{ lib
, stdenv
, writeText
, fetchurl
, buildcatrust
, blacklist ? []
, extraCertificateFiles ? []
, extraCertificateStrings ? []

# Used by update.sh
, nssOverride ? null

# Used for tests only
, runCommand
, cacert
, openssl
}:

let
  blocklist = writeText "cacert-blocklist.txt" (lib.concatStringsSep "\n" blacklist);
  extraCertificatesBundle = writeText "cacert-extra-certificates-bundle.crt" (lib.concatStringsSep "\n\n" extraCertificateStrings);

  srcVersion = "3.80";
  version = if nssOverride != null then nssOverride.version else srcVersion;
  meta = with lib; {
    homepage = "https://curl.haxx.se/docs/caextract.html";
    description = "A bundle of X.509 certificates of public Certificate Authorities (CA)";
    platforms = platforms.all;
    maintainers = with maintainers; [ fpletz lukegb ];
    license = licenses.mpl20;
  };
  certdata = stdenv.mkDerivation {
    pname = "nss-cacert-certdata";
    inherit version;

    src = if nssOverride != null then nssOverride.src else fetchurl {
      url = "mirror://mozilla/security/nss/releases/NSS_${lib.replaceStrings ["."] ["_"] version}_RTM/src/nss-${version}.tar.gz";
      sha256 = "sha256-wL8f0sfimmsCswliK6r8RD7skMiTS7FV2ku5iYh4S2o=";
    };

    dontBuild = true;

    installPhase = ''
      runHook preInstall

      mkdir $out
      cp nss/lib/ckfw/builtins/certdata.txt $out

      runHook postInstall
    '';

    inherit meta;
  };
in
stdenv.mkDerivation rec {
  pname = "nss-cacert";
  inherit version;

  src = certdata;

  outputs = [ "out" "unbundled" "p11kit" ];

  nativeBuildInputs = [ buildcatrust ];

  buildPhase = ''
    mkdir unbundled
    buildcatrust \
      --certdata_input certdata.txt \
      --ca_bundle_input "${extraCertificatesBundle}" ${lib.escapeShellArgs (map (arg: "${arg}") extraCertificateFiles)} \
      --blocklist "${blocklist}" \
      --ca_bundle_output ca-bundle.crt \
      --ca_unpacked_output unbundled \
      --p11kit_output ca-bundle.trust.p11-kit
  '';

  installPhase = ''
    install -D -t "$out/etc/ssl/certs" ca-bundle.crt

    # install p11-kit specific output to p11kit output
    install -D -t "$p11kit/etc/ssl/trust-source" ca-bundle.trust.p11-kit

    # install individual certs in unbundled output
    install -D -t "$unbundled/etc/ssl/certs" unbundled/*.crt
  '';

  setupHook = ./setup-hook.sh;

  passthru = {
    updateScript = ./update.sh;
    tests = let
      isTrusted = ''
        isTrusted() {
          # isTrusted <unbundled-dir> <ca name> <ca sha256 fingerprint>
          for f in $1/etc/ssl/certs/*.crt; do
            if ! [[ -s "$f" ]]; then continue; fi
            fingerprint="$(openssl x509 -in "$f" -noout -fingerprint -sha256 | cut -f2 -d=)"
            if [[ "x$fingerprint" == "x$3" ]]; then
              # If the certificate is treated as rejected for TLS Web Server, then we consider it untrusted.
              if openssl x509 -in "$f" -noout -text | grep -q '^Rejected Uses:'; then
                if openssl x509 -in "$f" -noout -text | grep -A1 '^Rejected Uses:' | grep -q 'TLS Web Server'; then
                  return 1
                fi
              fi
              return 0
            fi
          done
          return 1
        }
      '';
    in {
      # Test that building this derivation with a blacklist works, and that UTF-8 is supported.
      blacklist-utf8 = let
        blacklistCAToFingerprint = {
          # "blacklist" uses the CA name from the NSS bundle, but we check for presence using the SHA256 fingerprint.
          "CFCA EV ROOT" = "5C:C3:D7:8E:4E:1D:5E:45:54:7A:04:E6:87:3E:64:F9:0C:F9:53:6D:1C:CC:2E:F8:00:F3:55:C4:C5:FD:70:FD";
          "NetLock Arany (Class Gold) Főtanúsítvány" = "6C:61:DA:C3:A2:DE:F0:31:50:6B:E0:36:D2:A6:FE:40:19:94:FB:D1:3D:F9:C8:D4:66:59:92:74:C4:46:EC:98";
        };
        mapBlacklist = f: lib.concatStringsSep "\n" (lib.mapAttrsToList f blacklistCAToFingerprint);
      in runCommand "verify-the-cacert-filter-output" {
        cacert = cacert.unbundled;
        cacertWithExcludes = (cacert.override {
          blacklist = builtins.attrNames blacklistCAToFingerprint;
        }).unbundled;

        nativeBuildInputs = [ openssl ];
      } ''
        ${isTrusted}

        # Ensure that each certificate is in the main "cacert".
        ${mapBlacklist (caName: caFingerprint: ''
          isTrusted "$cacert" "${caName}" "${caFingerprint}" || ({
            echo "CA fingerprint ${caFingerprint} (${caName}) is missing from the CA bundle. Consider picking a different CA for the blacklist test." >&2
            exit 1
          })
        '')}

