[[servlet-authentication-unpwd]]
= Username/Password Authentication
:figures: images/servlet/authentication/unpwd
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One of the most common ways to authenticate a user is by validating a username and password.
As such, Spring Security provides comprehensive support for authenticating with a username and password.

[[servlet-authentication-unpwd-input]]
== Reading the Username & Password

Spring Security provides the following built in mechanisms for reading a username and password from the `HttpServletRequest`:

* <<servlet-authentication-form,Form Login>>
* <<servlet-authentication-basic,Basic Authentication>>
* <<servlet-authentication-digest,Digest Authentication>>

[[servlet-authentication-unpwd-storage]]
== Storage Mechanisms

Each of the supported mechanisms for reading a username and password can leverage any of the supported storage mechanisms:

* Simple Storage with <<servlet-authentication-inmemory>>
* Relational Databases with <<servlet-authentication-jdbc>>
* Custom data stores with <<servlet-authentication-userdetailsservice>>
* LDAP storage with <<servlet-authentication-ldap>>