<?php
// Start session
if (session_status() !== PHP_SESSION_ACTIVE) {
  session_name($SESSION_NAME);
  ini_set("session.cookie_httponly", 1);
  ini_set("session.cookie_samesite", $SESSION_SAMESITE_POLICY);
  ini_set('session.gc_maxlifetime', $SESSION_LIFETIME);
}

$_SESSION['access_all_exception'] = '0';

if (isset($_SERVER['HTTP_X_FORWARDED_PROTO']) &&
  strtolower($_SERVER['HTTP_X_FORWARDED_PROTO']) == "https") {
  if (session_status() !== PHP_SESSION_ACTIVE) {
    ini_set("session.cookie_secure", 1);
  }
  $IS_HTTPS = true;
}
elseif (isset($_SERVER['HTTPS'])) {
  if (session_status() !== PHP_SESSION_ACTIVE) {
    ini_set("session.cookie_secure", 1);
  }
  $IS_HTTPS = true;
}
else {
  $IS_HTTPS = false;
}

if (session_status() !== PHP_SESSION_ACTIVE) {
  session_start();
}

if (!isset($_SESSION['CSRF']['TOKEN'])) {
  $_SESSION['CSRF']['TOKEN'] = bin2hex(random_bytes(32));
}

// Set session UA
if (!isset($_SESSION['SESS_REMOTE_UA'])) {
  $_SESSION['SESS_REMOTE_UA'] = $_SERVER['HTTP_USER_AGENT'];
}

// Keep session active
if (isset($_SESSION['LAST_ACTIVITY']) && (time() - $_SESSION['LAST_ACTIVITY'] > $SESSION_LIFETIME)) {
  session_unset();
  session_destroy();
}
$_SESSION['LAST_ACTIVITY'] = time();

// API
if (!empty($_SERVER['HTTP_X_API_KEY'])) {
  $stmt = $pdo->prepare("SELECT * FROM `api` WHERE `api_key` = :api_key AND `active` = '1';");
  $stmt->execute(array(
    ':api_key' => preg_replace('/[^a-zA-Z0-9-]/', '', $_SERVER['HTTP_X_API_KEY'])
  ));
  $api_return = $stmt->fetch(PDO::FETCH_ASSOC);
  if (!empty($api_return['api_key'])) {
    $skip_ip_check = ($api_return['skip_ip_check'] == 1);
    $remote = get_remote_ip(false);
    $allow_from = array_map('trim', preg_split( "/( |,|;|\n)/", $api_return['allow_from']));
    if ($skip_ip_check === true || ip_acl($remote, $allow_from)) {
      $_SESSION['mailcow_cc_username'] = 'API';
      $_SESSION['mailcow_cc_role'] = 'admin';
      $_SESSION['mailcow_cc_api'] = true;
      if ($api_return['access'] == 'rw') {
        $_SESSION['mailcow_cc_api_access'] = 'rw';
      }
      else {
        $_SESSION['mailcow_cc_api_access'] = 'ro';
      }
      // Bind the session to this key, see the check below
      $_SESSION['mailcow_cc_api_key_id'] = $api_return['id'];
      $_SESSION['mailcow_cc_api_key_hash'] = hash('sha256', $api_return['api_key']);
    }
    else {
      $redis->publish("F2B_CHANNEL", "mailcow UI: Invalid password for API_USER by " . $_SERVER['REMOTE_ADDR']);
      error_log("mailcow UI: Invalid password for " . $user . " by " . $_SERVER['REMOTE_ADDR']);
      http_response_code(401);
      echo json_encode(array(
        'type' => 'error',
        'msg' => 'api access denied for ip ' . $_SERVER['REMOTE_ADDR']
      ));
      unset($_POST);
      exit();
    }
  }
  else {
    $redis->publish("F2B_CHANNEL", "mailcow UI: Invalid password for API_USER by " . $_SERVER['REMOTE_ADDR']);
    error_log("mailcow UI: Invalid password for " . $user . " by " . $_SERVER['REMOTE_ADDR']);
    http_response_code(401);
    echo json_encode(array(
      'type' => 'error',
      'msg' => 'authentication failed'
    ));
    unset($_POST);
    exit();
  }
}
elseif (!empty($_SESSION['mailcow_cc_api'])) {
  // API session without header: end it when its key was deleted, deactivated, regenerated or its access changed
  if (!isset($pdo)) {
    // sogo-auth.php (nginx auth_request) loads no prerequisites
    $pdo = new PDO($database_type . ":unix_socket=" . $database_sock . ";dbname=" . $database_name, $database_user, $database_pass, array(
      PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
      PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC,
      PDO::ATTR_EMULATE_PREPARES => false,
    ));
  }
  $stmt = $pdo->prepare("SELECT `api_key`, `access` FROM `api` WHERE `id` = :id AND `active` = '1';");
  $stmt->execute(array(':id' => intval($_SESSION['mailcow_cc_api_key_id'] ?? 0)));
  $api_return = $stmt->fetch(PDO::FETCH_ASSOC);
  if (empty($api_return['api_key']) ||
    !hash_equals((string)($_SESSION['mailcow_cc_api_key_hash'] ?? ''), hash('sha256', $api_return['api_key'])) ||
    $api_return['access'] != ($_SESSION['mailcow_cc_api_access'] ?? '')) {
    session_unset();
    session_destroy();
  }
}

