control of auth methods

[Darren Tucker]

Jefferson Ogata wrote:
> The current design of the config file is hardly a triumph of simplicity 
> and logic. The auth types have internal names, yet the auth controls are 
> this morass of booleans. It would make more sense to list the internal 
> names, a la Ciphers.

The current config file design pre-dates OpenSSH. If you look at the 
sample config file from ssh-1.2.12 you'll recognise the format (and many 
of the current options).  Ciphers was added when Markus added SSH 
protocol 2 support.

> Instead we have to figure out how various 
> combinations of peculiarly named flags such as 
> PAMAuthenticationViaKbdInt

That's gone (except as a deprecated warning).

> PermitRootLogin, 

This thread is discussing generalizing that.

> ChallengeResponseAuthentication, RhostsRSAAuthentication, UsePam, 
> AllowUsers, DenyUsers, etc. interact to produce which set of valid auth 
> types for whom. It ends up being trial-and-error to determine whether 
> the right users can authenticate the way you want to allow, and /can't/ 
> authenticate the way you want to prevent, and that's not a good design 
> for security.

You could read "trial-and-error" as "testing and validation" :-)

-- 
Darren Tucker (dtucker at zip.com.au)
GPG key 8FF4FA69 / D9A3 86E9 7EEE AF4B B2D4  37C9 C982 80C7 8FF4 FA69
     Good judgement comes with experience. Unfortunately, the experience
usually comes from bad judgement.