13 Using Oracle Database with Microsoft Active Directory

About Microsoft Active Directory

Active Directory is the LDAP-compliant directory server included with Windows server operating systems. Active Directory stores all Windows operating system information, including users, groups, and policies. Active Directory also stores information about network resources (such as databases) and makes this information available to application users and network administrators. Active Directory enables users to access network resources with a single login. The scope of Active Directory can range from storing all the resources of a small computer network to storing all the resources of several wide areas networks (WANs).

Accessing Active Directory

When using Oracle features that support Active Directory, ensure that the Active Directory computer can be successfully reached using all possible TCP/IP host name forms to reach the domain controller. For example, if the host name of the domain controller is server1 in the domain example.com, then ensure that you can ping that computer using all of the following:

• server1.example.com

• example.com

• server1

Active Directory often issues referrals back to itself in one or more of these forms, depending upon the operation being performed. If any of the forms cannot reach the Active Directory computer, then some LDAP operations may fail.

Directory Naming

Oracle Database provides Oracle Net Services directory naming, which makes use of a directory server. This feature has been enabled to work with Microsoft Active Directory. Directory Naming enables clients to connect to the database making use of information stored centrally in an LDAP-compliant directory server such as Active Directory. For example, any net service name previously stored in the tnsnames.ora file can now be stored in Active Directory.

Automatic Discovery of Directory Servers

Oracle Net Configuration Assistant provides automatic discovery of directory servers. When you select Active Directory as the directory server type, Oracle Net Configuration Assistant automatically discovers the directory server location and performs related tasks.

Integration with Windows Tools

Oracle Database services, net service names, and enterprise role entries in Active Directory can be displayed and tested in two Windows tools:

• Windows Explorer

• Active Directory Users and Computers

Windows Explorer displays the hierarchical structure of files, directories, and local and network drives on your computer. It can display and test Oracle Database service and net service name objects.

Active Directory Users and Computers is an administrative tool installed on Windows servers configured as domain controllers. This tool enables you to add, modify, delete, and organize Windows accounts and groups, and publish resources in the directory of your organization. Like Windows Explorer, it can display and test Oracle Database service and net service name objects. Additionally, it can manage access control.

User Interface Extensions for Oracle Net Directory Naming

The property menus of Oracle Database service and net service name objects in Windows Explorer and Active Directory Users and Computers have been enhanced. When you right-click these Oracle directory objects, you now see two new options for testing connectivity:

• Test

• Connect with SQL*Plus

The Test option tests whether the username, password, and net service name you initially entered can actually connect to Oracle Database. The Connect with SQL*Plus option starts SQL*Plus, which enables you to perform database administration, run scripts, and so on.

Enhancement of Directory Object Type Descriptions

Oracle directory object type descriptions in Active Directory have been enhanced to make them easier to understand. In the right pane of Figure 13-1, for example, the Type column reveals that sales is an Oracle Net Service name.

Integration with Windows Login Credentials

Oracle database and configuration tools can use the login credentials of the Windows user currently logged on to connect to Active Directory without having to re-enter the login credentials. This feature has the following benefits:

• Oracle clients and databases can securely connect to Active Directory and retrieve the net service name.

• Oracle configuration tools can connect automatically to Active Directory and configure Oracle Database and net service name objects. The enabled tools include Oracle Net Configuration Assistant and Database Configuration Assistant.

• In Oracle Database 11g, enhancements are made to make secure access over the internet to avoid anonymous binds to the directory. The enhanced security enables the sites to restrict access to Database Service by setting access control (ACL) on Database Service DN in Directory Server. The enhancement gives clients the option to use authenticated binds for LDAP name lookup. Clients will have access to Database Service object if the object (DN of Database Service Entry) has been configured with restrictive access control.

Configuration on machines that require authenticated name lookups

Add the following entry in sqlnet.ora to enable authenticated name lookup:

names.ldap_authenticate_bind = TRUE 

Oracle Directory Objects in Active Directory

If Oracle Database and Oracle Net Services are installed and configured to access Active Directory, then Active Directory Users and Computers displays Oracle directory objects, as illustrated in Figure 13-1:

Figure 13-1 Oracle Directory Objects in Active Directory Users and Computers

Description of "Figure 13-1 Oracle Directory Objects in Active Directory Users and Computers"

Table 13-1 describes the Oracle directory objects appearing in Figure 13-1.

Directory Naming Software Requirements

For client computers from which you want to manage Oracle Database enterprise users, roles and domains, you must have Oracle8i Client release 8.1.6 or later and one of the supported Windows operating systems.

For the database, you must have Oracle8i Database release 8.1.6 or later. This is required for registering the database service as an object in Active Directory. The database can use any of the supported Windows operating systems.

Both the client computers and the database must be members of a Windows server domain.

