Entra App Registration

Overview

Microsoft Entra ID (formerly Azure Active Directory) is Microsoft's cloud-based identity and access management service. App registrations allow applications to authenticate users and access Azure resources securely.

Key Concepts

Concept	Description
App Registration	Configuration that allows an app to use Microsoft identity platform
Application (Client) ID	Unique identifier for your application
Tenant ID	Unique identifier for your Azure AD tenant/directory
Client Secret	Password for the application (confidential clients only)
Redirect URI	URL where authentication responses are sent
API Permissions	Access scopes your app requests
Service Principal	Identity created in your tenant when you register an app

Application Types

Type	Use Case
Web Application	Server-side apps, APIs
Single Page App (SPA)	JavaScript/React/Angular apps
Mobile/Native App	Desktop, mobile apps
Daemon/Service	Background services, APIs

Core Workflow

Step 1: Register the Application

Create an app registration in the Azure portal or using Azure CLI.

Portal Method:

1. Navigate to Azure Portal → Microsoft Entra ID → App registrations
2. Click "New registration"
3. Provide name, supported account types, and redirect URI
4. Click "Register"

CLI Method: See references/cli-commands.md IaC Method: See references/BICEP-EXAMPLE.bicep

It's highly recommended to use the IaC to manage Entra app registration if you already use IaC in your project, need a scalable solution for managing lots of app registrations or need fine-grained audit history of the configuration changes.

Step 2: Configure Authentication

Set up authentication settings based on your application type.

• Web Apps: Add redirect URIs, enable ID tokens if needed
• SPAs: Add redirect URIs, enable implicit grant flow if necessary
• Mobile/Desktop: Use http://localhost or custom URI scheme
• Services: No redirect URI needed for client credentials flow

Step 3: Configure API Permissions

Grant your application permission to access Microsoft APIs or your own APIs.

Common Microsoft Graph Permissions:

• User.Read - Read user profile
• User.ReadWrite.All - Read and write all users
• Directory.Read.All - Read directory data
• Mail.Send - Send mail as a user

Details: See references/api-permissions.md

Step 4: Create Client Credentials (if needed)

For confidential client applications (web apps, services), create a client secret, certificate or federated identity credential.

Client Secret:

• Navigate to "Certificates & secrets"
• Create new client secret
• Copy the value immediately (only shown once)
• Store securely (Key Vault recommended)

Certificate: For production environments, use certificates instead of secrets for enhanced security. Upload certificate via "Certificates & secrets" section.

Federated Identity Credential: For dynamically authenticating the confidential client to Entra platform.

Step 5: Implement OAuth Flow

Integrate the OAuth flow into your application code.

See:

• references/oauth-flows.md - OAuth 2.0 flow details
• references/console-app-example.md - Console app implementation

Common Patterns

Pattern 1: First-Time App Registration

Walk user through their first app registration step-by-step.

Required Information:

• Application name
• Application type (web, SPA, mobile, service)
• Redirect URIs (if applicable)
• Required permissions

Script: See references/first-app-registration.md

Pattern 2: Console Application with User Authentication

Create a .NET/Python/Node.js console app that authenticates users.

Required Information:

• Programming language (C#, Python, JavaScript, etc.)
• Authentication library (MSAL recommended)
• Required permissions

Example: See references/console-app-example.md

Pattern 3: Service-to-Service Authentication

Set up daemon/service authentication without user interaction.

Required Information:

• Service/app name
• Target API/resource
• Whether to use secret or certificate

Implementation: Use Client Credentials flow (see references/oauth-flows.md#client-credentials-flow)

MCP Tools and CLI

Azure CLI Commands

Command	Purpose
az ad app create	Create new app registration
az ad app list	List app registrations
az ad app show	Show app details
az ad app permission add	Add API permission
az ad app credential reset	Generate new client secret
az ad sp create	Create service principal

Complete reference: See references/cli-commands.md

Microsoft Authentication Library (MSAL)

MSAL is the recommended library for integrating Microsoft identity platform.

Supported Languages:

• .NET/C# - Microsoft.Identity.Client
• JavaScript/TypeScript - @azure/msal-browser, @azure/msal-node
• Python - msal

Examples: See references/console-app-example.md

Security Best Practices

Practice	Recommendation
Never hardcode secrets	Use environment variables, Azure Key Vault, or managed identity
Rotate secrets regularly	Set expiration, automate rotation
Use certificates over secrets	More secure for production
Least privilege permissions	Request only required API permissions
Enable MFA	Require multi-factor authentication for users
Use managed identity	For Azure-hosted apps, avoid secrets entirely
Validate tokens	Always validate issuer, audience, expiration
Use HTTPS only	All redirect URIs must use HTTPS (except localhost)
Monitor sign-ins	Use Entra ID sign-in logs for anomaly detection

SDK Quick References

• Azure Identity: Python | .NET | TypeScript | Java | Rust
• Key Vault (secrets): Python | TypeScript
• Auth Events: .NET

References

• OAuth Flows - Detailed OAuth 2.0 flow explanations
• CLI Commands - Azure CLI reference for app registrations
• Console App Example - Complete working examples
• First App Registration - Step-by-step guide for beginners
• API Permissions - Understanding and configuring permissions
• Troubleshooting - Common issues and solutions

External Resources

• Microsoft Identity Platform Documentation
• OAuth 2.0 and OpenID Connect protocols
• MSAL Documentation
• Microsoft Graph API