/*
* $Id: SaslInputStream.java,v 1.1 2003/10/19 08:51:37 dog Exp $
* Copyright (C) 2002 The Free Software Foundation
*
* This file is part of GNU inetlib, a library.
*
* GNU inetlib is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* GNU inetlib is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* As a special exception, if you link this library with other files to
* produce an executable, this library does not by itself cause the
* resulting executable to be covered by the GNU General Public License.
* This exception does not however invalidate any other reasons why the
* executable file might be covered by the GNU General Public License.
*/
package gnu.inet.util;
import java.io.FilterInputStream;
import java.io.InputStream;
import java.io.IOException;
import javax.security.sasl.SaslClient;
/**
* A filter input stream that decodes all its received input using a SASL
* client.
*
* @author Chris Burdess
* @version $Revision: 1.1 $ $Date: 2003/10/19 08:51:37 $
*/
public class SaslInputStream
extends FilterInputStream
{
/*
* The SASL client.
*/
private final SaslClient sasl;
/*
* Overflow buffer.
*/
private byte[] buf;
/*
* Offset in overflow buffer.
*/
private int pos;
/**
* Constructor.
* @param sasl the SASL client
* @param in the underlying input stream
*/
public SaslInputStream(SaslClient sasl, InputStream in)
{
super(in);
this.sasl = sasl;
}
/**
* Reads a single character.
*/
public int read()
throws IOException
{
if (buf!=null)
{
// Return next characer in buffer
int c = (int)buf[pos++];
if (pos==buf.length)
buf = null;
return c;
}
int c = super.read();
if (c==-1)
return c;
byte[] bytes = new byte[1];
byte[] unwrapped = sasl.unwrap(bytes, 0, 1);
// FIXME if we get 0 bytes, we have a problem
c = (int)unwrapped[0];
if (unwrapped.length>1)
{
// Store in overflow buffer
int l = unwrapped.length-1;
buf = new byte[l];
System.arraycopy(unwrapped, 1, buf, 0, l);
pos = 0;
}
return c;
}
public int read(byte[] bytes)
throws IOException
{
return read(bytes, 0, bytes.length);
}
/**
* Block read.
*/
public int read(byte[] bytes, int off, int len)
throws IOException
{
if (buf!=null)
{
// Return bytes from buffer
int l = buf.length;
if (l-pos<=len)
{
System.arraycopy(buf, pos, bytes, off, l);
buf = null;
return l;
}
else
{
System.arraycopy(buf, pos, bytes, off, len);
pos += len;
return len;
}
}
int l = super.read(bytes, off, len);
if (l==-1)
return l;
byte[] unwrapped = sasl.unwrap(bytes, off, l);
int l2 = unwrapped.length;
if (l2>len)
{
// Store excess bytes in buffer
int d = l2-len;
buf = new byte[d];
System.arraycopy(unwrapped, 0, bytes, off, len);
System.arraycopy(unwrapped, len, buf, 0, d);
pos = 0;
return len;
}
else
{
System.arraycopy(unwrapped, 0, bytes, off, l2);
// Zero bytes from l2..l to ensure none of the original
// bytes received can be read by the caller
for (int i=l2; i