there is already login method written name as in res_user.py. You can take reference and apply same from your wizard.

@classmethod
def _login(cls, db, login, password):
    if not password:
        return False
    user_id = False
    try:
        with cls.pool.cursor() as cr:
            self = api.Environment(cr, SUPERUSER_ID, {})[cls._name]
            user = self.search([('login', '=', login)])
            if user:
                user_id = user.id
                user.sudo(user_id).check_credentials(password)
                user.sudo(user_id)._update_last_login()
    except AccessDenied:
        user_id = False