package com.lowagie.bc.asn1; import java.io.FilterOutputStream; import java.io.IOException; import java.io.OutputStream; public class DEROutputStream extends FilterOutputStream implements DERTags { public DEROutputStream( OutputStream os) { super(os); } private void writeLength( int length) throws IOException { if (length > 127) { int size = 1; int val = length; while ((val >>>= 8) != 0) { size++; } write((byte)(size | 0x80)); for (int i = (size - 1) * 8; i >= 0; i -= 8) { write((byte)(length >> i)); } } else { write((byte)length); } } void writeEncoded( int tag, byte[] bytes) throws IOException { write(tag); writeLength(bytes.length); write(bytes); } protected void writeNull() throws IOException { write(NULL); write(0x00); } public void writeObject( Object obj) throws IOException { if (obj == null) { writeNull(); } else if (obj instanceof DERObject) { ((DERObject)obj).encode(this); } else if (obj instanceof DEREncodable) { ((DEREncodable)obj).getDERObject().encode(this); } else { throw new IOException("object not DEREncodable"); } } }