/*

 * 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.util.*;

import sun.security.krb5.Asn1Exception;

import java.io.IOException;

import java.math.BigInteger;

/**

 * Implements the ASN.1 TransitedEncoding type.

 *

 *  TransitedEncoding      ::= SEQUENCE {

 *         tr-type         [0] Int32 -- must be registered --,

 *         contents        [1] OCTET STRING

 *  }

 *

 * <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 TransitedEncoding {

    public int trType;

    public byte[] contents;

    public TransitedEncoding(int type, byte[] cont) {

        trType = type;

        contents = cont;

    }

    /**

     * Constructs a TransitedEncoding object.

     * @param encoding a Der-encoded data.

     * @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 TransitedEncoding(DerValue encoding) throws Asn1Exception, IOException {

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

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        DerValue der;

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

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

            trType = der.getData().getBigInteger().intValue();

        }

        else

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

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

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

            contents = der.getData().getOctetString();

        }

        else

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

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

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

    }

    /**

     * Encodes a TransitedEncoding object.

     * @return the byte array of the encoded TransitedEncoding 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(trType));

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

        temp = new DerOutputStream();

        temp.putOctetString(contents);

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

        temp = new DerOutputStream();

        temp.write(DerValue.tag_Sequence, bytes);

        return temp.toByteArray();

    }

    /**

     * Parse (unmarshal) a TransitedEncoding object from a DER input stream.  This form

     * parsing might be used when expanding a value which is part of

     * a constructed sequence and uses explicitly tagged type.

     *

     * @exception Asn1Exception on error.

     * @param data the Der input stream value, which contains one or more marshaled value.

     * @param explicitTag tag number.

     * @param optional indicate if this data field is optional

     * @return an instance of TransitedEncoding.

     *

     */

    public static TransitedEncoding parse(DerInputStream data, byte explicitTag, boolean optional) throws Asn1Exception, IOException {

        if ((optional) && (((byte)data.peekByte() & (byte)0x1F) != explicitTag))

            return null;

        DerValue der = data.getDerValue();

        if (explicitTag != (der.getTag() & (byte)0x1F))  {

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        else {

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

            return new TransitedEncoding(subDer);

        }

    }

}