RUNTIME OPTIONS¶

threads NUM

Specifies the number of threads to start that can handle requests and perform LDAP queries. The default is to start 5 threads.

uid UID

This specifies which user id with which the daemon should be run. This can be a numerical id or a symbolic value. If no uid is specified no attempt to change the user will be made. Note that you should use values that don't need LDAP to resolve.

gid GID

This specifies which group id with which the daemon should be run. This can be a numerical id or a symbolic value. If no gid is specified no attempt to change the group will be made. Note that you should use values that don't need LDAP to resolve.

GENERAL CONNECTION OPTIONS¶

uri URI ...

Specifies the LDAP URI of the server to connect to. The URI scheme may be ldap, ldapi or ldaps, specifying LDAP over TCP, ICP or SSL respectively (if supported by the LDAP library). Alternatively, the value DNS may be used to try to lookup the server using DNS SRV records. By default the current domain is used but another domain can be queried by using the DNS:DOMAIN syntax.

When using the ldapi scheme, %2f should be used to escape slashes (e.g. ldapi://%2fvar%2frun%2fslapd%2fldapi/), although most of the time this should not be needed.

This option may be specified multiple times and/or with more URIs on the line, separated by space. Normally, only the first server will be used with the following servers as fall-back (see bind_timelimit below).

If LDAP lookups are used for host name resolution, any host names should be specified as an IP address or name that can be resolved without using LDAP.

ldap_version VERSION

Specifies the version of the LDAP protocol to use. The default is to use the maximum version supported by the LDAP library.

binddn DN

Specifies the distinguished name with which to bind to the directory server for lookups. The default is to bind anonymously.

bindpw PASSWORD

Specifies the clear text credentials with which to bind. This option is only applicable when used with binddn above. If you set this option you should consider changing the permissions of the nslcd.conf file to only grant access to the root user.

rootpwmoddn DN

Specifies the distinguished name to use when the root user tries to modify a user's password using the PAM module. The PAM module prompts the user for the admin password instead of the user's password.

KERBEROS AUTHENTICATION OPTIONS¶

krb5_ccname NAME

Set the name for the GSS-API Kerberos credentials cache.

SEARCH/MAPPING OPTIONS¶

base [MAP] DN

Specifies the base distinguished name (DN) to use as search base. This option may be supplied multiple times and all specified bases will be searched.

A global search base may be specified or a MAP-specific one. If no MAP-specific search bases are defined the global ones are used.

If, instead of a DN, the value DOMAIN is specified, the host's DNS domain is used to construct a search base.

If this value is not defined an attempt is made to look it up in the configured LDAP server. Note that if the LDAP server is unavailable during start-up nslcd will not start.

scope [MAP] sub[tree]|one[level]|base

Specifies the search scope (subtree, one level or base object). The default scope is subtree; base scope is almost never useful for name service lookups.

deref never|searching|finding|always

Specifies the policy for dereferencing aliases. The default policy is to never dereference aliases.

referrals yes|no

Specifies whether automatic referral chasing should be enabled. The default behaviour is to chase referrals.

filter MAP FILTER

The FILTER is an LDAP search filter to use for a specific map. The default filter is a basic search on the objectClass for the map (e.g. (objectClass=posixAccount)).

map MAP ATTRIBUTE NEWATTRIBUTE

This option allows for custom attributes to be looked up instead of the default RFC 2307 attributes. The MAP may be one of the supported maps below. The ATTRIBUTE is the one as used in RFC 2307 (e.g. userPassword, ipProtocolNumber or macAddress). The NEWATTRIBUTE may be any attribute as it is available in the directory.

If the NEWATTRIBUTE is presented in quotes (") it is treated as an expression which will be evaluated to build up the actual value used. See the section on attribute mapping expressions below for more details.

Only some attributes for passwd and shadow entries may be mapped with an expression (because other attributes may be used in search filters). For passwd entries the following attributes may be mapped with an expression: gidNumber, gecos, homeDirectory and loginShell. For shadow entries the following attributes may be mapped with an expression: shadowLastChange, shadowMin, shadowMax, shadowWarning, shadowInactive, shadowExpire and shadowFlag.

