`get_sni_extension` is no longer public which breaks our application about rustls

[svanharmelen]

Yeah that is clear (that rustls does not IO itself)...

Your solution seems like a perfect solution to use a higher level API instead of the lower level (now partly private) APIs we used before. I will give it a try and update the issues when I got a chance to test it.

Thank you very much for your help and the example!!

[ctz]

If you don't ever call into_connection() and then service the returned object for IO, nothing will happen. Remember rustls does no IO itself, so it has no real ability to accept the connection.

Here's a sample of decoding a client hello to read the SNI value:

fn main() {
    let client_hello = [
        22, 3, 1, 0, 229, 1, 0, 0, 225, 3, 3, 82, 109, 251, 33, 146, 168, 53, 86, 119, 127, 104,
        103, 229, 207, 90, 0, 60, 50, 71, 153, 239, 185, 68, 53, 28, 78, 90, 180, 131, 38, 213, 79,
        32, 245, 65, 141, 47, 134, 74, 85, 117, 157, 113, 190, 131, 101, 161, 239, 185, 23, 131,
        249, 81, 110, 181, 178, 73, 136, 231, 224, 104, 208, 145, 140, 118, 0, 20, 19, 2, 19, 1,
        19, 3, 192, 44, 192, 43, 204, 169, 192, 48, 192, 47, 204, 168, 0, 255, 1, 0, 0, 132, 0, 43,
        0, 3, 2, 3, 4, 0, 11, 0, 2, 1, 0, 0, 10, 0, 8, 0, 6, 0, 29, 0, 23, 0, 24, 0, 13, 0, 20, 0,
        18, 5, 3, 4, 3, 8, 7, 8, 6, 8, 5, 8, 4, 6, 1, 5, 1, 4, 1, 0, 23, 0, 0, 0, 5, 0, 5, 1, 0, 0,
        0, 0, 0, 0, 0, 14, 0, 12, 0, 0, 9, 108, 111, 99, 97, 108, 104, 111, 115, 116, 0, 51, 0, 38,
        0, 36, 0, 29, 0, 32, 185, 7, 102, 21, 198, 19, 186, 56, 168, 153, 237, 223, 201, 2, 247,
        62, 21, 207, 187, 23, 146, 248, 101, 251, 54, 83, 152, 253, 66, 172, 100, 39, 0, 45, 0, 2,
        1, 1, 0, 35, 0, 0,
    ];

    let mut acceptor = rustls::server::Acceptor::default();
    let cursor: &mut dyn std::io::Read = &mut &client_hello[..];
    acceptor.read_tls(cursor).unwrap();
    let maybe_accepted = acceptor
        .accept()
        .expect("invalid message received");
    let accepted = maybe_accepted.expect("`client_hello` was truncated");
    println!("sni: {:?}", accepted.client_hello().server_name());
}

[svanharmelen]

I guess one route could be to try and create a ClientHello struct (and use its server_name method) from the bytes that I now use to create a OpaqueMessage (which I then use to create a Message which contains the ClientHelloPayload).

But its unclear to me how to do that (if its even possible)... Yet it seems that might be a better possible solution?

[ctz]

Are you using the Acceptor API? It makes the SNI value available in ClientHello::server_name(), accessible via Accepted::client_hello().

[svanharmelen]

No we cannot use that because we do not want to accept the connection before we have determined the SNI (since we potentially need to route the connection to another service which will then accept the connection).

[cpu]

I'm going to close this since it sounds like there's a path forward. If you run into any additional issues we can reopen!