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Sun Java System Directory Server Enterprise Edition 6.0 Installation Guide

Chapter 3 Understanding the Product

Identity Synchronization for Windows provides bidirectional password and user attributes synchronization between the Sun Java System Directory Server 6.0 and the following:

Identity Synchronization for Windows handles synchronization events:

Before you install (or migrate to) Sun Java System Identity Synchronization for Windows version 6.0, you should become familiar with the concepts described in this chapter, which consists of the following sections:

Product Features

Identity Synchronization for Windows provides the following features and functionality:

Note –

The following features are not available for Windows NT:

System Components

Identity Synchronization for Windows consists of a set of Core components and any number of individual connectors and connector subcomponents that allow for the synchronization of password and user attribute updates between Sun Java System Directory Server and Windows directories.

Figure 3–1 System Components

Block diagram showing major system components.

This section defines and describes each of the Identity Synchronization for Windows components and is organized as follows:

Watchdog Process

The Watchdog is an Identity Synchronization for Windows Java process that is responsible for starting, restarting, and stopping individual background Java processes. The Watchdog launches and monitors the central logger, system manager, and connectors (but does not monitor subcomponents, Message Queue, or the Identity Synchronization for Windows Console).

The Watchdog is installed anywhere you install Core and it can be started as a Solaris daemon, Linux daemon, or a Windows service. (For information about starting and stopping services, see Starting and Stopping Services.)

Core

When you install Identity Synchronization for Windows, you install the Core component first, and then you configure it to match your environment.

The core component consists of the following components, which are each separate Java processes. A description each component, begins on the referenced page:

Configuration Directory

Identity Synchronization for Windows stores its configuration data in a Directory Server configuration directory (the program does not install a configuration directory).

The console, system manager, command line utility, and the installer all read and write the product’s configuration data to and from the configuration directory, including:

Console

The Identity Synchronization for Windows provides a Console that centralizes all of the product’s component configuration and administration tasks.

You can use the console to do the following:

Command Line Utilities

Identity Synchronization for Windows also provides command line utilities that enable you to perform the following tasks directly from the command line:

For a detailed description of the product’s command line utilities and how to use them, see Appendix A, Using the Identity Synchronization for Windows Command Line Utilities

System Manager

The Identity Synchronization for Windows system manager is a separate Java process that:

Central Logger

Connectors may be installed so that they are widely distributed across remote geographical locations; therefore, it is of great administrative value to have all logging information centralized, which allows the administrator to monitor synchronization activity, detect errors, and evaluate the health of the entire system from a single location.

Administrators can use the central logger logs to:

There are two different types of logs:

Note –

Identity Synchronization for Windows also writes all of the error log messages to the audit log to facilitate easy correlation with other events.

Connectors

A connector is a Java process that manages the synchronization process in a single data source type. A connector detects user changes in the data source, and publishes these changes to remote connectors over Message Queue.

Identity Synchronization for Windows provides the following directory-specific connectors, which are responsible for bidirectionally synchronizing user attributes and password updates between directories and domains:

Note –

The Watchdog is installed anywhere you install a connector, and it is responsible for starting, restarting, and stopping the connectors. For more information, see Watchdog Process.

Connector Subcomponents

A subcomponent is a lightweight process or library that runs separately from the connector. Connectors use subcomponents to access native resources that cannot be accessed remotely, such as capturing passwords inside Directory Server or Windows NT.

The following connector subcomponents are configured or installed with the directory being synchronized and communicated with the corresponding connector over an encrypted connection.

Note –

Active Directory Connectors do not require subcomponents.

Directory Server Plug-in

The Directory Server Plug-in is a subcomponent of the Directory Server Connector. You configure the Directory Server Plug-in on each Directory Server being synchronized.

This Plug-in:

Note –

The Directory Server Plug-in is functional in a N-way, multimaster replication (MMR) environments. (Previously, Identity Synchronization for Windows supported two-way MMR only.)

Windows NT Connector Subcomponents

If your installation requires synchronization with Windows NT SAM Registries, the Identity Synchronization for Windows installation program installs the following in the Primary Domain Controller (PDC) along with the Windows NT Connector:

Message Queue

Identity Synchronization for Windows uses Message Queue (a persistent message queue mechanism with a publish/subscribe model) to propagate attribute and password changes between directory sources and to distribute administrative and configuration information to the connectors managing synchronization for those directory sources.

Message Queue is an enterprise messaging system that implements the Java Message Service (JMS) open standard. The JMS specification describes a set of programming interfaces that provide a common way for Java applications to create, send, receive, and read messages in a distributed environment.

Message Queue consists of message publishers and subscribers that exchange messages using a common message service. This message service is composed of one or more dedicated message brokers, which are responsible for controlling access to the message queue, maintaining information about active publishers and subscribers, and ensuring that messages are delivered.

