/*

 * 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.  Oracle designates this

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

 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/*

 *

 *  (C) Copyright IBM Corp. 1999 All Rights Reserved.

 *  Copyright 1997 The Open Group Research Institute.  All rights reserved.

 */

package sun.security.krb5.internal;

import sun.security.krb5.EncryptedData;

import sun.security.krb5.Asn1Exception;

import sun.security.util.*;

import java.io.IOException;

import java.math.BigInteger;

/**

 * Implements the ASN.1 AP-REP type.

 *

 * <pre>{@code

 * AP-REP          ::= [APPLICATION 15] SEQUENCE {

 *         pvno            [0] INTEGER (5),

 *         msg-type        [1] INTEGER (15),

 *         enc-part        [2] EncryptedData -- EncAPRepPart

 * }

 * }</pre>

 *

 * <p>

 * This definition reflects the Network Working Group RFC 4120

 * specification available at

 * <a href="http://www.ietf.org/rfc/rfc4120.txt">

 * http://www.ietf.org/rfc/rfc4120.txt</a>.

 */

public class APRep {

    public int pvno;

    public int msgType;

    public EncryptedData encPart;

    public APRep(EncryptedData new_encPart) {

        pvno = Krb5.PVNO;

        msgType = Krb5.KRB_AP_REP;

        encPart = new_encPart;

    }

    public APRep(byte[] data) throws Asn1Exception,

            KrbApErrException, IOException {

        init(new DerValue(data));

    }

    public APRep(DerValue encoding) throws Asn1Exception,

            KrbApErrException, IOException {

        init(encoding);

    }

    /**

     * Initializes an APRep object.

     * @param encoding a single DER-encoded value.

     * @exception Asn1Exception if an error occurs while decoding an ASN1 encoded data.

     * @exception IOException if an I/O error occurs while reading encoded data.

     * @exception KrbApErrException if the value read from the DER-encoded data

     *  stream does not match the pre-defined value.

     */

    private void init(DerValue encoding) throws Asn1Exception,

            KrbApErrException, IOException {

        if (((encoding.getTag() & (byte) (0x1F)) != Krb5.KRB_AP_REP)

                || (encoding.isApplication() != true)

                || (encoding.isConstructed() != true)) {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        DerValue der = encoding.getData().getDerValue();

        if (der.getTag() != DerValue.tag_Sequence) {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        DerValue subDer = der.getData().getDerValue();

        if ((subDer.getTag() & (byte) 0x1F) != (byte) 0x00) {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        pvno = subDer.getData().getBigInteger().intValue();

        if (pvno != Krb5.PVNO) {

            throw new KrbApErrException(Krb5.KRB_AP_ERR_BADVERSION);

        }

        subDer = der.getData().getDerValue();

        if ((subDer.getTag() & (byte) 0x1F) != (byte) 0x01) {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        msgType = subDer.getData().getBigInteger().intValue();

        if (msgType != Krb5.KRB_AP_REP) {

            throw new KrbApErrException(Krb5.KRB_AP_ERR_MSG_TYPE);

        }

        encPart = EncryptedData.parse(der.getData(), (byte) 0x02, false);

        if (der.getData().available() > 0) {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

    }

    /**

     * Encodes an APRep object.

     * @return byte array of encoded APRep object.

     * @exception Asn1Exception if an error occurs while decoding an ASN1 encoded data.

     * @exception IOException if an I/O error occurs while reading encoded data.

     */

    public byte[] asn1Encode() throws Asn1Exception, IOException {

        DerOutputStream bytes = new DerOutputStream();

        DerOutputStream temp = new DerOutputStream();

        temp.putInteger(BigInteger.valueOf(pvno));

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte) 0x00), temp);

        temp = new DerOutputStream();

        temp.putInteger(BigInteger.valueOf(msgType));

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte) 0x01), temp);

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte) 0x02), encPart.asn1Encode());

        temp = new DerOutputStream();

        temp.write(DerValue.tag_Sequence, bytes);

        DerOutputStream aprep = new DerOutputStream();

        aprep.write(DerValue.createTag(DerValue.TAG_APPLICATION, true, (byte) 0x0F), temp);

        return aprep.toByteArray();

    }

}