/*
 *  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.harmony.javax.security.auth.kerberos;

import javax.crypto.SecretKey;
import javax.security.auth.DestroyFailedException;
import javax.security.auth.Destroyable;

import org.apache.harmony.auth.internal.nls.Messages;

/**
 * See <a href="http://www.ietf.org/rfc/rfc3961.txt">RFC3961</a>
 */
public class KerberosKey implements SecretKey, Destroyable {

	private static final long serialVersionUID = -4625402278148246993L;

	// principal
	private KerberosPrincipal principal;

	// key version number
	private int versionNum;

	// raw bytes for the secret key
	private final KeyImpl key;

	// indicates the ticket state
	private transient boolean destroyed;

	public KerberosKey(KerberosPrincipal principal, byte[] keyBytes,
			int keyType, int versionNumber) {

		if (keyBytes == null) {
			throw new NullPointerException(Messages.getString("auth.47")); //$NON-NLS-1$
		}

		this.principal = principal;
		versionNum = versionNumber;

		key = new KeyImpl(keyBytes, keyType);

	}

	public KerberosKey(KerberosPrincipal principal, char[] password,
			String algorithm) {

		this.principal = principal;

		key = new KeyImpl(principal, password, algorithm);
	}

	// if a key is destroyed then IllegalStateException must be thrown
	private void checkState() {
		if (destroyed) {
			throw new IllegalStateException(Messages.getString("auth.48")); //$NON-NLS-1$
		}
	}

	@Override
	public void destroy() throws DestroyFailedException {
		if (!destroyed) {
			principal = null;
			key.destroy();
			destroyed = true;
		}
	}

	@Override
	public boolean equals(Object other) {
		if ((other instanceof KerberosKey) && (!isDestroyed())) {
			final KerberosKey that = (KerberosKey) other;
			if ((!that.isDestroyed()) && (versionNum == that.versionNum)) {
				if (key.equals(((KerberosKey) other).key)) {
					if (principal != null) {
						return principal.equals(that.principal);
					} else {
						return that.principal == null;
					}
				}
			}
		}
		return false;
	}

	@Override
	public final String getAlgorithm() {
		return key.getAlgorithm();
	}

	@Override
	public final byte[] getEncoded() {
		return key.getEncoded();
	}

	@Override
	public final String getFormat() {
		return key.getFormat();
	}

	public final int getKeyType() {
		return key.getKeyType();
	}

	public final KerberosPrincipal getPrincipal() {
		checkState();
		return principal;
	}

	public final int getVersionNumber() {
		checkState();
		return versionNum;
	}

	@Override
	public int hashCode() {
		int hashcode = 0;
		if (principal != null) {
			hashcode += principal.hashCode();
		}
		hashcode += versionNum;
		hashcode += key.hashCode();
		return hashcode;
	}

	@Override
	public boolean isDestroyed() {
		return destroyed;
	}

	@Override
	public String toString() {
		checkState();
		final StringBuilder sb = new StringBuilder();
		sb.append("KerberosPrincipal ").append(principal.getName()).append("\n"); //$NON-NLS-1$ //$NON-NLS-2$
		sb.append("KeyVersion ").append(versionNum).append("\n"); //$NON-NLS-1$ //$NON-NLS-2$
		sb.append(key.toString());
		return sb.toString();
	}
}