Re: [hylafax-users] PAM Authentication

["Michael J. Pedersen" <pedermj@xxxxxxxxxxx>]

On Sat, Jun 26, 2004 at 11:02:54AM +1000, Kimble Young wrote:
> Suggestion 1 didn't work. I've also tried using pam_pwdb same results.  I
> have also tried pam_mysql which causes the hfaxd child processes to segfault
> repeatedly on authentication attempts.

Now that is truly disturbing. Nothing which is done by pam should cause
the segfault. Any chance you can get a core dump and email it to me? I'd
like to investigate this further.

> 1) Linux kernel 2.4.22-1.2188 on Fedora Core 1

That should be just fine. My machine where it is being used is running
debian, kernel 2.4.18. However, I've installed it on other machines and
kernels with no problems.

> 2) Have been running Hylafax successfully for a few months now with
> hosts.hfaxd authentication based on user/pass. Currently it contains:
> 
> 127.0.0.1

Again, that shouldn't be a problem for it. pam isn't looking at that
file. The only reason I checked is because it could, possibly create
conflicts if a user were to be in both places.

> 3) rpm -qa | grep pam
> 
> pam-0.77-15
> pam-devel-0.77-15
> pam_smb-1.1.7-2
> pam_krb5-2.0.5-1

Hmmm... I've been using versions 0.72 and 0.76 it turns out, and have
zero issues. I'll ask if you can try 0.76, and see if that works? If
not, it's not a big deal, but it would help to narrow things down still
further.

> 4,5,6) Users exist, can login on console and SSH and I have the correct
> password.

Good. I know, those were probably annoyingly stupid questions, but they
still had to be checked.

> More information:
> I am successfully using pam with pam_mysql to authenticate imap users on the
> same machine. Eventually I'd like to be using pam_mysql but I am starting
> simple as it's obviously not working.

Good. That eliminates one more possibility for failure. I'm glad to know
you've been using pam for more than this already, it makes life easier.

> http://www.kernel.org/pub/linux/libs/pam/Linux-PAM-html/pam_appl-8.html
> Which works just fine for me when I compile it.

Ah, now I'll ask what you mean by the statement that it works fine? Have
you modified the hylafax code to fix it? Or is it just testing the
reference code.

> I don't claim to be a C or C++ expert. In fact it's years since I've written
> anything in it.  There was one discrepency between the struct in the
> reference application and the code in Hylafax.
> 
> example application:
> 
> static struct pam_conv conv = {
>     misc_conv,
>     NULL
> };
> 
> Hylafax
>         struct pam_conv conv = {
>                 pamconv,
>                 (void*)pass
>         };
> 
> The difference looks fairly harmless to me but can anyone with more
> experience see any problems occurring?

Actually, that's necessary to minimize the damage to HylaFAX and still
have it support pam. the '(void*)pass' portion is a segment of client
supplied data, and is quite thoroughly legal to use in this way
according to the pam docs. I very much doubt that this is the issue.

I wish I had more to offer right now, but time grows short for me. Let
me know what you can, and I'll see what I can do.

-- 
Michael J. Pedersen
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