Delegating and controlling user password management

As a DBA, you might want to delegate the management of user passwords. Or, you might want to prevent database users from changing their passwords or reconfiguring password constraints, such as password lifetime. To ensure that only the database users that you choose can change password settings, you can turn on the restricted password management feature. When you activate this feature, only those database users that have been granted the rds_password role can manage passwords.

By default, this feature is off, as shown in the following:

postgres=> SHOW rds.restrict_password_commands;
  rds.restrict_password_commands
--------------------------------
 off
(1 row)

To turn on this feature, you use a custom parameter group and change the setting for rds.restrict_password_commands to 1. Be sure to reboot your RDS for PostgreSQL DB instance so that the setting takes effect.

With this feature active, rds_password privileges are needed for the following SQL commands:

CREATE ROLE myrole WITH PASSWORD 'mypassword';
CREATE ROLE myrole WITH PASSWORD 'mypassword' VALID UNTIL '2023-01-01';
ALTER ROLE myrole WITH PASSWORD 'mypassword' VALID UNTIL '2023-01-01';
ALTER ROLE myrole WITH PASSWORD 'mypassword';
ALTER ROLE myrole VALID UNTIL '2023-01-01';
ALTER ROLE myrole RENAME TO myrole2;

Renaming a role (ALTER ROLE myrole RENAME TO newname) is also restricted if the password uses the MD5 hashing algorithm.

With this feature active, attempting any of these SQL commands without the rds_password role permissions generates the following error:

ERROR: must be a member of rds_password to alter passwords

We recommend that you grant the rds_password to only a few roles that you use solely for password management. If you grant rds_password privileges to database users that don't have rds_superuser privileges, you need to also grant them the CREATEROLE attribute.

Make sure that you verify password requirements such as expiration and needed complexity on the client side. If you use your own client-side utility for password related changes, the utility needs to be a member of rds_password and have CREATE ROLE privileges.