apply_filters( 'authenticate', null|WP_User|WP_Error $user, string $username, string $password )

Filters whether a set of user login credentials are valid.

Description

A WP_User object is returned if the credentials authenticate a user.
WP_Error or null otherwise.

$user: WP_User if the user is authenticated.<br> WP_Error or null otherwise.
$username: Username or email address.
$password: User password.

Changelog
Version	Description
4.5.0	`$username` now accepts an email address.
2.8.0	Introduced.