Why does SSH prompt for 2 passwords?

[Gary D Kline]

On Sat, Apr 19, 2003 at 12:41:51PM +0200, Olivier Dony wrote:
> On Fri, Apr 18, 2003 at 03:02:23PM +0200, Willie Viljoen wrote:
> > On Friday 18 April 2003 0:48, someone, possibly Joe Lewis, typed:
> > 
> > > Password:
> > > Response:
> > > joe at 192.168.1.1's password:
> > 
> > The first prompt is PAM challenge response authentication. This uses the PAM 
> > system instead of a just a flat read of /etc/master.passwd to authenticate, 
> > and is also more secure than standard plaintext authentication.
> > 
> > Unless your sshd is misconfigured, your configuration files and binaries are 
> > out of sync (this happend when a system is upgraded without doing 
> > mergemaster), this should not be happening, and you should be able to log 
> > in at the first prompt. It might also be that the ssh client you are using 
> > does not handle challenge response authentication properly.
> 
> Indeed and one thing you should check is whether you are not using SSH v1 by
> mistake. This might happen if you are using it with arg -1 e.g :
> 
>   $ ssh -1 somehost.domain.tld
>   Password:
>   Response: 
>   $ ssh -2 somehost.domain.tld
>   Password:
>   
> or if your ssh client is setup to try SSH v1 first, eg if using FreeBSD's 
> one as it seem, that would be :
> 
>   Protocol 1,2


		You're absolutely right.  My config file was 
		looking at v1 first.  --Probably on at least 
		one other server too, come to think of it... .

> 
> in the relevant part of your /etc/ssh/ssh_config, see ssh_config(5) for more
> details.
> 
> > If you are happy with standard plaintext configuration, you may edit 
> > /etc/ssh/sshd_config and change the setting to this:
> > 
> > # Change to no to disable PAM authentication
> > ChallengeResponseAuthentication no
> 
> This will do if you control the ssh server you are connecting to, but that
> will only be a workaround and you probably want to fix the client problem,
> as the same could happen on other hosts.
> 
> > I'd recommend you rather get PAM fixed though, or use public key 
> > authentication instead, that's much more secure than any form of password 
> > authentication.
> 
> I'd second on using public key authentication, as this will make remote 
> logins even faster, and more secure, provided that your private key is 
> properly secured. The ssh(1) man page explains it somewhat in the SSH protocol
> version 2 section.
> 

	Right; there is more in ssh-keygen.  I've used ssh for a few
	years and have my keys in .identity and identity.pub.  If the
	newer authentication algorithms are lots better I'll switch.

	What's the general consensus on this?


	thanks much for yur help; it did.. !

	gary



-- 
   Gary Kline     kline at thought.org   www.thought.org     Public service Unix