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What Is LDAP Authentication?

Lightweight Directory Access Protocol (LDAP) Meaning

The Lightweight Directory Access Protocol (LDAP) is an open, cross-platform software protocol used for authentication and communication in directory services. LDAP provides the language that applications use to communicate with each other in directory services, which store computer accounts, users, and passwords and share them with other entities on networks. This allows applications and users to find and verify the information they need from across their organization.

LDAP has a wide range of uses, but the most popular is as a central hub for organizations to manage authentication. It is very effective for helping organizations store, manage, and access usernames and passwords across their networks and applications. If organizations use the right plugins, LDAP enables them to store and verify credentials every time a user attempts to access applications, directories, and systems. 

LDAP credentials do not only involve the standard username and password combinations. The protocol can also be used to manage other organizational attributes—such as storing addresses, structural data, and telephone numbers—which makes it crucial to managing and protecting user identities. LDAP also connects users with information on devices attached to a network, such as files, printers, and shared resources. 

Because of its ability to interact with directory services, such as Microsoft’s Active Directory (AD), LDAP is an essential tool for businesses. The protocol is used to communicate with AD and connects clients—computers that connect to and use the resources of remote computers or servers—to the information they need within directory services. 

Effectively, LDAP provides an efficient, shared language that simplifies the process of providing responses to client queries. When used securely, it allows organizations to build and manage effective databases and gives employees the tools they need to work effectively and productively.

What is the Origin of LDAP?

LDAP was created in 1993 by a group of developers who wanted to come up with a less complex replacement for Directory Access Protocol (DAP). They came up with a protocol that used less code and would be more accessible to people using desktop computers.

It has since become a very popular computing program, to the extent that the LDAPv3 version became a directory services standard and offered the foundation for Microsoft to build AD. It has also been crucial to developing cloud-based directories.

How Does LDAP Authentication Work?

LDAP is the language that allows servers to communicate with AD and other directory services. It enables messages, such as client requests, server responses, and data formatting, to flow between servers and client applications.

This process works by LDAP binding users to a server. When a client sends a request for particular information, such as user credentials, the LDAP server processes it using its internal language, then communicates with directory services before sending a response. When the client receives the response, LDAP unbinds the client from the server, and the client processes the data.

Another use for LDAP involves the System Security Services Daemon (SSSD), which is software originally created for Linux operating systems and provides simplified access to various remote identity and authentication providers. SSSD can be configured to use native LDAP domains, such as an LDAP identity provider with LDAP authentication or an LDAP identity provider with Kerberos authentication.

1. LDAP Authentication

One of LDAP’s key functions is to provide authentication. LDAPv2 offers two forms of authentication, which are simple and Simple Authentication and Security Layer (SASL).

Simple authentication enables three authentication mechanisms. Anonymous authentication provides a client with an anonymous status on LDAP. Unauthenticated authentication is only used for logging purposes and should not be used to grant access to clients. The name and password authentication provides access to a server using the credentials supplied.

SASL authentication works by binding the LDAP server to a separate authentication process, such as Kerberos. The LDAP server will then use the LDAP protocol to send a message to the Kerberos authentication process. This starts a series of response messages that will either deliver a successful authentication or an authentication failure. These messages are all sent in clear text as default, which means anyone snooping on them will be able to read them. It is therefore crucial to add security measures, such as encryption, around this authentication process to ensure that user details and the data being shared are protected.

2. LDAP Security

LDAP provides communication between clients and AD, which means it is responsible for transporting highly sensitive information. This includes valuable information pertaining to user identities and employee login details which, if lost or stolen, can be business-critical and result in a major data breach.

It is crucial that the data being transmitted between clients and AD is protected at all times to ensure it cannot be intercepted by hackers and malicious actors. The LDAP authentication process goes some way to providing a base security level with a layer of access management, but it is still possible for cyber criminals to snoop on information as it moves from AD to clients and then access organizations’ digital infrastructure using that information. 

To prevent this, organizations must add secure encryption through their LDAP authentication process. This will make LDAP authentication more resilient against the internal and external attack vectors that modern-day businesses face. For example, using secure sockets layer/transport layer security (SSL/TLS) encryption can add vital protection to information shared through LDAP and enhance the security of organizations’ communication channels. 

