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11g Release 1 (11.1) for Microsoft Windows

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9 Authenticating Database Users with Windows

This chapter describes authentication of Oracle Database users with Windows operating systems.

This chapter contains these topics:

Windows Native Authentication Overview

Oracle Database can use Windows user login credentials to authenticate database users. Benefits include:

The Windows native authentication adapter (automatically installed with Oracle Net Services) enables database user authentication through Windows. This enables client computers to make secure connections to Oracle Database on a Windows server. The server then permits the user to perform database actions on the server.


Current user database links are not supported with Windows native authentication.


This chapter describes using Windows native authentication methods with Windows 2000 and later. For information on Secure Sockets Layer (SSL) protocol and Oracle Internet Directory, see Oracle Database Advanced Security Administrator's Guide and Oracle Internet Directory Administrator's Guide.

Windows Authentication Protocols

The Windows native authentication adapter works with Windows authentication protocols to enable access to Oracle Database.

If the user is logged on as a Windows 2000 domain user from a Windows 2000 computer, then Kerberos is the authentication mechanism used by the NTS adapter. For all other users, NTLM is the authentication mechanism used by the NTS adapter.

If authentication is set to NTS on a standalone Windows computer, ensure that Windows service NTLM Security Support Provider is started. If this service is not started on a standalone Windows computer, then NTS authentication fails. This issue is applicable only if you are running Windows 2000 in standalone mode.

Client computers do not need to specify an authentication protocol when attempting a connection to Oracle Database. Instead, Oracle Database determines the protocol to use, completely transparent to the user. The only Oracle Database requirement is to ensure that parameter SQLNET.AUTHENTICATION_SERVICES contains nts in the following file on both the client and database server:


This is the default setting for both after installation. For Oracle8 release 8.0.x releases, you must manually set this value.

If typical, your Oracle Database network includes client computers and database servers, and computers on this network may use different Oracle Database software releases on different Windows operating systems on different domains. This combination of different releases means that the authentication protocol being used can vary.

Table 9-1 lists Oracle Database software and Windows operating system releases required to enable Kerberos as the default authentication protocol:

Table 9-1 Software Requirements to Enable Kerberos Authentication Protocol

Location Windows Software Oracle Database Software

Client Computer

Windows 2000

Oracle8i Client or later

Database Computer

Windows 2000

Oracle8i Database or later


Windows 2000


For all other combinations of Windows operating system and Oracle Database software releases used in your network, the authentication protocol used is NTLM.

See Also:

Your operating system documentation for more information on each authentication protocol

User Authentication and Role Authorization Methods

This section describes how user login credentials are authenticated and database roles are authorized in Windows 2000 domains. User authentication and role authorization are defined in Table 9-2.

Table 9-2 User Authentication and Role Authorization Defined

Feature Description More Information

User authentication

Process by which the database uses the user's Windows login credentials to authenticate the user.

Oracle Database 2 Day DBA

Role authorization

Process of granting an assigned set of roles to authenticated users.

Oracle Database 2 Day DBA

Oracle Database supports user authentication and role authorization in Windows 2000 domains. Table 9-3 provides descriptions of these basic features.

Table 9-3 Basic Features of User Authentication and Role Authorization

Feature Description

Authentication of external users

Users are authenticated by the database using the user's Windows login credentials enabling them to access Oracle Database without being prompted for additional login credentials.

Authorization of external roles

Roles are authorized using Windows local groups. Once an external role is created, you can grant or revoke that role to a database user. Initialization parameter OS_ROLES is set to false by default. You must set OS_ROLES to true to authorize external roles.

Authentication and Authorization Methods To Use

Table 9–4 describes user authentication and role authorization methods to use based on your Oracle Database environment:

Table 9-4 User Authentication and Role Authorization Methods

Method Database Environment

Enterprise users and roles

You have many users connecting to multiple databases.

Enterprise users have the same identity across multiple databases. Enterprise users require use of a directory server.

Use enterprise roles in environments where enterprise users assigned to these roles are located in many geographic regions and must access multiple databases. Each enterprise role can be assigned to more than one enterprise user in the directory. If you do not use enterprise roles, then you have to assign database roles manually to each database user. Enterprise roles require use of a directory server.

External users and roles

You have a smaller number of users accessing a limited number of databases. External users must be created individually in each database and do not require use of a directory server.

External roles must also be created individually in each database, and do not require use of a directory server. External roles are authorized using group membership of the users in local groups on the system.

See Also:

Oracle Database Enterprise User Security Administrator's Guide for more information on Enterprise users and roles

Operating System Authentication Enabled at Installation

When you install Oracle Database, a special Windows local group called ORA_DBA is created (if it does not already exist from an earlier Oracle Database installation), and your Windows username is automatically added to it. Members of local group ORA_DBA automatically receive the SYSDBA privilege.

Membership in ORA_DBA enables you to: