/*

 * Copyright 1997-2003 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

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 */

package java.security.cert;

import java.math.BigInteger;

import java.util.Date;

import javax.security.auth.x500.X500Principal;

import sun.security.x509.X509CRLEntryImpl;

/**

 * <p>Abstract class for a revoked certificate in a CRL (Certificate

 * Revocation List).

 *

 * The ASN.1 definition for <em>revokedCertificates</em> is:

 * <pre>

 * revokedCertificates    SEQUENCE OF SEQUENCE  {

 *     userCertificate    CertificateSerialNumber,

 *     revocationDate     ChoiceOfTime,

 *     crlEntryExtensions Extensions OPTIONAL

 *                        -- if present, must be v2

 * }  OPTIONAL

 *<p>

 * CertificateSerialNumber  ::=  INTEGER

 *<p>

 * Extensions  ::=  SEQUENCE SIZE (1..MAX) OF Extension

 *<p>

 * Extension  ::=  SEQUENCE  {

 *     extnId        OBJECT IDENTIFIER,

 *     critical      BOOLEAN DEFAULT FALSE,

 *     extnValue     OCTET STRING

 *                   -- contains a DER encoding of a value

 *                   -- of the type registered for use with

 *                   -- the extnId object identifier value

 * }

 * </pre>

 *

 * @see X509CRL

 * @see X509Extension

 *

 * @author Hemma Prafullchandra

 */

public abstract class X509CRLEntry implements X509Extension {

    /**

     * Compares this CRL entry for equality with the given

     * object. If the <code>other</code> object is an

     * <code>instanceof</code> <code>X509CRLEntry</code>, then

     * its encoded form (the inner SEQUENCE) is retrieved and compared

     * with the encoded form of this CRL entry.

     *

     * @param other the object to test for equality with this CRL entry.

     * @return true iff the encoded forms of the two CRL entries

     * match, false otherwise.

     */

    public boolean equals(Object other) {

        if (this == other)

            return true;

        if (!(other instanceof X509CRLEntry))

            return false;

        try {

            byte[] thisCRLEntry = this.getEncoded();

            byte[] otherCRLEntry = ((X509CRLEntry)other).getEncoded();

            if (thisCRLEntry.length != otherCRLEntry.length)

                return false;

            for (int i = 0; i < thisCRLEntry.length; i++)

                 if (thisCRLEntry[i] != otherCRLEntry[i])

                     return false;

        } catch (CRLException ce) {

            return false;

        }

        return true;

    }

    /**

     * Returns a hashcode value for this CRL entry from its

     * encoded form.

     *

     * @return the hashcode value.

     */

    public int hashCode() {

        int     retval = 0;

        try {

            byte[] entryData = this.getEncoded();

            for (int i = 1; i < entryData.length; i++)

                 retval += entryData[i] * i;

        } catch (CRLException ce) {

            return(retval);

        }

        return(retval);

    }

    /**

     * Returns the ASN.1 DER-encoded form of this CRL Entry,

     * that is the inner SEQUENCE.

     *

     * @return the encoded form of this certificate

     * @exception CRLException if an encoding error occurs.

     */

    public abstract byte[] getEncoded() throws CRLException;

    /**

     * Gets the serial number from this X509CRLEntry,

     * the <em>userCertificate</em>.

     *

     * @return the serial number.

     */

    public abstract BigInteger getSerialNumber();

    /**

     * Get the issuer of the X509Certificate described by this entry. If

     * the certificate issuer is also the CRL issuer, this method returns

     * null.

     *

     * <p>This method is used with indirect CRLs. The default implementation

     * always returns null. Subclasses that wish to support indirect CRLs

     * should override it.

     *

     * @return the issuer of the X509Certificate described by this entry

     * or null if it is issued by the CRL issuer.

     *

     * @since 1.5

     */

    public X500Principal getCertificateIssuer() {

        return null;

    }

    /**

     * Gets the revocation date from this X509CRLEntry,

     * the <em>revocationDate</em>.

     *

     * @return the revocation date.

     */

    public abstract Date getRevocationDate();

    /**

     * Returns true if this CRL entry has extensions.

     *

     * @return true if this entry has extensions, false otherwise.

     */

    public abstract boolean hasExtensions();

    /**

     * Returns a string representation of this CRL entry.

     *

     * @return a string representation of this CRL entry.

     */

    public abstract String toString();

    /**

     * Returns the reason the certificate has been revoked, as specified

     * in the Reason Code extension of this CRL entry.

     *

     * @return the reason the certificate has been revoked, or

     *    <code>null</code> if this CRL entry does not have

     *    a Reason Code extension

     * @since 1.7

     */

    public CRLReason getRevocationReason() {

        if (!hasExtensions()) {

            return null;

        }

        return X509CRLEntryImpl.getRevocationReason(this);

    }

}