Syntax
------

OLD_PASSWORD(str)

Description
-----------

OLD_PASSWORD() was added to MySQL when the implementation of PASSWORD() was
changed to improve security. OLD_PASSWORD() returns the value of the old
(pre-MySQL 4.1) implementation of PASSWORD() as a string, and is intended to
permit you to reset passwords for any pre-4.1 clients that need to connect to
a more recent MySQL server version, or any version of MariaDB, without locking
them out.

As of MariaDB 5.5, the return value is a nonbinary string in the connection
character set and collation, determined by the values of the
character_set_connection and collation_connection system variables. Before
5.5, the return value was a binary string.

The return value is 16 bytes in length, or NULL if the argument was NULL.

URL: https://mariadb.com/kb/en/old_password/