OVERVIEW:

                With oracle 12c, unified auditing has been introduced. It consolidates all audit trails into a single audit trail table.

It will capture audit records from below sources.

  1. SYS audit records ( which was written to os trail in traditional method, will now be written to db table)
  2. Unified audit policies for different action/privilege/statement/role etc.
  3. EXPDP/IMPDP events
  4. RMAN events
  5. Sql loader

TRADITIONAL VS UNIFIED

 

TRADITIONAL AUDITINGUNIFIED_AUDITING
Depends on db init parameter like audit_trail,audit_sys_logIndependent of db parameter,bydefault enabled
writes audit records to different trails depending upon audit typeall audit trails are writeen to single trail
sys records are written to os .aud filessys records are written to unified_audit_trail
auditing not possible for rman/expdp/sqllderauditing can be enabled for db compoenents like rman/datapump/sqlldr
each audit record was written to disk immediately, which causes i/o issueIf querywrite method is enabled(default), then all audit records will queued in sga
and later will be flushed to disk , which improves performance
auditing need to enabled for each action/statement individually.One policy can contain mulitiple actions/privilge/role audit option and
which can enabled or disables easily

There are two types of unified auditing mode in oracle 12c.

MODE OF UNIFIED_AUDITING:

1. Mixed auditing – By default it is enable in 12c. It enables to use both traditional auditing and unified auditing methods. I.e. apart from traditional auditing we can use all the features of unified auditing. Once we are comfortable with the unified concept, we can migrate exiting audit setup to unified policy , we can enable pure auditing.
This serves as a good mediator for an easy and hassle free switch to the preferred Unified auditing.
2. Pure auditing – Once pure auditing is enabled. We cannot use the traditional auditing methods.

Which unified auditing mode enabled for my database

SELECT value FROM v$option WHERE parameter = 'Unified Auditing';
VALUE
-----------------
FALSE

FALSE – > MIXED AUDTING
TRUE –> PURE AUDITING:
How to change from MIXED to PURE auditing:(relink library)

SELECT value FROM v$option WHERE parameter = 'Unified Auditing';
VALUE
-----------------
FALSE
sqlplus / as sysdba 

shutdown immediate;
exit

cd $ORACLE_HOME/rdbms/lib

make -f ins_rdbms.mk unaiaud_on ioracle

sqlplus / as sysdba

startup
SELECT value FROM v$option WHERE parameter = 'Unified Auditing';
VALUE
-----------------
TRUE

NOTE – FOR RAC, linking need to be done all the nodes

WHAT IS UNIFIED AUDIT POLICY AND HOW IT WORKS:

Unified audit policy is like a group of audit options with different conditions. It is like a ROLE which is a group of privileges.
For enabling auditing , first need to create a policy with different audit options and then need to enable or disable for all or few users depending upon the requirement.
All the audit records will be stored in unified_audit_trail table. By default 7 audit policies will be present in a 12c database.
DEFAULT POLICIES IN 12C DATABASE

SQL> select distinct POLICY_NAME from AUDIT_UNIFIED_POLICIES;

POLICY_NAME
-------------------------------------------------------------------------------
ORA_CIS_RECOMMENDATIONS
ORA_RAS_POLICY_MGMT
ORA_RAS_SESSION_MGMT
ORA_LOGON_FAILURES
ORA_SECURECONFIG
ORA_DATABASE_PARAMETER
ORA_ACCOUNT_MGMT

But not all are enabled. Query AUDIT_UNIFIED_ENABLED_POLICIES to find, which policies are enabled.
 Query to find which policies are enabled

SQL>  select distinct policy_name from AUDIT_UNIFIED_ENABLED_POLICIES;
POLICY_NAME
-----------------------------------------
ORA_LOGON_FAILURES
ORA_SECURECONFIG

 Query to check the audit options included in a policy:

SQL>  select AUDIT_OPTION from AUDIT_UNIFIED_POLICIES where POLICY_NAME='ORA_SECURECONFIG';

