NixOS acme selfsigned CA service failure test

acme2.nix

let
  commonConfig = ./common/acme/client;

  dnsServerIP = nodes: nodes.dnsserver.config.networking.primaryIPAddress;

  dnsScript = {pkgs, nodes}: let
    dnsAddress = dnsServerIP nodes;
  in pkgs.writeShellScript "dns-hook.sh" ''
    set -euo pipefail
    echo '[INFO]' "[$2]" 'dns-hook.sh' $*
    if [ "$1" = "present" ]; then
      ${pkgs.curl}/bin/curl --data '{"host": "'"$2"'", "value": "'"$3"'"}' http://${dnsAddress}:8055/set-txt
    else
      ${pkgs.curl}/bin/curl --data '{"host": "'"$2"'"}' http://${dnsAddress}:8055/clear-txt
    fi
  '';

  documentRoot = pkgs: pkgs.runCommand "docroot" {} ''
    mkdir -p "$out"
    echo hello world > "$out/index.html"
  '';

  vhostBase = pkgs: {
    forceSSL = true;
    locations."/".root = documentRoot pkgs;
  };

in import ./make-test-python.nix ({ lib, ... }: {
  name = "acme";
  meta.maintainers = lib.teams.acme.members;

  nodes = {
    # The fake ACME server which will respond to client requests
    acme = { nodes, lib, ... }: {
      imports = [ ./common/acme/server ];
      networking.nameservers = lib.mkForce [ (dnsServerIP nodes) ];
    };

    # A fake DNS server which can be configured with records as desired
    # Used to test DNS-01 challenge
    dnsserver = { nodes, pkgs, ... }: {
      networking.firewall.allowedTCPPorts = [ 8055 53 ];
      networking.firewall.allowedUDPPorts = [ 53 ];
      systemd.services.pebble-challtestsrv = {
        enable = true;
        description = "Pebble ACME challenge test server";
        wantedBy = [ "network.target" ];
        serviceConfig = {
          ExecStart = "${pkgs.pebble}/bin/pebble-challtestsrv -dns01 ':53' -defaultIPv6 '' -defaultIPv4 '${nodes.webserver.config.networking.primaryIPAddress}'";
          # Required to bind on privileged ports.
          AmbientCapabilities = [ "CAP_NET_BIND_SERVICE" ];
        };
      };
    };

    # A web server which will be the node requesting certs
    webserver = { pkgs, nodes, lib, config, ... }: {
      imports = [ commonConfig ];
      networking.nameservers = lib.mkForce [ (dnsServerIP nodes) ];
      networking.firewall.allowedTCPPorts = [ 80 443 ];

      # OpenSSL will be used for more thorough certificate validation
      environment.systemPackages = [ pkgs.openssl ];

      # Set log level to info so that we can see when the service is reloaded
      services.nginx.enable = true;
      services.nginx.logError = "stderr info";

      # First tests configure a basic cert and run a bunch of openssl checks
      services.nginx.virtualHosts."a.example.test" = (vhostBase pkgs) // {
        enableACME = true;
      };

      services.httpd.enable = true;
      services.httpd.adminAddr = "you@example.com";
      services.httpd.virtualHosts."z.example.test" = {
        enableACME = true;
        forceSSL = true;
      };

      specialisation.many-certs.configuration = { nodes, pkgs, lib, ... }: {
        services.nginx.virtualHosts."b.example.test" = (vhostBase pkgs) // {
            enableACME = true;
        };
        services.nginx.virtualHosts."c.example.test" = (vhostBase pkgs) // {
            enableACME = true;
        };
      };
      specialisation.many-certs-b.configuration = { nodes, pkgs, lib, ... }: {
        services.nginx.virtualHosts."d.example.test" = (vhostBase pkgs) // {
            enableACME = true;
        };
        services.nginx.virtualHosts."e.example.test" = (vhostBase pkgs) // {
            enableACME = true;
        };
      };
      specialisation.many-certs-c.configuration = { nodes, pkgs, lib, ... }: {
        services.nginx.virtualHosts."f.example.test" = (vhostBase pkgs) // {
            enableACME = true;
        };
        services.nginx.virtualHosts."g.example.test" = (vhostBase pkgs) // {
            enableACME = true;
        };
        services.nginx.virtualHosts."h.example.test" = (vhostBase pkgs) // {
            enableACME = true;
        };
        services.nginx.virtualHosts."i.example.test" = (vhostBase pkgs) // {
            enableACME = true;
        };
      };
    };

    # The client will be used to curl the webserver to validate configuration
    client = {nodes, lib, pkgs, ...}: {
      imports = [ commonConfig ];
      networking.nameservers = lib.mkForce [ (dnsServerIP nodes) ];

      # OpenSSL will be used for more thorough certificate validation
      environment.systemPackages = [ pkgs.openssl ];
    };
  };

  testScript = {nodes, ...}:
    let
      caDomain = nodes.acme.config.test-support.acme.caDomain;
      newServerSystem = nodes.webserver.config.system.build.toplevel;
      switchToNewServer = "${newServerSystem}/bin/switch-to-configuration test";
    in
    # Note, wait_for_unit does not work for oneshot services that do not have RemainAfterExit=true,
    # this is because a oneshot goes from inactive => activating => inactive, and never
    # reaches the active state. Targets do not have this issue.

