001package org.apache.commons.ssl.asn1;
002
003import java.io.IOException;
004import java.io.OutputStream;
005
006public class BEROctetStringGenerator
007    extends BERGenerator {
008    public BEROctetStringGenerator(OutputStream out)
009        throws IOException {
010        super(out);
011
012        writeBERHeader(DERTags.CONSTRUCTED | DERTags.OCTET_STRING);
013    }
014
015    public BEROctetStringGenerator(
016        OutputStream out,
017        int tagNo,
018        boolean isExplicit)
019        throws IOException {
020        super(out, tagNo, isExplicit);
021
022        writeBERHeader(DERTags.CONSTRUCTED | DERTags.OCTET_STRING);
023    }
024
025    public OutputStream getOctetOutputStream() {
026        return getOctetOutputStream(new byte[1000]); // limit for CER encoding.
027    }
028
029    public OutputStream getOctetOutputStream(
030        byte[] buf) {
031        return new BufferedBEROctetStream(buf);
032    }
033
034    private class BufferedBEROctetStream
035        extends OutputStream {
036        private byte[] _buf;
037        private int _off;
038
039        BufferedBEROctetStream(
040            byte[] buf) {
041            _buf = buf;
042            _off = 0;
043        }
044
045        public void write(
046            int b)
047            throws IOException {
048            _buf[_off++] = (byte) b;
049
050            if (_off == _buf.length) {
051                _out.write(new DEROctetString(_buf).getEncoded());
052                _off = 0;
053            }
054        }
055
056        public void write(byte[] b, int off, int len) throws IOException {
057            while (len > 0) {
058                int numToCopy = Math.min(len, _buf.length - _off);
059                System.arraycopy(b, off, _buf, _off, numToCopy);
060
061                _off += numToCopy;
062                if (_off < _buf.length) {
063                    break;
064                }
065
066                _out.write(new DEROctetString(_buf).getEncoded());
067                _off = 0;
068
069                off += numToCopy;
070                len -= numToCopy;
071            }
072        }
073
074        public void close()
075            throws IOException {
076            if (_off != 0) {
077                byte[] bytes = new byte[_off];
078                System.arraycopy(_buf, 0, bytes, 0, _off);
079
080                _out.write(new DEROctetString(bytes).getEncoded());
081            }
082
083            writeBEREnd();
084        }
085    }
086}