LOGMINING
TRANSLATE ANY SQL
EXEMPT REDACTION POLICY
PURGE DBA_RECYCLEBIN
ADMINISTER KEY MANAGEMENT
DROP ANY SQL TRANSLATION PROFILE
ALTER ANY SQL TRANSLATION PROFILE
CREATE ANY SQL TRANSLATION PROFILE
CREATE SQL TRANSLATION PROFILE
CREATE EXTERNAL JOB
CREATE ANY JOB
GRANT ANY OBJECT PRIVILEGE
EXEMPT ACCESS POLICY
CREATE ANY LIBRARY
GRANT ANY PRIVILEGE
DROP ANY PROCEDURE
ALTER ANY PROCEDURE
CREATE ANY PROCEDURE
ALTER DATABASE
GRANT ANY ROLE
DROP PUBLIC SYNONYM
CREATE PUBLIC SYNONYM
DROP ANY TABLE
ALTER ANY TABLE
CREATE ANY TABLE
DROP USER
CREATE USER
AUDIT SYSTEM
ALTER SYSTEM
CREATE DATABASE LINK
DROP DATABASE LINK
ALTER USER
CREATE ROLE
DROP ROLE
SET ROLE
CREATE PROFILE
DROP PROFILE
ALTER PROFILE
ALTER ROLE
CREATE DIRECTORY
DROP DIRECTORY
ALTER DATABASE LINK
CREATE PLUGGABLE DATABASE
ALTER PLUGGABLE DATABASE
DROP PLUGGABLE DATABASE
EXECUTE

Even if no new policy is created in database, Audit action of the above audit options will be recorded in unified_audit_trail.

Below are few test cases on unified audit policy :

TEST CASE 1 : ( default audit option):

DROP DIRECTORY , which is one of the audit option of the default policy ORA_SECURECONFIG.

Connect to bsstdba and drop a directory

SQL> show user
USER is "BSSTDBA"
SQL> drop directory TEST;
Directory dropped.

Check the audit report

set lines 299
col SQL_TEXT for a23
col action_name for a18
col UNIFIED_AUDIT_POLICIES for a23
SQL>  select action_name,SQL_TEXT,UNIFIED_AUDIT_POLICIES ,EVENT_TIMESTAMP from unified_AUDIT_trail where DBUSERNAME='BSSTDBA' and EVENT_TIMESTAMP > sysdate -1/24;


ACTION_NAME        SQL_TEXT                UNIFIED_AUDIT_POLICIES  EVENT_TIMESTAMP
------------------ ----------------------- ----------------------- ------------------------------
LOGON                                      ORA_LOGON_FAILURES      16-FEB-17 11.29.03.981436 PM
DROP DIRECTORY     drop directory TEST2    ORA_SECURECONFIG        16-FEB-17 11.29.59.924533 PM

TEST CASE 2 : CREATE AUDIT POLICY WITH MULTIPLE AUDIT OPTIONS:

create audit policy test_case2
  ACTIONS CREATE TABLE, 
  INSERT ON classdba.EMP_TAB,
  TRUNCATE TABLE,
  select on classdba.PROD_TAB;
set lines 299
col POLICY_NAME for a23
col AUDIT_OPTION for a12
col AUDIT_CONDITION for a12
col OBJECT_SCHEMA for a23
col OBJECT_NAME for a14
select POLICY_NAME,audit_option,AUDIT_CONDITION,OBJECT_SCHEMA,OBJECT_NAME FROM AUDIT_UNIFIED_POLICIES where POLICY_NAME='TEST_CASE2';

POLICY_NAME  AUDIT_OPTION          AUDIT_CONDITION    OBJECT_SCHEMA   OBJECT_NAME
------------ --------------------- ------------------ --------------- ------------------
TEST_CASE2   CREATE TABLE          NONE               NONE            NONE
TEST_CASE2   TRUNCATE TABLE        NONE               NONE            NONE
TEST_CASE2   INSERT                NONE               BSSTDBA         EMP_TAB
TEST_CASE2   SELECT                NONE               BSSTDBA         PROD_TAB


SQL> select distinct policy_name from AUDIT_UNIFIED_ENABLED_POLICIES where policy_name='TEST_CASE2';

no rows selected

Unless we enable the policy, auditing conditions wont be evaluated

SQL> audit policy TEST_CASE2;

Audit succeeded.

SQL> select distinct policy_name from AUDIT_UNIFIED_ENABLED_POLICIES where policy_name='TEST_CASE2';


POLICY_NAME
------------
TEST_CASE2

Do some changes and generate audit report:

SQL> select action_name,SQL_TEXT,UNIFIED_AUDIT_POLICIES ,EVENT_TIMESTAMP from unified_AUDIT_trail where DBUSERNAME='STCDBA' and EVENT_TIMESTAMP > sysdate -1/24;

ACTION_NAME        SQL_TEXT                UNIFIED_AUDIT_POLICIES  EVENT_TIMESTAMP
------------------ ----------------------- ----------------------- --------------------------------
CREATE TABLE       create table EMP_NUM as TEST_CASE2              17-FEB-17 09.19.16.054209 AM
                    select * from classdba.
                   emp_tab

