Menu callback; process one time login link and redirects to the user page on success.

File

drupal-6.x/modules/user/user.pages.inc, line 84

User page callback file for the user module.

Code

function user_pass_reset(&$form_state, $uid, $timestamp, $hashed_pass, $action = NULL) {
  global $user;

  // Check if the user is already logged in. The back button is often the culprit here.
  if ($user->uid) {
    drupal_set_message(t('You have already used this one-time login link. It is not necessary to use this link to login anymore. You are already logged in.'));
    drupal_goto();
  }
  else {
    // Time out, in seconds, until login URL expires. 24 hours = 86400 seconds.
    $timeout = 86400;
    $current = time();
    // Some redundant checks for extra security ?
    if ($timestamp < $current && $account = user_load(array('uid' => $uid, 'status' => 1))) {
      // Deny one-time login to blocked accounts.
      if (drupal_is_denied('user', $account->name) || drupal_is_denied('mail', $account->mail)) {
        drupal_set_message(t('You have tried to use a one-time login for an account which has been blocked.'), 'error');
        drupal_goto();
      }

      // No time out for first time login.
      if ($account->login && $current - $timestamp > $timeout) {
        drupal_set_message(t('You have tried to use a one-time login link that has expired. Please request a new one using the form below.'));
        drupal_goto('user/password');
      }
      else if ($account->uid && $timestamp > $account->login && $timestamp < $current && $hashed_pass == user_pass_rehash($account->pass, $timestamp, $account->login)) {
        // First stage is a confirmation form, then login
        if ($action == 'login') {
          watchdog('user', 'User %name used one-time login link at time %timestamp.', array('%name' => $account->name, '%timestamp' => $timestamp));
          // Set the new user.
          $user = $account;
          // user_authenticate_finalize() also updates the login timestamp of the
          // user, which invalidates further use of the one-time login link.
          user_authenticate_finalize($form_state['values']);
          drupal_set_message(t('You have just used your one-time login link. It is no longer necessary to use this link to login. Please change your password.'));
          drupal_goto('user/' . $user->uid . '/edit');
        }
        else {
          $form['message'] = array('#value' => t('<p>This is a one-time login for %user_name and will expire on %expiration_date.</p><p>Click on this button to login to the site and change your password.</p>', array('%user_name' => $account->name, '%expiration_date' => format_date($timestamp + $timeout))));
          $form['help'] = array('#value' => '<p>' . t('This login can be used only once.') . '</p>');
          $form['submit'] = array('#type' => 'submit', '#value' => t('Log in'));
          $form['#action'] = url("user/reset/$uid/$timestamp/$hashed_pass/login");
          return $form;
        }
      }
      else {
        drupal_set_message(t('You have tried to use a one-time login link which has either been used or is no longer valid. Please request a new one using the form below.'));
        drupal_goto('user/password');
      }
    }
    else {
      // Deny access, no more clues.
      // Everything will be in the watchdog's URL for the administrator to check.
      drupal_access_denied();
    }
  }
}