/*

 * 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-INFO-ENTRY     ::= SEQUENCE {

 *         etype        [0] Int32,

 *         salt         [1] OCTET STRING OPTIONAL

 *   }

 *

 * @author Seema Malkani

 */

public class ETypeInfo {

    private int etype;

    private String salt = null;

    private static final byte TAG_TYPE = 0;

    private static final byte TAG_VALUE = 1;

    private ETypeInfo() {

    }

    public ETypeInfo(int etype, String salt) {

        this.etype = etype;

        this.salt = salt;

    }

    public Object clone() {

        return new ETypeInfo(etype, salt);

    }

    /**

     * Constructs a ETypeInfo 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 ETypeInfo(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) {

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

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

                byte[] saltBytes = der.getData().getOctetString();

                // Although salt is defined as an OCTET STRING, it's the

                // encoding from of a string. As RFC 4120 says:

                //

                // "The salt, ..., is also completely unspecified with respect

                // to character set and is probably locale-specific".

                //

                // It's known that this field is using the same encoding as

                // KerberosString in most implementations.

                if (KerberosString.MSNAME) {

                    this.salt = new String(saltBytes, "UTF8");

                } else {

                    this.salt = new String(saltBytes);

                }

            }

        }

        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 (salt != null) {

            temp = new DerOutputStream();

            if (KerberosString.MSNAME) {

                temp.putOctetString(salt.getBytes("UTF8"));

            } else {

                temp.putOctetString(salt.getBytes());

            }

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

                                        TAG_VALUE), temp);

        }

        temp = new DerOutputStream();

        temp.write(DerValue.tag_Sequence, bytes);

        return temp.toByteArray();

    }

    // accessor methods

    public int getEType() {

        return etype;

    }

    public String getSalt() {

        return salt;

    }

}