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
About Packt

The TLS protocol

After a TCP connection is established, the TLS handshake is initiated by the client. The client sends a number of specifications to the server, including which versions of SSL/TLS it is running, which cipher suites it supports, and which compression methods it would like to use.

The server selects the highest mutually supported version of SSL/TLS to use. It also chooses a cipher suite and compression method from the choices given by the client.

If the client and server do not support any cipher suite in common, then no TLS connection can be established. This is not uncommon when using very old browsers with newer servers.

After the basic setup is done, the server sends the client its certificate. This is used by the client to verify that it's connected to a legitimate server. We'll discuss more on certificates in the next section.

Once the client has verified that the server really is who it claims to be, a key exchange is initiated. After key exchange completes, both the client...