org.opensaml.xmlsec.keyinfo.impl.provider.AbstractKeyInfoProvider Maven / Gradle / Ivy

/*
 * Licensed to the University Corporation for Advanced Internet Development,
 * Inc. (UCAID) under one or more contributor license agreements.  See the
 * NOTICE file distributed with this work for additional information regarding
 * copyright ownership. The UCAID 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.opensaml.xmlsec.keyinfo.impl.provider;

import java.security.Key;

import javax.annotation.Nullable;

import org.opensaml.security.credential.Credential;
import org.opensaml.xmlsec.keyinfo.impl.KeyInfoCredentialContext;
import org.opensaml.xmlsec.keyinfo.impl.KeyInfoProvider;
import org.opensaml.xmlsec.keyinfo.impl.KeyInfoResolutionContext;

/**
 * Abstract super class for {@link KeyInfoProvider} implementations.
 */
public abstract class AbstractKeyInfoProvider implements KeyInfoProvider {
    
    /**
     * Utility method to extract any key that might be present in the specified Credential.
     * 
     * @param cred the Credential to evaluate
     * @return the Key contained in the credential, or null if it does not contain a key.
     */
    @Nullable protected Key extractKeyValue(@Nullable final Credential cred) {
        if (cred != null) {
            if (cred.getPublicKey() != null) {
                return cred.getPublicKey();
            } 
            // This could happen if key is derived, e.g. key agreement, etc
            if (cred.getSecretKey() != null) {
                return cred.getSecretKey();
            }
            // Perhaps unlikely, but go ahead and check
            if (cred.getPrivateKey() != null) {
                return cred.getPrivateKey(); 
            }
        }
        return null;
    }
    
    /**
     * Build a credential context based on the current KeyInfo context, for return 
     * in a resolved credential.
     * 
     * @param kiContext the current KeyInfo resolution context
     * 
     * @return a new KeyInfo credential context
     */
    @Nullable protected KeyInfoCredentialContext buildCredentialContext(
            @Nullable final KeyInfoResolutionContext kiContext) {
        // Simple for now, might do other stuff later.
        // Just want to provide a single place to build credential contexts for a provider.
        if (kiContext != null) {
            return new KeyInfoCredentialContext(kiContext.getKeyInfo());
        } else {
            return null;
        }
    }

}