Is there a way to present a message to the user upon failed login that they have entered an invalid username, if that was indeed the case?
My scenario: Have recently migrated a database to an AIX 7.1 system and getting regular user requests coming in whereby they assert that they are definitely not typing their password incorrectly but still cannot login.
I have analysed the failed logins on the server and can see quite a number recorded as 'UNKNOWN_' which IBM explains is recorded when the user inputs an invalid username. It is not recorded as the incorrect username which was entered on the chance that it was a password, in which case the password would end up in the log in plain text.
I understand that a malicious actor could possibly attack the server repeatedly trying to gather valid usernames by guessing, however I would like to have this warning message as a temporary measure so that I can say with confidence to the team that they are making typo's and not that there is some other issue at play.
Alternatively if there was a way to have the typo usernames logged instead of UNKNOWN_ then it would achieve the same thing in helping me re-assure everyone that we are dealing with a simple user issue.
Giving further weight to the culprit being typo's, users report that after closing and re-opening their terminal emulator, they can then login.