RE: os authenticated accounts
Date: Wed, 5 Mar 2008 10:33:15 -0500
There are issues with using a database event logon trigger but my view is if you must allow remote OS authenticated accounts you want to make use of all available no cost features to help protect your database from unauthorized access.
Part of the security is not advertising the fact the logon trigger exists or what it keys on. Besides using the client IP address you might also use the machine name. Only usernames created as identified externally can use the feature so if these users have to come though a specific application server or a short list of local IP's you can edit on machine name and maybe also the program. The more information you can edit on the harder it is for someone to break it. Spoofing the IP takes more knowledge than your average user has and would require a serious attacker. Keying on additional information could well be enough to defeat the spoofed since he or she probably did not think to identify this.
Add this to your network security arrangement, sqlnet security, and normal database user privileges. Make use of everything you can. Limit the Oracle privileges to OS authenticated accounts to a few privileges as possible.
- Mark D Powell -- Phone (313) 592-5148
From: QuijadaReina, Julio C [mailto:QuijadJC_at_alfredstate.edu] Sent: Wednesday, March 05, 2008 10:02 AM To: pythianbrinsmead_at_gmail.com; Powell, Mark D Cc: oracle-l_at_freelists.org
Subject: RE: os authenticated accounts
You bring out excellent points. I agree about the security concern here. I believe Metalink 401251.1 shows one of those secure alternatives. One would actually need the Oracle Wallet Manager and orapki and avoid having to use a Certifcate Authority.
From: oracle-l-bounce_at_freelists.org [oracle-l-bounce_at_freelists.org] On Behalf Of Mark Brinsmead [pythianbrinsmead_at_gmail.com] Sent: Wednesday, March 05, 2008 12:18 AM To: mark.powell_at_eds.com
Subject: Re: os authenticated accounts
Is checking the source IP in a trigger reliable?
I do not recall the source, but I had the impression that that information is provided (directly) by the client, not by the TNS listener, and can (relatively) easily be spoofed. Also, the method would break down -- or be tricked -- when using "proxied" connections, e.g., port-forwarding through SSH, or possibly Oracle Connection Manager. (Never used the latter myself.) It would also be problematic if there are NAT-enabled firewalls anywhere along your network route.
Every case needs to be judged on its own merits, but basically it is my practice to award REMOTE_OS_AUTHENTICATION=TRUE an automatic "Fail" on any security review, even (or especially) where there are no EXTERNALLY IDENTIFIED accounts present in the database. While I have never actually attempted to "hack" or "spoof" it, my understanding is that it is all too easy.
For those who can afford it, though, the Advanced Security Option and/or Database Vault offer secure alternatives, I believe. I have stumbled across these options myself while answering similar questions, but it has been so many years since I've been at a site with pockets deep enough (or business needs serious enough) to actually consider these expensive options, I have never really investigated them in any real depth.
*sigh* Working for regulated utilities did have its advantages... :-)
Of course, the O.P. only asked "is this possible?", and the answer is "yes, it certainly is". What a shame he did not ask instead "is this wise?".
On Tue, Mar 4, 2008 at 12:02 PM, Powell, Mark D <mark.powell_at_eds.com<mailto:mark.powell_at_eds.com>> wrote:
I have always preferred to set the os_authent_prefix='' rather than OPS$. I am not sure if trying to limit the node access is practical since I do not think the node checking can be associated to usernames in the sqlnet layer. You might need to resort to checking the IP for any OS authenticated accounts in an after logon database event trigger.
- Mark D Powell -- Phone (313) 592-5148
oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> [mailto:oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.o rg>] On Behalf Of QuijadaReina, Julio C
Sent: Tuesday, March 04, 2008 9:52 AM
To: 'mdemenko_at_gmail.com<mailto:mdemenko_at_gmail.com>'; joe_dba_at_hotmail.com<mailto:joe_dba_at_hotmail.com> Cc: oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org> Subject: RE: os authenticated accounts
Yes, it is possible.
The following parameters on your database init.ora relating to this are (if my memory serves me correctly):
Create the account you will use on your Linux box. Then create the externally identified account on your database. From your Linux client you should be able to connect by issuing 'sqlplus /' after setting the client environment.
A word of caution: anyone knowing your database tnsnames and the name of the account could potentially connect to your database. That sounds pretty bad! You might want to look into tcp.validnode_checking and tcp.invited_nodes pars on your server's sqlnet.ora and/or have the OS firewall setting that opens the listener port only to your linux client.
oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> [mailto:oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.o rg>] On Behalf Of Maxim Demenko
Sent: Tuesday, March 04, 2008 1:05 AM
To: joe_dba_at_hotmail.com<mailto:joe_dba_at_hotmail.com> Cc: oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org> Subject: Re: os authenticated accounts
Joe Smith schrieb:
> Is it possible to use OS authenticated accounts ( i.e. identified > externally ) between two servers? > > I have a linux box with with an oracle client install and an aix > server with EE installed. > > The external account was originally on the aix server. We want to > move the 3rd party app and the account to a linux box. > > thanks. > > > ---------------------------------------------------------------------- > -- Shed those extra pounds with MSN and The Biggest Loser! Learn more. > <http://biggestloser.msn.com/>
You may look on the external users identified by ssl certificates (if you are on 10g onwards).
Not sure about additional licensing costs (i.e. whether it is part of ASO or not).
-- http://www.freelists.org/webpage/oracle-l -- Cheers,Received on Wed Mar 05 2008 - 09:33:15 CST
-- Mark Brinsmead
Senior DBA, The Pythian Group http://www.pythian.com/blogs -- http://www.freelists.org/webpage/oracle-l