Book Image

Hands-On Network Programming with C# and .NET Core

By : Sean Burns
Book Image

Hands-On Network Programming with C# and .NET Core

By: Sean Burns

Overview of this book

The C# language and the .NET Core application framework provide the tools and patterns required to make the discipline of network programming as intuitive and enjoyable as any other aspect of C# programming. With the help of this book, you will discover how the C# language and the .NET Core framework make this possible. The book begins by introducing the core concepts of network programming, and what distinguishes this field of programming from other disciplines. After this, you will gain insights into concepts such as transport protocols, sockets and ports, and remote data streams, which will provide you with a holistic understanding of how network software fits into larger distributed systems. The book will also explore the intricacies of how network software is implemented in a more explicit context, by covering sockets, connection strategies such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP), asynchronous processing, and threads. You will then be able to work through code examples for TCP servers, web APIs served over HTTP, and a Secure Shell (SSH) client. By the end of this book, you will have a good understanding of the Open Systems Interconnection (OSI) network stack, the various communication protocols for that stack, and the skills that are essential to implement those protocols using the C# programming language and the .NET Core framework.
Table of Contents (26 chapters)
Free Chapter
Section 1: Foundations of Network Architecture
Section 2: Communicating Over Networks
Section 3: Application Protocols and Connection Handling
Section 4: Security, Stability, and Scalability
Section 5: Advanced Subjects

Securing FTP requests

While you may suspect that the act of providing user credentials to our server meant there was some measure of security involved in our file access, we were actually interacting with our server in an entirely unsecure manner. Those credentials were only of value the moment they were received by the server and our command connection was established. After that though, they provided no more security of the data we were transmitting than if we had allowed entirely anonymous access to our directory. So, let's look at why that is, and how to fix it.

The risks of FTP

With our example software, there isn't any real concern for security because our data is never transmitted over an actual network connection...