svcadm(8)을 검색하려면 섹션에서 8 을 선택하고, 맨 페이지 이름에 svcadm을 입력하고 검색을 누른다.
sudoers.ldap(5)
SUDOERS.LDAP(5) File Formats Manual SUDOERS.LDAP(5)
NAME
sudoers.ldap - sudo LDAP configuration
DESCRIPTION
In addition to the standard sudoers file, sudo may be configured via
LDAP. This can be especially useful for synchronizing sudoers in a
large, distributed environment.
Using LDAP for sudoers has several benefits:
• sudo no longer needs to read sudoers in its entirety. When LDAP is
used, there are only two or three LDAP queries per invocation. This
makes it especially fast and particularly usable in LDAP
environments.
• It is possible to specify per-entry options that override the global
default options. /etc/sudoers only supports default options and
limited options associated with user/host/commands/aliases. The
syntax is complicated and can be difficult for users to understand.
Placing the options directly in the entry is more natural.
• The visudo program is no longer needed. visudo provides locking and
syntax checking of the /etc/sudoers file. Since LDAP updates are
atomic, locking is no longer necessary. Because syntax is checked
when the data is inserted into LDAP, there is no need for a
specialized tool to check syntax.
SUDOers LDAP container
The sudoers configuration is contained in the ‘ou=SUDOers’ LDAP
container.
Sudo first looks for the ‘cn=defaults’ entry in the SUDOers container.
If found, the multi-valued sudoOption attribute is parsed in the same
manner as a global Defaults line in /etc/sudoers. In the following
example, the SSH_AUTH_SOCK variable will be preserved in the
environment for all users.
dn: cn=defaults,ou=SUDOers,dc=my-domain,dc=com
objectClass: top
objectClass: sudoRole
cn: defaults
description: Default sudoOption's go here
sudoOption: env_keep+=SSH_AUTH_SOCK
The equivalent of a sudoer in LDAP is a sudoRole. It consists of the
following attributes:
sudoUser
A user name, user-ID (prefixed with ‘#’), Unix group name or ID
(prefixed with ‘%’ or ‘%#’ respectively), user netgroup (prefixed
with ‘+’), or non-Unix group name or ID (prefixed with ‘%:’ or
‘%:#’ respectively). User netgroups are matched using the user
and domain members only; the host member is not used when
matching. Non-Unix group support is only available when an
appropriate group_plugin is defined in the global defaults
sudoRole object. If a sudoUser entry is preceded by an
exclamation point, ‘!’, and the entry matches, the sudoRole in
which it resides will be ignored. Negated sudoUser entries are
only supported by version 1.9.9 or higher.
sudoHost
A host name, IP address, IP network, or host netgroup (prefixed
with a ‘+’). The special value ALL will match any host. Host
netgroups are matched using the host (both qualified and
unqualified) and domain members only; the user member is not used
when matching. If a sudoHost entry is preceded by an exclamation
point, ‘!’, and the entry matches, the sudoRole in which it
resides will be ignored. Negated sudoHost entries are only
supported by version 1.8.18 or higher.
sudoCommand
A fully-qualified Unix command name with optional command line
arguments, potentially including globbing characters (aka wild
cards). If a command name is preceded by an exclamation point,
‘!’, the user will be prohibited from running that command.
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. Unlike other
commands, “sudoedit” is built into sudo itself and must be
specified in without a leading path.
The special value ALL will match any command.
If a command name is prefixed with a SHA-2 digest, it will only
be allowed if the digest matches. This may be useful in
situations where the user invoking sudo has write access to the
command or its parent directory. The following digest formats
are supported: sha224, sha256, sha384, and sha512. The digest
name must be followed by a colon (‘:’) and then the actual
digest, in either hex or base64 format. For example, given the
following value for sudoCommand:
sha224:0GomF8mNN3wlDt1HD9XldjJ3SNgpFdbjO1+NsQ /bin/ls
The user may only run /bin/ls if its sha224 digest matches the
specified value. Command digests are only supported by version
1.8.7 or higher.
sudoOption
Identical in function to the global options described above, but
specific to the sudoRole in which it resides.
sudoRunAsUser
A user name or user-ID (prefixed with ‘#’) that commands may be
run as or a Unix group (prefixed with a ‘%’) or user netgroup
(prefixed with a ‘+’) that contains a list of users that commands
may be run as. The special value ALL will match any user. If a
sudoRunAsUser entry is preceded by an exclamation point, ‘!’, and
the entry matches, the sudoRole in which it resides will be
ignored. If sudoRunAsUser is specified but empty, it will match
the invoking user. If neither sudoRunAsUser nor sudoRunAsGroup
are present, the value of the runas_default sudoOption is used
(defaults to root).
The sudoRunAsUser attribute is only available in sudo versions
1.7.0 and higher. Older versions of sudo use the sudoRunAs
attribute instead. Negated sudoRunAsUser entries are only
supported by version 1.8.26 or higher.
sudoRunAsGroup
A Unix group or group-ID (prefixed with ‘#’) that commands may be
run as. The special value ALL will match any group. If a
sudoRunAsGroup entry is preceded by an exclamation point, ‘!’,
and the entry matches, the sudoRole in which it resides will be
ignored.
