Answer about login actions was given on stackoverflow.
Duplicating here the answer:
There are a few different hooks you can use (from wp_signon):
But you may do best to override the pluggable wp_authenticate (from wp-includes/pluggable.php):
if ( !function_exists('wp_authenticate') ) :
/**
* Checks a user's login information and logs them in if it checks out.
*
* @since 2.5.0
*
* @param string $username User's username
* @param string $password User's password
* @return WP_Error|WP_User WP_User object if login successful, otherwise WP_Error object.
*/
function wp_authenticate($username, $password) {
$username = sanitize_user($username);
$password = trim($password);
$user = apply_filters('authenticate', null, $username, $password);
if ( $user == null ) {
// TODO what should the error message be? (Or would these even happen?)
// Only needed if all authentication handlers fail to return anything.
$user = new WP_Error('authentication_failed', __('<strong>ERROR</strong>: Invalid username or incorrect password.'));
}
$ignore_codes = array('empty_username', 'empty_password');
if (is_wp_error($user) && !in_array($user->get_error_code(), $ignore_codes) ) {
do_action('wp_login_failed', $username);
}
return $user;
}
endif;
All you would need to do is define your own wp_authenticate mimicking the actions and adding a few lines to do your logging. That is assuming you don’t already have a function that is overriding it.
And as you can see right in the above code, you could use:
