Tomas Zezula, Author at Tomas Zezula

Kotlin

Conquer Authentication with Ktor: Part 8 – Protect Access with CORS

Ensuring security and flexibility of web services when it comes to cross-origin resource sharing is essential. This is elegantly managed through the implementation of Cross-Origin Resource Sharing (CORS), an established practice for modern web applications. A well defined CORS policy not only enhances security but also promotes a seamless interaction between different domains. Thankfully, Ktor makes this process straightforward and efficient. In this final part of our series on authentication with Ktor, we will provide clear examples to guide you. By the end of this post, you’ll see how effortless it is to integrate CORS into your Ktor projects, ensuring your services are both secure and accessible.

By Tomas Zezula, 2 monthsMarch 2, 2024 ago

Persistence

Managing Detached Entities with Spring Boot and Hibernate

Dealing with detached objects is a common issue when working with Spring Boot and Hibernate. When you load an entity from the database, make some changes, and then save it, sometimes the updated entity becomes detached from the Hibernate Session, which can lead to issues. This post shows how to effectively manage detached entities and avoid data inconsistencies.

By Tomas Zezula, 2 monthsFebruary 25, 2024 ago

Kotlin

Implementing Stateless OAuth in Ktor Using Google and JWT

In our previous post, we explored the theory behind OAuth 2.0. Today, we’re going to dive into practical application by implementing OAuth authentication with Google in a Ktor application. While the traditional approach leans towards using user session cookies to store access tokens, we’re taking a different approach. We’ll be leveraging JSON Web Tokens (JWT) to encapsulate the access token. By encapsulating the access token in JWT, we transition our authentication to a stateless model, making our server more resource efficient.

By Tomas Zezula, 2 monthsFebruary 18, 2024 ago

Kotlin

Conquer Authentication with Ktor: Part 7 – Introducing OAuth 2.0

In our previous post, we wrapped up the discussion on Json Web Tokens. We’ve come far in this tutorial, gradually uncovering more complex and practical use cases. Now, we’re turning our attention to a widely adopted authorization protocol – Open Authorization 2.0. While JWT primarily ensures secure communication, OAuth focuses on the delegation of access. Today, we’ll have a closer look at key concepts of this authorization protocol.

By Tomas Zezula, 2 monthsFebruary 12, 2024 ago

Kotlin

Gradle Multi-Module Builds: Setting Up Shared Dependencies

When you are managing a multi-module Gradle project, more often than not you’d want to share certain dependencies across different modules. This is particularly true for test dependencies. You can achieve this by defining common dependencies in the root build file and applying them to all subprojects. However, a problem often encountered is the dreaded Unresolved reference: testImplementation error. This blog post suggests a simple trick that resolves the issue. Give it a go and happy testing ever after!

By Tomas Zezula, 3 monthsFebruary 4, 2024 ago

Kotlin

Refreshing an Access Token with Ktor and JWT

We’re back with another part of the series Conquer Authentication with KtoRemember where we left off in Part 6? We learned how to implement authentication with JWT but that lingering question remained: What happens once the access token expires? Today, we will address this concern and learn how to easily refresh an expired token in the background, without asking the user to re-authenticate.

By Tomas Zezula, 3 monthsJanuary 28, 2024 ago