LDAP Integration — Complete Directory Authentication Guide

In this tutorial, you will learn about LDAP Integration. We cover key concepts, practical examples, and best practices to help you master this topic.

LDAP (Lightweight Directory Access Protocol) integration authenticates users against centralized directory services like Microsoft Active Directory, OpenLDAP, or FreeIPA. It is the standard for enterprise user management.

What You'll Learn

You'll learn how to bind to an LDAP server, authenticate users, search for groups, and implement authorization based on LDAP attributes.

Why It Matters

Most enterprises manage users in Active Directory. API authentication against LDAP enables seamless integration with existing corporate identity infrastructure.

Real-World Use

An internal HR API authenticates users against the company's Active Directory. When an employee leaves, the IT team disables their AD account, and all API access is immediately revoked.

Implementation

from ldap3 import Server, Connection, ALL
from flask import Flask, request, jsonify

app = Flask(__name__)

LDAP_SERVER = "ldaps://ldap.example.com:636"
BASE_DN = "dc=example,dc=com"

def authenticate_ldap(username, password):
    user_dn = f"cn={username},{BASE_DN}"
    try:
        server = Server(LDAP_SERVER, use_ssl=True)
        conn = Connection(server, user_dn, password, auto_bind=True)
        conn.search(BASE_DN, f"(cn={username})", attributes=["memberOf", "mail"])
        groups = [str(g) for g in conn.entries[0].memberOf]
        conn.unbind()
        return {"username": username, "groups": groups}
    except Exception:
        return None

Common Mistakes

What's Next

Learn about secure token storage for client-side applications.