java.security.cert.Certificate Maven / Gradle / Ivy

/*
 *  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 java.security.cert;

import java.io.ByteArrayInputStream;
import java.io.NotSerializableException;
import java.io.ObjectStreamException;
import java.io.ObjectStreamField;
import java.io.Serializable;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.PublicKey;
import java.security.SignatureException;
import java.util.Arrays;

/**
 * Abstract class to represent identity certificates. It represents a way to
 * verify the binding of a Principal and its public key. Examples are X.509,
 * PGP, and SDSI.
 */
public abstract class Certificate implements Serializable {

    private static final long serialVersionUID = -3585440601605666277L;

    // The standard name of the certificate type
    private final String type;

    /**
     * Creates a new {@code Certificate} with the specified type.
     *
     * @param type
     *        the certificate type.
     */
    protected Certificate(String type) {
        this.type = type;
    }

    /**
     * Returns the certificate type.
     *
     * @return the certificate type.
     */
    public final String getType() {
        return type;
    }

    /**
     * Compares the argument to the certificate, and returns {@code true} if they
     * represent the same object using a class specific comparison. The
     * implementation in Object returns {@code true} only if the argument is the
     * exact same object as the callee (==).
     *
     * @param other
     *            the object to compare with this object.
     * @return {@code true} if the object is the same as this object, {@code
     *         false} if it is different from this object.
     * @see #hashCode
     */
    public boolean equals(Object other) {
        // obj equal to itself
        if (this == other) {
            return true;
        }
        if (other instanceof Certificate) {
            try {
                // check that encoded forms match
                return Arrays.equals(this.getEncoded(),
                        ((Certificate)other).getEncoded());
            } catch (CertificateEncodingException e) {
                throw new RuntimeException(e);
            }
        }
        return false;
    }

    /**
     * Returns an integer hash code for the certificate. Any two objects which
     * return {@code true} when passed to {@code equals} must return the same
     * value for this method.
     *
     * @return the certificate's hash
     * @see #equals
     */
    public int hashCode() {
        try {
            byte[] encoded = getEncoded();
            int hash = 0;
            for (int i=0; i