Message Queue is the best approach because it:

System Components Distribution

Before you can develop an effective deployment, you must understand how Identity Synchronization for Windows components are organized and how the product operates. This section is organized as follows:

Core

Install all Core components only once in any of the supported operating system’s directory servers. Identity Synchronization for Windows installs Administration Server on your machine if it is not already installed. Install Message Queue 3.6 Enterprise Edition on the same machine where you are planning to instal Core.

Directory Server Connector and Plug-in

You can install Directory Server Connectors on any of the supported operating systems. You are not required to install a Directory Server Connector on the same machine where the Directory Server being synchronized is running. However, there must be one Directory Server Connector installed for each configured Directory Server source.

You must configure the Directory Server Plug-in on every host where a Directory Server to be synchronized resides.

Note –

A single Directory Server Connector is installed for each Directory Server source. However, Directory server Plug-ins should be configured for each master, hub, and consumer replica to be synchronized.

Active Directory Connector

You can install Active Directory Connectors on any of the supported operating systems. You are not required to install an Active Directory Connector in the Windows environment; however, there must be one Active Directory Connector installed per Active Directory domain.

Figure 3–2 Directory Server and Active Directory Component Distribution

Block diagram showing Active Directory components.

Windows NT Connector and Subcomponents

To synchronize with Windows NT SAM Registries you must install the Windows NT Connector in the Primary Domain Controller (PDC). In addition, the installation program installs the two NT Connector subcomponents (the Change Detector and the Password Filter DLL) along with the Connector in the PDC of the NT Domain. A single NT Connector synchronizes users and passwords for a single NT Domain.

Figure 3–3 Directory Server and NT Component Distribution

Block diagram showing NT Connectors and subcomponents.

How Identity Synchronization for Windows Detects Changes in Directory Sources

This section explains how user entry and password changes are detected by Sun Java System Directory Server (Directory Server), Windows Active Directory, and Windows NT Connectors.

The information is organized as follows:

How Directory Server Connectors Detect Changes

The Directory Server Connector examines the Directory Server retro changelog over LDAP to detect user entry and password change events. The Directory Server Plug-in helps the Connector to do the following:

For more information about retro changelog, see Replication and the Retro Change Log Plug-In in Sun Java System Directory Server Enterprise Edition 6.0 Reference in Sun Java System Directory Server Enterprise Edition 6.0 Reference

Figure 3–4 How Directory Server Connectors Detect Changes

Block diagram illustrating how Directory Server Connectors detect changes.

How Active Directory Connectors Detect Changes

The Windows 2000/2003 Server Active Directory Connector detects user entry and password changes by examining the Active Directory USNChanged and PwdLastSet attribute values.

Unlike the Directory Server’s Retro Changelog, when you change attributes in an entry, Active Directory does not report which attributes changed. Instead, Active Directory identifies entry changes by incrementing the USNchanged attribute. To detect changes to individual attributes, Active Directory and Windows NT Connectors use an in-process database called the object cache. The object cache stores a hashed copy of each Active Directory entry, which allows the Connector to determine exactly which attributes were modified in the entry.

You are not required to install Active Directory Connectors in the Windows environment. They can run also on other platforms such as Solaris or Linux and detect or make changes remotely over LDAP.

Figure 3–5 How Active Directory Connectors Detect Changes

Block diagram illustrating how Active Directory Connectors detect changes.

How Windows NT Connectors Detect Changes

The Windows NT Connector detects user entry and password changes by examining the Security log for audit events about user objects.

To synchronize with Windows NT SAM Registries (see Windows NT Connector and Subcomponents) you must install the Windows NT Connector in the Primary Domain Controller (PDC). In addition, the installer installs the two NT Connector subcomponents (the Change Detector and the Password Filter DLL) along with the Connector in the PDC of the NT Domain. A single NT Connector synchronizes users and passwords for a single NT Domain.

Figure 3–6 How Windows NT Connectors Detect Changes

Block diagram illustrating how Windows NT Connectors detect changes.

Note –

If you have a Windows NT machine in your deployment, auditing must be enabled or Identity Synchronization for Windows cannot read log messages from that machine. To verify whether audit logging is enabled on your Windows NT machine, see Enabling Auditing on a Windows NT Machine

For a description of the Change Detector and the Password Filter DLL subcomponents, review Windows NT Connector Subcomponents

Propagating Password Updates

This section explains the following methods for obtaining clear-text passwords needed to propagate password changes between Windows systems and Directory Server systems:

Using the Password Filter DLL to Obtain Clear-Text Passwords

Windows NT Connectors must obtain clear-text passwords to propagate password updates to the Sun Java System Directory Server. However, you cannot extract clear-text passwords from a Windows directory. By the time passwords are stored in the directories, they have already been encrypted.

