anchor.diff:  { stdenv, fetchurl, gmp, pkgconfig, python, autoreconfHook
  -, curl, trousers, sqlite
  +, curl, trousers, sqlite, iptables, libxml2
   , enableTNC ? false }:
   
   stdenv.mkDerivation rec {
  
positive.code:   ];
  
    configureFlags =
      [ "--enable-swanctl" "--enable-cmd" ]
      ++ stdenv.lib.optionals enableTNC [
           "--disable-gmp" "--disable-aes" "--disable-md5" "--disable-sha1" "--disable-sha2" "--disable-fips-prf"
           "--enable-curl" "--enable-openssl" "--enable-eap-identity" "--enable-eap-md5" "--enable-eap-mschapv2"
           "--enable-eap-tnc" "--enable-eap-ttls" "--enable-eap-dynamic" "--enable-tnccs-20"
           "--enable-tnc-imc" "--enable-imc-os" "--enable-imc-attestation"
           "--enable-tnc-imv" "--enable-imv-attestation"
           "--with-tss=trousers"
           "--enable-aikgen"
           "--enable-sqlite" ];
  
negative.code:   dontPatchELF = true;
  
    buildInputs =
      [ gmp pkgconfig python autoreconfHook iptables ]
      ++ stdenv.lib.optionals enableTNC [ curl trousers sqlite libxml2 ];
  
    patches = [
      ./ext_auth-path.patch
  