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      1 package org.bouncycastle.asn1;
      2 
      3 import java.io.ByteArrayOutputStream;
      4 import java.io.IOException;
      5 import java.util.Enumeration;
      6 
      7 /**
      8  * A DER encoded set object
      9  */
     10 public class DERSet
     11     extends ASN1Set
     12 {
     13     /**
     14      * create an empty set
     15      */
     16     public DERSet()
     17     {
     18     }
     19 
     20     /**
     21      * @param obj - a single object that makes up the set.
     22      */
     23     public DERSet(
     24         DEREncodable   obj)
     25     {
     26         this.addObject(obj);
     27     }
     28 
     29     /**
     30      * @param v - a vector of objects making up the set.
     31      */
     32     public DERSet(
     33         DEREncodableVector   v)
     34     {
     35         this(v, true);
     36     }
     37 
     38     /**
     39      * create a set from an array of objects.
     40      */
     41     public DERSet(
     42         ASN1Encodable[]   a)
     43     {
     44         for (int i = 0; i != a.length; i++)
     45         {
     46             this.addObject(a[i]);
     47         }
     48 
     49         this.sort();
     50     }
     51 
     52     /**
     53      * @param v - a vector of objects making up the set.
     54      */
     55     DERSet(
     56         DEREncodableVector   v,
     57         boolean              needsSorting)
     58     {
     59         for (int i = 0; i != v.size(); i++)
     60         {
     61             this.addObject(v.get(i));
     62         }
     63 
     64         if (needsSorting)
     65         {
     66             this.sort();
     67         }
     68     }
     69 
     70     /*
     71      * A note on the implementation:
     72      * <p>
     73      * As DER requires the constructed, definite-length model to
     74      * be used for structured types, this varies slightly from the
     75      * ASN.1 descriptions given. Rather than just outputing SET,
     76      * we also have to specify CONSTRUCTED, and the objects length.
     77      */
     78     void encode(
     79         DEROutputStream out)
     80         throws IOException
     81     {
     82         // TODO Intermediate buffer could be avoided if we could calculate expected length
     83         ByteArrayOutputStream   bOut = new ByteArrayOutputStream();
     84         DEROutputStream         dOut = new DEROutputStream(bOut);
     85         Enumeration             e = this.getObjects();
     86 
     87         while (e.hasMoreElements())
     88         {
     89             Object    obj = e.nextElement();
     90 
     91             dOut.writeObject(obj);
     92         }
     93 
     94         dOut.close();
     95 
     96         byte[]  bytes = bOut.toByteArray();
     97 
     98         out.writeEncoded(SET | CONSTRUCTED, bytes);
     99     }
    100 }
    101