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)

Fixing insufficient randomness

Pseudo-random numbers may suffice for less than critical operations, but these numbers are not genuinely random. Computers use mathematical formulas to produce these pseudo-random numbers, but they are not random enough to be used in cryptographic operations such as salt creation. The predictability and deterministic nature of the data that's produced by these random methods and function generators increases the chance of a password hash being cracked, thus causing hash collision attacks.

Getting ready

Using Visual Studio Code, open the sample Online Banking app folder at \Chapter13\insufficient-randomness\before\OnlineBankingApp.

How to do it…

Let's take a look at the steps for this recipe:

  1. Type the following command in the Terminal to build the sample app to confirm there are no compilation errors:
    dotnet build
  2. Open the \Chapter13\insufficient-randomness\before\OnlineBankingApp\Areas\Identity\PasswordHasher.cs...