问在c#中用IDPF标准对字体文件进行混淆

EN

public void serialize(OutputStream out) throws IOException {
            try {
                    byte[] buffer = new byte[4096];
                    int len;
                    InputStream in = source.getInputStream();
                    boolean first = true;
                    while ((len = in.read(buffer)) > 0) {
                            if( first && mask != null ) {
                                    first = false;
                                    for( int i = 0 ; i < 1040 ; i++ ) {
                                            buffer[i] = (byte)(buffer[i] ^ mask[i%mask.length]);
                                    }
                            }
                            out.write(buffer, 0, len);
                    }
            } catch (IOException e) {
                    e.printStackTrace();
            }
            out.close();
    }