Windows NT provides a Password Filter DLL interface, which allows components to capture clear-text passwords before they are stored in a directory permanently.

Using On-Demand Password Synchronization to Obtain Clear-Text Passwords

While Active Directory supports the same password filter as Windows NT, you must install the password filter DLL on every domain controller instead of just the Primary Domain Controller (PDC). Because this can be a significant installation burden, Identity Synchronization for Windows uses a different approach, called on-demand password synchronization, to synchronize password changes from Active Directory to Directory Server.

On-demand password synchronization provides a method to obtain new password values on Directory Server when the user tries to log-in after their password changes on Windows 2000.

On-demand password synchronization also allows you to synchronize passwords on Active Directory without the need of a password filter DLL.

ProcedureThe on-demand password synchronization process occurs as follows:

  1. User presses Ctrl-Alt-Del on a Windows workstation and changes his or her password. New passwords are stored in Active Directory.

  2. The Active Directory Connector polls the system at scheduled intervals.

    When the Connector detects the password change (based on changes made to the USNchanged (Update Sequence Number) and PwdLastSet attributes), the Connector publishes a message on Message Queue about the password change. The message is transferred on an SSL-encrypted channel.

    Figure 3–7 On-Demand Password Synchronization-Part 1

    Block diagram illustrating how On-Demand Password Synchronization works.

  3. The Directory Server Connector receives the password change message from Message Queue (over SSL).

  4. The Directory Server Connector sets the user entry’s dspswvalidate attribute to true which invalidates the old password and alerts the Directory Server Plug-in of the password change.

  5. When the user tries logging on, using an LDAP application (such as Portal Server) to authenticate against the Directory Server, the Sun Java System Directory Server Plug-in detects that the password value in the Directory Server entry is invalid.

  6. The Directory Server Plug-in searches for the corresponding user in Active Directory. When the Plug-in finds the user, the Plug-in tries to bind to Active Directory using the password provided when the user tried logging into Directory Server.

    Note –

    On-demand password synchronization requires the application to use simple authentication against the Directory Server instead of using a more-complex authentication mechanism, such as SASL Digest-MD5.

  7. If the bind against Active Directory succeeds, then the user provided his or her new Active Directory password and the Directory Server Plug-in set the password and removed the invalid password flag from the user entry on Directory Server.

    Figure 3–8 On-Demand Password Synchronization-Part II

    Diagram showing how user entry and password changes are updated on Active Directory and Directory Server.

    Note –

    If the user authentication fails, the user entry password remains in Directory Server and the passwords on Directory Server and Active Directory will be out-of-sync until the user logs in with a valid password (one that authenticates to Active Directory).

Reliable Synchronization

Identity Synchronization for Windows takes many precautions to ensure that you do not lose user change events— even when components become temporarily unavailable. Identity Synchronization for Windows’ reliability is similar to the TCP network protocol. TCP guarantees that even over a lossy and intermittently connected network, it will eventually deliver all data in order. Data sent during a temporary network outage is queued while the network is down and re-delivered once connectivity is restored. Identity Synchronization for Windows will eventually detect and apply user change events if one of the following components becomes temporarily unavailable:

Deployment Example: A Two-Machine Configuration

This section describes a deployment scenario in which Identity Synchronization for Windows is used to synchronize user object creation and bidirectional password modification operations between Sun and Windows directories.

The deployment scenario consists of two systems:

Note –

Though NT is not used in this scenario, it is important to note that Identity Synchronization for Windows also supports synchronization with NT domains.

This example illustrates the synchronization requirements (node structures with associated attribute values) used for this deployment scenario.

Figure 3–9 Synchronization Requirements

Synchronization requirements showing node structures and attribute values.

There are two goals for this scenario:

Note –

Identity Synchronization for Windows supports multiple synchronization sources of the same type (for example, you can have more than one Directory Server in a deployment or multiple Active Directory domains).

Creation, modification, and deletion synchronization settings are global for the entire set of directories, and cannot be specified for individual directory sources. If you synchronize user object creations from Directory Server to Windows directories, then user object creations will propagate from all Directory Servers to all Active Directory domains and Windows NT domains configured in the installation.

Physical Deployment

This section illustrates how all the product’s components are physically deployed on a single Solaris box, while the Active Directory domain resides in a separate Active Directory domain controller where no components have been installed.

Figure 3–10 Directory Server and Active Directory Scenario

Directory Server and Active Directory physical deployment.

Component Distribution

Host corp.example.com is a Directory Server installed in a Solaris operating system. The root suffix for the Directory Server being synchronized is dc=corp,dc=example,dc=com.

This machine contains: