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You are here: Home Documentation OMERO v4.2.2 OMERO.server LDAP


OMERO LDAP Authentication

LDAP is an open standard for querying and modifying directory services that is commonly used for authentication, authorization and accounting (AAA). OMERO.server supports the use of an LDAP server to query (but not modify) AAA information for the purposes of automatic user creation.

This allows OMERO users, ''Experimenters'' or ''Scientists'' in OMERO parlance, to be automatically created and placed in groups according to your existing institution policies. This can significantly simplify your user administration burden.

The OMERO.server LDAP implementation can handle a number of use cases. For example,

  • Allow every ''inetOrgPerson'' under omero.ldap.base to login
  • but restrict access based upon an arbitrary LDAP filter, e.g. "omero.ldap.user_filter=(memberOf=dn=someGroup,ou=Lab,o=College)"
  • and add that user to some number of groups, e.g. "omero.ldap.new_user_group=:query:(member=@{dn})"

LDAP Properties

The LDAP plugin is configured via several configuration properties, all starting with "omero.ldap.". The default values for these properties is set in the file etc/


These properties are the base requirements for logging in to LDAP. After having configured your connection, you can turn the LDAP on and off between restarts by setting "omero.ldap.config" to false.


These two user properties are used to look up users by login name and, if necessary, create new users based on the information in LDAP. "omero.ldap.user_filter" will be AND'ed to the username query, and can contain any valid LDAP filter string. The username query is taken from the LDAP attribute which gets mapped to "omeName" by "omero.ldap.user_mapping". Here, the "cn" is mapped to omeName, so the username query is (cn=[login name]). The final query is (&(objectClass=person)(cn=[login name])), which must return a single result to be considered valid.


The final set of properties are all concerned with what groups a user will be placed in on creation. The group filter and group mapping work just as the user filter and mapping do, but may not be used depending on the value of "new_user_group", which can have five separate meanings:

  • If equal to ":ou:", then a user's last organizational unit will be used as his or her group. For example, the user with the dn "cn=frank,ou=TheLab,ou=LifeSciences,o=TheCollege" will be placed in the group "TheLab".
  • If prefixed with ":attribute:", then the rest of the string is taken to be an attribute all of whose values will be taken as group names. For example, "omero.ldap.new_user_group=:attribute:memberOf" would add a user to all the groups named by memberOf.
  • If prefixed with ":query:", then the rest of the value is taken as a query to be AND'ed to the group filter. In the query, values from the user such as "@{cn}", "@{email}", or "@{dn}" can be used as place holders.
  • If prefixed with ":bean:", then the rest of the string is the name of a Spring bean which implements the NewUserGroupBean interface. See the developer documentation for more info.
  • If not prefixed at all, then the value is simply the name of a group which all users from LDAP should be added to.

LDAP Configuration

Like many pieces of OMERO.server configuration, LDAP-specific configuration is done by specifying extra properties during installation. The default values for the LDAP properties are listed in the etc/ file inside your OMERO installation directory. NOTE: Please remember that once a change has been made, a server restart will be needed.

Change any settings that are necessary via bin/omero config.

  • Enable or disable LDAP (true/false)

    bin/omero config set omero.ldap.config true
  • LDAP server URL string

    bin/omero config set omero.ldap.urls ldap://

    NOTE: A SSL URL above should look like this: ldaps://

  • LDAP server bind DN (if required; can be empty)

    bin/omero config set omero.ldap.username cn=Manager,dc=example,dc=com
  • LDAP server bind password (if required; can be empty)

    bin/omero config set omero.ldap.password secret
  • LDAP server base search DN

    bin/omero config set omero.ldap.base dc=example,dc=com
  • The filter applied to all users; can be empty in which case any LDAP user is valid

    bin/omero config set omero.ldap.user_filter '(objectClass=inetOrgPerson)'


If you are connecting to your server over SSL, that is, if your URL is of the form "ldaps://" you will need to configure a key and trust store for Java. See the Security page for more information.

See also

If you have LDAP requirements that are not covered by the above configuration, please see the forum discussion "What are your LDAP requirements?"

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