Async accept an ssl socket using asio and c++ - c++

Question

I am trying to write an async server using asio with SSL encrypted sockets. Currently I have code that does not use SSL, and after following this tutorial I have a basic idea of how to accept an SSL socket, however I do not know how to adapt this code to accept an SSL connection:
void waitForClients() {
acceptor.async_accept(
[this](std::error_code ec, asio::ip::tcp::socket socket) {
if (!ec) {
Conn newConn = std::make_shared<Connection>(ctx, std::move(socket));
connections.push_back(newConn);
} else {
std::cerr << "[SERVER] New connection error: " << ec.message() << "\n";
}
waitForClients();
}
);
}
//this is how the tutorial shows to accept a connection
ssl_socket socket(io_context, ssl_context);
acceptor.accept(socket.next_layer());
The issue is that the callback for acceptor.async_accept gives an ordinary asio::ip::tcp::socket rather than an asio::ssl::ssl_socket<asio::ip::tcp::socket>, and I cannot find any documentation that suggests there is a method of async_accepting an SSL socket in such a way. The only method I have seen is to construct a socket first then accept it afterwards, which cannot be done in this asynchronous manner.
Any help would be much appreciated.

Answer 1

I solved the problem by realising that the second argument to the constructor of asio::ssl::stream<asio::ip::tcp::socket> is any initialiser for the underlying type asio::ip::tcp::socket. Thus the problem can be solved:
void waitForClients() {
acceptor.async_accept(
[this](std::error_code ec, asio::ip::tcp::socket socket) {
if (!ec) {
//initialise an ssl stream from already created socket
asio::ssl::stream<asio::ip::tcp::socket> sslStream(sslCtx, std::move(socket);
//then pass it on to be used
Conn newConn = std::make_shared<Connection>(ctx, sslStream);
connections.push_back(newConn);
} else {
std::cerr << "[SERVER] New connection error: " << ec.message() << "\n";
}
waitForClients();
}
);
}