Pete Finnigan's Oracle Security Forum - securing database link

Forum

Home/Forum

Welcome, Guest. Please Login. Nov 22^nd, 2024, 6:32am News: Welcome to Pete Finnigan's Oracle security forum
Home \| Help \| Search \| Members \| Login

   Pete Finnigan's Oracle Security Forum
   Oracle Security
   Oracle Security (Moderator: Pete Finnigan)
   securing database link

« Previous topic | Next topic »

Pages: 1

Reply | Notify of replies | Send Topic | Print

Author

Topic: securing database link (Read 2630 times)

Pete Finnigan
PeteFinnigan.com Administrator

Oracle Security is easier if you design for it

View Profile | WWW | Email

Gender: male

Posts: 309

securing database link
« on: Nov 27^th, 2008, 3:45pm »

Quote | Modify

Hi,
I'm stuck with one problem for two days now, and looking for any possible help.
I have two databses, lets call them A and B. A is insecure. There should be a database link beetwen them so that users of database A can acces the information from database B. I would not like to store any passwords to database B in database A. The password should be passed with every single query. Moreover, I can not use the 'current_user authentication' as long as this option assumes usernames and passwords are the same.

Is it possible? If so, can anyone let me know what to do? I would be greatful for any help.

IP Logged

Pete Finnigan (email:pete@petefinnigan.com)
Oracle Security Web site: http://www.petefinnigan.com
Forum: http://www.petefinnigan.com/forum/yabb/YaBB.cgi
Oracle security blog: http://www.petefinnigan.com/weblog/entries/index.html

Pete Finnigan
PeteFinnigan.com Administrator

Oracle Security is easier if you design for it

View Profile | WWW | Email

Gender: male

Posts: 309

Re: securing database link
« Reply #1 on: Nov 27^th, 2008, 10:19pm »

Quote | Modify

"There should be a database link between them so that users of database A can access the information from database B."
What is the end-to-end situation ? Are they accessing database A directly through SQL or is there an application ? What do you mean when you say that "A is insecure" ?
1) usernames/passwords for database A are well known or easily 'cracked'
2) database accounts in database A are highly privileged (eg SELECT_CATALOG_ROLE, SELECT ANY..).
3) the underlying data files, or backups/extracts, for database A are stored in an easily accessible location

The first option is to drive from the secure database B to the less secure database.

Alternatively, since database A can't be trusted, I'd look at an application that supports concurrent connections to different databases. The application would have to 'simulate' joins between database objects on the different databases.

The only alternative I can think of is some web service style connection with userid and passwords as parameters. While the userids/passwords aren't stored in datafiles (which would address item 3 above), in 11g some bind variable information is exposed in v$sql so passwords passed in as bind variables may not be secure (and they are less secure if exposed as literals). Pre-11g, some trace events can expose bind variables too. So it is much less secure in regards to item 2.

IP Logged

Pete Finnigan
PeteFinnigan.com Administrator

Oracle Security is easier if you design for it

View Profile | WWW | Email

Gender: male

Posts: 309

Re: securing database link
« Reply #2 on: Dec 2^nd, 2008, 3:39am »

Quote | Modify

Another option is to define the database link, in the insecure database A, with a valid userid/password (for database B).

For example, define a userid in B, such as LIMITED_DBLINK, with limited privileges, preferably, just Create Session and select on a limited set of views.

Define a VPD policy in B which requires the connection of LIMITED_DBLINK to originate from database A. (Perhaps obtain the IP_ADDRESS via SYS_CONTEXT.)

But if your database A is insecure, then perhaps the IP_ADDRESS could be hacked. (Not my area of expertise). It depends upon your level of tolerance. If this solution sounds like too much risk, then Pete's ideas of a push from the secure database is best, or, alternatively, as he suggests, handle the query in a section of application logic which can be trusted with knowledge of B credentials.

IP Logged

Pete Finnigan
PeteFinnigan.com Administrator

Oracle Security is easier if you design for it

View Profile | WWW | Email

Gender: male

Posts: 309

Re: securing database link
« Reply #3 on: Dec 18^th, 2008, 12:15pm »

Quote | Modify

Hi,
In the end-to-end situation we have j2ee application which makes transfers between those two databases. What do I mean by saying A is insecure? usernames and passwords are easy to be cracked.

