User management and authentication providers in Spring Security are in charge of managing user information and validating user credentials during authentication. Let’s take a closer look at these ideas:
In-memory User Store: The UserDetailsService interface in Spring Security allows you to configure an in-memory user store. This is excellent for testing and developing tiny apps. Users, passwords, and roles may be defined directly in the settings.
Database User Store: It is typical in real-world applications to store user information in a database. The UserDetailsService interface in Spring Security allows for integration with a variety of databases. You may use this interface to retrieve user information from your database.
If you have a custom user store or user management system, you may use the UserDetailsService interface to load user information from it.
DaoAuthenticationProvider: When utilizing the UserDetailsService interface, this authentication provider is the default option. It obtains user information from a user store and validates passwords using password encoders.
LDAP Authentication Provider:: Spring Security includes an LDAP authentication provider if you use an LDAP (Lightweight Directory Access Protocol) server for user management. It connects to the LDAP server, looks for the user, and validates the password.
Custom Authentication Provider: We can implement the AuthenticationProvider interface and provide your authentication logic if you have a custom authentication method or wish to link with an external authentication provider (e.g., OAuth, SAML).