I am making a login form in WordPress and i want to have a validation on it, so i tried to look at the wp-login.php to see how they validate things. But i did not find what i am looking for. I would like to know how they validate things or what input do they need to validate things. I tried to search the WordPress forums all i can find is plugin, plugin and more plugin. I don't want a plugin. I want to hard code it. So please help me.
I want to know where you can find the part that searches for the user's username and password. Or if not, know what is needed for a successful login. example username or password or others. by the way here is the wp-login.php. Thanks