The sudoRunAsGroup attribute is only available in sudo versions
1.7.0 and higher. Negated sudoRunAsGroup entries are only
supported by version 1.8.26 or higher.
sudoNotBefore
A timestamp in the form ‘yyyymmddHHMMSSZ’ that can be used to
provide a start date/time for when the sudoRole will be valid.
If multiple sudoNotBefore entries are present, the earliest is
used. Timestamps must be in Coordinated Universal Time (UTC),
not the local timezone. The minute and seconds portions are
optional, but some LDAP servers require that they be present
(contrary to the RFC).
The sudoNotBefore attribute is only available in sudo versions
1.7.5 and higher and must be explicitly enabled via the
SUDOERS_TIMED option in /etc/ldap.conf.
sudoNotAfter
A timestamp in the form ‘yyyymmddHHMMSSZ’ that indicates an
expiration date/time, after which the sudoRole will no longer be
valid. If multiple sudoNotAfter entries are present, the last
one is used. Timestamps must be in Coordinated Universal Time
(UTC), not the local timezone. The minute and seconds portions
are optional, but some LDAP servers require that they be present
(contrary to the RFC).
The sudoNotAfter attribute is only available in sudo versions
1.7.5 and higher and must be explicitly enabled via the
SUDOERS_TIMED option in /etc/ldap.conf.
sudoOrder
The sudoRole entries retrieved from the LDAP directory have no
inherent order. The sudoOrder attribute is an integer (or
floating point value for LDAP servers that support it) that is
used to sort the matching entries. This allows LDAP-based
sudoers entries to more closely mimic the behavior of the sudoers
file, where the order of the entries influences the result. If
multiple entries match, the entry with the highest sudoOrder
attribute is chosen. This corresponds to the “last match”
behavior of the sudoers file. If the sudoOrder attribute is not
present, a value of 0 is assumed.
The sudoOrder attribute is only available in sudo versions 1.7.5
and higher.
Each attribute listed above should contain a single value, but there
may be multiple instances of each attribute type. A sudoRole must
contain at least one sudoUser, sudoHost, and sudoCommand.
The following example allows users in group wheel to run any command on
any host via sudo:
dn: cn=%wheel,ou=SUDOers,dc=my-domain,dc=com
objectClass: top
objectClass: sudoRole
cn: %wheel
sudoUser: %wheel
sudoHost: ALL
sudoCommand: ALL
Anatomy of LDAP sudoers lookup
When looking up a sudoer using LDAP there are only two or three LDAP
queries per invocation. The first query is to parse the global
options. The second is to match against the user's name and the groups
that the user belongs to. (The special ALL tag is matched in this
query too.) If no match is returned for the user's name and groups, a
third query returns all entries containing user netgroups and other
non-Unix groups and checks to see if the user belongs to any of them.
If timed entries are enabled with the SUDOERS_TIMED parameter, the LDAP
queries include a sub-filter that limits retrieval to entries that
satisfy the time constraints, if any.
If the NETGROUP_BASE parameter is present and NETGROUP_QUERY has not
been disabled (see Configuring ldap.conf below), queries are performed
to determine the list of netgroups the user belongs to before the
sudoers query. This makes it possible to include netgroups in the
sudoers query string in the same manner as Unix groups. The third
query mentioned above is not performed unless a group provider plugin
is also configured. The actual LDAP queries performed by sudo are as
follows:
1. Match all nisNetgroup records with a nisNetgroupTriple containing
the user, host, and NIS domain. The query will match
nisNetgroupTriple entries with either the short or long form of
the host name or no host name specified in the tuple. If the NIS
domain is set, the query will only match entries that include the
domain or for which there is no domain present. If the NIS domain
is not set, a wildcard is used to match any domain name but be
aware that the NIS schema used by some LDAP servers may not
support wild cards for nisNetgroupTriple.
2. Repeated queries are performed to find any nested nisNetgroup
records with a memberNisNetgroup entry that refers to an already-
matched record.
For sites with a large number of netgroups, using NETGROUP_BASE can
significantly speed up sudo's execution time as long as the LDAP server
supports querying the nisNetgroup object by its nisNetgroupTriple
attribute.
Differences between LDAP and non-LDAP sudoers
One of the major differences between LDAP and file-based sudoers is
that in LDAP, sudo-specific Aliases are not supported.
For the most part, there is little need for sudo-specific Aliases.
Unix groups, non-Unix groups (via the group_plugin), or user netgroups
can be used in place of User_Aliases and Runas_Aliases. Host netgroups
can be used in place of Host_Aliases. Since groups and netgroups can
also be stored in LDAP there is no real need for sudo-specific aliases.
There are also some subtle differences in the way sudoers is handled
once in LDAP. Probably the biggest is that according to the RFC, LDAP
ordering is arbitrary and you cannot expect that Attributes and Entries
are returned in any specific order.
The order in which different entries are applied can be controlled
using the sudoOrder attribute, but there is no way to guarantee the
order of attributes within a specific entry. If there are conflicting
command rules in an entry, the negative takes precedence. This is
called paranoid behavior (not necessarily the most specific match).
