These authentication types are part of the LDAP and or OpenLDAP standard.
Below you can find the details on some of the commonly used methods:
In the LDAP standard, authentication is supplied in the "bind" operation.
- Anonymous: a client that sends an LDAP request without doing a bind.
- Simple: sending the LDAP server the fully qualified DN of the user and the users' password.
- SASL: Simple Authentication and Security Layer: specifies a challenge-response protocol in which data is exchanged between the client and the server for the purposes of authentication and establishment of a security layer (RF 2222).