C++ client/server with SSL (TLS/DTLS) support (header file only)

About

This is a header file only implementation of a C++ client/server with or without SSL/TLS/DTLS. The implementation uses OpenSSL and BSD API to implement the underlying socket interfaces.

Compilation has been tested with:

• GCC 11.3.0 (GNU/Linux Ubuntu 22.04.1 LTS)
  • cmake 3.22.1
  • googletest 1.11.0-3
  • clang 14.0.0-1ubuntu1
• Visual Studio Community 2022 17.4.4 (64-bit) (Windows 11)
  • cmake 3.26.0-rc1
  • googletest 1.13.0

Usage

Socket

Base sockect class for BSD API class methods.

// default constructor - no socket created because type is unknown
Socket();
Socket::initSocket(domain, type, protocol); // creates socket

// create socket from previously created file descriptor
Socket(int);

// create socket of the given type - NOTE: This returns a Socket class type that is not a Tcp or Udp socket class
Socket(domain, type, protocol);

TCP server/client

Create a TCP server object for accepting TCP connections.

// default no IP/port bound but TCP socket created
TcpServer(); 

// TCP socket created, IP/port bound, but not listening
TcpServer(const uint16_t port, const std::string& ipAddr = "0.0.0.0");

// TCP socket created, IP/port bound, and listening for clients
TcpServer(const std::string& ipAddr, const uint16_t port, const int backlog);

Create a TCP client object to connect to a known TCP server.

// default TCP socket created but no server connection
TcpClient();

// create TcpClient with given TCP socket file descriptor
TcpClient(const int filedescriptor);

// TcpClient connected to a TcpServer IP/port
TcpClient(const std::string& ipAddr, const uint16_t port);

Create a SSL TCP Server for accepting SSL TCP clients.

// Create a SSL TCP Server not bound to IP/port
SecureTcpServer(const std::string& keyFile, const std::string& certFile);

// Create a SSL TCP Server bound to a given port and IP or default IP
SecureTcpServer(const std::string& keyFile, const std::string& certFile, const uint16_t port, const std::string& ipAddr = "0.0.0.0");

Create a SSL TCP client for connecting to SSL TCP servers.

// create a SSL TCP client with a given SSL context - used with SecureTcpServer::accept return
SecureTcpClient(const int filedescriptor, SSL_CTX *sslctx);

// create a SSL TCP client connected to a SSL TCP server
SecureTcpClient(const std::string& ipAddr, const uint16_t port);

// Client

// Connect to TCP server on IP 127.0.0.1 and port 54321
TcpClient client("127.0.0.1", 54321);

UDP server/client

Create a UDP server object for accepting UDP connections.

// default no IP/port bound but UDP socket created
UdpServer(); 

// UDP server socket created, IP/port bound
UdpServer(const uint16_t port, const std::string &ipAddr = "0.0.0.0");

Create a UDP client object to connect to a known UDP server.

// default UDP socket created but no server connection
UdpClient();

// UdpClient connected to a UdpServer IP/port
UdpClient(const std::string& ipAddr, const uint16_t port) noexcept(false)

Create a SSL UDP Server for accepting SSL UDP clients.

// Create a SSL UDP Server not bound to IP/port
SecureUdpServer(const std::string& keyFile, const std::string& certFile);

// Create a SSL UDP Server bound to a given port and IP or default IP
SecureUdpServer(const std::string& keyFile, const std::string& certFile, const uint16_t port, const std::string& ipAddr = "0.0.0.0");

Create a SSL UDP client for connecting to SSL UDP servers.

// Create a SSL UDP Client not attempting to connect to a SSL UDP Server (need to call SecureUdpClient::connect(IP, port) to connect)
SecureUdpClient(const std::string& keyFile, const std::string& certFile);

// create a SSL UDP client connected to a given SSL UDP server waiting in a SecureUdpServer::accept call on the given IP and port
SecureUdpClient(const std::string& ipAddr, const uint16_t port, const std::string& keyFile, const std::string& certFile);

Thread Safety

Do not share any of the socket objects across threads unless you provide your own thread safety on the send/read and accept calls.

Installation

Use the cppsocket.hpp file in your source tree and include it in the file that need to use it.

Run Unit Tests

Unit tests run with ctest:

ctest -C debug

Contribute

All contributions are highly appreciated.