If set, the four-digit year will be logged in the (non-syslog) \fBsudo\fR log file. This flag is off by default. .Ip "shell_noargs" 12 If set and \fBsudo\fR is invoked with no arguments it acts as if the \f(CW-s\fR flag had been given. That is, it runs a shell as root (the shell is determined by the \f(CWSHELL\fR 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. .Ip "set_home" 12 If set and \fBsudo\fR is invoked with the \f(CW-s\fR flag the \f(CWHOME\fR environment variable will be set to the home directory of the target user (which is root unless the \f(CW-u\fR option is used). This effectively makes the \f(CW-s\fR flag imply \f(CW-H\fR. This flag is off by default. .Ip "path_info" 12 Normally, \fBsudo\fR will tell the user when a command could not be found in their \f(CW$PATH\fR. Some sites may wish to disable this as it could be used to gather information on the location of executables that the normal user does not have access to. The disadvantage is that if the executable is simply not in the user's \f(CW$PATH\fR, \fBsudo\fR will tell the user that they are not allowed to run it, which can be confusing. This flag is off by default. .Ip "fqdn" 12 Set this flag if you want to put fully qualified hostnames in the \fIsudoers\fR file. Ie: instead of myhost you would use myhost.mydomain.edu. You may still use the short form if you wish (and even mix the two). Beware that turning on \fIfqdn\fR requires \fBsudo\fR to make \s-1DNS\s0 lookups which may make \fBsudo\fR unusable if \s-1DNS\s0 stops working (for example if the machine is not plugged into the network). Also note that you must use the host's official name as \s-1DNS\s0 knows it. That is, you may not use a host alias (\f(CWCNAME\fR entry) due to performance issues and the fact that there is no way to get all aliases from \s-1DNS\s0. If your machine's hostname (as returned by the \f(CWhostname\fR command) is already fully qualified you shouldn't need to set \fIfqfn\fR. This flag is off by default. .Ip "insults" 12 If set, \fBsudo\fR will insult users when they enter an incorrect password. This flag is off by default. .Ip "requiretty" 12 If set, \fBsudo\fR will only run when the user is logged in to a real tty. This will disallow things like \f(CW"rsh somehost sudo ls"\fR since \fIrsh\fR\|(1) does not allocate a tty. Because it is not possible to turn of echo when there is no tty present, some sites may with to set this flag to prevent a user from entering a visible password. This flag is off by default. .Ip "env_editor" 12 If set, \fBvisudo\fR will use the value of the \s-1EDITOR\s0 or \s-1VISUAL\s0 environment falling back on the default editor. Note that this may create a security hole as most editors allow a user to get a shell (which would be a root shell and not be logged). .Ip "rootpw" 12 If set, \fBsudo\fR will prompt for the root password instead of the password of the invoking user. .Ip "runaspw" 12 If set, \fBsudo\fR will prompt for the password of the user defined by the \fIrunas_default\fR option (defaults to root) instead of the password of the invoking user. .Ip "targetpw" 12 If set, \fBsudo\fR will prompt for the password of the user specified by the \f(CW-u\fR flag (defaults to root) instead of the password of the invoking user. .Ip "set_logname" 12 Normally, \fBsudo\fR will set the \f(CWLOGNAME\fR and \f(CWUSER\fR environment variables to the name of the target user (usually root unless the \f(CW-u\fR flag is given). However, since some programs (including the \s-1RCS\s0 revision control system) use \f(CWLOGNAME\fR 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. .PP \fBIntegers\fR: .Ip "passwd_tries" 12 The number of tries a user gets to enter his/her password before \fBsudo\fR logs the failure and exits. The default is 3. .PP \fBIntegers that can be used in a boolean context\fR: .Ip "loglinelen" 12 