        # Ensure that each certificate is NOT in the "cacertWithExcludes".
        ${mapBlacklist (caName: caFingerprint: ''
          isTrusted "$cacertWithExcludes" "${caName}" "${caFingerprint}" && ({
            echo "CA fingerprint ${caFingerprint} (${caName}) is present in the cacertWithExcludes bundle." >&2
            exit 1
          })
        '')}

        touch "$out"
      '';

      # Test that we can add additional certificates to the store, and have them be trusted.
      extra-certificates = let
        extraCertificateStr = ''
          -----BEGIN CERTIFICATE-----
          MIIB5DCCAWqgAwIBAgIUItvsAYEIdYDkOIo5sdDYMcUaNuIwCgYIKoZIzj0EAwIw
          KTEnMCUGA1UEAwweTml4T1MgY2FjZXJ0IGV4dHJhIGNlcnRpZmljYXRlMB4XDTIx
          MDYxMjE5MDQzMFoXDTIyMDYxMjE5MDQzMFowKTEnMCUGA1UEAwweTml4T1MgY2Fj
          ZXJ0IGV4dHJhIGNlcnRpZmljYXRlMHYwEAYHKoZIzj0CAQYFK4EEACIDYgAEuP8y
          lAm6ZyQt9v/P6gTlV/a9R+D61WjucW04kaegOhg8csiluimYodiSv0Pbgymu+Zxm
          A3Bz9QGmytaYTiJ16083rJkwwIhqoYl7kWsLzreSTaLz87KH+rdeol59+H0Oo1Mw
          UTAdBgNVHQ4EFgQUCxuHfvqI4YVU5M+A0+aKvd1LrdswHwYDVR0jBBgwFoAUCxuH
          fvqI4YVU5M+A0+aKvd1LrdswDwYDVR0TAQH/BAUwAwEB/zAKBggqhkjOPQQDAgNo
          ADBlAjEArgxgjdNmRlSEuai0dzlktmBEDZKy2Iiul+ttSoce9ohfEVYESwO602HW
          keVvI56vAjBCro3dc3m2TuktiKO6lQV56PUEyxko4H/sR5pnHlduCGRDlFzQKXf/
          pMMmtj7cVb8=
          -----END CERTIFICATE-----
        '';
        extraCertificateFile = ./test-cert-file.crt;
        extraCertificatesToFingerprint = {
          # String above
          "NixOS cacert extra certificate string" = "A3:20:D0:84:96:97:25:FF:98:B8:A9:6D:A3:7C:89:95:6E:7A:77:21:92:F3:33:E9:31:AF:5E:03:CE:A9:E5:EE";

          # File
          "NixOS cacert extra certificate file" = "88:B8:BE:A7:57:AC:F1:FE:D6:98:8B:50:E0:BD:0A:AE:88:C7:DF:70:26:E1:67:5E:F5:F6:91:27:FF:02:D4:A5";
        };
        mapExtra = f: lib.concatStringsSep "\n" (lib.mapAttrsToList f extraCertificatesToFingerprint);
      in runCommand "verify-the-cacert-extra-output" {
        cacert = cacert.unbundled;
        cacertWithExtras = (cacert.override {
          extraCertificateStrings = [ extraCertificateStr ];
          extraCertificateFiles = [ extraCertificateFile ];
        }).unbundled;

        nativeBuildInputs = [ openssl ];
      } ''
        ${isTrusted}

        # Ensure that the extra certificate is not in the main "cacert".
        ${mapExtra (extraName: extraFingerprint: ''
          isTrusted "$cacert" "${extraName}" "${extraFingerprint}" && ({
            echo "'extra' CA fingerprint ${extraFingerprint} (${extraName}) is present in the main CA bundle." >&2
            exit 1
          })
        '')}

        # Ensure that the extra certificates ARE in the "cacertWithExtras".
        ${mapExtra (extraName: extraFingerprint: ''
          isTrusted "$cacertWithExtras" "${extraName}" "${extraFingerprint}" || ({
            echo "CA fingerprint ${extraFingerprint} (${extraName}) is not present in the cacertWithExtras bundle." >&2
            exit 1
          })
        '')}

        touch "$out"
      '';
    };
  };

  inherit meta;
}