src/org/bouncycastle/asn1/DEROutputStream.java

   1 package org.bouncycastle.asn1;
   2
   3 import java.io.FilterOutputStream;
   4
   5 import java.io.OutputStream;
   6 import java.io.IOException;
   7 import java.io.EOFException;
   8
   9 public class DEROutputStream
  10     extends FilterOutputStream implements DERTags
  11 {
  12     public DEROutputStream(
  13         OutputStream    os)
  14     {
  15         super(os);
  16     }
  17
  18     private void writeLength(
  19         int length)
  20         throws IOException
  21     {
  22         if (length > 127)
  23         {
  24             int size = 1;
  25             int val = length;
  26
  27             while ((val >>>= 8) != 0)
  28             {
  29                 size++;
  30             }
  31
  32             write((byte)(size | 0x80));
  33
  34             for (int i = (size - 1) * 8; i >= 0; i -= 8)
  35             {
  36                 write((byte)(length >> i));
  37             }
  38         }
  39         else
  40         {
  41             write((byte)length);
  42         }
  43     }
  44
  45     void writeEncoded(
  46         int     tag,
  47         byte[]  bytes)
  48         throws IOException
  49     {
  50         write(tag);
  51         writeLength(bytes.length);
  52         write(bytes);
  53     }
  54
  55     protected void writeNull()
  56         throws IOException
  57     {
  58         write(NULL);
  59         write(0x00);
  60     }
  61
  62     public void writeObject(
  63         Object    obj)
  64         throws IOException
  65     {
  66         if (obj == null)
  67         {
  68             writeNull();
  69         }
  70         else if (obj instanceof DERObject)
  71         {
  72             ((DERObject)obj).encode(this);
  73         }
  74         else if (obj instanceof DEREncodable)
  75         {
  76             ((DEREncodable)obj).getDERObject().encode(this);
  77         }
  78         else
  79         {
  80             throw new IOException("object not DEREncodable");
  81         }
  82     }
  83 }