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 to disable word wrap). .Ip "timestamp_timeout" 12 Number of minutes that can elapse before \fBsudo\fR will ask for a passwd again. The default is 5, set this to 0 to always prompt for a password. .Ip "passwd_timeout" 12 Number of minutes before the \fBsudo\fR password prompt times out. The default is 5, set this to 0 for no password timeout. .Ip "umask" 12 Umask to use when running the root command. Set this to 0777 to not override the user's umask. The default is 0022. .PP \fBStrings\fR: .Ip "mailsub" 12 Subject of the mail sent to the \fImailto\fR user. The escape \f(CW%h\fR will expand to the hostname of the machine. Default is \*(L"*** \s-1SECURITY\s0 information for \f(CW%h\fR ***\*(R". .Ip "badpass_message" 12 Message that is displayed if a user enters an incorrect password. The default is \*(L"Sorry, try again.\*(R" unless insults are enabled. .Ip "timestampdir" 12 The directory in which \fBsudo\fR stores its timestamp files. The default is \fI@\s-1TIMEDIR\s0@\fR. .Ip "passprompt" 12 The default prompt to use when asking for a password; can be overridden via the \f(CW-p\fR option or the \f(CWSUDO_PROMPT\fR environment variable. Supports two escapes: \*(L"%u\*(R" expands to the user's login name and \*(L"%h\*(R" expands to the local hostname. The default value is \*(L"Password:\*(R". .Ip "runas_default" 12 The default user to run commands as if the \f(CW-u\fR flag is not specified on the command line. This defaults to \*(L"root\*(R". .Ip "syslog_goodpri" 12 Syslog priority to use when user authenticates successfully. Defaults to \*(L"notice\*(R". .Ip "syslog_badpri" 12 Syslog priority to use when user authenticates unsuccessfully. Defaults to \*(L"alert\*(R". .Ip "editor" 12 Path to the editor to be used by \fBvisudo\fR. The default is the path to vi on your system. .PP \fBStrings that can be used in a boolean context\fR: .Ip "logfile" 12 Path to the \fBsudo\fR log file (not the syslog log file). Setting a path turns on logging to a file, negating this option turns it off. .Ip "syslog" 12 Syslog facility if syslog is being used for logging (negate to disable syslog logging). Defaults to \*(L"local2\*(R". .Ip "mailerpath" 12 Path to mail program used to send warning mail. Defaults to the path to sendmail found at configure time. .Ip "mailerflags" 12 Flags to use when invoking mailer. Defaults to \f(CW-t\fR. .Ip "mailto" 12 Address to send warning and erorr mail to. Defaults to \*(L"root\*(R". .Ip "exempt_group" 12 Users in this group are exempt from password and \s-1PATH\s0 requirements. This is not set by default. .Ip "secure_path" 12 Path used for every command run from \fBsudo\fR. If you don't trust the people running \fBsudo\fR to have a sane \f(CWPATH\fR environment variable you may want to use this. Another use is if you want to have the \*(L"root path\*(R" be separate from the \*(L"user path.\*(R" This is not set by default. .Ip "verifypw" 12 This option controls when a password will be required when a user runs \fBsudo\fR with the \fB\-v\fR. It has the following possible values: .Sp .Vb 3 \& all All the user's I entries for the \& current host must have the C \& flag set to avoid entering a password. .Ve .Vb 4 \& any At least one of the user's I entries \& for the current host must have the \& C flag set to avoid entering a \& password. .Ve .Vb 2 \& never The user need never enter a password to use \& the B<-v> flag. .Ve .Vb 2 \& always The user must always enter a password to use \& the B<-v> flag. .Ve The default value is `all\*(R'. .Ip "listpw" 12 This option controls when a password will be required when a user runs \fBsudo\fR with the \fB\-l\fR. It has the following possible values: .Sp .Vb 3 \& all All the user's I entries for the \& current host must have the C \& flag set to avoid entering a password. .Ve .Vb 4 \& any At least one of the user's I entries \& for