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)

Syntactic and semantic validation

The preceding recipe is one form of syntactic validation, where we validate the correctness of the field's structure (in this case, the names should only contain alphabetical characters).

Another type of validation is based on semantics, where the validity of the input relies on a specific business context.

Creating a custom validation attribute to implement semantic validation

In semantic validation, a context check is done to ensure that the data conforms to a business rule. Using our Online Banking app as an example, we can define a business rule, stating that a customer must have a reputable email address before a record can be created.

In this recipe, you will learn how to perform semantic validation using custom validation attributes.

Getting ready

Request a free API key at https://emailrep.io/key. EmailRep is a simple public API for checking an email's reputation. Once your request has been approved, you will receive...