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      1 package org.bouncycastle.asn1;
      2 
      3 import java.io.IOException;
      4 import java.util.Enumeration;
      5 
      6 public class DLSequence
      7     extends ASN1Sequence
      8 {
      9     private int bodyLength = -1;
     10 
     11     /**
     12      * create an empty sequence
     13      */
     14     public DLSequence()
     15     {
     16     }
     17 
     18     /**
     19      * create a sequence containing one object
     20      */
     21     public DLSequence(
     22         ASN1Encodable obj)
     23     {
     24         super(obj);
     25     }
     26 
     27     /**
     28      * create a sequence containing a vector of objects.
     29      */
     30     public DLSequence(
     31         ASN1EncodableVector v)
     32     {
     33         super(v);
     34     }
     35 
     36     /**
     37      * create a sequence containing an array of objects.
     38      */
     39     public DLSequence(
     40         ASN1Encodable[] array)
     41     {
     42         super(array);
     43     }
     44 
     45     private int getBodyLength()
     46         throws IOException
     47     {
     48         if (bodyLength < 0)
     49         {
     50             int length = 0;
     51 
     52             for (Enumeration e = this.getObjects(); e.hasMoreElements();)
     53             {
     54                 Object    obj = e.nextElement();
     55 
     56                 length += ((ASN1Encodable)obj).toASN1Primitive().toDLObject().encodedLength();
     57             }
     58 
     59             bodyLength = length;
     60         }
     61 
     62         return bodyLength;
     63     }
     64 
     65     int encodedLength()
     66         throws IOException
     67     {
     68         int    length = getBodyLength();
     69 
     70         return 1 + StreamUtil.calculateBodyLength(length) + length;
     71     }
     72 
     73     /*
     74      * A note on the implementation:
     75      * <p>
     76      * As DL requires the constructed, definite-length model to
     77      * be used for structured types, this varies slightly from the
     78      * ASN.1 descriptions given. Rather than just outputting SEQUENCE,
     79      * we also have to specify CONSTRUCTED, and the objects length.
     80      */
     81     void encode(
     82         ASN1OutputStream out)
     83         throws IOException
     84     {
     85         ASN1OutputStream       dOut = out.getDLSubStream();
     86         int                    length = getBodyLength();
     87 
     88         out.write(BERTags.SEQUENCE | BERTags.CONSTRUCTED);
     89         out.writeLength(length);
     90 
     91         for (Enumeration e = this.getObjects(); e.hasMoreElements();)
     92         {
     93             Object    obj = e.nextElement();
     94 
     95             dOut.writeObject((ASN1Encodable)obj);
     96         }
     97     }
     98 }
     99