chore: Add rustls examples (#968)

examples/Cargo.toml

@@ -54,10 +54,18 @@ path = "src/dynamic_load_balance/server.rs"
 name = "tls-client"
 path = "src/tls/client.rs"
 
+[[bin]]
+name = "tls-client-rustls"
+path = "src/tls/client_rustls.rs"
+
 [[bin]]
 name = "tls-server"
 path = "src/tls/server.rs"
 
+[[bin]]
+name = "tls-server-rustls"
+path = "src/tls/server_rustls.rs"
+
 [[bin]]
 name = "tls-client-auth-server"
 path = "src/tls_client_auth/server.rs"
@@ -214,6 +222,11 @@ tonic-web = { path = "../tonic-web" }
 # streaming example
 h2 = "0.3"
 
+tokio-rustls = "*"
+hyper-rustls = { version = "0.23", features = ["http2"] }
+rustls-pemfile = "*"
+tower-http = { version = "0.2", features = ["add-extension"] }
+
 
 [build-dependencies]
 tonic-build = { path = "../tonic-build", features = ["prost", "compression"] }

examples/src/tls/client_rustls.rs

@@ -0,0 +1,85 @@
+//! This examples shows how you can combine `hyper-rustls` and `tonic` to
+//! provide a custom `ClientConfig` for the tls configuration.
+
+pub mod pb {
+    tonic::include_proto!("/grpc.examples.echo");
+}
+
+use hyper::{client::HttpConnector, Uri};
+use pb::{echo_client::EchoClient, EchoRequest};
+use tokio_rustls::rustls::{ClientConfig, RootCertStore};
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let fd = std::fs::File::open("examples/data/tls/ca.pem")?;
+
+    let mut roots = RootCertStore::empty();
+
+    let mut buf = std::io::BufReader::new(&fd);
+    let certs = rustls_pemfile::certs(&mut buf)?;
+    roots.add_parsable_certificates(&certs);
+
+    let tls = ClientConfig::builder()
+        .with_safe_defaults()
+        .with_root_certificates(roots)
+        .with_no_client_auth();
+
+    let mut http = HttpConnector::new();
+    http.enforce_http(false);
+
+    // We have to do some wrapping here to map the request type from
+    // `https://example.com` -> `https://[::1]:50051` because `rustls`
+    // doesn't accept ip's as `ServerName`.
+    let connector = tower::ServiceBuilder::new()
+        .layer_fn(move |s| {
+            let tls = tls.clone();
+
+            hyper_rustls::HttpsConnectorBuilder::new()
+                .with_tls_config(tls)
+                .https_or_http()
+                .enable_http2()
+                .wrap_connector(s)
+        })
+        // Since our cert is signed with `example.com` but we actually want to connect
+        // to a local server we will override the Uri passed from the `HttpsConnector`
+        // and map it to the correct `Uri` that will connect us directly to the local server.
+        .map_request(|_| Uri::from_static("https://[::1]:50051"))
+        .service(http);
+
+    let client = hyper::Client::builder().build(connector);
+
+    // Hyper expects an absolute `Uri` to allow it to know which server to connect too.
+    // Currently, tonic's generated code only sets the `path_and_query` section so we
+    // are going to write a custom tower layer in front of the hyper client to add the
+    // scheme and authority.
+    //
+    // Again, this Uri is `example.com` because our tls certs is signed with this SNI but above
+    // we actually map this back to `[::1]:50051` before the `Uri` is passed to hyper's `HttpConnector`
+    // to allow it to correctly establish the tcp connection to the local `tls-server`.
+    let uri = Uri::from_static("https://example.com");
+    let svc = tower::ServiceBuilder::new()
+        .map_request(move |mut req: http::Request<tonic::body::BoxBody>| {
+            let uri = Uri::builder()
+                .scheme(uri.scheme().unwrap().clone())
+                .authority(uri.authority().unwrap().clone())
+                .path_and_query(req.uri().path_and_query().unwrap().clone())
+                .build()
+                .unwrap();
+
+            *req.uri_mut() = uri;
+            req
+        })
+        .service(client);
+
+    let mut client = EchoClient::new(svc);
+
+    let request = tonic::Request::new(EchoRequest {
+        message: "hello".into(),
+    });
+
+    let response = client.unary_echo(request).await?;
+
+    println!("RESPONSE={:?}", response);
+
+    Ok(())
+}