// Handle logouts
if (isset($_POST["logout"])) {
  if (isset($_SESSION["dual-login"])) {
    $_SESSION["mailcow_cc_username"] = $_SESSION["dual-login"]["username"];
    $_SESSION["mailcow_cc_role"] = $_SESSION["dual-login"]["role"];
    unset($_SESSION['sogo-sso-user-allowed']);
    unset($_SESSION['sogo-sso-pass']);
    unset($_SESSION["dual-login"]);
    if ($_SESSION["mailcow_cc_role"] == "admin"){
      header("Location: /admin/mailbox");
    } elseif ($_SESSION["mailcow_cc_role"] == "domainadmin") {
      header("Location: /domainadmin/mailbox");
    } else {
      header("Location: /");
    }
    exit();
  }
  else {
    $role = $_SESSION["mailcow_cc_role"];
    session_regenerate_id(true);
    session_unset();
    session_destroy();
    session_write_close();
    if ($role == "admin") {
      header("Location: /admin");
    }
    elseif ($role == "domainadmin") {
      header("Location: /domainadmin");
    }
    else {
      header("Location: /");
    }
  }
}

// Check session
function session_check() {
  if (isset($_SESSION['mailcow_cc_api']) && $_SESSION['mailcow_cc_api'] === true) {
    return true;
  }
  if (!isset($_SESSION['SESS_REMOTE_UA']) || ($_SESSION['SESS_REMOTE_UA'] != $_SERVER['HTTP_USER_AGENT'])) {
    $_SESSION['return'][] = array(
      'type' => 'warning',
      'msg' => 'session_ua'
    );
    return false;
  }
  // Check if this is a POST request (form-encoded or JSON)
  $is_post_request = !empty($_POST) || (
    isset($_SERVER['CONTENT_TYPE']) &&
    strpos($_SERVER['CONTENT_TYPE'], 'application/json') !== false
  );

  if ($is_post_request) {
    // Skip CSRF check for DataTables server-side processing endpoints
    // These are read-only operations (equivalent to GET) authenticated by session
    $is_search_endpoint = (
      isset($_GET['query']) &&
      preg_match('#^search/(domain|mailbox)$#', $_GET['query'])
    );

    if (!$is_search_endpoint && !empty($_POST)) {
      if ($_SESSION['CSRF']['TOKEN'] != $_POST['csrf_token']) {
        $_SESSION['return'][] = array(
          'type' => 'warning',
          'msg' => 'session_token'
        );
        return false;
      }
      unset($_POST['csrf_token']);
      $_SESSION['CSRF']['TOKEN'] = bin2hex(random_bytes(32));
      $_SESSION['CSRF']['TIME'] = time();
    }
  }
  return true;
}

if (isset($_SESSION['mailcow_cc_role']) && session_check() === false) {
  $_POST = array();
  $_FILES = array();
}