the current host must have the \& C flag set to avoid entering a \& password. .Ve .Vb 2 \& never The user need never enter a password to use \& the B<-l> flag. .Ve .Vb 2 \& always The user must always enter a password to use \& the B<-l> flag. .Ve The default value is `any\*(R'. .PP When logging via \fIsyslog\fR\|(3), \fBsudo\fR accepts the following values for the syslog facility (the value of the \fBsyslog\fR Parameter): \fBauthpriv\fR (if your \s-1OS\s0 supports it), \fBauth\fR, \fBdaemon\fR, \fBuser\fR, \fBlocal0\fR, \fBlocal1\fR, \fBlocal2\fR, \fBlocal3\fR, \fBlocal4\fR, \fBlocal5\fR, \fBlocal6\fR, and \fBlocal7\fR. The following syslog priorities are supported: \fBalert\fR, \fBcrit\fR, \fBdebug\fR, \fBemerg\fR, \fBerr\fR, \fBinfo\fR, \fBnotice\fR, and \fBwarning\fR. .Sh "User Specification" .PP .Vb 2 \& User_Spec ::= User_list Host_List '=' User_List Cmnd_Spec_List \e \& (':' User_Spec)* .Ve .Vb 2 \& Cmnd_Spec_List ::= Cmnd_Spec | \& Cmnd_Spec ',' Cmnd_Spec_List .Ve .Vb 1 \& Cmnd_Spec ::= Runas_Spec? ('NOPASSWD:' | 'PASSWD:')? Cmnd .Ve .Vb 1 \& Runas_Spec ::= '(' Runas_List ')' .Ve A \fBuser specification\fR determines which commands a user may run (and as what user) on specified hosts. By default, commands are run as \fBroot\fR but this can be changed on a per-command basis. .PP Let's break that down into its constituent parts: .Sh "Runas_Spec" A \f(CWRunas_Spec\fR is simply a \f(CWRunas_List\fR (as defined above) enclosed in a set of parentheses. If you do not specify a \f(CWRunas_Spec\fR in the user specification, a default \f(CWRunas_Spec\fR of \fBroot\fR will be used. A \f(CWRunas_Spec\fR sets the default for commands that follow it. What this means is that for the entry: .PP .Vb 1 \& dgb boulder = (operator) /bin/ls, /bin/kill, /usr/bin/who .Ve The user \fBdgb\fR may run \fI/bin/ls\fR, \fI/bin/kill\fR, and \fI/usr/bin/lprm\fR -- but only as \fBoperator\fR. Eg. .PP .Vb 1 \& sudo -u operator /bin/ls. .Ve It is also possible to override a \f(CWRunas_Spec\fR later on in an entry. If we modify the entry like so: .PP .Vb 1 \& dgb boulder = (operator) /bin/ls, (root) /bin/kill, /usr/bin/lprm .Ve Then user \fBdgb\fR is now allowed to run \fI/bin/ls\fR as \fBoperator\fR, but \fI/bin/kill\fR and \fI/usr/bin/lprm\fR as \fBroot\fR. .Sh "\s-1NOPASSWD\s0 and \s-1PASSWD\s0" By default, \fBsudo\fR requires that a user authenticate him or herself before running a command. This behavior can be modified via the \f(CWNOPASSWD\fR tag. Like a \f(CWRunas_Spec\fR, the \f(CWNOPASSWD\fR tag sets a default for the commands that follow it in the \f(CWCmnd_Spec_List\fR. Conversely, the \f(CWPASSWD\fR tag can be used to reverse things. For example: .PP .Vb 1 \& ray rushmore = NOPASSWD: /bin/kill, /bin/ls, /usr/bin/lprm .Ve would allow the user \fBray\fR to run \fI/bin/kill\fR, \fI/bin/ls\fR, and \fI/usr/bin/lprm\fR as root on the machine rushmore as \fBroot\fR without authenticating himself. If we only want \fBray\fR to be able to run \fI/bin/kill\fR without a password the entry would be: .PP .Vb 1 \& ray rushmore = NOPASSWD: /bin/kill, PASSWD: /bin/ls, /usr/bin/lprm .Ve Note however, that the \f(CWPASSWD\fR tag has no effect on users who are in the group specified by the exempt_group option. .PP By default, if the \f(CWNOPASSWD\fR tag is applied to any of the entries for a user on the current host, he or she will be able to run \f(CWsudo -l\fR without a password. Additionally, a user may only run \f(CWsudo -v\fR without a password if the \f(CWNOPASSWD\fR tag is present for all a user's entries that pertain to the current host. This behavior may be overridden via the verifypw and listpw options. .Sh "Wildcards (aka meta characters):" \fBsudo\fR allows shell-style \fIwildcards\fR to be used in pathnames as well as command line arguments in the \fIsudoers\fR file. Wildcard matching is done via the \fB\s-1POSIX\s0\fR \f(CWfnmatch(3)\fR routine. Note that these are \fInot\fR regular expressions. .Ip "\f(CW*\fR" 8 Matches any set of zero or more characters. .Ip "\f(CW?