Since I am told OpenSSH works with radius, it should work with TACACS as
well. I believe I have the /etc/pam.d/sshd setup correctly as below:

auth required service=tacacs
auth required
account sufficient service=tacacs
password required service=tacacs
session sufficient service=tacacs
session required
session optional

So my TACACS pam is getting called with the incoming user. OpenSSH
complains that the incoming user is not found but continues processing.
My pam authenticates the incoming user and sends back the response to
OpenSSH to prompt for the password. I enter the password. Now the
incoming request to my pam does not have the password that was entered
but the hardcorded value in OpenSSH of "****INCORRECT" which indicates
that sshpam_authctxt->valid is 0. Obviously this fails from the TACACS

I am wondering if I am missing something in the sshd_config
configuration. Or is the interaction between the pam and sshd incorrect?


Asif Iqbal wrote:
> On 8/1/06, Gary Schlachter wrote:
>> Thank you for your reply. The PAM is getting called which in turn
>> contacts the TACACS server. However, my problem is that OpenSSH is
>> authenticating the user against /etc/passwd instead of letting the user
>> be authenticated by the TACACS server. I am looking for a way to
>> configure SSH to stop the /etc/passwd authentication. When the user is
>> in /etc/passwd a but does not have a local password and is defined on
>> the TACACS server, TACACS authenticates the user correctly. I am
>> looking for a way to not have to configure the same user id on both the
>> TACACS server and the local system.

> I am using PAM with Radius Server Auth. So we should have similar setup.
> This is all I have in /etc/pam.conf (Solaris) for sshd to use only one
> pam_radius module and no other pam libraries.
> sshd auth required debug
> You may be using other pam libraries--specially the library that talks
> to /etc/passwd.
>> BTW, I am the PAM developer.
>> Thanks,
>> Gary
>> Asif Iqbal wrote:
>> > On 7/27/06, Gary Schlachter wrote:
>> >> I know this question has been asked several times over the

>> years
>> >> but I have not seen a definitive answer/solution if one exists.

>> If one
>> >> does not exist or I need to develop one, then I can stop looking!

>> I am
>> >> attempting to integrate a Tacacs+ PAM with OpenSSH. I would like to
>> >> have the PAM authenticate the User ID as well as the password.

>> Thus the
>> >> users do not exist in /etc/passwd. I am not using NIS or any other
>> >> system for user ids. The Tacacs server is the only place the user

>> ids
>> >> exist. Ultimately when the user authenticates via Tacacs, I will

>> switch
>> >> the user to a known user in /etc/passwd and provide the logging in

>> user
>> >> with a specific TTY interface via the shell. When attempting this on
>> >> linux with OpenSSH 4.3p2 compiled with with_pam and seemingly the
>> >> correct sshd_config options, I received the infamous
>> >
>> > This is how I test
>> >
>> > Make sure ldd to sshd shows pam library in the list
>> >
>> > Modify the sshd_config file with the following two parameters
>> >
>> > Syslog Fascility auth
>> > Loglevel Debug
>> >
>> > restart OpenSSH
>> >
>> > touch a file /var/log/sshd.log.
>> >
>> > modify the syslog.conf with auth.debug point to /var/log/sshd.log and
>> > restart syslog.
>> >
>> > Now ssh with your tacacs account and see if your tacacs server
>> > receiving any connection logs from you as well as your
>> > /var/log/sshd.log file.
>> >
>> > If all fails I would ask the tacacs pam module developer about the

>> issue.
>> >
>> >
>> >>
>> >> Thanks in advance,
>> >> Gary
>> >>
>> >>
>> >
>> >