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Oracle proxy user authentication
Oracle Database Tips by Donald Burleson |
Today, systems with thousands
of individual Oracle user ID's are not very common. Almost all enterprise
applications (ERP packages like SAP, Oracle Financials) use pre-spawned Oracle
connections that are created by a single Oracle user ID with names like AR or
SAPR3.
Also see my notes on
grant
connect through.
The application server manages
the connections to Oracle for us.
This is called a "proxy",
the term proxy meaning an act where a 3rd party does something on our behalf.
Unfortunately, when our end-users connect anonymously through a proxy, we do not
have any end-user level security through traditional security tools like
granting privileges or using roles and the only Oracle security is that is
granted the the ERP "master" user ID.
Who goes there?
From a DBA perspective, all
database activity is being done by this single user and a query of the
v$session view for an ERP does not identify any specific user, because they
are connected to Oracle via the proxy on the application server.
This is a special nightmare for
Oracle auditing, and all database auditing must now be done within the
application server because is not aware of the "real" end-user, behind the proxy
connection.
For complete information on
Oracle auditing for ERP's see my notes in my bestselling security book "Oracle
Privacy Security Auditing" with Arup Nanda.
The answer is to create a
method whereby the ERP can maintain it's pre-spawned connection to Oracle while
giving Oracle the ability to impose traditional security management (via roles,
privileges, VPD's, etc.).
Oracle proxy connect
authentication in 10gr2
To address this issue of
unknown specific users within pre-spawned Oracle connections, Oracle has
introduced a new proxy identification in Oracle 10g release 2 and bayond.
Under this new architecture,
the ERP user ID is given limited privileges (create session only), and
individual Oracle user ID's are created for each ERP user, using the traditional
"create user" syntax.
Traditionally, you always
connected to Oracle by only specifying your user ID and password:
connect scott/tiger
New with 10r2 proxy
identification in SQL*Plus, the "connect" command has been enhanced to allow for
a "proxy":
connect sapr3[scott]/tiger
You can also use this syntax to
connect to SQL*Plus directly from the OS prompt:
root> sqlplus
sapr3[scott]/tiger@mydb
As we see, we have a second, "proxy" user ID in the connect request (scott,
in this case). When Oracle establishes the database connection, he will
first connect as SAPR3 (who only has connect and resource privileges) and then
open a proxy connection as scott.
Now, we have complete Oracle privileges and access control, just as if the
scott user was connected, but in reality we have connected with the SAPR3 user,
keeping our pre-spawned connection pool happy.
Note: To see the "proxy owner" of any Oracle session, you can see a
proxy connection by using the sys_context package:
-- Here we see that Oracle has scott as the
user ID
select user from dual;
USER
---------------------------------------
SCOTT
-- Here we call sys_context to reveal the proxy user:
select sys_context('USERENV','PROXY_USER')
from dual;
SYS_CONTEXT('USERENV','PROXY_USER')
---------------------------------------
SAPR3