\fR" 8 Matches any single character. .Ip "\f(CW[...]\fR" 8 Matches any character in the specified range. .Ip "\f(CW[!...]\fR" 8 Matches any character \fBnot\fR in the specified range. .Ip "\f(CW\ex\fR" 8 For any character \*(L"x\*(R", evaluates to \*(L"x\*(R". This is used to escape special characters such as: \*(L"*\*(R", \*(L"?\*(R", \*(L"[\*(R", and \*(L"}\*(R". .PP Note that a forward slash ('/') will \fBnot\fR be matched by wildcards used in the pathname. When matching the command line arguments, however, as slash \fBdoes\fR get matched by wildcards. This is to make a path like: .PP .Vb 1 \& /usr/bin/* .Ve match \f(CW/usr/bin/who\fR but not \f(CW/usr/bin/X11/xterm\fR. .Sh "Exceptions to wildcard rules:" The following exceptions apply to the above rules: .Ip \f(CW""\fR 8 If the empty string \f(CW""\fR is the only command line argument in the \fIsudoers\fR entry it means that command is not allowed to be run with \fBany\fR arguments. .Sh "Other special characters and reserved words:" The pound sign ('#') is used to indicate a comment (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 uid). Both the comment character and any text after it, up to the end of the line, are ignored. .PP The reserved word \fB\s-1ALL\s0\fR is a built in \fIalias\fR that always causes a match to succeed. It can be used wherever one might otherwise use a \f(CWCmnd_Alias\fR, \f(CWUser_Alias\fR, \f(CWRunas_Alias\fR, or \f(CWHost_Alias\fR. You should not try to define your own \fIalias\fR called \fB\s-1ALL\s0\fR as the built in alias will be used in preference to your own. Please note that using \fB\s-1ALL\s0\fR can be dangerous since in a command context, it allows the user to run \fBany\fR command on the system. .PP An exclamation point (\*(R'!') can be used as a logical \fInot\fR operator both in an \fIalias\fR and in front of a \f(CWCmnd\fR. This allows one to exclude certain values. Note, however, that using a \f(CW!\fR in conjunction with the built in \f(CWALL\fR alias to allow a user to run \*(L"all but a few\*(R" commands rarely works as intended (see \s-1SECURITY\s0 \s-1NOTES\s0 below). .PP Long lines can be continued with a backslash (\*(R'\e') as the last character on the line. .PP Whitespace between elements in a list as well as specicial syntactic characters in a \fIUser Specification\fR ('=\*(R', \*(L':\*(R', \*(L'(\*(R', \*(L')') is optional. .PP The following characters must be escaped with a backslash (\*(R'\e') when used as part of a word (e.g. a username or hostname): \&'@\*(R', \*(L'!\*(R', \*(L'=\*(R', \*(L':\*(R', \*(L',\*(R', \*(L'(\*(R', \*(L')\*(R', \*(L'\e\*(R'. .SH "EXAMPLES" Below are example \fIsudoers\fR entries. Admittedly, some of these are a bit contrived. First, we define our \fIaliases\fR: .PP .Vb 4 \& # User alias specification \& User_Alias FULLTIMERS = millert, mikef, dowdy \& User_Alias PARTTIMERS = bostley, jwfox, crawl \& User_Alias WEBMASTERS = will, wendy, wim .Ve .Vb 3 \& # Runas alias specification \& Runas_Alias OP = root, operator \& Runas_Alias DB = oracle, sybase .Ve .Vb 9 \& # Host alias specification \& Host_Alias SPARC = bigtime, eclipse, moet, anchor :\e \& SGI = grolsch, dandelion, black :\e \& ALPHA = widget, thalamus, foobar :\e \& 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 = master, mail, www, ns \& Host_Alias CDROM = orion, perseus, hercules .Ve .Vb 12 \& # Cmnd alias specification \& Cmnd_Alias DUMPS = /usr/bin/mt, /usr/sbin/dump, /usr/sbin/rdump,\e \& /usr/sbin/restore, /usr/sbin/rrestore \& 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, /usr/sbin/fasthalt \& Cmnd_Alias REBOOT = /usr/sbin/reboot, /usr/sbin/fastboot \& Cmnd_Alias SHELLS = /usr/bin/sh, /usr/bin/csh, /usr/bin/ksh, \e \& /usr/local/bin/tcsh, /usr/bin/rsh, \e \& /usr/local/bin/zsh \& Cmnd_Alias SU = /usr/bin/su .Ve Here we override some of the compiled in default values. We want \fBsudo\fR to log via \fIsyslog\fR\|(3) using the \fIauth\fR facility in all cases. We don't want to subject the full time staff to the \fBsudo\fR lecture, and user \fBmillert\fR need not give a password. In addition, on the machines in the \fISERVERS\fR \f(CWHost_Alias\fR, 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. .PP .Vb 5 \& # Override builtin defaults \& Defaults syslog=auth \& Defaults:FULLTIMERS !lecture \& Defaults:millert !authenticate \& Defaults@SERVERS log_year, logfile=/var/log/sudo.log .Ve The \fIUser specification\fR is the part that actually determines who may run what. .PP .Vb 2 \& root ALL = (ALL) ALL \& %wheel ALL = (ALL) ALL .Ve We let \fBroot\fR and any user in group \fBwheel\fR run any command on any host as any user. .PP .Vb 1 \& FULLTIMERS ALL = NOPASSWD: ALL .Ve Full time sysadmins (\fBmillert\fR, \fBmikef\fR, and \fBdowdy\fR) may run any command on any host without authenticating themselves. .PP .Vb 1 \& PARTTIMERS ALL = ALL .Ve Part time sysadmins (\fBbostley\fR, \fBjwfox\fR, and \fBcrawl\fR) may run any command on any host but they must authenticate themselves first (since the entry lacks the \f(CWNOPASSWD\fR tag). .PP .Vb 1 \& jack CSNETS = ALL .Ve The user \fBjack\fR may run any command on the machines in the \fICSNETS\fR alias (the networks \f(CW128.138.243.0\fR, \f(CW128.138.204.0\fR, and \f(CW128.138.242.0\fR). 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 \fICSNETS\fR, the local machine's netmask will be used during matching. .PP .Vb 1 \& lisa CUNETS = ALL .Ve The user \fBlisa\fR may run any command on any host in the \fICUNETS\fR alias (the class B network \f(CW128.138.0.0\fR). .PP .Vb 2 \& operator ALL = DUMPS, KILL, PRINTING, SHUTDOWN, HALT, REBOOT,\e \& /usr/oper/bin/ .Ve The \fBoperator\fR 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 \fI/usr/oper/bin/\fR. .PP .Vb 1 \& joe ALL = /usr/bin/su operator .Ve The user \fBjoe\fR may only \fIsu\fR\|(1) to operator. .PP .Vb 1 \& pete HPPA = /usr/bin/passwd [A-z]*, !/usr/bin/passwd root .Ve The user \fBpete\fR is allowed to change anyone's password except for root on the \fIHPPA\fR machines. Note that this assumes \fIpasswd\fR\|(1) does not take multiple usernames on the command line. .PP .Vb 1 \& bob SPARC = (OP) ALL : SGI = (OP) ALL .Ve The user \fBbob\fR may run anything on the \fISPARC\fR and \fISGI\fR machines as any user listed in the \fIOP\fR \f(CWRunas_Alias\fR (\fBroot\fR and \fBoperator\fR). .PP .Vb 1 \& jim +biglab = ALL .Ve The user \fBjim\fR may run any command on machines in the \fIbiglab\fR netgroup. \fBSudo\fR knows that \*(L"biglab\*(R" is a netgroup due to the \*(L'+\*(R' prefix. .PP .Vb 1 \& +secretaries ALL = PRINTING, /usr/bin/adduser, /usr/bin/rmuser .Ve Users in the \fBsecretaries\fR 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. .PP .Vb 1 \& fred ALL = (DB) NOPASSWD: ALL .Ve The user \fBfred\fR can run commands as any user in the \fIDB\fR \f(CWRunas_Alias\fR (\fBoracle\fR or \fBsybase\fR) without giving a password. .PP .Vb 1 \& john ALPHA = /usr/bin/su [!-]*, !/usr/bin/su *root* .Ve On the \fIALPHA\fR machines, user \fBjohn\fR may su to anyone except root but he is not allowed to give \fIsu\fR\|(1) any flags. .PP .Vb 1 \& jen ALL, !SERVERS = ALL .Ve The user \fBjen\fR may run any command on any machine except for those in the \fISERVERS\fR \f(CWHost_Alias\fR (master, mail, www and ns). .PP .Vb 1 \& jill SERVERS = /usr/bin/, !SU, !SHELLS .Ve For any machine in the \fISERVERS\fR \f(CWHost_Alias\fR, \fBjill\fR may run any commands in the directory /usr/bin/ except for those commands belonging to the \fISU\fR and \fISHELLS\fR \f(CWCmnd_Aliases\fR. .PP .Vb 1 \& steve CSNETS = (operator) /usr/local/op_commands/ .Ve The user \fBsteve\fR may run any