src/org/bouncycastle/asn1/DEROutputStream.java

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