TIMING/RECONNECT OPTIONS¶

bind_timelimit SECONDS

Specifies the time limit (in seconds) to use when connecting to the directory server. This is distinct from the time limit specified in timelimit and affects the setup of the connection only. Note that not all LDAP client libraries have support for setting the connection time out. The default bind_timelimit is 10 seconds.

timelimit SECONDS

Specifies the time limit (in seconds) to wait for a response from the LDAP server. A value of zero (0), which is the default, is to wait indefinitely for searches to be completed.

idle_timelimit SECONDS

Specifies the period if inactivity (in seconds) after which the connection to the LDAP server will be closed. The default is not to time out connections.

reconnect_sleeptime SECONDS

Specifies the number of seconds to sleep when connecting to all LDAP servers fails. By default 1 second is waited between the first failure and the first retry.

reconnect_retrytime SECONDS

Specifies the time after which the LDAP server is considered to be permanently unavailable. Once this time is reached retries will be done only once per this time period. The default value is 10 seconds.

Note that the reconnect logic as described above is the mechanism that is used between nslcd and the LDAP server. The mechanism between the NSS client library and nslcd is simpler with a fixed compiled-in time out of a 10 seconds for writing to nslcd and a time out of 60 seconds for reading answers. nslcd itself has a read time out of 0.5 seconds and a write time out of 60 seconds.

SSL/TLS OPTIONS¶

ssl on|off|start_tls

Specifies whether to use SSL/TLS or not (the default is not to). If start_tls is specified then StartTLS is used rather than raw LDAP over SSL. Not all LDAP client libraries support both SSL, StartTLS and all related configuration options.

tls_reqcert never|allow|try|demand|hard

Specifies what checks to perform on a server-supplied certificate. The meaning of the values is described in the ldap.conf(5) manual page. At least one of tls_cacertdir and tls_cacertfile is required if peer verification is enabled.

tls_cacertdir PATH

Specifies the directory containing X.509 certificates for peer authentication.

tls_cacertfile PATH

Specifies the path to the X.509 certificate for peer authentication.

tls_randfile PATH

Specifies the path to an entropy source.

tls_ciphers CIPHERS

Specifies the ciphers to use for TLS. See your TLS implementation's documentation for further information.

tls_cert PATH

Specifies the path to the file containing the local certificate for client TLS authentication.

tls_key PATH

Specifies the path to the file containing the private key for client TLS authentication.

OTHER OPTIONS¶

pagesize NUMBER

Set this to a number greater than 0 to request paged results from the LDAP server in accordance with RFC2696. The default (0) is to not request paged results.

This is useful for LDAP servers that contain a lot of entries (e.g. more than 500) and limit the number of entries that are returned with one request. For OpenLDAP servers you may need to set sizelimit size.prtotal=unlimited for allowing more entries to be returned over multiple pages.

nss_initgroups_ignoreusers user1,user2,...

This option prevents group membership lookups through LDAP for the specified users. This can be useful in case of unavailability of the LDAP server. This option may be specified multiple times.

Alternatively, the value ALLLOCAL may be used. With that value nslcd builds a full list of non-LDAP users on startup.

validnames REGEX

This option can be used to specify how user and group names are verified within the system. This pattern is used to check all user and group names that are requested and returned from LDAP.

The regular expression should be specified as a POSIX extended regular expression. The expression itself needs to be separated by slash (/) characters and the 'i' flag may be appended at the end to indicate that the match should be case-insensitive.

The default value is
/^[a-z0-9._@$()][a-z0-9._@$() \~-]*[a-z0-9._@$()~-]?$/i

pam_authz_search FILTER

This option allows flexible fine tuning of the authorisation check that should be performed. The search filter specified is executed and if any entries match, access is granted, otherwise access is denied.

The search filter can contain the following variable references: $username, $service, $ruser, $rhost, $tty, $hostname, $dn, and $uid. These references are substituted in the search filter using the same syntax as described in the section on attribute mapping expressions below.

For example, to check that the user has a proper authorizedService value if the attribute is present: (&(objectClass=posixAccount)(uid=$username) (|(authorizedService=$service)(!(authorizedService=*))))

The default behaviour is not to do this extra search and always grant access.