examples/src/tls/server_rustls.rs

@@ -0,0 +1,143 @@
+pub mod pb {
+    tonic::include_proto!("/grpc.examples.echo");
+}
+
+use futures::Stream;
+use hyper::server::conn::Http;
+use pb::{EchoRequest, EchoResponse};
+use std::{pin::Pin, sync::Arc};
+use tokio::net::TcpListener;
+use tokio_rustls::{
+    rustls::{Certificate, PrivateKey, ServerConfig},
+    TlsAcceptor,
+};
+use tonic::{transport::Server, Request, Response, Status, Streaming};
+use tower_http::ServiceBuilderExt;
+
+#[tokio::main]
+async fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let certs = {
+        let fd = std::fs::File::open("examples/data/tls/server.pem")?;
+        let mut buf = std::io::BufReader::new(&fd);
+        rustls_pemfile::certs(&mut buf)?
+            .into_iter()
+            .map(Certificate)
+            .collect()
+    };
+    let key = {
+        let fd = std::fs::File::open("examples/data/tls/server.key")?;
+        let mut buf = std::io::BufReader::new(&fd);
+        rustls_pemfile::pkcs8_private_keys(&mut buf)?
+            .into_iter()
+            .map(PrivateKey)
+            .next()
+            .unwrap()
+
+        // let key = std::fs::read("examples/data/tls/server.key")?;
+        // PrivateKey(key)
+    };
+
+    let mut tls = ServerConfig::builder()
+        .with_safe_defaults()
+        .with_no_client_auth()
+        .with_single_cert(certs, key)?;
+    tls.alpn_protocols = vec![b"h2".to_vec()];
+
+    let server = EchoServer::default();
+
+    let svc = Server::builder()
+        .add_service(pb::echo_server::EchoServer::new(server))
+        .into_service();
+
+    let mut http = Http::new();
+    http.http2_only(true);
+
+    let listener = TcpListener::bind("[::1]:50051").await?;
+    let tls_acceptor = TlsAcceptor::from(Arc::new(tls));
+
+    loop {
+        let (conn, addr) = match listener.accept().await {
+            Ok(incoming) => incoming,
+            Err(e) => {
+                eprintln!("Error accepting connection: {}", e);
+                continue;
+            }
+        };
+
+        let http = http.clone();
+        let tls_acceptor = tls_acceptor.clone();
+        let svc = svc.clone();
+
+        tokio::spawn(async move {
+            let mut certificates = Vec::new();
+
+            let conn = tls_acceptor
+                .accept_with(conn, |info| {
+                    if let Some(certs) = info.peer_certificates() {
+                        for cert in certs {
+                            certificates.push(cert.clone());
+                        }
+                    }
+                })
+                .await
+                .unwrap();
+
+            let svc = tower::ServiceBuilder::new()
+                .add_extension(Arc::new(ConnInfo { addr, certificates }))
+                .service(svc);
+
+            http.serve_connection(conn, svc).await.unwrap();
+        });
+    }
+}
+
+#[derive(Debug)]
+struct ConnInfo {
+    addr: std::net::SocketAddr,
+    certificates: Vec<Certificate>,
+}
+
+type EchoResult<T> = Result<Response<T>, Status>;
+type ResponseStream = Pin<Box<dyn Stream<Item = Result<EchoResponse, Status>> + Send>>;
+
+#[derive(Default)]
+pub struct EchoServer;
+
+#[tonic::async_trait]
+impl pb::echo_server::Echo for EchoServer {
+    async fn unary_echo(&self, request: Request<EchoRequest>) -> EchoResult<EchoResponse> {
+        let conn_info = request.extensions().get::<Arc<ConnInfo>>().unwrap();
+        println!(
+            "Got a request from: {:?} with certs: {:?}",
+            conn_info.addr, conn_info.certificates
+        );
+
+        let message = request.into_inner().message;
+        Ok(Response::new(EchoResponse { message }))
+    }
+
+    type ServerStreamingEchoStream = ResponseStream;
+
+    async fn server_streaming_echo(
+        &self,
+        _: Request<EchoRequest>,
+    ) -> EchoResult<Self::ServerStreamingEchoStream> {
+        Err(Status::unimplemented("not implemented"))
+    }
+
+    async fn client_streaming_echo(
+        &self,
+        _: Request<Streaming<EchoRequest>>,
+    ) -> EchoResult<EchoResponse> {
+        Err(Status::unimplemented("not implemented"))
+    }
+
+    type BidirectionalStreamingEchoStream = ResponseStream;
+
+    async fn bidirectional_streaming_echo(
+        &self,
+        _: Request<Streaming<EchoRequest>>,
+    ) -> EchoResult<Self::BidirectionalStreamingEchoStream> {
+        Err(Status::unimplemented("not implemented"))
+    }
+}