HttpServer::bind_ssl not upgrading connections to HTTP/2

[transkatgirl]

When connecting to a HTTPS server built with actix-web, TLS-ALPN fails to work properly, and HTTP/1.1 is used instead of HTTP/2.

The documentation says that "actix-web automatically upgrades connections to HTTP/2.0 if possible", but it appears that it's not being upgraded properly.

Here's a simple example server to show the issue:

extern crate actix_web;
extern crate openssl;
use actix_web::{server, App, HttpRequest};
use openssl::ssl::{SslMethod, SslAcceptor, SslFiletype};

fn index(_req: &HttpRequest) -> &'static str {
    "Hello world!"
}

fn main() {
    let mut builder = SslAcceptor::mozilla_intermediate(SslMethod::tls()).unwrap();
    builder.set_private_key_file("key.pem", SslFiletype::PEM).unwrap();
    builder.set_certificate_chain_file("cert.pem").unwrap();

    server::new(|| App::new().resource("/", |r| r.f(index)))
	.bind_ssl("[::]:8181", builder)
	.unwrap()
	.run();
}

And, here's the output when I attempt to connect to it through curl (truncated):

* Connected to localhost (::1) port 8181 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
...
* SSL connection using TLSv1.2 / ECDHE-ECDSA-CHACHA20-POLY1305
* ALPN, server did not agree to a protocol
...
> GET / HTTP/1.1
> Host: localhost:8181
> User-Agent: curl/7.62.0-DEV
> Accept: */*
> 
< HTTP/1.1 200 OK
< content-length: 12
< content-type: text/plain; charset=utf-8
< date: Sun, 23 Sep 2018 03:13:37 GMT

[OtaK]

I think we should give the utmost attention to this issue since one of the biggest selling points of actix-web plain doesn't work anymore.

Currently trying to pinpoint the faulty version that caused the regression

Edit: Found.

Actix-web 0.7.3:

starting benchmark...
spawning thread #0: 100 total client(s). 1000 total requests
TLS Protocol: TLSv1.2
Cipher: ECDHE-RSA-AES128-GCM-SHA256
Server Temp Key: ECDH P-256 256 bits
Application protocol: h2

Actix 0.7.4 and above:

starting benchmark...
spawning thread #0: 100 total client(s). 1000 total requests
TLS Protocol: TLSv1.2
Cipher: ECDHE-RSA-AES128-GCM-SHA256
Server Temp Key: ECDH P-256 256 bits
No protocol negotiated. Fallback behaviour may be activated
Server does not support NPN/ALPN. Falling back to HTTP/1.1.
Application protocol: http/1.1

@fafhrd91 @DoumanAsh

[DoumanAsh]

Sorry, I forgot about it. I'll check it