Java tutorial
/* * Copyright 2004, 2005, 2006 Acegi Technology Pty Limited * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * https://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 "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.springframework.security.remoting.rmi; import org.aopalliance.intercept.MethodInvocation; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.remoting.support.RemoteInvocation; import org.springframework.security.authentication.UsernamePasswordAuthenticationToken; import org.springframework.security.core.Authentication; import org.springframework.security.core.SpringSecurityCoreVersion; import org.springframework.security.core.context.SecurityContextHolder; import java.lang.reflect.InvocationTargetException; /** * The actual {@code RemoteInvocation} that is passed from the client to the server. * <p> * The principal and credentials information will be extracted from the current security * context and passed to the server as part of the invocation object. * <p> * To avoid potential serialization-based attacks, this implementation interprets the * values as {@code String}s and creates a {@code UsernamePasswordAuthenticationToken} on * the server side to hold them. If a different token type is required you can override * the {@code createAuthenticationRequest} method. * * @author James Monaghan * @author Ben Alex * @author Luke Taylor */ public class ContextPropagatingRemoteInvocation extends RemoteInvocation { private static final long serialVersionUID = SpringSecurityCoreVersion.SERIAL_VERSION_UID; private static final Log logger = LogFactory.getLog(ContextPropagatingRemoteInvocation.class); // ~ Instance fields // ================================================================================================ private final String principal; private final String credentials; // ~ Constructors // =================================================================================================== /** * Constructs the object, storing the principal and credentials extracted from the * client-side security context. * * @param methodInvocation the method to invoke */ public ContextPropagatingRemoteInvocation(MethodInvocation methodInvocation) { super(methodInvocation); Authentication currentUser = SecurityContextHolder.getContext().getAuthentication(); if (currentUser != null) { principal = currentUser.getName(); Object userCredentials = currentUser.getCredentials(); credentials = userCredentials == null ? null : userCredentials.toString(); } else { principal = credentials = null; } if (logger.isDebugEnabled()) { logger.debug("RemoteInvocation now has principal: " + principal); if (credentials == null) { logger.debug("RemoteInvocation now has null credentials."); } } } // ~ Methods // ======================================================================================================== /** * Invoked on the server-side. * <p> * The transmitted principal and credentials will be used to create an unauthenticated * {@code Authentication} instance for processing by the {@code AuthenticationManager}. * * @param targetObject the target object to apply the invocation to * * @return the invocation result * * @throws NoSuchMethodException if the method name could not be resolved * @throws IllegalAccessException if the method could not be accessed * @throws InvocationTargetException if the method invocation resulted in an exception */ public Object invoke(Object targetObject) throws NoSuchMethodException, IllegalAccessException, InvocationTargetException { if (principal != null) { Authentication request = createAuthenticationRequest(principal, credentials); request.setAuthenticated(false); SecurityContextHolder.getContext().setAuthentication(request); if (logger.isDebugEnabled()) { logger.debug("Set SecurityContextHolder to contain: " + request); } } try { return super.invoke(targetObject); } finally { SecurityContextHolder.clearContext(); if (logger.isDebugEnabled()) { logger.debug("Cleared SecurityContextHolder."); } } } /** * Creates the server-side authentication request object. */ protected Authentication createAuthenticationRequest(String principal, String credentials) { return new UsernamePasswordAuthenticationToken(principal, credentials); } }