Posts Tagged security

AUDIT_SYS_OPERATIONS defaults to TRUE in #Oracle 12c

A small but remarkable change in Oracle Database 12c is the default value of AUDIT_SYS_OPERATIONS has changed to TRUE now. In other words, all actions done by the superuser sys are being audited now by default!

[oracle@uhesse ~]$ sqlplus / as sysdba

SQL*Plus: Release 12.1.0.2.0 Production on Fri Jul 24 15:23:10 2015

Copyright (c) 1982, 2014, Oracle.  All rights reserved.


Connected to:
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

SQL> select name,value from v$spparameter where isspecified='TRUE';

NAME                                     VALUE
---------------------------------------- --------------------------------------------------
memory_target                            1073741824
control_files                            /u01/app/oracle/oradata/prima/control01.ctl
db_block_size                            8192
compatible                               12.1.0.2
db_recovery_file_dest                    /u02/fra
db_recovery_file_dest_size               2147483648
undo_management                          auto
undo_tablespace                          undotbs1
remote_login_passwordfile                exclusive
db_name                                  prima
diagnostic_dest                          /u01/app/oracle

11 rows selected.


SQL> show parameter sys_oper

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
audit_sys_operations                 boolean     TRUE
SQL> select count(*) from scott.dept;

  COUNT(*)
----------
         4

SQL> show parameter audit_file

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
audit_file_dest                      string      /u01/app/oracle/product/12.1.0
                                                 /dbhome_1/rdbms/audit
SQL> exit
Disconnected from Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
[oracle@uhesse ~]$ cd /u01/app/oracle/product/12.1.0/dbhome_1/rdbms/audit

[oracle@uhesse audit]$ cat prima_ora_6204_20150724152310753136143795.aud
Audit file /u01/app/oracle/product/12.1.0/dbhome_1/rdbms/audit/prima_ora_6204_20150724152310753136143795.aud
Oracle Database 12c Enterprise Edition Release 12.1.0.2.0 - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options
ORACLE_HOME = /u01/app/oracle/product/12.1.0/dbhome_1
System name:    Linux
Node name:      uhesse
Release:        3.8.13-68.2.2.el7uek.x86_64
Version:        #2 SMP Tue May 12 14:38:58 PDT 2015
Machine:        x86_64
Instance name: prima
Redo thread mounted by this instance: 1
Oracle process number: 41
Unix process pid: 6204, image: oracle@uhesse (TNS V1-V3)

Fri Jul 24 15:23:10 2015 +02:00
LENGTH : '160'
ACTION :[7] 'CONNECT'
DATABASE USER:[1] '/'
PRIVILEGE :[6] 'SYSDBA'
CLIENT USER:[6] 'oracle'
CLIENT TERMINAL:[5] 'pts/1'
STATUS:[1] '0'
DBID:[10] '2113606181'
[Output shortened...]
Fri Jul 24 15:23:56 2015 +02:00
LENGTH : '185'
ACTION :[31] 'select count(*) from scott.dept'
DATABASE USER:[1] '/'
PRIVILEGE :[6] 'SYSDBA'
CLIENT USER:[6] 'oracle'
CLIENT TERMINAL:[5] 'pts/1'
STATUS:[1] '0'
DBID:[10] '2113606181'

Something you might need to know as a DBA, don’t you think? 🙂

,

2 Comments

Flashback Data Archive in #Oracle 12c

This article highlights some 12c changes of Flashback Data Archive (FDA). See here for an introduction. Remarkably, the feature is now included in all editions. I will focus here on the 12c enhancement that an application can be registered to FDA. That has two major benefits:

1. FDA can be turned on and off for all tables of that application with one command

2. Protection (better than READ ONLY) can be turned on and off for all tables of that application with one command

The playing field:

SQL> select * from v$version;

BANNER                                                                               CON_ID
-------------------------------------------------------------------------------- ----------
Oracle Database 12c Enterprise Edition Release 12.1.0.1.0 - 64bit Production              0
PL/SQL Release 12.1.0.1.0 - Production                                                    0
CORE    12.1.0.1.0      Production                                                        0
TNS for Linux: Version 12.1.0.1.0 - Production                                            0
NLSRTL Version 12.1.0.1.0 - Production                                                    0
SQL> grant dba to quaid identified by quaid;

Grant succeeded.

SQL> connect quaid/quaid
Connected.
SQL> create tablespace flatbs datafile '/home/oracle/prima/flatbs01.dbf' size 50m;

Tablespace created.

SQL> create table t1 as select * from dual;

Table created.

SQL> create table t2 as select * from dual;

Table created.

SQL> create flashback archive fla_10y tablespace flatbs retention 10 year;

Flashback archive created.

So far no new feature as the same can be done with 11g. No I register the application – that is just declarative:

SQL> begin
     dbms_flashback_archive.register_application
     (application_name=>'MYAPP',
     flashback_archive_name=>'FLA_10Y');
     end;
     /  

PL/SQL procedure successfully completed.

Now I add all tables of that application:

SQL> begin
     dbms_flashback_archive.add_table_to_application
     (application_name=>'MYAPP',
     table_name=>'t1',
     schema_name=>'QUAID');
     end;
     /  

PL/SQL procedure successfully completed.

