Authentication and Authorization in C#: Identity, OAuth2, and JWT

Authentication and Authorization in C#: Identity, OAuth2, and JWT
Master Modern Security Patterns in ASP.NET Core Applications
In today's interconnected world, security isn't optional—it's essential. Yet implementing robust authentication and authorization remains one of the most challenging aspects of web development. Data breaches, stolen credentials, and unauthorized access can devastate companies and destroy user trust. Every professional .NET developer needs to understand how to properly secure their applications, but navigating the complex landscape of identity protocols, tokens, and security frameworks can be overwhelming.
"Authentication and Authorization in C#" is your comprehensive, code-focused guide to implementing professional security patterns in ASP.NET Core applications. This practical resource takes you beyond basic tutorials to provide production-ready solutions for real-world identity challenges.
Whether you're building traditional web applications with Razor Pages, modern SPAs with secure APIs, or microservices requiring robust token-based authentication, this book delivers clear, actionable guidance with complete working examples.
What You'll Learn:

• Local Authentication Mastery: Implement and customize ASP.NET Core Identity with secure registration, login flows, email confirmation, and account recovery
• API Security with JWT: Build token-based authentication systems with proper access and refresh token implementation, validation, and secure storage
• External Authentication: Integrate Google, Microsoft, GitHub and other OAuth2/OpenID Connect providers while maintaining consistent authorization
• Advanced Authorization Patterns: Implement role-based and claims-based security with custom policies, requirements, and resource-based authorization
• Production-Ready Deployment: Configure secure applications across environments with proper secrets management, HTTPS enforcement, and security headers

Deep Dive into Four Essential Security Areas:
ASP.NET Identity for Local Authentication Build a rock-solid foundation for user management with ASP.NET Core Identity. You'll customize the user model, implement registration and login workflows, and add role-based security to restrict access to sensitive areas.
JWT Authentication for APIs Master token-based authentication for Web APIs and SPAs. You'll learn the internal structure of JWTs, implement proper signing and validation, create refresh token mechanisms, and handle secure storage on both server and client.
External Authentication and OAuth2 Seamlessly integrate third-party identity providers into your applications. Understand the OAuth2 authorization code flow, implement social logins, and map external user information to your application's authorization system.
Advanced Topics and Best Practices Take your implementation to production level with advanced authorization policies, resource-based security, and deployment best practices.
Practical, Production-Ready Code:
Each chapter includes complete C# implementations you can adapt to your projects immediately. You'll build:

• A traditional web application with local identity and role-based security
• A secure API with JWT validation and refresh token support
• A modern SPA application integrated with external providers
• Custom authorization policies for fine-grained access control

Start building more secure applications now.