int len = 2 + 2 + der.length + 4 + nb.length;
        byte[] out = new byte[len];
        int i = 0;
        out[i++] = 0x04; // TOK_ID[0]
        out[i++] = 0x01; // TOK_ID[1]
        out[i++] = (byte) ((der.length >> 8) & 0xFF);
        out[i++] = (byte) (der.length & 0xFF);
        System.arraycopy(der, 0, out, i, der.length);
        i += der.length;
        out[i++] = (byte) ((nb.length >> 24) & 0xFF);