Instead of telling the user when they press enter that they have entered an invalid key (wrong length), we should validate on each keypress and disable the Connect button if the passphrase is bad (wrong length, or non-ascii characters in an ascii passphrase, non-hex chars in a hex passphrase, etc).
With Carrick 1.1.13, the inputted password can be validated. But the connect button isn't disabled when the password is invalide.