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Mert Özen's blog posts on software development, backend, frontend, and DevOps.

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.NET Core Web API 36 Angular 31 JavaScript Basics 19 JavaScript Intermediate 18 JavaScript Advanced 16 TypeScript Basics 14 TypeScript Intermediate 14 TypeScript Advanced 12 Entity Framework Core 28 Dapper 16 Git & GitHub 29 Web Security (OWASP Top 10) 21 LLM Fundamentals 20 C# Fundamentals 20 Object-Oriented Programming in C# 16 C# Collections and Generics 11 LINQ 17 Asynchronous Programming in C# 17 Advanced C# 14 C# Versions 6 Solution Patterns 22 SOLID and Design Principles 12 Clean Code 13 Design Patterns 23 UML and Modeling 18 Introduction to Software Architecture 9 Clean, Onion and Hexagonal Architecture 8 Vertical Slice Architecture 6 Domain-Driven Design 12 CQRS and Event Sourcing 10 Messaging and Event-Driven Architecture 9 Modular Monolith 2 Microservices 10 UI Architecture Patterns 9 Architecture Decisions 7 System Design 15 Distributed Systems Fundamentals 11 Background Jobs and Scheduled Jobs 11 Working with Message Queues 14 Logging in .NET 10 Caching 10 Real-time Applications 9 ASP.NET Core MVC and Razor Pages 13 CI/CD Fundamentals 8 GitHub Actions 16 Jenkins 12 Web Servers and Hosting 12 Deployment Strategies 9 Kubernetes 19 Authentication and Authorization 18

2 posts found #passkey

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Security PART 06

Passkeys 1: How WebAuthn and FIDO2 Work: RP ID, Challenge, Attestation and Assertion

A passkey resists phishing because the browser uses the credential only on origins of its registered RP ID, and the signature covers the clientDataJSON that carries the origin and the challenge. We decode real attestation and assertion data captured in the Bookstore lab with CBOR, verify the signature by hand, and explain the UV, BE and BS flags, synced versus device-bound passkeys and account recovery design.

8 Nov 2026 9 min 4

Security PART 07

Passkeys 2: Passkey Registration and Passwordless Sign-in with ASP.NET Core Identity 10 and an Angular Client

ASP.NET Core Identity 10 ships passkey registration and passwordless sign-in through SignInManager's MakePasskeyCreationOptionsAsync, PerformPasskeyAttestationAsync and PasskeySignInAsync; but with an empty ServerDomain the RP ID comes from the Host header, and a passkey sign-in writes pwd as amr. We build the Angular client, conditional UI and an end-to-end test with headless Chrome's virtual authenticator.

8 Nov 2026 10 min 5