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