C++ SSL Virtualhosting

Question

While implementing a C++ Server I came around the problem of having two domains pointing to the same server. Implementing a standard SSL Server using boost is not really a problem, but I now need to somehow decide which certificate to use when connected. I know it is possible because it is common practice in Mass Webhosting.

For example a single Apache/nginx is capable of providing two different https websites using two different certificates on the same port (443). I'd like to implement a similar behaviour in C++.

How does apache handle this ?

Is it possible to implement this using boost asio or do I need to use some lower level API (OpenSSL/OS) ?

Answer 1

The way to tell the server in advance which host is desired is to use Server Name Indication, as described in RFC 6066 . It adds an extension field server_name to TLS including a server name list which the server can then use.

This is not a required field, so not all browsers or servers support it. But the support in mainstream products is good at the moment.