Directory Naming adaptor connects anonymously to directory by default.

Creating an OracleContext

You must create an Oracle Context to use net directory naming features with Active Directory. Oracle Context is the top-level Oracle entry in the Active Directory tree. It contains Oracle Database service and Oracle Net service name object information.

• You can create only one Oracle Context for each Windows server domain (administrative context).

• You must have the right to create domain and enterprise objects to create the Oracle Context in Active Directory with Oracle Net Configuration Assistant.

• Use Oracle Net Configuration Assistant to create your Oracle Context. You can create the Oracle Context during or after Oracle Database Custom installation.

Oracle Schema Objects Creation

You must create Oracle schema objects to use net directory naming features with Active Directory. Schema objects are sets of rules for Oracle Net Services and Oracle Database entries and their attributes stored in Active Directory. The following restrictions apply to creating Oracle schema objects to use with Active Directory:

• Only one Oracle schema object can be created for each forest.

• The Windows server domain controller must be the operations master that allows schema updates. See your operating system documentation for instructions.

To create an Oracle schema object:

1. Log in as a member of the Schema Administrator group. Domain administrators are in the Schema Administrator group by default.

2. Use Oracle Net Configuration Assistant to create the Oracle schema object. You can create your schema object during or after database installation.

If the Active Directory display is not configured to accept all 24 default languages, then Oracle schema object creation can fail while Oracle Net Configuration Assistant is configuring Active Directory as the directory server. Before Oracle Net Configuration Assistant to complete directory access configuration, verify that the display specifiers for all 24 languages are populated by entering the following at the command prompt:

ldifde -p OneLevel -d cn=DisplaySpecifiers,cn=Configuration,domain context -f 
temp file

where:

• domain context is the domain context for this Active Directory server.

  For example, dc=example,dc=com.

• temp file is a file where you want to put the output.

If the command reports that fewer than 24 entries were found, then you can still use Oracle Net Configuration Assistant. However, the report will indicate that Oracle schema object creation failed, rather than simply reporting that display specifiers for some languages were not created.

Display Specifiers Not Created

When Net Configuration Assistant creates the Oracle schema object in Active Directory, the display specifiers for Oracle entries are not created. This means you cannot view Oracle database entries in Active Directory interfaces.

You can manually add these entries into Active Directory after the Oracle schema object has been created by doing the following, using the same Windows user identification you used when creating the Oracle schema object with Net Configuration Assistant:

1. Open a command shell.

2. Change directory to ORACLE_HOME\ldap\schema\ad.

3. Copy adDisplaySpecifiers_us.sbs to adDisplaySpecifiers_us.ldif.

4. Copy adDisplaySpecifiers_other.sbs to adDisplaySpecifiers_other.ldif.

5. Edit each of these .ldif files, replacing all occurrences of %s_AdDomainDN% with the domain DN for the specific Active Directory into which you want to load the display specifiers (for example, dc=example,dc=com).

6. Run the following commands:

   ldapmodify -h <ad hostname> -Z -f adDisplaySpecifiers_us.ldif
   ldapmodify -h <ad hostname> -Z -f adDisplaySpecifiers_other.ldif
   

   where <ad hostname> is the host name of the Active Directory domain controller to which you want to load the display specifiers.

Testing Connectivity from Client Computers

When using Oracle Net directory naming, client computers connect to a database by specifying the database or net service name entry that appears in the Oracle Context. For example, if the database entry under the Oracle Context in Active Directory is orcl, and the client and the database are in the same domain, then a user connects to the database through SQL*Plus by entering the following connect string:

SQL> CONNECT username@orcl
Enter password: password

If the client and the database are in different domains, then a user connects to the database through SQL*Plus by entering:

SQL> CONNECT username@orcl.domain
Enter password: password

where domain is the domain in which the Oracle Database server is located.

The LDAP naming adapter has an internal function which we call simplified naming, which will attempt to translate a DNS-style name into an x500 (LDAP) style name (DN) based on the naming convention used in ldap.ora:DEFAULT_ADMIN_CONTEXT.

It relies on ldap.ora:default_admin_context using either an org form or a domain component (dc) form. This cues the mechanism to use either of the following conventions to convert the domain name to an x500 DN:

• 'dc=, dc='

• 'ou=, o='

• 'ou=, o=, c='

For example,

SQL> CONNECT SCOTT@hr.example.com 
Enter password: password

The following values for default_admin_context will result in the associated DN:

DEFAULT_ADMIN_CONTEXT="o=stdev"

The resulting DN is

cn=HR,cn=OracleContext,ou=EXAMPLE,o=COM


DEFAULT_ADMIN_CONTEXT="dc=oracle, dc=com"

The resulting DN is

cn=HR,cn=OracleContext,dc=EXAMPLE,dc=COM


DEFAULT_ADMIN_CONTEXT="o=oracle,c=us"

The resulting DN is

cn=HR,cn=OracleContext,o=EXAMPLE,c=COM

DNS-style conventions enable client users to access an Oracle Database server through a directory server by entering minimal connection information, even when the client computer and Oracle Database server are in separate domains. Names following the X.500 convention are longer, especially when the client and Oracle Database server are located in different domains (also known as administrative contexts).