command in the directory /usr/local/op_commands/ but only as user operator. .PP .Vb 1 \& matt valkyrie = KILL .Ve On his personal workstation, valkyrie, \fBmatt\fR needs to be able to kill hung processes. .PP .Vb 1 \& WEBMASTERS www = (www) ALL, (root) /usr/bin/su www .Ve On the host www, any user in the \fIWEBMASTERS\fR \f(CWUser_Alias\fR (will, wendy, and wim), may run any command as user www (which owns the web pages) or simply \fIsu\fR\|(1) to www. .PP .Vb 2 \& ALL CDROM = NOPASSWD: /sbin/umount /CDROM,\e \& /sbin/mount -o nosuid\e,nodev /dev/cd0a /CDROM .Ve Any user may mount or unmount a CD\-ROM on the machines in the CDROM \f(CWHost_Alias\fR (orion, perseus, hercules) without entering a password. This is a bit tedious for users to type, so it is a prime candiate for encapsulating in a shell script. .SH "SECURITY NOTES" It is generally not effective to \*(L"subtract\*(R" commands from \f(CWALL\fR using the \*(L'!\*(R' operator. A user can trivially circumvent this by copying the desired command to a different name and then executing that. For example: .PP .Vb 1 \& bill ALL = ALL, !SU, !SHELLS .Ve Doesn't really prevent \fBbill\fR from running the commands listed in \fISU\fR or \fISHELLS\fR 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). .SH "CAVEATS" The \fIsudoers\fR file should \fBalways\fR be edited by the \fBvisudo\fR command which locks the file and does grammatical checking. It is imperative that \fIsudoers\fR be free of syntax errors since \fBsudo\fR will not run with a syntactically incorrect \fIsudoers\fR file. .PP When using netgroups of machines (as opposed to users), if you store fully qualified hostnames in the netgroup (as is usually the case), you either need to have the machine's hostname be fully qualified as returned by the \f(CWhostname\fR command or use the \fIfqdn\fR option in \fIsudoers\fR. .SH "FILES" .PP .Vb 3 \& /etc/sudoers List of who can run what \& /etc/group Local groups file \& /etc/netgroup List of network groups .Ve .SH "SEE ALSO" \fIsudo\fR\|(8), \fIvisudo\fR\|(8), \fIsu\fR\|(1), \fIfnmatch\fR\|(3). .rn }` '' .IX Title "sudoers 5" .IX Name "sudoers - list of which users may execute what" .IX Header "NAME" .IX Header "DESCRIPTION" .IX Subsection "Quick guide to \s-1EBNF\s0" .IX Item "\f(CW?\fR" .IX Item "\f(CW*\fR" .IX Item "\f(CW+\fR" .IX Subsection "Aliases" .IX Subsection "Defaults" .IX Item "long_otp_prompt" .IX Item "ignore_dot" .IX Item "mail_always" .IX Item "mail_no_user" .IX Item "mail_no_host" .IX Item "mail_no_perms" .IX Item "tty_tickets" .IX Item "lecture" .IX Item "authenticate" .IX Item "root_sudo" .IX Item "log_host" .IX Item "log_year" .IX Item "shell_noargs" .IX Item "set_home" .IX Item "path_info" .IX Item "fqdn" .IX Item "insults" .IX Item "requiretty" .IX Item "env_editor" .IX Item "rootpw" .IX Item "runaspw" .IX Item "targetpw" .IX Item "set_logname" .IX Item "passwd_tries" .IX Item "loglinelen" .IX Item "timestamp_timeout" .IX Item "passwd_timeout" .IX Item "umask" .IX Item "mailsub" .IX Item "badpass_message" .IX Item "timestampdir" .IX Item "passprompt" .IX Item "runas_default" .IX Item "syslog_goodpri" .IX Item "syslog_badpri" .IX Item "editor" .IX Item "logfile" .IX Item "syslog" .IX Item "mailerpath" .IX Item "mailerflags" .IX Item "mailto" .IX Item "exempt_group" .IX Item "secure_path" .IX Item "verifypw" .IX Item "listpw" .IX Subsection "User Specification" .IX Subsection "Runas_Spec" .IX Subsection "\s-1NOPASSWD\s0 and \s-1PASSWD\s0" .IX Subsection "Wildcards (aka meta characters):" .IX Item "\f(CW*\fR" .IX Item "\f(CW?\fR" .IX Item "\f(CW[...]\fR" .IX Item "\f(CW[!...]\fR" .IX Item "\f(CW\ex\fR" .IX Subsection "Exceptions to wildcard rules:" .IX Item \f(CW""\fR .IX Subsection "Other special characters and reserved words:" .IX Header "EXAMPLES" .IX Header "SECURITY NOTES" .IX Header "CAVEATS" .IX Header "FILES" .IX Header "SEE ALSO"