/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.apache.cxf.sts.token.delegation;

import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import org.w3c.dom.Element;

import org.apache.cxf.common.logging.LogUtils;
import org.apache.cxf.sts.request.ReceivedToken;
import org.apache.wss4j.common.ext.WSSecurityException;
import org.apache.wss4j.common.saml.SamlAssertionWrapper;
import org.apache.wss4j.common.saml.builder.SAML1Constants;
import org.apache.wss4j.common.saml.builder.SAML2Constants;

/**
 * This TokenDelegationHandler implementation extends the Default implementation to allow SAML
 * Tokens with HolderOfKey Subject Confirmation.
 */
public class HOKDelegationHandler extends SAMLDelegationHandler {
    
    private static final Logger LOG = 
        LogUtils.getL7dLogger(HOKDelegationHandler.class);
    
    /**
     * Is Delegation allowed for a particular token
     */
    @Override
    protected boolean isDelegationAllowed(
        ReceivedToken receivedToken, String appliesToAddress
    ) {
        Element validateTargetElement = (Element)receivedToken.getToken();
        try {
            SamlAssertionWrapper assertion = new SamlAssertionWrapper(validateTargetElement);

            for (String confirmationMethod : assertion.getConfirmationMethods()) {
                if (!(SAML1Constants.CONF_BEARER.equals(confirmationMethod)
                    || SAML1Constants.CONF_HOLDER_KEY.equals(confirmationMethod)
                    || SAML2Constants.CONF_BEARER.equals(confirmationMethod)
                    || SAML2Constants.CONF_HOLDER_KEY.equals(confirmationMethod))) {
                    return false;
                }
            }

            if (isCheckAudienceRestriction() && appliesToAddress != null) {
                List<String> addresses = getAudienceRestrictions(assertion);
                if (!(addresses.isEmpty() || addresses.contains(appliesToAddress))) {
                    return false;
                }
            }
        } catch (WSSecurityException ex) {
            LOG.log(Level.WARNING, "Error in ascertaining whether delegation is allowed", ex);
            return false;
        }

        return true;
    }
    
}