Here is an example:
# /etc/sudoers:
# Allow all commands except shell
johnny ALL=(root) ALL,!/bin/sh
# Always allows all commands because ALL is matched last
puddles ALL=(root) !/bin/sh,ALL
# LDAP equivalent of johnny
# Allows all commands except shell
dn: cn=role1,ou=Sudoers,dc=my-domain,dc=com
objectClass: sudoRole
objectClass: top
cn: role1
sudoUser: johnny
sudoHost: ALL
sudoCommand: ALL
sudoCommand: !/bin/sh
# LDAP equivalent of puddles
# Notice that even though ALL comes last, it still behaves like
# role1 since the LDAP code assumes the more paranoid configuration
dn: cn=role2,ou=Sudoers,dc=my-domain,dc=com
objectClass: sudoRole
objectClass: top
cn: role2
sudoUser: puddles
sudoHost: ALL
sudoCommand: !/bin/sh
sudoCommand: ALL
Converting between file-based and LDAP sudoers
The cvtsudoers(1) utility can be used to convert between file-based and
LDAP sudoers. However, there are features in the file-based sudoers
that have no equivalent in LDAP-based sudoers (and vice versa). These
cannot be converted automatically.
For example, a Cmnd_Alias in a sudoers file may be converted to a
sudoRole that contains multiple commands. Multiple users and/or groups
may be assigned to the sudoRole.
Also, host, user, runas, and command-based Defaults entries are not
supported. However, a sudoRole may contain one or more sudoOption
attributes which can often serve the same purpose.
Consider the following sudoers lines:
Cmnd_Alias PAGERS = /usr/bin/more, /usr/bin/pg, /usr/bin/less
Defaults!PAGERS noexec
alice, bob ALL = ALL
In this example, alice and bob are allowed to run all commands, but the
commands listed in PAGERS will have the noexec flag set, preventing
shell escapes.
When converting this to LDAP, two sudoRole objects can be used:
dn: cn=PAGERS,ou=SUDOers,dc=my-domain,dc=com
objectClass: top
objectClass: sudoRole
cn: PAGERS
sudoUser: alice
sudoUser: bob
sudoHost: ALL
sudoCommand: /usr/bin/more
sudoCommand: /usr/bin/pg
sudoCommand: /usr/bin/less
sudoOption: noexec
sudoOrder: 900
dn: cn=ADMINS,ou=SUDOers,dc=my-domain,dc=com
objectClass: top
objectClass: sudoRole
cn: ADMINS
sudoUser: alice
sudoUser: bob
sudoHost: ALL
sudoCommand: ALL
sudoOrder: 100
In the LDAP version, the sudoOrder attribute is used to guarantee that
the PAGERS sudoRole with noexec has precedence. Unlike the sudoers
version, the LDAP version requires that all users for whom the
restriction should apply be assigned to the PAGERS sudoRole. Using a
Unix group or netgroup in PAGERS rather than listing each user would
make this easier to maintain.
Per-user Defaults entries can be emulated by using one or more
sudoOption attributes in a sudoRole. Consider the following sudoers
lines:
User_Alias ADMINS = john, sally
Defaults:ADMINS !authenticate
ADMINS ALL = (ALL:ALL) ALL
In this example, john and sally are allowed to run any command as any
user or group.
When converting this to LDAP, we can use a Unix group instead of the
User_Alias.
dn: cn=admins,ou=SUDOers,dc=my-domain,dc=com
objectClass: top
objectClass: sudoRole
cn: admins
sudoUser: %admin
sudoHost: ALL
sudoRunAsUser: ALL
sudoRunAsGroup: ALL
sudoCommand: ALL
sudoOption: !authenticate
This assumes that users john and sally are members of the “admins” Unix
group.
Sudoers schema
In order to use sudo's LDAP support, the sudo schema must be installed
on your LDAP server. In addition, be sure to index the sudoUser
attribute.
The sudo distribution includes versions of the sudoers schema for
multiple LDAP servers:
schema.ActiveDirectory
Microsoft Active Directory
schema.IBM_LDAP
IBM Directory Server, also known as IBM Tivoli Directory Server,
IBM Security Directory Server, and IBM Security Verify Directory
schema.iPlanet
Netscape-derived servers such as the iPlanet, Oracle, and 389
Directory Servers
schema.olcSudo
OpenLDAP slapd 2.3 and higher when on-line configuration is
enabled
schema.OpenLDAP
OpenLDAP slapd and OpenBSD ldapd
The schema in OpenLDAP format is also included in the EXAMPLES section.
Configuring ldap.conf
Sudo reads the /etc/ldap.conf file for LDAP-specific configuration.
Typically, this file is shared between different LDAP-aware clients.
As such, most of the settings are not sudo-specific. The
/etc/ldap.conf file is parsed by sudo itself and may support options
that differ from those described in the system's ldap.conf(5) manual.
The path to ldap.conf may be overridden via the ldap_conf plugin
argument in sudo.conf(5).
On systems using the OpenLDAP libraries, default values specified in
/etc/openldap/ldap.conf or the user's .ldaprc files are not used.
sudo supports a variety of LDAP library implementations, including
OpenLDAP, Netscape-derived (also used by Solaris and HP-UX), and IBM
LDAP (aka Tivoli). Some options are specific to certain LDAP
implementations or have implementation-specific behavior. These
differences are noted below where applicable.
