private void reset() {
        if (socketProcess != null) {
            socketProcess.cancel(true);
            socketProcess = null;
        }
        if (serverSocket != null) {
            try {
                serverSocket.close();
            }
            catch (IOException e) {
                Log.warn("Error closing proxy listening socket", e);
            }
        }
    }
Creates the digest needed for a byte stream. It is the SHA1(sessionID +
initiator + target).

@param sessionID The sessionID of the stream negotiation
@param initiator The initiator of the stream negotiation
@param target The target of the stream negotiation
@return SHA-1 hash of the three parameters
xmppserver/src/main/java/org/jivesoftware/openfire/filetransfer/proxy/ProxyConnectionManager.java