# Authentication Services This creates an instance of Spring Security’s `ProviderManager` class, which needs to be configured with a list of one or more `AuthenticationProvider` instances. These can either be created using syntax elements provided by the namespace, or they can be standard bean definitions, marked for addition to the list using the `authentication-provider` element. ## \ Every Spring Security application which uses the namespace must have include this element somewhere. It is responsible for registering the `AuthenticationManager` which provides authentication services to the application. All elements which create `AuthenticationProvider` instances should be children of this element. ### \ Attributes * **alias**This attribute allows you to define an alias name for the internal instance for use in your own configuration. * **erase-credentials**If set to true, the AuthenticationManager will attempt to clear any credentials data in the returned Authentication object, once the user has been authenticated. Literally it maps to the `eraseCredentialsAfterAuthentication` property of the [`ProviderManager`](../../authentication/architecture.html#servlet-authentication-providermanager). * **id**This attribute allows you to define an id for the internal instance for use in your own configuration. It is the same as the alias element, but provides a more consistent experience with elements that use the id attribute. ### Child Elements of \ * [authentication-provider](#nsa-authentication-provider) * [ldap-authentication-provider](ldap.html#nsa-ldap-authentication-provider) ## \ Unless used with a `ref` attribute, this element is shorthand for configuring a `DaoAuthenticationProvider`.`DaoAuthenticationProvider` loads user information from a `UserDetailsService` and compares the username/password combination with the values supplied at login. The `UserDetailsService` instance can be defined either by using an available namespace element (`jdbc-user-service` or by using the `user-service-ref` attribute to point to a bean defined elsewhere in the application context). ### Parent Elements of \ * [authentication-manager](#nsa-authentication-manager) ### \ Attributes * **ref**Defines a reference to a Spring bean that implements `AuthenticationProvider`. If you have written your own `AuthenticationProvider` implementation (or want to configure one of Spring Security’s own implementations as a traditional bean for some reason, then you can use the following syntax to add it to the internal list of `ProviderManager`: ``` ``` * **user-service-ref**A reference to a bean that implements UserDetailsService that may be created using the standard bean element or the custom user-service element. ### Child Elements of \ * [jdbc-user-service](#nsa-jdbc-user-service) * [ldap-user-service](ldap.html#nsa-ldap-user-service) * [password-encoder](#nsa-password-encoder) * [user-service](#nsa-user-service) ## \ Causes creation of a JDBC-based UserDetailsService. ### \ Attributes * **authorities-by-username-query**An SQL statement to query for a user’s granted authorities given a username. The default is ``` select username, authority from authorities where username = ? ``` * **cache-ref**Defines a reference to a cache for use with a UserDetailsService. * **data-source-ref**The bean ID of the DataSource which provides the required tables. * **group-authorities-by-username-query**An SQL statement to query user’s group authorities given a username. The default is ``` select g.id, g.group_name, ga.authority from groups g, group_members gm, group_authorities ga where gm.username = ? and g.id = ga.group_id and g.id = gm.group_id ``` * **id**A bean identifier, used for referring to the bean elsewhere in the context. * **role-prefix**A non-empty string prefix that will be added to role strings loaded from persistent storage (default is "ROLE\_"). Use the value "none" for no prefix in cases where the default is non-empty. * **users-by-username-query**An SQL statement to query a username, password, and enabled status given a username. The default is ``` select username, password, enabled from users where username = ? ``` ## \ Authentication providers can optionally be configured to use a password encoder as described in the [Password Storage](../../../features/authentication/password-storage.html#authentication-password-storage). This will result in the bean being injected with the appropriate `PasswordEncoder` instance. ### Parent Elements of \ * [authentication-provider](#nsa-authentication-provider) * [password-compare](#nsa-password-compare) ### \ Attributes * **hash**Defines the hashing algorithm used on user passwords. We recommend strongly against using MD4, as it is a very weak hashing algorithm. * **ref**Defines a reference to a Spring bean that implements `PasswordEncoder`. ## \ Creates an in-memory UserDetailsService from a properties file or a list of "user" child elements. Usernames are converted to lower-case internally to allow for case-insensitive lookups, so this should not be used if case-sensitivity is required. ### \ Attributes * **id**A bean identifier, used for referring to the bean elsewhere in the context. * **properties**The location of a Properties file where each line is in the format of ``` username=password,grantedAuthority[,grantedAuthority][,enabled|disabled] ``` ### Child Elements of \ * [user](#nsa-user) ## \ Represents a user in the application. ### Parent Elements of \ * [user-service](#nsa-user-service) ### \ Attributes * **authorities**One of more authorities granted to the user. Separate authorities with a comma (but no space). For example, "ROLE\_USER,ROLE\_ADMINISTRATOR" * **disabled**Can be set to "true" to mark an account as disabled and unusable. * **locked**Can be set to "true" to mark an account as locked and unusable. * **name**The username assigned to the user. * **password**The password assigned to the user. This may be hashed if the corresponding authentication provider supports hashing (remember to set the "hash" attribute of the "user-service" element). This attribute be omitted in the case where the data will not be used for authentication, but only for accessing authorities. If omitted, the namespace will generate a random value, preventing its accidental use for authentication. Cannot be empty. [XML Namespace](index.html)[Web Security](http.html)