This optional parameter specifies a Perl hook that can be used
to convert, translate or transform plaintext passwords after retrieval
from a user database and before comparison with the submitted password
received from the client. The hook is passed the following
arguments:
- $_[0] The correct password as retrieved from the user
database.
- $_[1] A reference to the current AuthBy module object.
- $_[2] The user name being authenticated.
- $_[3] A flag saying whether the correct password is encrypted by
crypt() or MSCHAP.
- $_[4] A reference to the current RADIUS request.
The hook is expected to return a single scalar value containing
the transformed password. In the following example, all passwords are
transformed to uppercase.
# Translate all passwords to UPPERCASE
TranslatePasswordHook sub {$_[0] =~ tr/a-z/A-Z/; return $_[0]}
