Re: [PHP] Kerberos, Apache2, mod_auth_kerb, PHP, and PostgreSQL in

Hi,
I've been trying to Kerberize our Apache and PostgreSQL servers for
our company's web applications.

Goal: To connect from a PHP web app to a PostgreSQL database
using the users credentials, so all authorization is managed via
privileges within the database.

Our IT dept has recently installed Windows 2003 Server to provide
authentication & directories via Kerberos and LDAP.

I've managed to configure Apache (2.0.49) to authenticate users using
mod_auth_kerb (5.0-rc6), and also PostgreSQL (7.4.3) to use Kerberos.
(Linux hosts use MIT KerberosV5 1.3.3 client libs, KDC is Windows 2003)

mod_auth_kerb is configured with:

KrbSaveCredentials on

So in PHP (4.3.8) we end up with the variables:

$_SERVER['REMOTE_USER'] (eg: 'gibsonm(at)OUR-REALM(dot)CO(dot)UK')
$_SERVER['KRB5CCNAME'] (eg: 'FILE:/tmp/krb5cc_apache_tVFJCd')

Even HTTP Negotiate works with Firefox/Linux (but not IE/XP yet!) :)

But this is where I get stuck.
How do I use the supplied credentials file to connect to PostgreSQL?

In the PostgreSQL docs it says:
(http://www.postgresql.org/docs/7.4/interactive/auth-methods.html#KERBEROS-AUTH)

> If you use mod_auth_kerb from http://modauthkerb.sf.net and mod_perl
> on your Apache web server, you can use AuthType
> KerberosV5SaveCredentials with a mod_perl script. This gives secure
> database access over the web, no extra passwords required.

I'm assuming this is out of date, or has changed with mod_auth_kerb 5.0,
and that the KrbSaveCredentials directive does this job instead.

Is there any examples of this mod_perl script?
Can the alleged mod_perl method be adapted to PHP?
Has anyone got this to work?
What are the alternatives to my goal stated above?

Cheers
--
Mark Gibson <gibsonm |AT| cromwell |DOT| co |DOT| uk>
Web Developer & Database Admin
Cromwell Tools Ltd.
Leicester, England.

Mark Gibson wrote:
> Hi,
> I've been trying to Kerberize our Apache and PostgreSQL servers for
> our company's web applications.
>
> Goal: To connect from a PHP web app to a PostgreSQL database
> using the users credentials, so all authorization is managed via
> privileges within the database.
>
> Our IT dept has recently installed Windows 2003 Server to provide
> authentication & directories via Kerberos and LDAP.
>
> I've managed to configure Apache (2.0.49) to authenticate users using
> mod_auth_kerb (5.0-rc6), and also PostgreSQL (7.4.3) to use Kerberos.
> (Linux hosts use MIT KerberosV5 1.3.3 client libs, KDC is Windows 2003)
>
> mod_auth_kerb is configured with:
>
> KrbSaveCredentials on
>
> So in PHP (4.3.8) we end up with the variables:
>
> $_SERVER['REMOTE_USER'] (eg: 'gibsonm(at)OUR-REALM(dot)CO(dot)UK')
> $_SERVER['KRB5CCNAME'] (eg: 'FILE:/tmp/krb5cc_apache_tVFJCd')
>
> Even HTTP Negotiate works with Firefox/Linux (but not IE/XP yet!) :)
>
> But this is where I get stuck.
> How do I use the supplied credentials file to connect to PostgreSQL?
>
> In the PostgreSQL docs it says:
> (http://www.postgresql.org/docs/7.4/interactive/auth-methods.html#KERBEROS-AUTH)
>
>
> > If you use mod_auth_kerb from http://modauthkerb.sf.net and mod_perl
> > on your Apache web server, you can use AuthType
> > KerberosV5SaveCredentials with a mod_perl script. This gives secure
> > database access over the web, no extra passwords required.
>
> I'm assuming this is out of date, or has changed with mod_auth_kerb 5.0,
> and that the KrbSaveCredentials directive does this job instead.

I'VE DONE IT! THE HOLY GRAIL OF WEB/DB APPS! :)

All it takes it this line your PHP script:

putenv("KRB5CCNAME={$_SERVER['KRB5CCNAME']}");

Then pg_connect works :)

--
Mark Gibson <gibsonm |AT| cromwell |DOT| co |DOT| uk>
Web Developer & Database Admin
Cromwell Tools Ltd.
Leicester, England.

Mark Gibson wrote:
> Mark Gibson wrote:
>
>> Hi,
>> I've been trying to Kerberize our Apache and PostgreSQL servers for
>> our company's web applications.
[snip]
>
> I'VE DONE IT! THE HOLY GRAIL OF WEB/DB APPS! :)
>
> All it takes it this line your PHP script:
>
> putenv("KRB5CCNAME={$_SERVER['KRB5CCNAME']}");
>
> Then pg_connect works :)

Or, not, as the case may be.
Well, sometimes it connects and sometimes it doesn't,
PostgreSQL logs the following error:

Kerberos recvauth returned error 103

Any ideas???

--
Mark Gibson <gibsonm |AT| cromwell |DOT| co |DOT| uk>
Web Developer & Database Admin
Cromwell Tools Ltd.
Leicester, England.

AFAIK, redirecting credentials is not supported in mod_auth_krb.

I remember listening something that makes it impossible due to way
Linux/UNIX works, but don't take this as something more than a rumor.

Regards.

Mark Gibson wrote:
> Mark Gibson wrote:
>
>> Mark Gibson wrote:
>>
>>> Hi,
>>> I've been trying to Kerberize our Apache and PostgreSQL servers for
>>> our company's web applications.
>
> [snip]
>
>>
>> I'VE DONE IT! THE HOLY GRAIL OF WEB/DB APPS! :)
>>
>> All it takes it this line your PHP script:
>>
>> putenv("KRB5CCNAME={$_SERVER['KRB5CCNAME']}");
>>
>> Then pg_connect works :)
>
>
> Or, not, as the case may be.
> Well, sometimes it connects and sometimes it doesn't,
> PostgreSQL logs the following error:
>
> Kerberos recvauth returned error 103
>
> Any ideas???
>