Only those options explicitly listed in /etc/ldap.conf as being
supported by sudo are honored. Configuration options are listed below
in upper case but are parsed in a case-independent manner.
Lines beginning with a pound sign (‘#’) are ignored. Leading white
space is removed from the beginning of lines.
BIND_TIMELIMIT seconds
The BIND_TIMELIMIT parameter specifies the amount of time, in
seconds, to wait while trying to connect to an LDAP server. If
multiple URIs or HOSTs are specified, this is the amount of time
to wait before trying the next one in the list.
BINDDN DN
The BINDDN parameter specifies the identity, in the form of a
Distinguished Name (DN), to use when performing LDAP operations.
If not specified, LDAP operations are performed with an anonymous
identity. By default, most LDAP servers will allow anonymous
access.
BINDPW secret
The BINDPW parameter specifies the password to use when
performing LDAP operations. This is typically used in
conjunction with the BINDDN parameter. The secret may be a
plaintext password or a base64-encoded string with a “base64:”
prefix. For example:
BINDPW base64:dGVzdA==
If a plaintext password is used, it should be a simple string
without quotes. Plain text passwords may not include the comment
character (‘#’) and the escaping of special characters with a
backslash (‘\’) is not supported.
DEREF never/searching/finding/always
How alias dereferencing is to be performed when searching. See
the ldap.conf(5) manual for a full description of this option.
HOST name[:port] ...
If no URI is specified (see below), the HOST parameter specifies
a white space-delimited list of LDAP servers to connect to. Each
host may include an optional port separated by a colon (‘:’).
The HOST parameter is deprecated in favor of the URI
specification and is included for backward compatibility only.
KRB5_CCNAME file name
The path to the Kerberos 5 credential cache to use when
authenticating with the remote server.
This option is only relevant when using SASL authentication (see
below).
LDAP_VERSION number
The version of the LDAP protocol to use when connecting to the
server. The default value is protocol version 3.
NETGROUP_BASE base
The base DN to use when performing LDAP netgroup queries.
Typically this is of the form ‘ou=netgroup,dc=my-domain,dc=com’
for the domain my-domain.com. Multiple NETGROUP_BASE lines may
be specified, in which case they are queried in the order
specified.
When this option is enabled, sudo will query the LDAP server
directly when matching netgroups present in a sudoRole instead of
relying on the C library's innetgr() function.
Additionally, if the NETGROUP_QUERY parameter (which is enabled
by default) has not been disabled, the user's netgroups will be
queried directly via LDAP for use in the main sudoers query.
This is usually faster than fetching every sudoRole object
containing a sudoUser that begins with a ‘+’ prefix and checking
whether the user is a member of each one. The NIS schema used by
some LDAP servers needs a modification to support querying the
nisNetgroup object by its nisNetgroupTriple attribute. For
example, OpenLDAP's slapd requires the following change to the
nisNetgroupTriple attribute:
attributetype ( 1.3.6.1.1.1.1.14 NAME 'nisNetgroupTriple'
DESC 'Netgroup triple'
EQUALITY caseIgnoreIA5Match
SUBSTR caseIgnoreIA5SubstringsMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )
Before enabling NETGROUP_BASE, you should verify that your LDAP
server supports matching nisNetgroupTriple. For example, using
ldapsearch:
$ ldapsearch -b $NETGROUP_BASE \
'(&(objectClass=nisNetgroup)(nisNetgroupTriple=\28*,USER,\29))'
where your nisNetgroup data includes an object with the following
nisNetgroupTriple:
nisNetgroupTriple: (,USER,)
NETGROUP_QUERY on/true/yes/off/false/no
The NETGROUP_QUERY parameter indicates whether or not the LDAP
server supports querying nisNetgroup objects by matching on
nisNetgroupTriple attributes. By default, sudoers expects to be
able to perform queries that match on nisNetgroupTriple
attributes when NETGROUP_BASE is set, but not all LDAP servers
support this.
If NETGROUP_QUERY is disabled, sudoers will not attempt to
determine the list of netgroups the user belongs to, but will
still use NETGROUP_BASE directly when matching netgroups. This
can be used to support netgroups on systems that lack the
innetgr() C library function. See the description of the
NETGROUP_BASE parameter for more information.
NETGROUP_SEARCH_FILTER ldap_filter
An LDAP filter which is used to restrict the set of records
returned when performing an LDAP netgroup query. Typically, this
is of the form ‘attribute=value’ or
‘(&(attribute=value)(attribute2=value2))’. The default search
filter is: ‘objectClass=nisNetgroup’. If ldap_filter is omitted,
no search filter will be used.
This option is only used when querying netgroups directly via
LDAP.
NETWORK_TIMEOUT seconds
An alias for BIND_TIMELIMIT provided for OpenLDAP compatibility.
PORT port_number
If no URI is specified, the PORT parameter specifies the default
port to connect to on the LDAP server if a HOST parameter does
not specify the port itself. If no PORT parameter is used, the
default is port 389 for LDAP and port 636 for LDAP over TLS
(SSL). The PORT parameter is deprecated in favor of the URI
specification and is included for backward compatibility only.
