path: root/nixos/tests/curl-impersonate.nix

/*
  Test suite for curl-impersonate

  Abstract:
    Uses the test suite from the curl-impersonate source repo which:

    1. Performs requests with libcurl and captures the TLS client-hello
       packets with tcpdump to compare against known-good signatures
    2. Spins up an nghttpd2 server to test client HTTP/2 headers against
       known-good headers

    See https://github.com/lwthiker/curl-impersonate/tree/main/tests/signatures
    for details.

  Notes:
    - We need to have our own web server running because the tests expect to be able
      to hit domains like wikipedia.org and the sandbox has no internet
    - We need to be able to do (verifying) TLS handshakes without internet access.
      We do that by creating a trusted CA and issuing a cert that includes
      all of the test domains as subject-alternative names and then spoofs the
      hostnames in /etc/hosts.
*/

import ./make-test-python.nix ({ pkgs, lib, ... }: let
  # Update with domains in TestImpersonate.TEST_URLS if needed from:
  # https://github.com/lwthiker/curl-impersonate/blob/main/tests/test_impersonate.py
  domains = [
    "www.wikimedia.org"
    "www.wikipedia.org"
    "www.mozilla.org"
    "www.apache.org"
    "www.kernel.org"
    "git-scm.com"
  ];

  tls-certs = let
    # Configure CA with X.509 v3 extensions that would be trusted by curl
    ca-cert-conf = pkgs.writeText "curl-impersonate-ca.cnf" ''
      basicConstraints = critical, CA:TRUE
      subjectKeyIdentifier = hash
      authorityKeyIdentifier = keyid:always, issuer:always
      keyUsage = critical, cRLSign, digitalSignature, keyCertSign
    '';

    # Configure leaf certificate with X.509 v3 extensions that would be trusted
    # by curl and set subject-alternative names for test domains
    tls-cert-conf = pkgs.writeText "curl-impersonate-tls.cnf" ''
      basicConstraints = critical, CA:FALSE
      subjectKeyIdentifier = hash
      authorityKeyIdentifier = keyid:always, issuer:always
      keyUsage = critical, nonRepudiation, digitalSignature, keyEncipherment, keyAgreement
      extendedKeyUsage = critical, serverAuth
      subjectAltName = @alt_names

      [alt_names]
      ${lib.concatStringsSep "\n" (lib.imap0 (idx: domain: "DNS.${toString idx} = ${domain}") domains)}
    '';
  in pkgs.runCommand "curl-impersonate-test-certs" {
    nativeBuildInputs = [ pkgs.openssl ];
  } ''
    # create CA certificate and key
    openssl req -newkey rsa:4096 -keyout ca-key.pem -out ca-csr.pem -nodes -subj '/CN=curl-impersonate-ca.nixos.test'
    openssl x509 -req -sha512 -in ca-csr.pem -key ca-key.pem -out ca.pem -extfile ${ca-cert-conf} -days 36500
    openssl x509 -in ca.pem -text

    # create server certificate and key
    openssl req -newkey rsa:4096 -keyout key.pem -out csr.pem -nodes -subj '/CN=curl-impersonate.nixos.test'
    openssl x509 -req -sha512 -in csr.pem -CA ca.pem -CAkey ca-key.pem -CAcreateserial -out cert.pem -extfile ${tls-cert-conf} -days 36500
    openssl x509 -in cert.pem -text

    # output CA cert and server cert and key
    mkdir -p $out
    cp key.pem cert.pem ca.pem $out
  '';

  # Test script
  curl-impersonate-test = let
    # Build miniature libcurl client used by test driver
    minicurl = pkgs.runCommandCC "minicurl" {
      buildInputs = [ pkgs.curl ];
    } ''
      mkdir -p $out/bin
      $CC -Wall -Werror -o $out/bin/minicurl ${pkgs.curl-impersonate.src}/tests/minicurl.c `curl-config --libs`
    '';
  in pkgs.writeShellScript "curl-impersonate-test" ''
    set -euxo pipefail

    # Test driver requirements
    export PATH="${with pkgs; lib.makeBinPath [
      bash
      coreutils
      python3Packages.pytest
      nghttp2
      tcpdump
    ]}"
    export PYTHONPATH="${with pkgs.python3Packages; makePythonPath [
      pyyaml
      pytest-asyncio
      dpkt
    ]}"

    # Prepare test root prefix
    mkdir -p usr/{bin,lib}
    cp -rs ${pkgs.curl-impersonate}/* ${minicurl}/* usr/

    cp -r ${pkgs.curl-impersonate.src}/tests ./

    # Run tests
    cd tests
    pytest . --install-dir ../usr --capture-interface eth1
  '';
in {
  name = "curl-impersonate";

  meta = with lib.maintainers; {
    maintainers = [ lilyinstarlight ];
  };

  nodes = {
    web = { nodes, pkgs, lib, config, ... }: {
      networking.firewall.allowedTCPPorts = [ 80 443 ];

      services = {
        nginx = {
          enable = true;
          virtualHosts."curl-impersonate.nixos.test" = {
            default = true;
            addSSL = true;
            sslCertificate = "${tls-certs}/cert.pem";
            sslCertificateKey = "${tls-certs}/key.pem";
          };
        };
      };
    };

    curl = { nodes, pkgs, lib, config, ... }: {
      networking.extraHosts = lib.concatStringsSep "\n" (map (domain: "${nodes.web.networking.primaryIPAddress}  ${domain}") domains);

      security.pki.certificateFiles = [ "${tls-certs}/ca.pem" ];
    };
  };

  testScript = { nodes, ... }: ''
    start_all()

    with subtest("Wait for network"):
        web.wait_for_unit("network-online.target")
        curl.wait_for_unit("network-online.target")

    with subtest("Wait for web server"):
        web.wait_for_unit("nginx.service")
        web.wait_for_open_port(443)

    with subtest("Run curl-impersonate tests"):
        curl.succeed("${curl-impersonate-test}")
  '';
})