Check user's password is valid or not in plsql

Question

I need to check if a database user is valid.

I will allow users to change their passwords using the ALTER command, but before I do I want to validate t

Answer 1

I don't think Oracle database gives you an API for doing this. One kludge you could use would be to use a loopback database link to check it. Like this:

DECLARE
  p_username        VARCHAR2 (30) := 'MMCP';  -- Change to the user whose password you are validating
  p_test_password   VARCHAR2 (30) := 'NOT_MY_PASSWORD';  
  p_loopback_connection_string VARCHAR2(80) := 'ORCLQA';  -- Change this for your environment
BEGIN

  BEGIN
    EXECUTE IMMEDIATE q'[drop database link password_test_loopback]';
  EXCEPTION
    WHEN OTHERS THEN
      NULL;
  END;

  EXECUTE IMMEDIATE
    'create database link password_test_loopback connect to "' || p_username || '" identified by "' || p_test_password || '" using ''' || p_loopback_connection_string || '''';

  EXECUTE IMMEDIATE q'[SELECT * FROM dual@password_test_loopback]';

  EXECUTE IMMEDIATE q'[drop database link password_test_loopback]';
  
  dbms_output.put_line('Password is good');
EXCEPTION WHEN OTHERS THEN
  IF SQLCODE = -1017 THEN
    DBMS_OUTPUT.PUT_LINE('Password is wrong');
  ELSE
    raise;
  END IF;
END;

More advanced options would be to find a way to use single signon / LDAP for your Oracle authentication. Then, your problem becomes -- how do I validate a username/password in my LDAP dictionary, which is much easier.