Drupal 6/7: Auth as first admin if no ssh no Drush no money no honey...

_auth_as_1.php

<?php
define('DRUPAL_ROOT', getcwd());

require_once DRUPAL_ROOT . '/includes/bootstrap.inc';
drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);

$user = user_load(1);

if ($user) {
  $edit = (array)$user;
  list($major_version, ) = explode('.', VERSION);
  if ($major_version == '6') {
    user_authenticate_finalize($edit);
  }
  elseif ($major_version == '7') {
    user_login_finalize($edit);
  }

  drupal_set_message("Don't forget to delete " . __FILE__, 'warning');
  drupal_goto();
}
else {
  echo '<h2>Error.</h2>';
}