ROOTBINDDN DN
The ROOTBINDDN parameter specifies the identity, in the form of a
Distinguished Name (DN), to use when performing privileged LDAP
operations, such as sudoers queries. The password corresponding
to the identity should be stored in the or the path specified by
the ldap_secret plugin argument in sudo.conf(5), which defaults
to /etc/ldap.secret. If no ROOTBINDDN is specified, the BINDDN
identity is used (if any).
ROOTUSE_SASL on/true/yes/off/false/no
Enable ROOTUSE_SASL to enable SASL authentication when connecting
to an LDAP server from a privileged process, such as sudo.
SASL_AUTH_ID identity
The SASL user name to use when connecting to the LDAP server. By
default, sudo will use an anonymous connection.
This option is only relevant when using SASL authentication.
SASL_MECH mechanisms
A white space-delimited list of SASL authentication mechanisms to
use. By default, sudo will use GSSAPI authentication.
SASL_SECPROPS none/properties
SASL security properties or none for no properties. See the SASL
programmer's manual for details.
This option is only relevant when using SASL authentication.
SSL on/true/yes/off/false/no
If the SSL parameter is set to on, true, or yes TLS (SSL)
encryption is always used when communicating with the LDAP
server. Typically, this involves connecting to the server on
port 636 (ldaps).
SSL start_tls
If the SSL parameter is set to start_tls, the LDAP server
connection is initiated normally and TLS encryption is begun
before the bind credentials are sent. This has the advantage of
not requiring a dedicated port for encrypted communications.
This parameter is only supported by LDAP servers that honor the
start_tls extension, such as the OpenLDAP and IBM Tivoli
Directory servers.
SUDOERS_BASE base
The base DN to use when performing sudo LDAP queries. Typically
this is of the form ‘ou=SUDOers,dc=my-domain,dc=com’ for the
domain my-domain.com. Multiple SUDOERS_BASE lines may be
specified, in which case they are queried in the order specified.
SUDOERS_DEBUG debug_level
This sets the debug level for sudo LDAP queries. Debugging
information is printed to the standard error. A value of 1
results in a moderate amount of debugging information. A value
of 2 shows the results of the matches themselves. This parameter
should not be set in a production environment as the extra
information is likely to confuse users.
The SUDOERS_DEBUG parameter is deprecated and will be removed in
a future release. The same information is now logged via the
sudo debugging framework using the “ldap” subsystem at priorities
diag and info for debug_level values 1 and 2 respectively. See
the sudo.conf(5) manual for details on how to configure sudo
debugging.
SUDOERS_SEARCH_FILTER ldap_filter
An LDAP filter which is used to restrict the set of records
returned when performing a sudo LDAP query. Typically, this is
of the form ‘attribute=value’ or
‘(&(attribute=value)(attribute2=value2))’. The default search
filter is: ‘objectClass=sudoRole’. If ldap_filter is omitted, no
search filter will be used.
SUDOERS_TIMED on/true/yes/off/false/no
Whether or not to evaluate the sudoNotBefore and sudoNotAfter
attributes that implement time-dependent sudoers entries.
TIMELIMIT seconds
The TIMELIMIT parameter specifies the amount of time, in seconds,
to wait for a response to an LDAP query.
TIMEOUT seconds
The TIMEOUT parameter specifies the amount of time, in seconds,
to wait for a response from the various LDAP APIs.
TLS_CACERT file name
An alias for TLS_CACERTFILE for OpenLDAP compatibility.
TLS_CACERTFILE file name
The path to a certificate authority bundle which contains the
certificates for all the Certificate Authorities the client knows
to be valid, e.g., /etc/ssl/ca-bundle.pem.
This option is only supported by the OpenLDAP libraries.
Netscape-derived LDAP libraries use the same certificate database
for CA and client certificates (see TLS_CERT).
TLS_CACERTDIR directory
Similar to TLS_CACERTFILE but instead of a file, it is a
directory containing individual Certificate Authority
certificates, e.g., /etc/ssl/certs. The directory specified by
TLS_CACERTDIR is checked after TLS_CACERTFILE.
This option is only supported by the OpenLDAP libraries.
TLS_CERT file name
The path to a file containing the client certificate which can be
used to authenticate the client to the LDAP server. The
certificate type depends on the LDAP libraries used.
OpenLDAP:
‘tls_cert /etc/ssl/client_cert.pem’
Netscape-derived:
‘tls_cert /var/ldap/cert7.db’
IBM LDAP:
Unused, the key database specified by TLS_KEY contains both
keys and certificates.
When using Netscape-derived libraries, this file may also contain
Certificate Authority certificates.
TLS_CHECKPEER on/true/yes/off/false/no
If enabled, TLS_CHECKPEER will cause the LDAP server's TLS
certificated to be verified. If the server's TLS certificate
cannot be verified (usually because it is signed by an unknown
certificate authority), sudo will be unable to connect to it. If
TLS_CHECKPEER is disabled, no check is made. Disabling this
check creates an opportunity for man-in-the-middle attacks since
the server's identity will not be authenticated. If possible,
the CA's certificate should be installed locally so it can be
verified.