SQL> begin
     dbms_flashback_archive.add_table_to_application
     (application_name=>'MYAPP',
     table_name=>'t2',
     schema_name=>'QUAID');
     end;
     /  

PL/SQL procedure successfully completed.

I can now turn FDA on and off for all the tables with one command:

SQL> select table_name,status from user_flashback_archive_tables;

no rows selected

SQL> exec dbms_flashback_archive.enable_application(application_name=>'MYAPP')

PL/SQL procedure successfully completed.

SQL> select table_name,status from user_flashback_archive_tables;

TABLE_NAME STATUS
---------- ----------
T1         ENABLED
T2         ENABLED

SQL> exec dbms_flashback_archive.disable_application(application_name=>'MYAPP')

PL/SQL procedure successfully completed.

SQL> select table_name,status from user_flashback_archive_tables;

no rows selected

Furthermore, I can now protect these tables with one command against modification and drop:

SQL> exec dbms_flashback_archive.lock_down_application(application_name=>'MYAPP')

PL/SQL procedure successfully completed.

SQL> delete from t1;
delete from t1
            *
ERROR at line 1:
ORA-55622: DML, ALTER and CREATE UNIQUE INDEX operations are not allowed on table "QUAID"."T1"

SQL> drop table t1;
drop table t1
           *
ERROR at line 1:
ORA-55622: DML, ALTER and CREATE UNIQUE INDEX operations are not allowed on table "QUAID"."T1"

This is a much better protection than just making tables READ ONLY:

SQL> create table t3 as select * from dual;

Table created.

SQL> alter table t3 read only;

Table altered.

SQL> drop table t3;

Table dropped.

Please notice also that the tables need not to be in FDA mode to be protected by the lock_down_application call. The doc by the way doesn’t mention the unlock procedure:

SQL> exec dbms_flashback_archive.unlock_application(application_name=>'MYAPP')

PL/SQL procedure successfully completed.

Conclusion: The 12c enhancements of Flashback Data Archive enable the fast change of the FDA mode for multiple tables. Furthermore, it is now easily possible to prevent tables from being modified and dropped.

, , ,

7 Comments

Fine Grained Access Control with DBMS_RLS using UPDATE_CHECK=>true

Fine Grained Access Control aka Virtual Private Database (VPD) has been there since Oracle 8 and got enhanced in each subsequent version. One minor New Feature of 11.2 was the addition of the parameter UPDATE_CHECK to the DBMS_RLS.ADD_POLICY procedure. During the OCM Preparation Workshop that I deliver presently, one of the attendees asked me what this parameter is actually doing – the doc is not so clear about it – which is why I came up with this simplified example. Hope you find it useful also 🙂

SQL> grant dba to adam identified by adam;

Grant succeeded.

SQL> connect adam/adam
Connected.
SQL> create table emp (ename varchar2(5),salary number);

Table created.

SQL> insert into emp values ('SCOTT',3000);

1 row created.

SQL> insert into emp values ('KING',9000);

1 row created.

SQL> commit;

Commit complete.

SQL> grant create session to scott identified by tiger;

Grant succeeded.

SQL> grant select,update on adam.emp to scott;

Grant succeeded.

The user SCOTT is not supposed to see the salary of the other employees and VPD is an elegant way to achieve that. The following technique will silently attach a WHERE-condition to statements hitting the table emp:

SQL> connect adam/adam
Connected.
SQL> create or replace function whoisit(schema varchar2, tab varchar2) return varchar2 
as
begin 
return '''' || sys_context('userenv','session_user') || ''' = ename ';     
end; 
/    

Function created.

SQL> begin
 dbms_rls.add_policy
  (object_schema=>'ADAM',
   object_name=>'EMP',
   policy_name=>'EMP_POLICY',
   function_schema=>'ADAM',
   policy_function=>'WHOISIT',
   update_check=>true);
end;
/    

PL/SQL procedure successfully completed.

SQL> connect scott/tiger
Connected.
SQL> select * from adam.emp;

ENAME	  SALARY
----- ----------
SCOTT	    3000

Although there are two rows in the table, SCOTT sees only his own salary! So far, this has been the same in earlier versions already. Now to the effect of update_check:

SQL> update adam.emp set ename='KING';
update adam.emp set ename='KING'
            *
ERROR at line 1:
ORA-28115: policy with check option violation

Without that parameter setting, the update would succeed – and the row would vanish for the user SCOTT as if the update would have deleted the row. Imagine the confusion of the user about that weird behavior 🙂

Talking about weird, by the way:

SQL> connect adam/adam
Connected.
SQL> select * from adam.emp;

no rows selected

SQL> connect / as sysdba
Connected.
SQL> select * from adam.emp;

ENAME	  SALARY
----- ----------
SCOTT	    3000
KING	    9000

SQL> grant exempt access policy to adam;

Grant succeeded.

SQL> connect adam/adam
Connected.
SQL> select * from adam.emp;

ENAME	  SALARY
----- ----------
SCOTT	    3000
KING	    9000

That was funny, wasn’t it?

Conclusion: The new parameter UPDATE_CHECK in the DBMS_RLS.ADD_POLICY procedure restricts updates that would else lead to the updated rows to fall out of the allowed visibility for that user. Check out the old behavior by just omitting that parameter. Because: Don’t believe it, test it 🙂

, , , ,

4 Comments

%d bloggers like this: