Unwrap Oracle 10g/11g PLSQL

Article and Script Courtesy: Niels Teusink


The Oracle wrap utility can be used to obfuscate PL/SQL code, to ensure it can't be easily read. Pete Finnigan described (pdf) the wrapping process for Oracle 9g, but for 10g and 11g it still remains a bit of a mystery. I decided to release my Python unwrapping utility (supports 10g and 11g).

The unwrapping steps for 10g are nicely described in the Oracle Hacker's Handbook, but the actual substitution table needed to decode the package is omitted. Nobody (as far as I know) has published it. A lot of people seem to know how to do it though, there is even an online unwrapper available (and I'm sure everyone seriously involved in Oracle security knows how to do it). A Russian-made closed source tool is also available, but tends to upset virus scanners.

So to save everyone a couple of hours of figuring it out, here it is: unwrap.py

It's easy to use (I've used the wrapped procedure from this article as an example):

$ ./unwrap.py wrapped.txt
=== Oracle 10g/11g PL/SQL unwrapper - by Niels Teusink - blog.teusink.net ===

PROCEDURE WRAP_IT (SEED_IN NUMBER)
IS
  V_RAND INTEGER;
BEGIN
  DBMS_RANDOM.INITIALIZE (SEED_IN);
  FOR I IN 1..5 LOOP
   V_RAND := MOD(ABS(DBMS_RANDOM.RANDOM),45);
   DBMS_OUTPUT.PUT_LINE(I||': '||V_RAND);
  END LOOP;
END;


Ask Anantha Team thanks Niels for permitting to post his article here.