/*

 * Copyright (c) 2005, 2009, Oracle and/or its affiliates. All rights reserved.

 * 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

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 */

package sun.security.krb5.internal;

import sun.security.util.*;

import sun.security.krb5.Asn1Exception;

import java.io.IOException;

import sun.security.krb5.internal.util.KerberosString;

/**

 * Implements the ASN.1 ETYPE-INFO-ENTRY type.

 *

 * ETYPE-INFO2-ENTRY    ::= SEQUENCE {

 *          etype       [0] Int32,

 *          salt        [1] KerberosString OPTIONAL,

 *          s2kparams   [2] OCTET STRING OPTIONAL

 * }

 *

 * @author Seema Malkani

 */

public class ETypeInfo2 {

    private int etype;

    private String saltStr = null;

    private byte[] s2kparams = null;

    private static final byte TAG_TYPE = 0;

    private static final byte TAG_VALUE1 = 1;

    private static final byte TAG_VALUE2 = 2;

    private ETypeInfo2() {

    }

    public ETypeInfo2(int etype, String salt, byte[] s2kparams) {

        this.etype = etype;

        this.saltStr = salt;

        if (s2kparams != null) {

            this.s2kparams = s2kparams.clone();

        }

    }

    public Object clone() {

        ETypeInfo2 etypeInfo2 = new ETypeInfo2();

        etypeInfo2.etype = etype;

        etypeInfo2.saltStr = saltStr;

        if (s2kparams != null) {

            etypeInfo2.s2kparams = new byte[s2kparams.length];

            System.arraycopy(s2kparams, 0, etypeInfo2.s2kparams,

                                0, s2kparams.length);

        }

        return etypeInfo2;

    }

    /**

     * Constructs a ETypeInfo2 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 ETypeInfo2(DerValue encoding) throws Asn1Exception, IOException {

        DerValue der = null;

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

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        }

        // etype

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

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

            this.etype = der.getData().getBigInteger().intValue();

        }

        else

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

        // salt

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

            if ((encoding.getData().peekByte() & 0x1F) == 0x01) {

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

                this.saltStr = new KerberosString(

                        der.getData().getDerValue()).toString();

            }

        }

        // s2kparams

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

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

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

                this.s2kparams = der.getData().getOctetString();

            }

        }

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

            throw new Asn1Exception(Krb5.ASN1_BAD_ID);

    }

    /**

     * Encodes this object to an OutputStream.

     *

     * @return byte array of the encoded data.

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

     * @exception Asn1Exception on encoding errors.

     */

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

        DerOutputStream bytes = new DerOutputStream();

        DerOutputStream temp = new DerOutputStream();

        temp.putInteger(etype);

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

                                        TAG_TYPE), temp);

        if (saltStr != null) {

            temp = new DerOutputStream();

            temp.putDerValue(new KerberosString(saltStr).toDerValue());

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

                                        TAG_VALUE1), temp);

        }

        if (s2kparams != null) {

            temp = new DerOutputStream();

            temp.putOctetString(s2kparams);

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

                                        TAG_VALUE2), temp);

        }

        temp = new DerOutputStream();

        temp.write(DerValue.tag_Sequence, bytes);

        return temp.toByteArray();

    }

    // accessor methods

    public int getEType() {

        return etype;

    }

    public String getSalt() {

        return saltStr;

    }

    public byte[] getParams() {

        return ((s2kparams == null) ? null : s2kparams.clone());

    }

}