BEROctetStringGenerator.java revision e6bf3e8dfa2804891a82075cb469b736321b4827 
1package org.bouncycastle.asn1;
2
3import java.io.IOException;
4import java.io.OutputStream;
5
6public class BEROctetStringGenerator
7    extends BERGenerator
8{
9    public BEROctetStringGenerator(OutputStream out)
10        throws IOException
11    {
12        super(out);
13
14        writeBERHeader(BERTags.CONSTRUCTED | BERTags.OCTET_STRING);
15    }
16
17    public BEROctetStringGenerator(
18        OutputStream out,
19        int tagNo,
20        boolean isExplicit)
21        throws IOException
22    {
23        super(out, tagNo, isExplicit);
24
25        writeBERHeader(BERTags.CONSTRUCTED | BERTags.OCTET_STRING);
26    }
27
28    public OutputStream getOctetOutputStream()
29    {
30        return getOctetOutputStream(new byte[1000]); // limit for CER encoding.
31    }
32
33    public OutputStream getOctetOutputStream(
34        byte[] buf)
35    {
36        return new BufferedBEROctetStream(buf);
37    }
38
39    private class BufferedBEROctetStream
40        extends OutputStream
41    {
42        private byte[] _buf;
43        private int    _off;
44        private DEROutputStream _derOut;
45
46        BufferedBEROctetStream(
47            byte[] buf)
48        {
49            _buf = buf;
50            _off = 0;
51            _derOut = new DEROutputStream(_out);
52        }
53
54        public void write(
55            int b)
56            throws IOException
57        {
58            _buf[_off++] = (byte)b;
59
60            if (_off == _buf.length)
61            {
62                DEROctetString.encode(_derOut, _buf);
63                _off = 0;
64            }
65        }
66
67        public void write(byte[] b, int off, int len) throws IOException
68        {
69            while (len > 0)
70            {
71                int numToCopy = Math.min(len, _buf.length - _off);
72                System.arraycopy(b, off, _buf, _off, numToCopy);
73
74                _off += numToCopy;
75                if (_off < _buf.length)
76                {
77                    break;
78                }
79
80                DEROctetString.encode(_derOut, _buf);
81                _off = 0;
82
83                off += numToCopy;
84                len -= numToCopy;
85            }
86        }
87
88        public void close()
89            throws IOException
90        {
91            if (_off != 0)
92            {
93                byte[] bytes = new byte[_off];
94                System.arraycopy(_buf, 0, bytes, 0, _off);
95
96                DEROctetString.encode(_derOut, bytes);
97            }
98
99             writeBEREnd();
100        }
101    }
102}
103