Restoring a user's original password

WARNING
=======

The method described in this article is not officially supported by development,
therefore when you get errors using this procedure support cannot file a bug for it.
Please make no mistakes when setting the HEX value with the VALUES keyword as bad
values may cause internal errors. This undocumented feature exists to support
export / import and retain the original passwords.

Problem Description:
====================

How can you restore a users original password ?

Solution Description:
=====================
With the output of dba_users you can restore a user's old password by
issuing the following:

   alter user <name> identified by values '<original_encrypted_password>';

For example:
============
SQL> create user test identified by test
  2  default tablespace users temporary tablespace temp;

User created.

SQL> select username, password from dba_users where username= 'TEST';

USERNAME   PASSWORD
---------- ------------------------------
TEST       CDC423BEB32B1812

SQL> alter user test identified by test1;
User altered.

SQL> select username, password from dba_users where username= 'TEST';

USERNAME   PASSWORD
---------- ------------------------------
TEST       22F2E341BF4B8764

SQL> alter user test identified by values 'CDC423BEB32B1812';
User altered.

SQL> connect test/test
Connected.

Solution Explanation:
=====================
To do this you would need a spool of dba_users taken before the password was
changed.