Prevent connections for some users through SQL*Plus, TOAD

Hello to you all,

I've an old fashion application that uses an Oracle Database where each application user, is also a database user. That way, each user can connect to the database through other tools beside the application, like TOAD, SQL*Plus, etc.

For security reasons I would like to prevent these users to connect to the database using any other program than the application itself(No SQL*Plus, no Toad, etc …). I thought in using a "trigger after logon" with a kill session statement, but it's true :) a session can't kill itself (ORA-00027)

At the moment I'm not figuring out a way to achieve what I want. Can anyone give me a hand ?

Thanks in advance,

Ricardo Bateiras.

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