Book Image

Hands-On Network Programming with C

By : Lewis Van Winkle
Book Image

Hands-On Network Programming with C

By: Lewis Van Winkle

Overview of this book

Network programming enables processes to communicate with each other over a computer network, but it is a complex task that requires programming with multiple libraries and protocols. With its support for third-party libraries and structured documentation, C is an ideal language to write network programs. Complete with step-by-step explanations of essential concepts and practical examples, this C network programming book begins with the fundamentals of Internet Protocol, TCP, and UDP. You’ll explore client-server and peer-to-peer models for information sharing and connectivity with remote computers. The book will also cover HTTP and HTTPS for communicating between your browser and website, and delve into hostname resolution with DNS, which is crucial to the functioning of the modern web. As you advance, you’ll gain insights into asynchronous socket programming and streams, and explore debugging and error handling. Finally, you’ll study network monitoring and implement security best practices. By the end of this book, you’ll have experience of working with client-server applications and be able to implement new network programs in C. The code in this book is compatible with the older C99 version as well as the latest C18 and C++17 standards. You’ll work with robust, reliable, and secure code that is portable across operating systems, including Winsock sockets for Windows and POSIX sockets for Linux and macOS.
Table of Contents (26 chapters)
Title Page
Dedication
About Packt
Contributors
Preface
Index

HTTPS overview


HTTPS provides security to HTTP. We covered HTTP in Chapter 6, Building a Simple Web Client. HTTPS secures HTTP by using TLS over TCP on port 443. TLS is a protocol that can provide security to any TCP connection.

TLS is the successor to Secure Socket Layer (SSL), an earlier protocol also used by HTTPS. TLS and SSL are compatible, and most of the information in this chapter also applies to SSL. Generally, establishing an HTTPS connection involves the client and server negotiating which protocol to use. The ideal outcome is that the client and server agree on the most secure, mutually supported protocol and cipher.

When we talk about protocol security, we are generally looking for the following three things:

  • Authentication: We need a way to prevent impostors from posing as legitimate communication partners. TLS provides peer authentication methods for this reason.
  • Encryption: TLS uses encryption to obfuscate transmitted data. This prevents an eavesdropper from correctly interpreting...