Lightweight Directory Access Protocol (LDAP) is a directory service protocol that allows for connecting, searching, and modifying internet directories. Unfortunately, LDAP doesn't support reactive bindings; this means that reactive programming is not possible (similar to JDBC) with it. The function of LDAP authentication is shown in the following diagram:
Figure 3: LDAP authentication
Similar to the previous example, we will clone/copy the previous project (any Spring Boot project will do; I am cloning the spring-boot-in-memory-saml2-authentication project). Again, similar to the previous project, we will modify a couple of files and add a few more files to the project. We will use the built-in Java-based LDAP server to validate the user credentials.