Azure Entra App Registration

Entra ID app registration

Register a Microsoft Entra ID application, choose the right OAuth 2.0 flow, assign least-privilege API permissions, and wire MSAL into the calling application without embedding long-lived secrets.

When to invoke

• "Create an Entra ID app registration for my API."
• "Configure OAuth 2.0 and add API permissions."
• "Generate a service principal for this application."
• "Show an MSAL sign-in example for a console app."

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

Application Types

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

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

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

Output template

## App registration result

**Status:** registered | configured | blocked
**Summary:** <one sentence covering scope and outcome>

### Details
Application and service principal identifiers, permissions, and auth flow.

### Validation
- <check performed>: <result and evidence>

Quality gate

• The selected OAuth flow matches the client type.
• Secrets are stored outside source control or replaced by certificates or federation.
• The output follows ## Output template exactly.
• Every reported check was performed and its evidence is shown.
• Irreversible Azure actions were confirmed with the user first.