/*
* Copyright 2002-2016 the original author or authors.
*
* 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
*
* 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 "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.access.prepost;
import java.util.Collection;
import org.aopalliance.intercept.MethodInvocation;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.security.access.AccessDecisionVoter;
import org.springframework.security.access.ConfigAttribute;
import org.springframework.security.core.Authentication;
/**
* Voter which performs the actions using a PreInvocationAuthorizationAdvice
* implementation generated from @PreFilter and @PreAuthorize annotations.
* <p>
* In practice, if these annotations are being used, they will normally contain all the
* necessary access control logic, so a voter-based system is not really necessary and a
* single <tt>AccessDecisionManager</tt> which contained the same logic would suffice.
* However, this class fits in readily with the traditional voter-based
* <tt>AccessDecisionManager</tt> implementations used by Spring Security.
*
* @author Luke Taylor
* @since 3.0
*/
public class PreInvocationAuthorizationAdviceVoter implements
AccessDecisionVoter<MethodInvocation> {
protected final Log logger = LogFactory.getLog(getClass());
private final PreInvocationAuthorizationAdvice preAdvice;
public PreInvocationAuthorizationAdviceVoter(PreInvocationAuthorizationAdvice pre) {
this.preAdvice = pre;
}
public boolean supports(ConfigAttribute attribute) {
return attribute instanceof PreInvocationAttribute;
}
public boolean supports(Class<?> clazz) {
return MethodInvocation.class.isAssignableFrom(clazz);
}
public int vote(Authentication authentication, MethodInvocation method,
Collection<ConfigAttribute> attributes) {
// Find prefilter and preauth (or combined) attributes
// if both null, abstain
// else call advice with them
PreInvocationAttribute preAttr = findPreInvocationAttribute(attributes);
if (preAttr == null) {
// No expression based metadata, so abstain
return ACCESS_ABSTAIN;
}
boolean allowed = preAdvice.before(authentication, method, preAttr);
return allowed ? ACCESS_GRANTED : ACCESS_DENIED;
}
private PreInvocationAttribute findPreInvocationAttribute(
Collection<ConfigAttribute> config) {
for (ConfigAttribute attribute : config) {
if (attribute instanceof PreInvocationAttribute) {
return (PreInvocationAttribute) attribute;
}
}
return null;
}
}