LastReq.java

/*
 * 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.util.Vector;
import java.io.IOException;

/**
 * Implements the ASN.1 LastReq type.
 *
 * <xmp>
 * LastReq	   ::=	   SEQUENCE OF SEQUENCE {
 *	   lr-type	   [0] Int32,
 *	   lr-value	   [1] KerberosTime
 * }
 * </xmp>
 *
 * <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 LastReq {
    private LastReqEntry[] entry = null;

    public LastReq(LastReqEntry[] entries) throws IOException {
	if (entries != null) {
	    entry = new LastReqEntry[entries.length];
	    for (int i = 0; i < entries.length; i++) {
		if (entries[i] == null) {
		    throw new IOException("Cannot create a LastReqEntry");
		} else {
		    entry[i] = (LastReqEntry)entries[i].clone();
		}
	    }
	}

    }
    	
    /**
     * Constructs a LastReq 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 LastReq(DerValue encoding) throws Asn1Exception, IOException {  
	Vector<LastReqEntry> v= new Vector<LastReqEntry> ();
        if (encoding.getTag() != DerValue.tag_Sequence) {
	    throw new Asn1Exception(Krb5.ASN1_BAD_ID);
	}
	while (encoding.getData().available() > 0) {
	    v.addElement(new LastReqEntry(encoding.getData().getDerValue()));
	}
	if (v.size() > 0) {
	    entry = new LastReqEntry[v.size()];
	    v.copyInto(entry);
	}
    }

    /**
     * Encodes an LastReq object.
     * @return the byte array of encoded LastReq 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();
	if (entry != null && entry.length > 0) {
	    DerOutputStream temp = new DerOutputStream();
	    for (int i = 0; i < entry.length; i++) 
		temp.write(entry[i].asn1Encode());
	    bytes.write(DerValue.tag_Sequence, temp);
	    return bytes.toByteArray();
	}
	return null;
    }

    /**
     * Parse (unmarshal) a last request 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 indicates if this data field is optional
     * @return an instance of LastReq.
     *
     */

    public static LastReq 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 LastReq(subDer);
	}
    }

}