Testing Connectivity from Microsoft Tools

Oracle directory objects in Active Directory are integrated with two Microsoft tools:

• Windows Explorer

• Active Directory Users and Computers

You can test connectivity to an Oracle Database server from within these Microsoft tools by actually connecting to it, or you can just test the connection with actually connecting. To test connectivity:

1. Start Windows Explorer or Active Directory Users and Computers.

   To start Windows Explorer:

   1. From the Start menu, select Programs, then select Accessories and then select Windows Explorer.

   2. Expand My Network Places.

   3. Expand Entire Network.

   4. Expand Directory.

   To start Active Directory Users and Computers:

   From the Start menu, select Programs, then select Administrative Tools, and then select Active Directory Users and Computers.

   Note:

   All clients accessing an Oracle Database server through Active Directory require read access on all net service name objects in the Oracle Context. If Oracle Net will not be configured to require authentication for name lookup, then clients must be able to authenticate anonymously with Active Directory. With Windows Server 2003, Windows Server 2003 R2, and Windows Server 2008, Windows Server 2008 R2 domain, this will require changing the Active Directory default setting so that anonymous access will be allowed. If anonymous access is not going to be allowed to this directory the clients must be configured to authenticate and net service objects must have access control definitions which allow clients to read them as appropriate.

   See also:

   Oracle Database Net Services Administrator's Guide for more information

2. Expand the domain in which your Oracle Context is located.

3. Expand your Oracle Context.

4. Right-click a database service or Oracle Net Service name object.

   A menu appears with several options. This section covers only the Test and Connect with SQL*Plus options.

   
   Description of the illustration adtest.gif
   
   

5. If you want to test the database connection without actually connecting to it, then choose Test. A status message appears describing the status of your connection attempt.

   
   Description of the illustration adtstcon.gif
   
   

6. If you want to test the database connection by actually connecting to it, then choose Connect with SQL*Plus. The Oracle SQL*Plus Logon dialog appears.

   
   Description of the illustration adsqlpls.gif
   
   

7. Enter your user name and password, then click OK. A status message appears describing the status of your connection attempt.

Security Groups

Security groups are automatically created when the Oracle Context is created in Active Directory. The user configuring access (and thus creating the Oracle Context) is automatically added to each group. The relevant groups are:

• OracleDBCreators

• OracleNetAdmins

• NetService Objects

Setting ACLs on NetService Entries

Use Dsacls tool to set ACLs on Directory Object.

Dsacls.exe command-line tool displays and changes permissions (access control entries) in the access control list (ACL) of objects in Active Directory. This command-line tool will be included in Support Tools on the product media.

Examples:

To enable anonymous generic read on orcl service, run the following command:

dsacls "CN=orcl,CN=OracleContext,OU=Example,O=Com" /G "anonymous logon":GR

To enable generic read on orcl service for the user scott in EXAMPLE domain, run the following command:

dsacls "CN=orcl,CN=OracleContext,OU=Example,O=Com" /G example\scott:GR

To disable anonymous generic read on orcl service, run following command:

dsacls "CN=orcl,CN=OracleContext,OU=Example,O=Com" /R "anonymous logon"

To disable generic read on orcl service for the user scott in EXAMPLE domain, run the following command:

dsacls "CN=orcl,CN=OracleContext,OU=Example,O=com" /R example\scott

Adding and Deleting Security Group Members

You can add or remove users in the security groups with Active Directory Users and Computers.

To add or remove users:

1. From the Start menu, select Programs, then select Administrative Tools, and then select Active Directory Users and Computers.

2. Choose Advanced Features from the View main menu.

   This enables you to view and edit information that is normally hidden.

3. Expand the domain (administrative context) in which your Oracle Context is located.

4. Expand Users.

   The security groups appear in the right window pane.

   
   Description of the illustration adsecgrp.gif
   
   

5. Right-click the Oracle security group that you want to view or modify.

   A menu appears with several options.

6. Choose Properties.

7. Choose the Members tab.

   The Properties dialog for the group you selected appears (in this example, OracleDBCreators).

   
   Description of the illustration admembrs.gif
   
   

8. To add users, click Add.

   The Select Users, Contacts, Computers, or Groups dialog appears.

9. Select the users or groups you want to add and click Add.

   Your selections appear in the Select Users, Contacts, Computers, or Groups dialog.

10. To remove a user, select the user name from the Members list and click Remove.

11. When you are finished adding and removing users, click OK.