/*

 * 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.*;

import sun.security.util.*;

import java.io.IOException;

import java.math.BigInteger;

/**

 * Implements the ASN.1 KDC-REP type.

 *

 * <pre>{@code

 * KDC-REP         ::= SEQUENCE {

 *         pvno            [0] INTEGER (5),

 *         msg-type        [1] INTEGER (11 -- AS -- | 13 -- TGS --),

 *         padata          [2] SEQUENCE OF PA-DATA OPTIONAL

 *                                   -- NOTE: not empty --,

 *         crealm          [3] Realm,

 *         cname           [4] PrincipalName,

 *         ticket          [5] Ticket,

 *         enc-part        [6] EncryptedData

 *                                   -- EncASRepPart or EncTGSRepPart,

 *                                   -- as appropriate

 * }

 * }</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 KDCRep {

    public PrincipalName cname;

    public Ticket ticket;

    public EncryptedData encPart;

    public EncKDCRepPart encKDCRepPart; //not part of ASN.1 encoding

    private int pvno;

    private int msgType;

    public PAData[] pAData = null; //optional

    private boolean DEBUG = Krb5.DEBUG;

    public KDCRep(

            PAData[] new_pAData,

            PrincipalName new_cname,

            Ticket new_ticket,

            EncryptedData new_encPart,

            int req_type) throws IOException {

        pvno = Krb5.PVNO;

        msgType = req_type;

        if (new_pAData != null) {

            pAData = new PAData[new_pAData.length];

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

                if (new_pAData[i] == null) {

                    throw new IOException("Cannot create a KDCRep");

                } else {

                    pAData[i] = (PAData) new_pAData[i].clone();

                }

            }

        }

        cname = new_cname;

        ticket = new_ticket;

        encPart = new_encPart;

    }

    public KDCRep() {

    }

    public KDCRep(byte[] data, int req_type) throws Asn1Exception,

            KrbApErrException, RealmException, IOException {

        init(new DerValue(data), req_type);

    }

    public KDCRep(DerValue encoding, int req_type) throws Asn1Exception,

            RealmException, KrbApErrException, IOException {

        init(encoding, req_type);

    }

    /*

    // Not used? Don't know what keyusage to use here %%%

    public void decrypt(EncryptionKey key) throws Asn1Exception,

            IOException, KrbException, RealmException {

        encKDCRepPart = new EncKDCRepPart(encPart.decrypt(key), msgType);

    }

     */

    /**

     * Initializes an KDCRep object.

     *

     * @param encoding a single DER-encoded value.

     * @param req_type reply message type.

     * @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 RealmException if an error occurs while constructing

     * a Realm object from DER-encoded data.

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

     * data stream does not match the pre-defined value.

     *

     */

    protected void init(DerValue encoding, int req_type)

            throws Asn1Exception, RealmException, IOException,

            KrbApErrException {

        DerValue der, subDer;

        if ((encoding.getTag() & 0x1F) != req_type) {

            if (DEBUG) {

                System.out.println(">>> KDCRep: init() " +

                        "encoding tag is " +

                        encoding.getTag() +

                        " req type is " + req_type);

            }

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

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

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

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

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

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

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

            if (pvno != Krb5.PVNO) {

                throw new KrbApErrException(Krb5.KRB_AP_ERR_BADVERSION);

            }

        } else {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

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

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

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

            if (msgType != req_type) {

                throw new KrbApErrException(Krb5.KRB_AP_ERR_MSG_TYPE);

            }

        } else {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        if ((der.getData().peekByte() & 0x1F) == 0x02) {

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

            DerValue[] padata = subDer.getData().getSequence(1);

            pAData = new PAData[padata.length];

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

                pAData[i] = new PAData(padata[i]);

            }

        } else {

            pAData = null;

        }

        Realm crealm = Realm.parse(der.getData(), (byte) 0x03, false);

        cname = PrincipalName.parse(der.getData(), (byte) 0x04, false, crealm);

        ticket = Ticket.parse(der.getData(), (byte) 0x05, false);

        encPart = EncryptedData.parse(der.getData(), (byte) 0x06, false);

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

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

    }

    /**

     * Encodes this object to a byte array.

     * @return byte array of encoded APReq 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);

        if (pAData != null && pAData.length > 0) {

            DerOutputStream padata_stream = new DerOutputStream();

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

                padata_stream.write(pAData[i].asn1Encode());

            }

            temp = new DerOutputStream();

            temp.write(DerValue.tag_SequenceOf, padata_stream);

            bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT,

                    true, (byte) 0x02), temp);

        }

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT,

                true, (byte) 0x03), cname.getRealm().asn1Encode());

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT,

                true, (byte) 0x04), cname.asn1Encode());

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT,

                true, (byte) 0x05), ticket.asn1Encode());

        bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT,

                true, (byte) 0x06), encPart.asn1Encode());

        temp = new DerOutputStream();

        temp.write(DerValue.tag_Sequence, bytes);

        return temp.toByteArray();

    }

}