package org.bouncycastle.asn1; import java.io.ByteArrayOutputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import org.bouncycastle.util.io.Streams; public abstract class DERGenerator extends ASN1Generator { private boolean _tagged = false; private boolean _isExplicit; private int _tagNo; protected DERGenerator( OutputStream out) { super(out); } public DERGenerator( OutputStream out, int tagNo, boolean isExplicit) { super(out); _tagged = true; _isExplicit = isExplicit; _tagNo = tagNo; } private void writeLength( OutputStream out, int length) throws IOException { if (length > 127) { int size = 1; int val = length; while ((val >>>= 8) != 0) { size++; } out.write((byte)(size | 0x80)); for (int i = (size - 1) * 8; i >= 0; i -= 8) { out.write((byte)(length >> i)); } } else { out.write((byte)length); } } void writeDEREncoded( OutputStream out, int tag, byte[] bytes) throws IOException { out.write(tag); writeLength(out, bytes.length); out.write(bytes); } void writeDEREncoded( int tag, byte[] bytes) throws IOException { if (_tagged) { int tagNum = _tagNo | BERTags.TAGGED; if (_isExplicit) { int newTag = _tagNo | BERTags.CONSTRUCTED | BERTags.TAGGED; ByteArrayOutputStream bOut = new ByteArrayOutputStream(); writeDEREncoded(bOut, tag, bytes); writeDEREncoded(_out, newTag, bOut.toByteArray()); } else { if ((tag & BERTags.CONSTRUCTED) != 0) { writeDEREncoded(_out, tagNum | BERTags.CONSTRUCTED, bytes); } else { writeDEREncoded(_out, tagNum, bytes); } } } else { writeDEREncoded(_out, tag, bytes); } } void writeDEREncoded( OutputStream out, int tag, InputStream in) throws IOException { writeDEREncoded(out, tag, Streams.readAll(in)); } }