EXCLUDE ONE USER FROM THE POLICY:

SQL> select USER_NAME,POLICY_NAME,ENABLED_OPT from AUDIT_UNIFIED_ENABLED_POLICIES where POLICY_NAME='TEST_CASE2';


USER_NAME     POLICY_NAME  ENABLED_OPT
------------- ------------ -----------------------
ALL USERS     TEST_CASE2   BY


SQL> audit policy TEST_CASE2 except proddba;
audit policy TEST_CASE2 except proddba
*
ERROR at line 1:
ORA-46350: Audit policy TEST_CASE2 already applied with the BY clause.

Once audit policy is enabled, if we try to enable again, it will throw error. So to change the audit condition, disable and enable with new condition.

SQL> noaudit policy TEST_CASE2;

Noaudit succeeded.

SQL> audit policy TEST_CASE2 except stcdba;

Audit succeeded.

SQL> select USER_NAME,POLICY_NAME,ENABLED_OPT from AUDIT_UNIFIED_ENABLED_POLICIES where POLICY_NAME='TEST_CASE2';

USER_NAME     POLICY_NAME  ENABLED_OPT
------------- ------------ -----------------------
PRODDBA        TEST_CASE2   EXCEPT

Now create a table from stcdba.

SQL> SQL> connect stcdba
Enter password:
Connected.
SQL> create table TEST4 ( empnum number);

Table created.

SQL> conn / as sysdba
Connected.
SQL>  select action_name,SQL_TEXT,UNIFIED_AUDIT_POLICIES ,EVENT_TIMESTAMP from unified_AUDIT_trail where DBUSERNAME='STCDBA' and EVENT_TIMESTAMP > sysdate -1/24;

ACTION_NAME        SQL_TEXT                UNIFIED_AUDIT_POLICIES  EVENT_TIMESTAMP
------------------ ----------------------- ----------------------- ---------------------------------------------------------------------------
CREATE TABLE       create table EMP_NUM as TEST_CASE2              17-FEB-17 09.19.16.054209 AM
                    select * from classdba.
                   emp_tab

We can see the new audit action ( CREATE TABLE TEST4 is not recorded in audit trail table) as expected.
We can mention success/failure condition similar to traditional auditing:

audit policy TEST_CASE2 whenever successful;
audit policy TEST_CASE2 Whenever not successful;

3. TEST_CASE 3 :

Create an audit policy, to audit delete on table bsstdba.EMP_TAB,insert on bsstdba.PROD_TAB and update on bsstdba.SAL_TAB TABLE BY user STCDBA.

This can be achieved by using the same method of test_case2, But here we will define the condition in the audit policy itself, instead of mentioning it while enabling audit.

SQL> create AUDIT POLICY test_case3
  ACTIONS DELETE ON classdba.EMP_TAB,
          INSERT ON classdba.PROD_TAB,
          UPDATE ON classdba.SAL_TAB
  WHEN    'SYS_CONTEXT(''USERENV'', ''SESSION_USER'') = ''STCDBA'''
    EVALUATE PER SESSION;  2    3    4    5    6

Audit policy created.

SQL>  audit policy TEST_CASE3;

Audit succeeded.

EVALUATE PER refers to the following options:
 STATEMENT evaluates the condition for each relevant auditable statement that
occurs.
 SESSION evaluates the condition only once during the session, and then caches
and re-uses the result during the remainder of the session. Oracle Database
evaluates the condition the first time the policy is used, and then stores the result
in UGA memory afterward.
 INSTANCE evaluates the condition only once during the database instance
lifetime. After Oracle Database evaluates the condition, it caches and re-uses the
result for the remainder of the instance lifetime. As with the SESSION evaluation,
the evaluation takes place the first time it is needed, and then the results are stored
in UGA memory afterward

SQL> select POLICY_NAME,audit_option,AUDIT_CONDITION,OBJECT_SCHEMA,OBJECT_NAME,CONDITION_EVAL_OPT FROM AUDIT_UNIFIED_POLICIES where POLICY_NAME='TEST_CASE3';

POLICY_NAME  AUDIT_OPTION          AUDIT_CONDITION    OBJECT_SCHEMA   OBJECT_NAME        CONDITION
------------ --------------------- ------------------ --------------- ------------------ ---------
TEST_CASE3   UPDATE                SYS_CONTEXT('USERE CLASSDBA         SAL_TAB            SESSION
                                   NV', 'SESSION_USER
                                   ') = 'PRODDBA'