This option is not supported by the IBM LDAP libraries.
TLS_KEY file name
The path to a file containing the private key which matches the
certificate specified by TLS_CERT. The private key must not be
password-protected. The key type depends on the LDAP libraries
used.
OpenLDAP:
‘tls_key /etc/ssl/client_key.pem’
Netscape-derived:
‘tls_key /var/ldap/key3.db’
IBM LDAP:
‘tls_key /usr/ldap/ldapkey.kdb’
When using IBM LDAP libraries, this file may also contain
Certificate Authority and client certificates and may be
encrypted.
TLS_CIPHERS cipher list
The TLS_CIPHERS parameter allows the administer to restrict which
encryption algorithms may be used for TLS (SSL) connections. See
the OpenLDAP or IBM Tivoli Directory Server manual for a list of
valid ciphers.
This option is not supported by Netscape-derived libraries.
TLS_KEYPW secret
The TLS_KEYPW contains the password used to decrypt the key
database on clients using the IBM LDAP library. The secret may
be a plaintext password or a base64-encoded string with a
“base64:” prefix. For example:
TLS_KEYPW base64:dGVzdA==
If a plaintext password is used, it should be a simple string
without quotes. Plain text passwords may not include the comment
character (‘#’) and the escaping of special characters with a
backslash (‘\’) is not supported. If this option is used,
/etc/ldap.conf must not be world-readable to avoid exposing the
password. Alternately, a stash file can be used to store the
password in encrypted form (see below).
If no TLS_KEYPW is specified, a stash file will be used if it
exists. The stash file must have the same path as the file
specified by TLS_KEY, but use a ‘.sth’ file extension instead of
‘.kdb’, for example ‘ldapkey.sth’. The default ‘ldapkey.kdb’
that ships with the IBM Tivoli Directory Server is encrypted with
the password ‘ssl_password’. The gsk8capicmd utility can be used
to manage the key database and create a stash file.
This option is only supported by the IBM LDAP libraries.
TLS_REQCERT level
The TLS_REQCERT parameter controls how the LDAP server's TLS
certificated will be verified (if at all). If the server's TLS
certificate cannot be verified (usually because it is signed by
an unknown certificate authority), sudo will be unable to connect
to it. The following level values are supported:
never
The server certificate will not be requested or
checked.
allow
The server certificate will be requested. A missing or
invalid certificate is ignored and not considered an
error.
try The server certificate will be requested. A missing
certificate is ignored but an invalid certificate will
result in a connection error.
demand | hard
The server certificate will be requested. A missing or
invalid certificate will result in a connection error.
This is the default behavior.
This option is only supported by the OpenLDAP libraries. Other
LDAP libraries only support the TLS_CHECKPEER parameter.
TLS_RANDFILE file name
The TLS_RANDFILE parameter specifies the path to an entropy
source for systems that lack a random device. It is generally
used in conjunction with prngd or egd.
This option is only supported by the OpenLDAP libraries.
URI ldap[s]://[hostname[:port]] ...
Specifies a white space-delimited list of one or more URIs
describing the LDAP server(s) to connect to. The protocol may be
either ldap ldaps, the latter being for servers that support TLS
(SSL) encryption. If no port is specified, the default is port
389 for ‘ldap://’ or port 636 for ‘ldaps://’. If no hostname is
specified, sudo will connect to localhost. Multiple URI lines
are treated identically to a URI line containing multiple
entries. Only systems using the OpenSSL libraries support the
mixing of ‘ldap://’ and ‘ldaps://’ URIs. Both the Netscape-
derived and IBM LDAP libraries used on most commercial versions
of Unix are only capable of supporting one or the other.
USE_SASL on/true/yes/off/false/no
Enable USE_SASL for LDAP servers that support SASL
authentication.
ROOTSASL_AUTH_ID identity
The SASL user name to use when ROOTUSE_SASL is enabled.
See the ldap.conf entry in the EXAMPLES section.
Configuring nsswitch.conf
Unless it is disabled at build time, sudo consults the Name Service
Switch file, /etc/nsswitch.conf, to specify the sudoers search order.
Sudo looks for a line beginning with sudoers: and uses this to
determine the search order. By default, sudo does not stop searching
after the first match and later matches take precedence over earlier
ones (unless ‘[SUCCESS=return]’ is used, see below). The following
sources are recognized:
files read sudoers from /etc/sudoers
ldap read sudoers from LDAP
In addition, a subset of nsswitch.conf-style action statements is
supported, specifically ‘[SUCCESS=return]’ and ‘[NOTFOUND=return]’.
These will unconditionally terminate the search if the user was either
found ‘[SUCCESS=return]’ or not found ‘[NOTFOUND=return]’ in the
immediately preceding source. Other action statements tokens are not
supported, nor is test negation with ‘!’.
To consult LDAP first followed by the local sudoers file (if it
exists), use:
sudoers: ldap files
To consult LDAP only when no match is found in the local sudoers file
(if it exists), use:
sudoers: files [SUCCESS=return] ldap
The local sudoers file can be ignored completely by using:
sudoers: ldap
If the /etc/nsswitch.conf file is not present or there is no sudoers
line, the following default is assumed:
sudoers: files
The /etc/nsswitch.conf file is supported even when the underlying
operating system does not support it, except on AIX (see below).
Configuring netsvc.conf
On AIX systems, the /etc/netsvc.conf file is consulted instead of
/etc/nsswitch.conf. sudo simply treats netsvc.conf as a variant of
nsswitch.conf; information in the previous section unrelated to the
file format itself still applies.
To consult LDAP first followed by the local sudoers file (if it
exists), use:
sudoers = ldap, files
The local sudoers file can be ignored completely by using:
sudoers = ldap
To treat LDAP as authoritative and only use the local sudoers file if
the user is not present in LDAP, use:
sudoers = ldap = auth, files
In the above example, the auth qualifier only affects user lookups;
both LDAP and sudoers will be queried for Defaults entries.
If the /etc/netsvc.conf file is not present or there is no sudoers
line, the following default is assumed:
sudoers = files
Integration with sssd
On systems with the System Security Services Daemon (SSSD) and where
sudo has been built with SSSD support, it is possible to use SSSD to
cache LDAP sudoers rules. To use SSSD as the sudoers source, you
should use sss instead of ldap for the sudoers entry in
/etc/nsswitch.conf. The /etc/ldap.conf file is not used by the SSSD
sudo back end. See sssd-sudo(5) for more information on configuring
sudo to work with SSSD.
FILES
/etc/ldap.conf LDAP configuration file
/etc/nsswitch.conf determines sudoers source order
/etc/netsvc.conf determines sudoers source order on AIX
EXAMPLES
Example ldap.conf
# Either specify one or more URIs or one or more host:port pairs.
# If neither is specified sudo will default to localhost, port 389.
#
#host ldapserver
#host ldapserver1 ldapserver2:390
#
# Default port if host is specified without one, defaults to 389.
#port 389
#
# URI will override the host and port settings.
uri ldap://ldapserver
#uri ldaps://secureldapserver
#uri ldaps://secureldapserver ldap://ldapserver
#
# The amount of time, in seconds, to wait while trying to connect to
# an LDAP server.
bind_timelimit 30
#
# The amount of time, in seconds, to wait while performing an LDAP query.
timelimit 30
#
# Must be set or sudo will ignore LDAP; may be specified multiple times.
sudoers_base ou=SUDOers,dc=my-domain,dc=com
#
# verbose sudoers matching from ldap
#sudoers_debug 2
#
# Enable support for time-based entries in sudoers.
#sudoers_timed yes
#
# optional proxy credentials
#binddn <who to search as>
#bindpw <password>
#rootbinddn <who to search as, uses /etc/ldap.secret for bindpw>
#
# LDAP protocol version, defaults to 3
#ldap_version 3
#
# Define if you want to use an encrypted LDAP connection.
# Typically, you must also set the port to 636 (ldaps).
#ssl on
#
# Define if you want to use port 389 and switch to
# encryption before the bind credentials are sent.
# Only supported by LDAP servers that support the start_tls
# extension such as OpenLDAP.
#ssl start_tls
#
# Additional TLS options follow that allow tweaking of the
# SSL/TLS connection.
#
#tls_checkpeer yes # verify server SSL certificate
#tls_checkpeer no # ignore server SSL certificate
#
# If you enable tls_checkpeer, specify either tls_cacertfile
# or tls_cacertdir. Only supported when using OpenLDAP.
#
#tls_cacertfile /etc/certs/trusted_signers.pem
#tls_cacertdir /etc/certs
#
# For systems that don't have /dev/random
# use this along with PRNGD or EGD.pl to seed the
# random number pool to generate cryptographic session keys.
# Only supported when using OpenLDAP.
#
#tls_randfile /etc/egd-pool
#
# You may restrict which ciphers are used. Consult your SSL
# documentation for which options go here.
# Only supported when using OpenLDAP.
#
#tls_ciphers <cipher-list>
#
# Sudo can provide a client certificate when communicating to
# the LDAP server.
# Tips:
# * Enable both lines at the same time.
# * Do not password protect the key file.
# * Ensure the keyfile is only readable by root.
#
# For OpenLDAP:
#tls_cert /etc/certs/client_cert.pem
#tls_key /etc/certs/client_key.pem
#
# For Netscape-derived LDAP, tls_cert and tls_key may specify either
# a directory, in which case the files in the directory must have the
# default names (e.g., cert8.db and key4.db), or the path to the cert
# and key files themselves. However, a bug in version 5.0 of the LDAP
# SDK will prevent specific file names from working. For this reason
# it is suggested that tls_cert and tls_key be set to a directory,
# not a file name.
#
# The certificate database specified by tls_cert may contain CA certs
# and/or the client's cert. If the client's cert is included, tls_key
# should be specified as well.
# For backward compatibility, "sslpath" may be used in place of tls_cert.
#tls_cert /var/ldap
#tls_key /var/ldap
#
# If using SASL authentication for LDAP (OpenSSL)
# use_sasl yes
# sasl_auth_id <SASL user name>
# rootuse_sasl yes
# rootsasl_auth_id <SASL user name for root access>
# sasl_secprops none
# krb5_ccname /etc/.ldapcache
Sudoers schema for OpenLDAP
The following schema, in OpenLDAP format, is included with sudo source
and binary distributions as schema.OpenLDAP. Simply copy it to the
schema directory (e.g., /etc/openldap/schema), add the proper include
line in slapd.conf and restart slapd. Sites using the optional on-line
configuration supported by OpenLDAP 2.3 and higher should apply the
schema.olcSudo file instead.
