/*

 * 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 EncKrbPrivPart type.

 *

 * <pre>{@code

 *     METHOD-DATA ::=    SEQUENCE {

 *                        method-type[0]   INTEGER,

 *                        method-data[1]   OCTET STRING OPTIONAL

 *  }

 * }</pre>

 */

public class MethodData {

    private int methodType;

    private byte[] methodData = null; //optional

    public MethodData(int type, byte[] data) {

        methodType = type;

        if (data != null) {

            methodData = data.clone();

        }

    }

    /**

     * Constructs a MethodData 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 MethodData(DerValue encoding) throws Asn1Exception, IOException {

        DerValue der;

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

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

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

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

            BigInteger bint = der.getData().getBigInteger();

            methodType = bint.intValue();

        }

        else

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

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

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

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

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

            }

            else throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

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

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

    }

    /**

     * Encodes an MethodData object.

     * @return the byte array of encoded MethodData 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(methodType));

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

        if (methodData != null) {

            temp = new DerOutputStream();

            temp.putOctetString(methodData);

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

        }

        temp = new DerOutputStream();

        temp.write(DerValue.tag_Sequence, bytes);

        return temp.toByteArray();

    }

}