TEST_CASE3   DELETE                SYS_CONTEXT('USERE CLASSDBA         EMP_TAB            SESSION
                                   NV', 'SESSION_USER
                                   ') = 'PRODDBA'

TEST_CASE3   INSERT                SYS_CONTEXT('USERE CLASSDBA         PROD_TAB           SESSION
                                   NV', 'SESSION_USER
                                   ') = 'PRODDBA'



SQL> select USER_NAME,POLICY_NAME,ENABLED_OPT from AUDIT_UNIFIED_ENABLED_POLICIES where POLICY_NAME='TEST_CASE3';

USER_NAME     POLICY_NAME  ENABLED_OPT
------------- ------------ -----------------------
ALL USERS     TEST_CASE3   BY

TESTCASE_4:

Create an audit policy, to audit insert on bsstdba.PROD_TAB and update on bsstdba.SAL_TAB TABLE WHEN USER_NAME NOT IN (‘STCDBA’,’TCSDBA’)

SQL>
  CREATE AUDIT POLICY test_case4
ACTIONS insert on classdba.PROD_TAB,
        update on classdba.SAL_TAB
WHEN 'sys_context(''userenv'',''SESSION_USER'') not in ( ''STCDBA'',''TCSDBA'')'
  EVALUATE PER STATEMENT;SQL>   2    3    4    5

Audit policy created.


SQL> AUDIT POLICY test_case4;
Audit succeeded.

SQL> SQL> select POLICY_NAME,audit_option,AUDIT_CONDITION,OBJECT_SCHEMA,OBJECT_NAME,CONDITION_EVAL_OPT FROM AUDIT_UNIFIED_POLICIES where POLICY_NAME='TEST_CASE4';

POLICY_NAME  AUDIT_OPTION          AUDIT_CONDITION    OBJECT_SCHEMA   OBJECT_NAME        CONDITION
------------ --------------------- ------------------ --------------- ------------------ ---------
TEST_CASE4   UPDATE                sys_context('usere BSSTDBA         SAL_TAB            STATEMENT
                                   nv','SESSION_USER'
                                   ) not in ( 'PRODDBA
                                   ','DEVDBA')

TEST_CASE4   INSERT                sys_context('usere BSSTDBA         PROD_TAB           STATEMENT
                                   nv','SESSION_USER'
                                   ) not in ( 'PRODDBA
                                   ','DEVDBA')


								   
SQL> connect stcdba
Enter password:
Connected.
SQL> insert into BSSTDBA.PROD_TAB select * from BSSTDBA.PROD_TAB;


4 rows created.

SQL> SQL> commit;

Commit complete. 
								   
							   
SQL> select action_name,SQL_TEXT,UNIFIED_AUDIT_POLICIES ,EVENT_TIMESTAMP from unified_AUDIT_trail where UNIFIED_AUDIT_POLICIES='TEST_CASE4';

no rows selected

No audit record found for stcdba as expected.

TEST_CASE 5 ( AUDITING ROLE)

It will audit all users using a particular ROLE

Create an user with dba privs

CREATE USER TCSDBA IDENTIFIED BY TCSDBA;
GRANT DBA TO TCSDBA;

 Enable audit for the role DBA

CREATE AUDIT POLICY ROLE_AUDIT roles dba;
audit policy ROLE_AUDIT;

 Do any dba activity and check report

SQL> show user
USER is "DEVDBA"
SQL>
SQL>
SQL> truncate table bsstdba.emp_tab';

SQL> select action_name,SQL_TEXT,UNIFIED_AUDIT_POLICIES ,EVENT_TIMESTAMP from unified_AUDIT_trail where DBUSERNAME='DEVDBA' and action_name like 'TRUNCATE%';

ACTION_NAME        SQL_TEXT                           UNIFIED_AUDIT_POLICIES  EVENT_TIMESTAMP
------------------ ---------------------------------- ----------------------- --------------------------------
TRUNCATE TABLE     truncate table bsstdba.emp_tab     ORA_SECURECONFIG, ROLE_ 17-FEB-17 01.31.58.862039 PM
                                                     AUDIT

TEST CASE 6 ( FILTER BY HOSTNAME)

Now we can define to exclude auditing for few hosts

CREATE AUDIT POLICY test_case6
ACTIONS UPDATE ON OE.ORDERS, DELETE ON SALES.ORDERS
WHEN 'SYS_CONTEXT (''USERENV'', ''HOST'') NOT IN
(''sedbhost1'',''sedbhost2'')'
EVALUATE PER STATEMENT;

DATAPUMP AUDITING:

SQL> create audit policy expdp_aduit actions component=datapump export;
 Audit policy created.
 
