source: branches/TaskRewrite/src/plugins/acegi-0.5.1/src/groovy/org/codehaus/groovy/grails/plugins/springsecurity/AuthenticatedVetoableDecisionManager.groovy @ 58

/* Copyright 2006-2009 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.codehaus.groovy.grails.plugins.springsecurity

import org.springframework.security.AccessDeniedException
import org.springframework.security.Authentication
import org.springframework.security.ConfigAttribute
import org.springframework.security.ConfigAttributeDefinition
import org.springframework.security.vote.AbstractAccessDecisionManager
import org.springframework.security.vote.AccessDecisionVoter
import org.springframework.security.vote.AuthenticatedVoter

/**
 * Uses the affirmative-based logic for roles, i.e. any in the list will grant access, but allows
 * an authenticated voter to 'veto' access. This allows specification of roles and
 * <code>IS_AUTHENTICATED_FULLY</code> on one line in SecurityConfig.groovy.
 *
 * @author <a href='mailto:beckwithb@studentsonly.com'>Burt Beckwith</a>
 */
class AuthenticatedVetoableDecisionManager extends AbstractAccessDecisionManager {

        /**
         * {@inheritDoc}
         * @see org.springframework.security.vote.AbstractAccessDecisionManager#decide(
         *      org.springframework.security.Authentication, java.lang.Object,
         *      org.springframework.security.ConfigAttributeDefinition)
         */
        void decide(Authentication authentication, Object object, ConfigAttributeDefinition config)
            throws AccessDeniedException {

                boolean authenticatedVotersGranted = checkAuthenticatedVoters(authentication, object, config)
                boolean otherVotersGranted = checkOtherVoters(authentication, object, config)

                if (!authenticatedVotersGranted && !otherVotersGranted) {
                        checkAllowIfAllAbstainDecisions()
                }
        }

        /**
         * Allow any {@link AuthenticatedVoter} to veto. If any voter denies,
         * throw an exception; if any grant, return <code>true</code>;
         * otherwise return <code>false</code> if all abstain.
         */
        private boolean checkAuthenticatedVoters(authentication, object, config) {
                boolean grant = false
                for (AccessDecisionVoter voter in decisionVoters) {
                        if (voter instanceof AuthenticatedVoter) {
                                int result = voter.vote(authentication, object, config)
                                switch (result) {
                                        case AccessDecisionVoter.ACCESS_GRANTED:
                                                grant = true
                                                break
                                        case AccessDecisionVoter.ACCESS_DENIED:
                                                deny()
                                                break
                                        default: // abstain
                                                break
                                }
                        }
                }
                return grant
        }

        /**
         * Check the other (non-{@link AuthenticatedVoter}) voters. If any voter grants,
         * return true. If any voter denies, throw exception. Otherwise return <code>false</code>
         * to indicate that all abstained.
         */
        private boolean checkOtherVoters(authentication, object, config) {
                int denyCount = 0
                for (AccessDecisionVoter voter in decisionVoters) {
                        if (voter instanceof AuthenticatedVoter) {
                                continue
                        }

                        int result = voter.vote(authentication, object, config)
                        switch (result) {
                case AccessDecisionVoter.ACCESS_GRANTED:
                        return true
                case AccessDecisionVoter.ACCESS_DENIED:
                        denyCount++
                        break
                                default: // abstain
                        break
            }
        }

        if (denyCount) {
            deny()
        }

        // all abstain
        return false
        }

        private void deny() {
                throw new AccessDeniedException(messages.getMessage(
                                "AbstractAccessDecisionManager.accessDenied",
                                "Access is denied"))
        }
}