anchor.diff:  { stdenv
  +, fetchFromGitHub
   , fetchurl
  +, lib
   
   , kernel
   
  
positive.code:   ];
  
    passthru = {
      srcVerification = fetchurl rec {
        failEarly = true;
        urls = tarballUrls "1.9";
        pgpsigUrls = map (n: "${n}.sig") urls;
        pgpKeyFingerprint = "EE81 2532 E317 608B 671D  9760 DA30 48E2 7A12 7A6F";
        inherit (src) outputHashAlgo;
        outputHash = "9f4c0b49b30e267d776f79455d09c70cc9c12c86eee400a0d0a0cd1d8e467950";
      };
    };
  
    meta = with stdenv.lib; {
      description = "Device that allows access to Linux kernel cryptographic drivers";
      homepage = http://home.gna.org/cryptodev-linux/;
      license = licenses.gpl2Plus;
  
negative.code: }:
  
  let
    inherit (lib)
      optionalString;
  
    #tarballUrls = version: [
    #  "http://nwl.cc/pub/cryptodev-linux/cryptodev-linux-${version}.tar.gz"
    #];
  
    version = "1.10";
  in
  stdenv.mkDerivation rec {
    name = "cryptodev-linux-${version}";
  
    src = fetchurl {
      url = "https://cryptodev-linux-${version}.tar.br";
      # Inject the tarball generated by fetchFromGitHub
      multihash = "QmNTdvMaDTzNP11eZh1zcVrRWpPdALaMkRV8VTrVLF6Wj5";
      hashOutput = false;
      sha256 = "7bf74db0e48741659c1f55eac5e429fd53d06dff19daa3e447fe964594d3ada9";
    };
  
    # If we are only building headers, just do that
    buildCommand = optionalString onlyHeaders ''
      unpackPhase
      install -D -m644 -v */crypto/cryptodev.h "$out"/include/crypto/cryptodev.h
    '';
  
    preBuild = optionalString (!onlyHeaders) ''
  