attributetype ( 1.3.6.1.4.1.15953.9.1.1
NAME 'sudoUser'
DESC 'User(s) who may run sudo'
EQUALITY caseExactMatch
SUBSTR caseExactSubstringsMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 )
attributetype ( 1.3.6.1.4.1.15953.9.1.2
NAME 'sudoHost'
DESC 'Host(s) who may run sudo'
EQUALITY caseExactIA5Match
SUBSTR caseExactIA5SubstringsMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )
attributetype ( 1.3.6.1.4.1.15953.9.1.3
NAME 'sudoCommand'
DESC 'Command(s) to be executed by sudo'
EQUALITY caseExactIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )
attributetype ( 1.3.6.1.4.1.15953.9.1.4
NAME 'sudoRunAs'
DESC 'User(s) impersonated by sudo'
EQUALITY caseExactIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )
attributetype ( 1.3.6.1.4.1.15953.9.1.5
NAME 'sudoOption'
DESC 'Options(s) followed by sudo'
EQUALITY caseExactIA5Match
SYNTAX 1.3.6.1.4.1.1466.115.121.1.26 )
attributetype ( 1.3.6.1.4.1.15953.9.1.6
NAME 'sudoRunAsUser'
DESC 'User(s) impersonated by sudo'
EQUALITY caseExactMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 )
attributetype ( 1.3.6.1.4.1.15953.9.1.7
NAME 'sudoRunAsGroup'
DESC 'Group(s) impersonated by sudo'
EQUALITY caseExactMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.15 )
attributetype ( 1.3.6.1.4.1.15953.9.1.8
NAME 'sudoNotBefore'
DESC 'Start of time interval for which the entry is valid'
EQUALITY generalizedTimeMatch
ORDERING generalizedTimeOrderingMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.24 )
attributetype ( 1.3.6.1.4.1.15953.9.1.9
NAME 'sudoNotAfter'
DESC 'End of time interval for which the entry is valid'
EQUALITY generalizedTimeMatch
ORDERING generalizedTimeOrderingMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.24 )
attributetype ( 1.3.6.1.4.1.15953.9.1.10
NAME 'sudoOrder'
DESC 'an integer to order the sudoRole entries'
EQUALITY integerMatch
ORDERING integerOrderingMatch
SYNTAX 1.3.6.1.4.1.1466.115.121.1.27 )
objectclass ( 1.3.6.1.4.1.15953.9.2.1 NAME 'sudoRole' SUP top STRUCTURAL
DESC 'Sudoer Entries'
MUST ( cn )
MAY ( sudoUser $ sudoHost $ sudoCommand $ sudoRunAs $ sudoRunAsUser $
sudoRunAsGroup $ sudoOption $ sudoNotBefore $ sudoNotAfter $
sudoOrder $ description )
)
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
box; cbp-1 | cbp-1 l | l . ATTRIBUTE TYPE ATTRIBUTE VALUE =
Availability security/sudo = Stability Pass-through volatile
SEE ALSO
cvtsudoers(1), ldap.conf(5), sssd-sudo(5), sudo.conf(5), sudoers(5)
AUTHORS
Many people have worked on sudo over the years; this version consists
of code written primarily by:
Todd C. Miller
See the CONTRIBUTORS.md file in the sudo distribution
(https://www.sudo.ws/about/contributors/) for an exhaustive list of
people who have contributed to sudo.
CAVEATS
There are differences in the way that LDAP-based sudoers is parsed
compared to file-based sudoers. See the Differences between LDAP and
non-LDAP sudoers section for more information.
BUGS
If you believe you have found a bug in sudoers.ldap, you can either
file a bug report in the sudo bug database, https://bugzilla.sudo.ws/,
or open an issue at https://github.com/sudo-project/sudo/issues. If
you would prefer to use email, messages may be sent to the sudo-workers
mailing list, https://www.sudo.ws/mailman/listinfo/sudo-workers
(public) or <sudo@sudo.ws> (private).
Please do not report security vulnerabilities through public GitHub
issues, Bugzilla or mailing lists. Instead, report them via email to
<Todd.Miller@sudo.ws>. You may encrypt your message with PGP if you
would like, using the key found at https://www.sudo.ws/dist/PGPKEYS.
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.md file distributed with sudo or
https://www.sudo.ws/about/license/ for complete details.
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at:
https://github.com/oracle/solaris-userland
The original community source was downloaded from:
https://www.sudo.ws/sudo/dist/sudo-1.9.17p1.tar.gz
Further information about this software can be found on the open source
community website at https://www.sudo.ws/.
Sudo 1.9.17p1 June 25, 2024 SUDOERS.LDAP(5)