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      1 /*
      2  *  Licensed to the Apache Software Foundation (ASF) under one or more
      3  *  contributor license agreements.  See the NOTICE file distributed with
      4  *  this work for additional information regarding copyright ownership.
      5  *  The ASF licenses this file to You under the Apache License, Version 2.0
      6  *  (the "License"); you may not use this file except in compliance with
      7  *  the License.  You may obtain a copy of the License at
      8  *
      9  *     http://www.apache.org/licenses/LICENSE-2.0
     10  *
     11  *  Unless required by applicable law or agreed to in writing, software
     12  *  distributed under the License is distributed on an "AS IS" BASIS,
     13  *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14  *  See the License for the specific language governing permissions and
     15  *  limitations under the License.
     16  */
     17 
     18 /**
     19 * @author Vladimir N. Molotkov, Stepan M. Mishura
     20 * @version $Revision$
     21 */
     22 
     23 package org.apache.harmony.security.asn1;
     24 
     25 import java.io.IOException;
     26 
     27 /**
     28  * This class represents explicitly tagged ASN.1 type.
     29  *
     30  * @see <a href="http://asn1.elibel.tm.fr/en/standards/index.htm">ASN.1</a>
     31  */
     32 public final class ASN1Explicit extends ASN1Constructed {
     33 
     34     /** Tagged type */
     35     public final ASN1Type type;
     36 
     37     /**
     38      * Constructs explicitly tagged ASN.1 type
     39      * with context-specific tag class and specified tag number.
     40      *
     41      * @param tagNumber - ASN.1 tag number
     42      * @param type - ASN.1 type to be tagged
     43      * @throws IllegalArgumentException - if tagNumber is invalid
     44      */
     45     public ASN1Explicit(int tagNumber, ASN1Type type) {
     46         this(CLASS_CONTEXTSPECIFIC, tagNumber, type);
     47     }
     48 
     49     /**
     50      * Constructs explicitly tagged ASN.1 type.
     51      *
     52      * @param tagClass - ASN.1 tag class.
     53      * @param tagNumber - ASN.1 tag number
     54      * @param type - ASN.1 type to be tagged
     55      * @throws IllegalArgumentException - if tagClass or tagNumber is invalid
     56      */
     57     public ASN1Explicit(int tagClass, int tagNumber, ASN1Type type) {
     58         super(tagClass, tagNumber);
     59         this.type = type;
     60     }
     61 
     62     public Object decode(BerInputStream in) throws IOException {
     63         if (constrId != in.tag) {
     64             throw new ASN1Exception("ASN.1 explicitly tagged type is expected at [" +
     65                     in.tagOffset + "]. Expected tag: " + Integer.toHexString(constrId) + ", " +
     66                     "but encountered tag " + Integer.toHexString(in.tag));
     67         }
     68         in.next();
     69 
     70         in.content = type.decode(in);
     71 
     72         if (in.isVerify) {
     73             return null;
     74         }
     75         return getDecodedObject(in);
     76     }
     77 
     78     public void encodeContent(BerOutputStream out) {
     79         out.encodeExplicit(this);
     80     }
     81 
     82     public void setEncodingContent(BerOutputStream out) {
     83         out.getExplicitLength(this);
     84     }
     85 
     86     @Override public String toString() {
     87         return super.toString() + " for type " + type;
     88     }
     89 }
     90