login username from database

[Trev]

Hi,

I have a login window with a username and password fields. The
program checks the username and password from a mysql DB table. If I
enter a username that is not in the database, how do I get it to
display a message that the username does not exist.

Thanks
Trevor

 

[Richard Reynolds]

Hi,

I have a login window with a username and password fields. The
program checks the username and password from a mysql DB table. If I
enter a username that is not in the database, how do I get it to
display a message that the username does not exist.

Thanks
Trevor

JOptionPane?

 

[rossum]

Hi,

I have a login window with a username and password fields. The
program checks the username and password from a mysql DB table. If I
enter a username that is not in the database, how do I get it to
display a message that the username does not exist.

Thanks
Trevor

That is insecure, you are giving out more information than needed.
Just say "Invalid username/password" so any attacker does not know
whether it is the username, the password or both that failed. This
makes it more difficult for them to try all possible combinations.

rossum