The passwordcheck module checks users' passwords
whenever they are set with
CREATE ROLE or
ALTER ROLE (it doesn't work,
if a non-default profile is assigned to the user).
If a password is considered too weak, it will be rejected and
the command will terminate with an error.
To enable this module, add '$libdir/passwordcheck'
to shared_preload_libraries in
postgresql.conf, then restart the server.
To prevent unencrypted passwords from being sent across the network, written to the server log or otherwise stolen by a database administrator, Postgres Pro allows the user to supply pre-encrypted passwords. Many client programs make use of this functionality and encrypt the password before sending it to the server.
This limits the usefulness of the passwordcheck
module, because in that case it can only try to guess the password.
For this reason, passwordcheck is not
recommended if your security requirements are high.
It is more secure to use an external authentication method such as GSSAPI
(see Chapter 20) than to rely on
passwords within the database.