Configure the ldap identity provider to validate user names and passwords against an LDAPv3 server, using simple bind authentication.

About LDAP authentication

During authentication, the LDAP directory is searched for an entry that matches the provided user name. If a single unique match is found, a simple bind is attempted using the distinguished name (DN) of the entry plus the provided password.

These are the steps taken:

  1. Generate a search filter by combining the attribute and filter in the configured url with the user-provided user name.

  2. Search the directory using the generated filter. If the search does not return exactly one entry, deny access.

  3. Attempt to bind to the LDAP server using the DN of the entry retrieved from the search, and the user-provided password.

  4. If the bind is unsuccessful, deny access.

  5. If the bind is successful, build an identity using the configured attributes as the identity, email address, display name, and preferred user name.

The configured url is an RFC 2255 URL, which specifies the LDAP host and search parameters to use. The syntax of the URL is:

ldap://host:port/basedn?attribute?scope?filter

For this URL:

URL Component Description

ldap

For regular LDAP, use the string ldap. For secure LDAP (LDAPS), use ldaps instead.

host:port

The name and port of the LDAP server. Defaults to localhost:389 for ldap and localhost:636 for LDAPS.

basedn

The DN of the branch of the directory where all searches should start from. At the very least, this must be the top of your directory tree, but it could also specify a subtree in the directory.

attribute

The attribute to search for. Although RFC 2255 allows a comma-separated list of attributes, only the first attribute will be used, no matter how many are provided. If no attributes are provided, the default is to use uid. It is recommended to choose an attribute that will be unique across all entries in the subtree you will be using.

scope

The scope of the search. Can be either one or sub. If the scope is not provided, the default is to use a scope of sub.

filter

A valid LDAP search filter. If not provided, defaults to (objectClass=*)

When doing searches, the attribute, filter, and provided user name are combined to create a search filter that looks like:

(&(<filter>)(<attribute>=<username>))

For example, consider a URL of:

ldap://ldap.example.com/o=Acme?cn?sub?(enabled=true)

When a client attempts to connect using a user name of bob, the resulting search filter will be (&(enabled=true)(cn=bob)).

If the LDAP directory requires authentication to search, specify a bindDN and bindPassword to use to perform the entry search.