org.apache.shiro.realm.Realm Maven / Gradle / Ivy
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* to you under the Apache License, Version 2.0 (the
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* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
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*/
package org.apache.shiro.realm;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationInfo;
import org.apache.shiro.authc.AuthenticationToken;
/**
* A Realm is a security component that can access application-specific security entities
* such as users, roles, and permissions to determine authentication and authorization operations.
*
* Realms usually have a 1-to-1 correspondance with a datasource such as a relational database,
* file sysetem, or other similar resource. As such, implementations of this interface use datasource-specific APIs to
* determine authorization data (roles, permissions, etc), such as JDBC, File IO, Hibernate or JPA, or any other
* Data Access API. They are essentially security-specific
* DAOs.
*
*
Because most of these datasources usually contain Subject (a.k.a. User) information such as usernames and
* passwords, a Realm can act as a pluggable authentication module in a
* PAM configuration. This allows a Realm to
* perform both authentication and authorization duties for a single datasource, which caters to the large
* majority of applications. If for some reason you don't want your Realm implementation to perform authentication
* duties, you should override the {@link #supports(org.apache.shiro.authc.AuthenticationToken)} method to always
* return false.
*
*
Because every application is different, security data such as users and roles can be
* represented in any number of ways. Shiro tries to maintain a non-intrusive development philosophy whenever
* possible - it does not require you to implement or extend any User, Group or Role
* interfaces or classes.
*
*
Instead, Shiro allows applications to implement this interface to access environment-specific datasources
* and data model objects. The implementation can then be plugged in to the application's Shiro configuration.
* This modular technique abstracts away any environment/modeling details and allows Shiro to be deployed in
* practically any application environment.
*
*
Most users will not implement the Realm interface directly, but will extend one of the subclasses,
* {@link org.apache.shiro.realm.AuthenticatingRealm AuthenticatingRealm} or {@link org.apache.shiro.realm.AuthorizingRealm}, greatly reducing the effort requird
* to implement a Realm from scratch.
*
* @see org.apache.shiro.realm.CachingRealm CachingRealm
* @see org.apache.shiro.realm.AuthenticatingRealm AuthenticatingRealm
* @see org.apache.shiro.realm.AuthorizingRealm AuthorizingRealm
* @see org.apache.shiro.authc.pam.ModularRealmAuthenticator ModularRealmAuthenticator
* @since 0.1
*/
public interface Realm {
/**
* Returns the (application-unique) name assigned to this Realm. All realms configured for a single
* application must have a unique name.
*
* @return the (application-unique) name assigned to this Realm.
*/
String getName();
/**
* Returns true if this realm wishes to authenticate the Subject represented by the given
* {@link org.apache.shiro.authc.AuthenticationToken AuthenticationToken} instance, false otherwise.
*
* If this method returns false, it will not be called to authenticate the Subject represented by
* the token - more specifically, a false return value means this Realm instance's
* {@link #getAuthenticationInfo} method will not be invoked for that token.
*
* @param token the AuthenticationToken submitted for the authentication attempt
* @return true if this realm can/will authenticate Subjects represented by specified token,
* false otherwise.
*/
boolean supports(AuthenticationToken token);
/**
* Returns an account's authentication-specific information for the specified token,
* or null if no account could be found based on the token.
*
*
This method effectively represents a login attempt for the corresponding user with the underlying EIS datasource.
* Most implementations merely just need to lookup and return the account data only (as the method name implies)
* and let Shiro do the rest, but implementations may of course perform eis specific login operations if so
* desired.
*
* @param token the application-specific representation of an account principal and credentials.
* @return the authentication information for the account associated with the specified token,
* or null if no account could be found.
* @throws org.apache.shiro.authc.AuthenticationException
* if there is an error obtaining or constructing an AuthenticationInfo object based on the
* specified token or implementation-specifc login behavior fails.
*/
AuthenticationInfo getAuthenticationInfo(AuthenticationToken token) throws AuthenticationException;
}