alt login example

altlogin.module

<?php
/**
 * @file
 * Provides a web service for logging in.
 */

/**
 * Implements hook_menu().
 */
function altlogin_menu() {
  $items = array();
  $items['altlogin'] = array(
    'page callback' => 'altlogin_login_callback',
    'delivery callback' => 'altlogin_delivery',
    'access callback' => TRUE,
    //'theme callback' => 'ajax_base_page_theme',
    'type' => MENU_CALLBACK
  );
  return $items;
}

/**
 * Login callback.
 */
function altlogin_login_callback() {
  // Pass login through user_login_authenticate_validate
  // so we can hit the flood/ip validation logic.
  $form = array();
  $form_state = array(
    'values' => array(
      'name' => $_POST['name'],
      'pass' => $_POST['pass']
    )
  );
  user_login_authenticate_validate($form, $form_state);

  // If $form_state['uid'] is set, then we passed validation.
  if ($form_state['uid'] > 0) {
    // Seal the deal with a new session
    // and invoke login implementations
    user_login_finalize();
    // Return a json success: status 1, or whatever makes sense.
    return drupal_json_encode(array('status' => 1));
  }

  // Return json failure: status 0
  return drupal_json_encode(array('status' => 0));
}

/**
 * Delivery plain json.
 */
function altlogin_delivery($json) {
  // Set header
  drupal_add_http_header('Content-Type', 'application/json; charset=utf-8');
  print $json;
}