 
 SQL> audit policy expdp_aduit;
 Audit succeeded.

SQL> set lines 299
col POLICY_NAME for a23
col AUDIT_OPTION for a12
col AUDIT_CONDITION for a12
col OBJECT_SCHEMA for a23
col OBJECT_NAME for a14

SQL> select POLICY_NAME,audit_option,AUDIT_CONDITION,OBJECT_SCHEMA,OBJECT_NAME FROM AUDIT_UNIFIED_POLICIES where POLICY_NAME='EXPDP_ADUIT';

POLICY_NAME             AUDIT_OPTION AUDIT_CONDIT OBJECT_SCHEMA           OBJECT_NAME
----------------------- ------------ ------------ ----------------------- --------------
EXPDP_ADUIT             EXPORT       NONE         NONE                    NONE



expdp dumpfile=test.dmp logfile=test.log directory=T tables=catalog.TRANSACTIONS
Export: Release 12.1.0.2.0 - Production on Fri Feb 17 11:38:41 2017
Copyright (c) 1982, 2014, Oracle and/or its affiliates.  All rights reserved.
Username: / as sysdba
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
Starting "SYS"."SYS_EXPORT_TABLE_01":  /******** AS SYSDBA dumpfile=test.dmp logfile=test.log directory=T tables=catalog.TRANSACTIONS
Estimate in progress using BLOCKS method...
Processing object type TABLE_EXPORT/TABLE/TABLE_DATA
Total estimation using BLOCKS method: 128 KB
Processing object type TABLE_EXPORT/TABLE/TABLE
Processing object type TABLE_EXPORT/TABLE/INDEX/INDEX
Processing object type TABLE_EXPORT/TABLE/INDEX/FUNCTIONAL_INDEX/INDEX
Processing object type TABLE_EXPORT/TABLE/CONSTRAINT/CONSTRAINT
Processing object type TABLE_EXPORT/TABLE/INDEX/STATISTICS/INDEX_STATISTICS
Processing object type TABLE_EXPORT/TABLE/INDEX/STATISTICS/FUNCTIONAL_INDEX/INDEX_STATISTICS
Processing object type TABLE_EXPORT/TABLE/CONSTRAINT/REF_CONSTRAINT
Processing object type TABLE_EXPORT/TABLE/STATISTICS/TABLE_STATISTICS
Processing object type TABLE_EXPORT/TABLE/STATISTICS/MARKER
. . exported "CATALOG"."TRANSACTIONS"                    63.94 KB     689 rows
Master table "SYS"."SYS_EXPORT_TABLE_01" successfully loaded/unloaded
******************************************************************************
Dump file set for SYS.SYS_EXPORT_TABLE_01 is:
  /export/home/oracle/test.dmp
Job "SYS"."SYS_EXPORT_TABLE_01" successfully completed at Fri Feb 17 11:39:19 2017 elapsed 0 00:00:34



SQL> select DBUSERNAME,DP_TEXT_PARAMETERS1 from UNIFIED_AUDIT_TRAIL where DP_TEXT_PARAMETERS1 is not null;

DBUSERNAME                     DP_TEXT_PARAMETERS1
------------------------------ ------------------------------------------------------------------------------
SYS                            MASTER TABLE:  "SYS"."SYS_EXPORT_TABLE_01" , JOB_TYPE: EXPORT, METADATA_JOB_MO
                               DE: TABLE_EXPORT, JOB VERSION: 12.1.0.2.0, ACCESS METHOD: AUTOMATIC, DATA OPTI
                               ONS: 0, DUMPER DIRECTORY: NULL  REMOTE LINK: NULL, TABLE EXISTS: NULL, PARTITI
                               ON OPTIONS: NONE

TEST_CASE7 ( AUDITING FOR SYSTEM PRIVILEGES):

We can enable auditing for system privileges as below.

create audit policy aud_syspriv_pol 
  PRIVILEGES alter any table;

NOTE- Instead of privilege keyword , I have created policy with action keyword in test_case2 , and it is showing similar result.

SYS AUDITING:

With mix auditing, sys audit records will be written to both os level and unified_trail also if audit action policy is enable.

As per Oracle doc:
FOR MIXED AUDITING
Administrative user sessions generate SYS audit records. These records are written if the AUDIT_SYS_OPERATIONS initialization parameter is set to TRUE.This process writes the records only to the traditional audit trails. However, when unified audit policies are enabled for administrative users,
these unified audit records are also written to unified audit trail.

FOR PURE UNIFIED AUDITING:
All sys audit records will be written to UNIFIED_AUDIT_TRAIL TABLE ONLY

set lines 299
col SQL_TEXT for a23
col action_name for a18
col UNIFIED_AUDIT_POLICIES for a23
select action_name,SQL_TEXT,UNIFIED_AUDIT_POLICIES ,EVENT_TIMESTAMP from unified_AUDIT_trail where DBUSERNAME='SYS' and EVENT_TIMESTAMP > sysdate -1/24;

DROPPING AUDIT POLICY:

SQL> DROP AUDIT POLICY TEST_CASE5;
DROP AUDIT POLICY TEST_CASE5
*
ERROR at line 1:
ORA-46361: Audit policy cannot be dropped as it is currently enabled.

We can’t drop a policy when it is enabled.

SQL> NOAUDIT POLICY TEST_CASE5;

Noaudit succeeded.

SQL> DROP AUDIT POLICY TEST_CASE5;

Audit Policy dropped.

PURGE AUDIT TRAIL:

Purging mechanism is similar to that of previous dbms_audit_mgmt(11g) , Only we need to set the audit_trail_type to unified

exec DBMS_AUDIT_MGMT.SET_LAST_ARCHIVE_TIMESTAMP ( -
AUDIT_TRAIL_TYPE => DBMS_AUDIT_MGMT.AUDIT_TRAIL_UNIFIED, -
LAST_ARCHIVE_TIME => sysdate-30)

exec DBMS_AUDIT_MGMT.CLEAN_AUDIT_TRAIL( -
AUDIT_TRAIL_TYPE => DBMS_AUDIT_MGMT.AUDIT_TRAIL_UNIFIED, -
USE_LAST_ARCH_TIMESTAMP => TRUE)

Refer – Purge audit table using dbms_mgmt

AUDIT WRITE MODE:

Oracle 12c writes audit records first to SGA. And then periodically flush the queue to AUDSYS schema audit table in sysaux table.

MODES:

1. QUEUED-WRITE MODE (DEFAULT) – PERIODICALLY FLUSHED TO DISK
2. IMMEDIATE-WRITE MODE – IMMEDIATELY FLUSHED ( PRE 12C MODE, NOT RECOMMENDED)

set lines 2999
col PARAMETER_NAME for a31
col PARAMETER_VALUE for a34
select * from dba_audit_mgmt_config_params;

PARAMETER_NAME PARAMETER_VALUE AUDIT_TRAIL
------------------------------- ---------------------------------- ------------------------
DB AUDIT TABLESPACE SYSAUX STANDARD AUDIT TRAIL
DB AUDIT TABLESPACE SYSAUX FGA AUDIT TRAIL
DB AUDIT TABLESPACE SYSAUX UNIFIED AUDIT TRAIL
AUDIT FILE MAX SIZE 10000 OS AUDIT TRAIL
AUDIT FILE MAX SIZE 10000 XML AUDIT TRAIL
AUDIT FILE MAX AGE 5 OS AUDIT TRAIL
AUDIT FILE MAX AGE 5 XML AUDIT TRAIL
DB AUDIT CLEAN BATCH SIZE 10000 STANDARD AUDIT TRAIL
DB AUDIT CLEAN BATCH SIZE 10000 FGA AUDIT TRAIL
OS FILE CLEAN BATCH SIZE 1000 OS AUDIT TRAIL
OS FILE CLEAN BATCH SIZE 1000 XML AUDIT TRAIL
AUDIT WRITE MODE QUEUED WRITE MODE UNIFIED AUDIT TRAIL
AUDIT FILE MAX SIZE 10000 UNIFIED AUDIT TRAIL
AUDIT FILE MAX AGE 5 UNIFIED AUDIT TRAIL

Role segregation:

AUDYS is the schema, which keeps audit trail info. No user can connect to this user including SYS.

SQL> show user
USER is "SYS"
SQL> connect AUDSYS/AUDSYS
ERROR:
ORA-46370: cannot connect as AUDSYS user

Warning: You are no longer connected to ORACLE.

Below two new roles are present in 12c

AUDIT_ADMIN – For creating and managing audit policies
AUDIT_VIEWER – For viewing audit reports ( Mostly for auditors)