How do you connect to an oracle database with os authentication linux

Let’s say we want to create a database user who logs in with their OS account. To do so, we will use the “external authentication” option offered by oracle.

Check the value of the os_authent_prefix parameter

SQL> show parameter os_authent_prefix

NAME                                 TYPE        VALUE

------------------------------------ ----------- ------------------------------

os_authent_prefix                    string      ops$

The ops$ value is the prefix that oracle will use for each OS account. As we can see, our user is prefixed with ops$. Oracle uses the prefix to recognize OS users when they attempt to connect. It is also a way for Oracle to separate a database account and an OS account.

Let’s create the external user account in the database

SQL> create user ops$mikando identified externally;

As we can see, our user is prefixed with ops$.

Give the necessary privileges

SQL> grant connect, resource, create session to ops$mikando;

Let’s create the user named mikando and his password.

[root@svrosisdb ~]# useradd -g oinstall -G dba,oper,asmdba mikando

[root@svrosisdb ~]# passwd mikando

Open a new session and connect with the new operating system (os) user created “mikando”

login as: mikando

[email protected]'s password

Load the  database

[mikando@svrosisdb ~]$  . oraenvoracle database 11

ORACLE_SID = [mikando] ? achats

ORACLE_BASE environment variable is not being set since this

information is not available for the current user ID mikando.

You can set ORACLE_BASE manually if it is required.

Resetting ORACLE_BASE to its previous value or ORACLE_HOME

The Oracle base has been set to /u01/app/oracle/product/12.1.0/db

Here, our target database is called achats

Connect to database

[mikando@svrosisdb ~]$ sqlplus /

SQL*Plus: Release 12.1.0.2.0 Production on Mon Dec 23 09:47:48 2019

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, Automatic Storage Management, OLAP, Advanced Analytics

and Real Application Testing options

SQL>

Now the os user named “mikando” can connect to the database without being asked for a password.