/*

 * 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.util.Vector;

import java.io.IOException;

import java.math.BigInteger;

/**

 * Implements the ASN.1 EncAPRepPart type.

 *

 * <pre>{@code

 * EncAPRepPart ::= [APPLICATION 27] SEQUENCE {

 *      ctime           [0] KerberosTime,

 *      cusec           [1] Microseconds,

 *      subkey          [2] EncryptionKey OPTIONAL,

 *      seq-number      [3] UInt32 OPTIONAL

 * }

 * }</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 EncAPRepPart {

    public KerberosTime ctime;

    public int cusec;

    EncryptionKey subKey; //optional

    Integer seqNumber; //optional

    public EncAPRepPart(

            KerberosTime new_ctime,

            int new_cusec,

            EncryptionKey new_subKey,

            Integer new_seqNumber) {

        ctime = new_ctime;

        cusec = new_cusec;

        subKey = new_subKey;

        seqNumber = new_seqNumber;

    }

    public EncAPRepPart(byte[] data)

            throws Asn1Exception, IOException {

        init(new DerValue(data));

    }

    public EncAPRepPart(DerValue encoding)

            throws Asn1Exception, IOException {

        init(encoding);

    }

    /**

     * Initializes an EncaPRepPart 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.

     */

    private void init(DerValue encoding) throws Asn1Exception, IOException {

        DerValue der, subDer;

        if (((encoding.getTag() & (byte) 0x1F) != (byte) 0x1B)

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

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

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

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

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

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        ctime = KerberosTime.parse(der.getData(), (byte) 0x00, true);

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

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

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

        } else {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

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

            subKey = EncryptionKey.parse(der.getData(), (byte) 0x02, true);

        } else {

            subKey = null;

            seqNumber = null;

        }

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

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

            if ((subDer.getTag() & 0x1F) != 0x03) {

                throw new Asn1Exception(Krb5.ASN1_BAD_ID);

            }

            seqNumber = new Integer(subDer.getData().getBigInteger().intValue());

        } else {

            seqNumber = null;

        }

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

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

    }

    /**

     * Encodes an EncAPRepPart object.

     * @return byte array of encoded EncAPRepPart 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 {

        Vector<DerValue> v = new Vector<>();

        DerOutputStream temp = new DerOutputStream();

        v.addElement(new DerValue(DerValue.createTag(DerValue.TAG_CONTEXT,

                true, (byte) 0x00), ctime.asn1Encode()));

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

        v.addElement(new DerValue(DerValue.createTag(DerValue.TAG_CONTEXT,

                true, (byte) 0x01), temp.toByteArray()));

        if (subKey != null) {

            v.addElement(new DerValue(DerValue.createTag(DerValue.TAG_CONTEXT,

                    true, (byte) 0x02), subKey.asn1Encode()));

        }

        if (seqNumber != null) {

            temp = new DerOutputStream();

            // encode as an unsigned integer (UInt32)

            temp.putInteger(BigInteger.valueOf(seqNumber.longValue()));

            v.addElement(new DerValue(DerValue.createTag(DerValue.TAG_CONTEXT,

                    true, (byte) 0x03), temp.toByteArray()));

        }

        DerValue der[] = new DerValue[v.size()];

        v.copyInto(der);

        temp = new DerOutputStream();

        temp.putSequence(der);

        DerOutputStream out = new DerOutputStream();

        out.write(DerValue.createTag(DerValue.TAG_APPLICATION,

                true, (byte) 0x1B), temp);

        return out.toByteArray();

    }

    public final EncryptionKey getSubKey() {

        return subKey;

    }

    public final Integer getSeqNumber() {

        return seqNumber;

    }

}