Book Image

ASP.NET Core 5 Secure Coding Cookbook

By : Roman Canlas
Book Image

ASP.NET Core 5 Secure Coding Cookbook

By: Roman Canlas

Overview of this book

ASP.NET Core developers are often presented with security test results showing the vulnerabilities found in their web apps. While the report may provide some high-level fix suggestions, it does not specify the exact steps that you need to take to resolve or fix weaknesses discovered by these tests. In ASP.NET Secure Coding Cookbook, you’ll start by learning the fundamental concepts of secure coding and then gradually progress to identifying common web app vulnerabilities in code. As you progress, you’ll cover recipes for fixing security misconfigurations in ASP.NET Core web apps. The book further demonstrates how you can resolve different types of Cross-Site Scripting. A dedicated section also takes you through fixing miscellaneous vulnerabilities that are no longer in the OWASP Top 10 list. This book features a recipe-style format, with each recipe containing sample unsecure code that presents the problem and corresponding solutions to eliminate the security bug. You’ll be able to follow along with each step of the exercise and use the accompanying sample ASP.NET Core solution to practice writing secure code. By the end of this book, you’ll be able to identify unsecure code causing different security flaws in ASP.NET Core web apps and you’ll have gained hands-on experience in removing vulnerabilities and security defects from your code.
Table of Contents (15 chapters)

Output encoding

Output encoding or escaping is yet another defensive technique that helps neutralize injection attacks. This process replaces the characters in the untrusted data, which allows the application to display the output safely in its proper context.

In an ASP.NET Core web application, there's different contextual output that a developer should know about to understand the right encoder to use in a given context. These are HTML, HTML attribute context, CSS context, and JavaScript context.

By default, the Razor engine in ASP.NET Core automatically escapes output, apart from a few exceptions, where a method will disable such encoding. ASP.NET Core also provides a variety of encoders that we can use to explicitly implement proper contextual output.

In the next few recipes, we will learn how to perform output encoding with HtmlEncoder, UrlEncoder, and JavascriptEncoder.