package org.bouncycastle.crypto.io;import java.io.FilterInputStream;import java.io.IOException;import java.io.InputStream;import org.bouncycastle.crypto.Mac;public class MacInputStream    extends FilterInputStream{    protected Mac mac;    public MacInputStream(        InputStream stream,        Mac         mac)    {        super(stream);        this.mac = mac;    }    public int read()        throws IOException    {        int b = in.read();        if (b >= 0)        {            mac.update((byte)b);        }        return b;    }    public int read(        byte[] b,        int off,        int len)        throws IOException    {        int n = in.read(b, off, len);        if (n >= 0)        {            mac.update(b, off, n);        }        return n;    }    public Mac getMac()    {        return mac;    }}