The web service style connection seems to be interesting. Is there any way to parametrize the queries in pre-11g? I mean passing credentials with query.

IP Logged

Pete Finnigan
PeteFinnigan.com Administrator

Oracle Security is easier if you design for it

View Profile | WWW | Email

Gender: male

Posts: 309

Re: securing database link
« Reply #4 on: Dec 28^th, 2008, 12:17am »

Quote | Modify

"Is there any way to parametrize the queries in pre-11g? I mean passing credentials with query. "
In theory you can have a PL/SQL function returning a table or collection type, and query it with

"select * from table(func(:user,:pass))"

But complex data types don't work across DB links so I don't think it would help here, and as I mentioned before, bind variables aren't particularly secure.

"In the end-to-end situation we have j2ee application which makes transfers between those two databases. "
I'd have that application make two separate connections, one to each database. Or connect to the more secure and push to the less secure.

What do I mean by saying A is insecure? usernames and passwords are easy to be cracked.

The web service style connection seems to be interesting.

IP Logged

Pages: 1

Reply | Notify of replies | Send Topic | Print


« Previous topic \| Next topic »

PFCLScan
Simply connect PFCLScan to your Oracle database and it will automatically discover the security issues that could make your Oracle database vulnerable to attack and to the potential loss of your data.

Learn more
PFCLObfuscate
PFCLObfuscate is the only tool available that can automatically add license controls to your PL/SQL code. PFCLObfuscate protects your Intellectual Property invested in your PL/SQL database code.

Learn more
PFCLCode
PFCLCode is a tool to allow you to analyse your PL/SQL code for many different types of security issues. PFCLCode gives you a detailed review and reports and includes a powerful colour syntax highlighting code editor

Learn more
PFCLForensics
PFCLForensics is the only tool available to allow you to do a detailed live response of a breached Oracle database and to then go on and do a detailed forensic analysis of the data gathered.

Learn more
PFCLReselling
PeteFinnigan.com Limited has partnered with a small number of relevant companies to resell their products where they enhance or compliment what we do

Learn more
PFCLATK
PFCLATK is a toolkit that allows detailed pre-defined policy driven audit trails for your Oracle database. The toolkit also provides for a centralised audit trail and centralised activity reporting

Learn more
PFCLCookie
PFCLCookie is a useful tool to use to audit your websites for tracking cookies. Scan websites in a natural way using powerful browser driven scanner

Learn more
PFCLTraining
PFCLTraining is a set of expert training classes for you, aimed at teaching how to audit your own Oracle database, design audit trails, secure code in PL/SQL and secure and lock down your Oracle database.

Learn more
PFCLServices
Choose PFCLServices to add PeteFinnigan.com Ltd to your team for your Oracle Security needs. We are experts in performing detailed security audits, data security design work and policy creation

Learn more
PFCLConsulting
Choose PFCLConsulting to ask PeteFinnigan.com Limited to set up and use our products on your behalf

Learn more
PFCLCustom
All of our software products can be customised at a number of levels. Choose this to see how our products can be part of your products and services

Learn more
PFCLCloud
Private cloud, public cloud, hybrid cloud or no cloud. Learn how all of our services, trainings and products will work in the cloud

Learn more
PFCLUserRights
PFCLUserRights allows you to create a very detailed view of database users rights. The focus of the reports is to allow you to decide what privileges and accounts to keep and which to remove.

Learn more
PFCLSTK
PFCLSTK is a toolkit application that allows you to provide database security easily to an existing database. PFCLSTK is a policy driven toolkit of PL/SQL that creates your security

Learn more
PFCLSFTK
PFCLSFTK is a toolkit that solves the problem of securing third party applications written in PL/SQL. It does this by creating a thin layer between the application and database and this traps SQL Injection attempts. This is a static firewall.

Learn more
PFCLSEO
PFCLSEO is a web scanner based on the PFCLScan technology so that a user can easily scan a website for technical SEO issues

Learn more