Botan::TLS::Server, TLS::Client VS. boost::asio, boost::beast

[fasxmut]

What is the difference between Botan::TLS::Server, TLS::Client and boost::asio, boost::beast? Does botan implement its own network api?

[randombit]

I'm not familiar with the Beast library so cannot comment there.

With regards to TLS Botan does not implement the network layer. The TLS::Server and TLS::Client classes provide a wrapper around some other network API which you as the application developer must provide. This is done by implementing various functions in TLS::Callbacks for example tls_emit_data is called when the TLS layer needs to send something to the network. At that point it is up to the application and it might well use something like asio to accomplish that.

It may clear things up to look at some of the command line utility implementations like tls_http_server which use asio to access the network layer.

[reneme]

It may be worth mentioning that Botan also provides an adapter for Boost asio that aims to be compatible with Asio's ssl::stream. With that it is easy to integrate Botan's TLS implementation with networking provided by asio.

See here for an example HTTPS client based on asio, beast and Botan: https://github.com/hrantzsch/beast-botan-https-client

[reneme]

For what it's worth: There's also a blog post on how to use Botan to provide TLS for Boost ASIO and beast and essentially write a minimal HTTPS client: https://botan-crypto.org/using-botan-tls-with-boost-beast/

[fasxmut]

Thank you for the answer.