Book Image

C# 9 and .NET 5 – Modern Cross-Platform Development - Fifth Edition

By : Mark J. Price
Book Image

C# 9 and .NET 5 – Modern Cross-Platform Development - Fifth Edition

By: Mark J. Price

Overview of this book

In C# 9 and .NET 5 – Modern Cross-Platform Development, Fifth Edition, expert teacher Mark J. Price gives you everything you need to start programming C# applications. This latest edition uses the popular Visual Studio Code editor to work across all major operating systems. It is fully updated and expanded with a new chapter on the Microsoft Blazor framework. The book’s first part teaches the fundamentals of C#, including object-oriented programming and new C# 9 features such as top-level programs, target-typed new object instantiation, and immutable types using the record keyword. Part 2 covers the .NET APIs, for performing tasks like managing and querying data, monitoring and improving performance, and working with the file system, async streams, serialization, and encryption. Part 3 provides examples of cross-platform apps you can build and deploy, such as websites and services using ASP.NET Core or mobile apps using Xamarin.Forms. The best type of application for learning the C# language constructs and many of the .NET libraries is one that does not distract with unnecessary application code. For that reason, the C# and .NET topics covered in Chapters 1 to 13 feature console applications. In Chapters 14 to 20, having mastered the basics of the language and libraries, you will build practical applications using ASP.NET Core, Model-View-Controller (MVC), and Blazor. By the end of the book, you will have acquired the understanding and skills you need to use C# 9 and .NET 5 to create websites, services, and mobile apps.
Table of Contents (23 chapters)
22
Index

Signing data

To prove that some data has come from someone we trust, it can be signed. Actually, you do not sign the data itself; instead, you sign a hash of the data.

We will be using the SHA256 algorithm for generating the hash, combined with the RSA algorithm for signing the hash.

We could use DSA for both hashing and signing. DSA is faster than RSA for generating a signature, but it is slower than RSA for validating a signature. Since a signature is generated once but validated many times, it is best to have faster validation than generation.

More Information: The RSA algorithm is based on the factorization of large integers, compared to the DSA algorithm, which is based on the discrete logarithm calculation. You can read more at the following link: http://mathworld.wolfram.com/RSAEncryption.html

Signing with SHA256 and RSA

Let's explore signing data and checking the signature with a public key:

  1. In the CryptographyLib class library...