Another potential security concern is that port 289, the default port for the LDAP authentication process, is not secure by itself. It requires additional security extensions, such as the LDAPv3 TLS extension or the StartTLS mode, that offer a more secure and protected connection. 

Organizations can also keep their LDAP server safe using a representational state transfer application programming interface (REST API) to handle their LDAP operations over Hypertext Transfer Protocol (HTTP).  

3. LDAP Query

An LDAP query is a request to directory services for specific information, such as a request to understand which groups a user has been assigned to. In most cases, organizations will not need to carry out LDAP queries manually. This is because they can use management interfaces or command line shells that do the hard work for them and remove the technical difficulties.

What Is Active Directory?

AD is the most widely used directory services system. AD stores and manages shared resources, such as domains and user information, across an organization’s network. This Microsoft product provides organizations with functionalities like authentication, group management, policy administration, and user management. 

AD is a crucial tool for organizations that need to locate thousands of objects across their various digital environments and infrastructure. It is also vital to any organization that needs to regulate which users have access to which resources.

AD is not a cross-platform tool, which means businesses have to implement access management software to control logins from various devices and platforms. AD supports LDAP and Kerberos, which is another network authentication protocol, so it can be used within organizations’ access management process. LDAP connects clients to the information stored on directory services. It functions as a shared language that makes it easier for all clients to access the assets they need and provide coordinated and coherent responses.

AD is one of several directory services available, with others including Apache Directory Server and OpenLDAP.

LDAP vs. Active Directory

LDAP and AD are related but not the same. LDAP is a software language used by directory services for authentication and to exchange formatted messages between clients. AD is a directory server that provides critical directory services to organizations, such as authenticating user credentials, handling group user management, authenticating core identities, and managing users. 

LDAP and AD work together to enable clients across an organization to access the information they need, use the applications they need, and execute the responsibilities they have. AD stores the user information and logs the organization’s digital policies. LDAP enables queries to be formatted, which can be used to extract the information required and communicated between clients.

How To Secure LDAP

LDAP effectively relies on ensuring that the business and user information it communicates is both organized and secure. Organizations must properly protect and store the information being shared via LDAP. Failing to do so puts them at risk of losing critical business data and suffering data leakage, which can lead to business disruption, reputational damage, the loss of customers, major financial costs, and potential fines and legal action.

To ensure they have the appropriate level of protection in place, organizations must invest in cybersecurity tools that not only secure their data but also monitor, prevent, and mitigate possible cyberattacks. For example, organizations can secure their LDAP server and authenticate their users using Spring Security. Furthermore, in the event an organization does suffer a cyberattack, they must have appropriate business continuity processes and contingency plans in place to manage the situation quickly and in line with various compliance regulations. 

How Fortinet Can Help

The Fortinet FortiGate next-generation firewalls (NGFWs) help organizations protect their data, devices, and users across all of their on-premises and cloud environments. The technology enables organizations to filter network traffic from internal and external sources, which allows them to monitor all traffic, such as LDAP communication between clients and AD. The Fortinet NGFWs also provide deep content inspection alongside features like Internet Protocol security (IPsec), SSL support, SSL virtual private network (VPN) support, IP mapping, and network monitoring, which are crucial to securing LDAP authentication.

With a Fortinet NGFW in place, organizations can identify attacks and block malicious threats. The technology enables future updates, which ensure organizations are always protected against the latest malware and attack vectors and have visibility into emerging threats across their entire attack surface.

The Fortinet NGFWs also help organizations reduce the cost and complexity of their network security by consolidating industry-leading features like SSL inspection, intrusion prevention system (IPS), and web filtering. This is vital to securing hybrid and hyperscale architectures, delivering optimal user experience, preventing downtime, and ensuring business continuity.


What is LDAP Authentication?

The Lightweight Directory Access Protocol (LDAP) is an open, cross-platform software protocol used for authentication and communication in directory services.

How does LDAP authentication work?

LDAP provides the language that applications use to communicate with each other in directory services, which store computer accounts, users, and passwords and share them with other entities on networks. 

What are the two forms of LDAP authentication?

LDAPv2 offers two forms of authentication, which are simple and Simple Authentication and Security Layer (SASL).