LDAP as a user store

Directories are designed for fast reading. They are stricter compared to databases when it comes to the data types they can contain. Directories are organized according to a hierarchical structure. Directories can store user details, which can be queried and authenticated against. Directories are also designed to replicate easily. This makes directories the ideal user store.

LDAP is a protocol for accessing a directory over a TCP/IP network. It can be used to store public e-mail addresses, authenticate users, manage digital certificates, and supply information about the nodes or devices on a network. Novell's eDirectory and Microsoft Active Directory both contain an LDAP server component. An alternative to this is the open source OpenLDAP project. OpenLDAP is a very mature project with reliable LDAP software used in many places and by many projects. The server component is called slapd. This section will use a very basic slapd server to demonstrate the use of LDAP...