001    /**
002     *
003     *  Licensed to the Apache Software Foundation (ASF) under one or more
004     *  contributor license agreements.  See the NOTICE file distributed with
005     *  this work for additional information regarding copyright ownership.
006     *  The ASF licenses this file to You under the Apache License, Version 2.0
007     *  (the "License"); you may not use this file except in compliance with
008     *  the License.  You may obtain a copy of the License at
009     *
010     *     http://www.apache.org/licenses/LICENSE-2.0
011     *
012     *  Unless required by applicable law or agreed to in writing, software
013     *  distributed under the License is distributed on an "AS IS" BASIS,
014     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     *  See the License for the specific language governing permissions and
016     *  limitations under the License.
017     */
018    
019    package org.apache.geronimo.util.asn1;
020    
021    import java.io.ByteArrayOutputStream;
022    import java.io.IOException;
023    import java.util.Enumeration;
024    
025    public class DERSequence
026        extends ASN1Sequence
027    {
028        /**
029         * create an empty sequence
030         */
031        public DERSequence()
032        {
033        }
034    
035        /**
036         * create a sequence containing one object
037         */
038        public DERSequence(
039            DEREncodable    obj)
040        {
041            this.addObject(obj);
042        }
043    
044        /**
045         * create a sequence containing a vector of objects.
046         */
047        public DERSequence(
048            DEREncodableVector   v)
049        {
050            for (int i = 0; i != v.size(); i++)
051            {
052                this.addObject(v.get(i));
053            }
054        }
055    
056        /**
057         * create a sequence containing an array of objects.
058         */
059        public DERSequence(
060            ASN1Encodable[]   a)
061        {
062            for (int i = 0; i != a.length; i++)
063            {
064                this.addObject(a[i]);
065            }
066        }
067    
068        /*
069         * A note on the implementation:
070         * <p>
071         * As DER requires the constructed, definite-length model to
072         * be used for structured types, this varies slightly from the
073         * ASN.1 descriptions given. Rather than just outputing SEQUENCE,
074         * we also have to specify CONSTRUCTED, and the objects length.
075         */
076        void encode(
077            DEROutputStream out)
078            throws IOException
079        {
080            ByteArrayOutputStream   bOut = new ByteArrayOutputStream();
081            DEROutputStream         dOut = new DEROutputStream(bOut);
082            Enumeration             e = this.getObjects();
083    
084            while (e.hasMoreElements())
085            {
086                Object    obj = e.nextElement();
087    
088                dOut.writeObject(obj);
089            }
090    
091            dOut.close();
092    
093            byte[]  bytes = bOut.toByteArray();
094    
095            out.writeEncoded(SEQUENCE | CONSTRUCTED, bytes);
096        }
097    }