/*
* Copyright 2015 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.statemachine.security;
import java.util.Collection;
import org.springframework.security.access.AccessDecisionVoter;
import org.springframework.security.access.ConfigAttribute;
import org.springframework.security.core.Authentication;
import org.springframework.statemachine.transition.Transition;
/**
* Votes if any {@link ConfigAttribute#getAttribute()} starts with a prefix indicating
* that it is a transition source or target. The default prefixes strings are
* <Code>TRANSITION_SOURCE</code> and <Code>TRANSITION_TARGET</code>, but
* those may be overridden to any value. It may also be set to empty, which means that
* essentially any attribute will be voted on. As described further below, the effect
* of an empty prefix may not be quite desirable.
* <p>
* All comparisons and prefixes are case sensitive.
*
* @author Janne Valkealahti
*
* @param <S> the type of state
* @param <E> the type of event
*/
public class TransitionVoter<S, E> implements AccessDecisionVoter<Transition<S, E>> {
private String transitionSourcePrefix = "TRANSITION_SOURCE_";
private String transitionTargetPrefix = "TRANSITION_TARGET_";
@Override
public boolean supports(ConfigAttribute attribute) {
if ((attribute.getAttribute() != null) && (attribute.getAttribute().startsWith(getTransitionSourcePrefix())
|| attribute.getAttribute().startsWith(getTransitionTargetPrefix()))) {
return true;
} else {
return false;
}
}
@Override
public boolean supports(Class<?> clazz) {
return Transition.class.isAssignableFrom(clazz);
}
@Override
public int vote(Authentication authentication, Transition<S, E> transition, Collection<ConfigAttribute> attributes) {
int result = ACCESS_ABSTAIN;
if (authentication == null) {
return result;
}
S source = transition.getSource().getId();
S target = transition.getTarget().getId();
for (ConfigAttribute attribute : attributes) {
if (this.supports(attribute)) {
result = ACCESS_DENIED;
String attr = attribute.getAttribute();
if (attr.startsWith(getTransitionSourcePrefix())
&& attr.equals(getTransitionSourcePrefix() + source.toString())) {
return ACCESS_GRANTED;
} else if (attr.startsWith(getTransitionTargetPrefix())
&& attr.equals(getTransitionTargetPrefix() + target.toString())) {
return ACCESS_GRANTED;
}
}
}
return result;
}
/**
* Gets the transition source prefix.
*
* @return the transition source prefix
*/
public String getTransitionSourcePrefix() {
return transitionSourcePrefix;
}
/**
* Allows the default transition source prefix of <code>TRANSITION_SOURCE_</code> to
* be overridden. May be set to an empty value, although this is usually not desirable.
*
* @param transitionSourcePrefix the new transition source prefix
*/
public void setTransitionSourcePrefix(String transitionSourcePrefix) {
this.transitionSourcePrefix = transitionSourcePrefix;
}
/**
* Gets the transition target prefix.
*
* @return the transition target prefix
*/
public String getTransitionTargetPrefix() {
return transitionTargetPrefix;
}
/**
* Allows the default transition target prefix of <code>TRANSITION_TARGET_</code> to
* be overridden. May be set to an empty value, although this is usually not desirable.
*
* @param transitionTargetPrefix the new transition source prefix
*/
public void setTransitionTargetPrefix(String transitionTargetPrefix) {
this.transitionTargetPrefix = transitionTargetPrefix;
}
}