    ''
      import time


      has_switched = False


      def switch_to(node, name):
          global has_switched
          if has_switched:
              node.succeed(
                  "${switchToNewServer}"
              )
          has_switched = True
          node.succeed(
              f"/run/current-system/specialisation/{name}/bin/switch-to-configuration test"
          )


      # Ensures the issuer of our cert matches the chain
      # and matches the issuer we expect it to be.
      # It's a good validation to ensure the cert.pem and fullchain.pem
      # are not still selfsigned afer verification
      def check_issuer(node, cert_name, issuer):
          for fname in ("cert.pem", "fullchain.pem"):
              actual_issuer = node.succeed(
                  f"openssl x509 -noout -issuer -in /var/lib/acme/{cert_name}/{fname}"
              ).partition("=")[2]
              print(f"{fname} issuer: {actual_issuer}")
              assert issuer.lower() in actual_issuer.lower()


      # Ensure cert comes before chain in fullchain.pem
      def check_fullchain(node, cert_name):
          subject_data = node.succeed(
              f"openssl crl2pkcs7 -nocrl -certfile /var/lib/acme/{cert_name}/fullchain.pem"
              " | openssl pkcs7 -print_certs -noout"
          )
          for line in subject_data.lower().split("\n"):
              if "subject" in line:
                  print(f"First subject in fullchain.pem: {line}")
                  assert cert_name.lower() in line
                  return

          assert False


      def check_connection(node, domain, retries=3):
          assert retries >= 0, f"Failed to connect to https://{domain}"

          result = node.succeed(
              "openssl s_client -brief -verify 2 -CAfile /tmp/ca.crt"
              f" -servername {domain} -connect {domain}:443 < /dev/null 2>&1"
          )

          for line in result.lower().split("\n"):
              if "verification" in line and "error" in line:
                  time.sleep(3)
                  return check_connection(node, domain, retries - 1)


      def check_connection_key_bits(node, domain, bits, retries=3):
          assert retries >= 0, f"Did not find expected number of bits ({bits}) in key"

          result = node.succeed(
              "openssl s_client -CAfile /tmp/ca.crt"
              f" -servername {domain} -connect {domain}:443 < /dev/null"
              " | openssl x509 -noout -text | grep -i Public-Key"
          )
          print("Key type:", result)

          if bits not in result:
              time.sleep(3)
              return check_connection_key_bits(node, domain, bits, retries - 1)


      def check_stapling(node, domain, retries=3):
          assert retries >= 0, "OCSP Stapling check failed"

          # Pebble doesn't provide a full OCSP responder, so just check the URL
          result = node.succeed(
              "openssl s_client -CAfile /tmp/ca.crt"
              f" -servername {domain} -connect {domain}:443 < /dev/null"
              " | openssl x509 -noout -ocsp_uri"
          )
          print("OCSP Responder URL:", result)

          if "${caDomain}:4002" not in result.lower():
              time.sleep(3)
              return check_stapling(node, domain, retries - 1)


      def download_ca_certs(node, retries=5):
          assert retries >= 0, "Failed to connect to pebble to download root CA certs"

          exit_code, _ = node.execute("curl https://${caDomain}:15000/roots/0 > /tmp/ca.crt")
          exit_code_2, _ = node.execute(
              "curl https://${caDomain}:15000/intermediate-keys/0 >> /tmp/ca.crt"
          )

          if exit_code + exit_code_2 > 0:
              time.sleep(3)
              return download_ca_certs(node, retries - 1)


      client.start()
      dnsserver.start()

      dnsserver.wait_for_unit("pebble-challtestsrv.service")
      client.wait_for_unit("default.target")

      client.succeed(
          'curl --data \'{"host": "${caDomain}", "addresses": ["${nodes.acme.config.networking.primaryIPAddress}"]}\' http://${dnsServerIP nodes}:8055/add-a'
      )

      acme.start()
      webserver.start()

      acme.wait_for_unit("network-online.target")
      acme.wait_for_unit("pebble.service")

      download_ca_certs(client)

      with subtest("Can request certificate with HTTPS-01 challenge"):
          webserver.wait_for_unit("acme-finished-a.example.test.target")
          webserver.wait_for_unit("nginx.service")
          _, output = webserver.execute("systemctl status acme-selfsigned-ca.service || true")
          print(output)

      with subtest("Can create many certs at once"):
          switch_to(webserver, "many-certs")
          webserver.wait_for_unit("acme-finished-b.example.test.target")
          webserver.wait_for_unit("acme-finished-c.example.test.target")
          webserver.wait_for_unit("nginx.service")
          _, output = webserver.execute("systemctl status acme-selfsigned-ca.service")
          print(output)

      with subtest("many certs b"):
          switch_to(webserver, "many-certs-b")
          webserver.wait_for_unit("acme-finished-d.example.test.target")
          webserver.wait_for_unit("acme-finished-e.example.test.target")
          webserver.wait_for_unit("nginx.service")
          _, output = webserver.execute("systemctl status acme-selfsigned-ca.service")
          print(output)

      with subtest("many certs c"):
          switch_to(webserver, "many-certs-c")
          webserver.wait_for_unit("acme-finished-f.example.test.target")
          webserver.wait_for_unit("nginx.service")
          _, output = webserver.execute("systemctl status acme-selfsigned-ca.service")
          print(output)
    '';
})