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filter is not described

check_password filter-hook . WP 2.5.0

Filters whether the plaintext password matches the encrypted password.

Usage

add_filter( 'check_password', 'filter_function_name_7022', 10, 4 );
function filter_function_name_7022( $check, $password, $hash, $user_id ){
	// filter...

	return $check;
}
$check(true/false)
Whether the passwords match.
$password(string)
The plaintext password.
$hash(string)
The hashed password.
$user_id(string/int)
User ID. Can be empty.

Where the hook is called

wp_check_password()
wp-includes/pluggable.php 2259
return apply_filters( 'check_password', $check, $password, $hash, $user_id );
wp-includes/pluggable.php 2273
return apply_filters( 'check_password', $check, $password, $hash, $user_id );

Where the hook is used (in WP core)

Does not used.