via-httplib: A C++ HTTP Library

A library for embedding HTTP or HTTPS, IPV6 and IPV4 servers in C++ applications.

via-httplib is an asynchronous C++ HTTP server built upon boost asio that aims to provide a simple, secure and efficient server that complies with the requirements of rfc7230 wherever possible.

SSL / TLS Configuration

The server is via::http_server, a class template requiring a SocketAdaptor to instantiate it:

• a tcp_adaptor for a plain HTTP server
• an ssl_tcp_adaptor for an HTTPS server

IPV6 / IPV4 Configuration

Whether the server accepts IPV6 and IPV4 connections or just IPV4 connections depends upon how the port is configured:

• IPV6, (the default) the server accepts both IPV6 and IPV4 connections
• IPV4 only, the server only accepts IPV4 connections

Data / Text Configuration

The server can be configured to pass HTTP message bodies in different types of containers, e.g.:

• std::vector<char> (the default) for handing binary data, e.g. images, files, etc.
• std::string for handing textural data, e.g. HTML, JSON, etc.

Socket Adaptor	Container	Description
tcp_adaptor	std::vector<char>	An HTTP data server.
tcp_adaptor	std::string	An HTTP text server.
ssl_tcp_adaptor	std::vector<char>	An HTTPS data server.
ssl_tcp_adaptor	std::string	An HTTPS text server.

The HTTP message bodies can be sent using buffered or unbuffered methods.
The unbuffered methods use "scatter-gather" writes to avoid copying data.

Requirements

• A C++11 compiler.
  This version requires a complier that supports: lambdas, enum classes, member function delete and std::functional. It's been tested with MSVC 2015, MSVC 2013, GCC 4.9.1 and MinGw 4.9.1.

• The boost C++ library, especially asio, see boost.

• For HTTPS, the OpenSSL library, see openssl.

• For C++ code documentation, Doxygen, see Doxygen

• Note: there is currently an issue building boost asio with Visual Studio 2015 Update 2, see Issue 4

Getting Started

Download the latest tagged version of via-httplib from Github and follow the instructions here: Make.
Or simply build the .cpp files into your application (there are 8 of them).

via-http lib depends on the boost libraries. If boost is not installed on your machine then download the latest package from boost and follow the instructions here: boost getting started.

The boost asio library (and hence via-httplib) depends upon the OpenSSL library to implement SSL/TLS sockets. If you require an HTTPS server or client then you'll need to install the OpenSSL library as well. Please note that a plain HTTP server should not require OpenSLL.

If OpenSLL is not installed on your machine then you may download the latest stable package from openssl source and build it. Note: a binary distribution may be available for your machine, see: OpenSSL binaries.

Document	Description
Build Guide	How to build the library.
Server User Guide	How to use the library to create HTTP servers.
Client User Guide	How to use the library to create HTTP clients.
Security Guide	How to configure the library securely.
Design	The library design.
examples/server	Example HTTP & HTTPS servers.
examples/client	Example HTTP & HTTPS clients.

Namespace Structure

Directory Structure

Directory	Contents
via	The via-httplib API classes: http_server, http_connection and http_client.
examples/server	Example HTTP & HTTPS servers.
examples/client	Example HTTP & HTTPS clients.
tests	A unit tests for the HTTP parsers and encoders.
docs	The User Guides and design documents.
docs/html	Doxygen output directory. Created by running doxygen Doxyfile in the docs directory.

Acknowledgements

Thanks to:

• Neil Tisdale for encouraging and inspiring me to create the library
• Louis Nayegon for helping to develop it and recommending GitHub
• Adam Leggett for helping to identify and fix security, efficiency and CMake issues
• Christopher Kohlhoff for the asio library, without which, this library wouldn't exist.