Re: [PATCHES] [HACKERS] PAM authentication fails for local UNIX users

2007-09-13 Thread Bruce Momjian

Applied:

 PAM does work authenticating against Unix system authentication
 because the postgres server is started by a non-root user.  In order
 to enable this functionality, the root user must provide additional
 permissions to the postgres user (for reading
 /etc/shadow).

---

Dhanaraj M wrote:
> Hi all,
> 
> This is the continuation to the discussion that we had in the hacker's list.
> 
> http://www.postgresql.org/docs/8.2/interactive/auth-methods.html#AUTH-PAM
> Here, I like to add some details in 20.2.6. PAM authentication section.
> 
> Can someone review and make changes, if required? Thanks.
> 
> *** client-auth.sgml.orig   Tue Aug 21 16:52:45 2007
> --- client-auth.sgmlTue Aug 21 17:02:52 2007
> ***
> *** 987,992 
> --- 987,1001 
>   and the http://www.sun.com/software/solaris/pam/";>
>   Solaris PAM Page.
>  
> +
> +
> + 
> +  The local UNIX user authentication is not permitted,
> +  because the postgres server is started by a non-root user.
> +  In order to enable this functionality, the root user must provide
> +  additional permissions to the postgres user (for reading 
> /etc/shadow file).
> + 
> +
> 
>
>  
> 
> >
> >
> > Zdenek Kotala wrote:
> >>
> >> The problem what Dhanaraj tries to address is how to secure solve 
> >> problem with PAM and local user. Other servers (e.g. sshd) allow to 
> >> run master under root (with limited privileges) and forked process 
> >> under normal user. But postgresql
> >> requires start as non-root user. It limits to used common pattern.
> >>
> >> There is important question:
> >>
> >> Is current requirement to run postgresql under non-root OK? If yes, 
> >> than we must update PAM documentation to explain this situation which 
> >> will never works secure. Or if we say No, it is stupid limitation (in 
> >> case when UID 0 says nothing about user's privileges) then we must 
> >> start discussion about solution.
> >>
> >>
> >
> > For now I think we should update the docs. You really can't compare 
> > postgres with sshd - ssh connections are in effect autonomous. I 
> > suspect the changes involved in allowing us to  run as root and then 
> > give up privileges safely would be huge, and the gain quite small.
> >
> > I'd rather see an HBA fallback mechanism, which I suspect might 
> > overcome most of the  problems being encountered here.
> >
> > cheers
> >
> > andrew
> 
> 
> -- 
> 
> Dhanaraj M
> x40049/+91-9880244950
> Solaris RPE, Bangalore, India
> http://blogs.sun.com/dhanarajm/
>  
> 
> 
> ---(end of broadcast)---
> TIP 6: explain analyze is your friend

-- 
  Bruce Momjian  <[EMAIL PROTECTED]>  http://momjian.us
  EnterpriseDB   http://www.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +

---(end of broadcast)---
TIP 7: You can help support the PostgreSQL project by donating at

http://www.postgresql.org/about/donate


Re: [PATCHES] [HACKERS] PAM authentication fails for local UNIX users

2007-08-21 Thread Dhanaraj M

Hi all,

This is the continuation to the discussion that we had in the hacker's list.

http://www.postgresql.org/docs/8.2/interactive/auth-methods.html#AUTH-PAM
Here, I like to add some details in 20.2.6. PAM authentication section.

Can someone review and make changes, if required? Thanks.

*** client-auth.sgml.orig   Tue Aug 21 16:52:45 2007
--- client-auth.sgmlTue Aug 21 17:02:52 2007
***
*** 987,992 
--- 987,1001 
 and the http://www.sun.com/software/solaris/pam/";>
 Solaris PAM Page.

+
+
+ 
+  The local UNIX user authentication is not permitted,
+  because the postgres server is started by a non-root user.
+  In order to enable this functionality, the root user must provide
+  additional permissions to the postgres user (for reading 
/etc/shadow file).

+ 
+
   
  





Zdenek Kotala wrote:


The problem what Dhanaraj tries to address is how to secure solve 
problem with PAM and local user. Other servers (e.g. sshd) allow to 
run master under root (with limited privileges) and forked process 
under normal user. But postgresql

requires start as non-root user. It limits to used common pattern.

There is important question:

Is current requirement to run postgresql under non-root OK? If yes, 
than we must update PAM documentation to explain this situation which 
will never works secure. Or if we say No, it is stupid limitation (in 
case when UID 0 says nothing about user's privileges) then we must 
start discussion about solution.





For now I think we should update the docs. You really can't compare 
postgres with sshd - ssh connections are in effect autonomous. I 
suspect the changes involved in allowing us to  run as root and then 
give up privileges safely would be huge, and the gain quite small.


I'd rather see an HBA fallback mechanism, which I suspect might 
overcome most of the  problems being encountered here.


cheers

andrew



--

Dhanaraj M
x40049/+91-9880244950
Solaris RPE, Bangalore, India
http://blogs.sun.com/dhanarajm/
 



---(end of broadcast)---
TIP 6: explain analyze is your friend