fix(rustproxy-http): preserve original Host header when proxying and add X-Forwarded-* headers; add TLS WebSocket echo backend helper and integration test for terminate-and-reencrypt websocket

rust/crates/rustproxy/tests/integration_http_proxy.rs

@@ -490,6 +490,12 @@ async fn test_terminate_and_reencrypt_http_routing() {
         "Expected /api/data path, got: {}",
         alpha_body
     );
+    // Verify original Host header is preserved (not replaced with backend IP:port)
+    assert!(
+        alpha_body.contains(r#""host":"alpha.example.com"#),
+        "Expected original Host header alpha.example.com, got: {}",
+        alpha_body
+    );
 
     // Test beta domain - different host goes to different backend
     let beta_result = with_timeout(async {
@@ -527,10 +533,136 @@ async fn test_terminate_and_reencrypt_http_routing() {
         "Expected /other path, got: {}",
         beta_body
     );
+    // Verify original Host header is preserved for beta too
+    assert!(
+        beta_body.contains(r#""host":"beta.example.com"#),
+        "Expected original Host header beta.example.com, got: {}",
+        beta_body
+    );
 
     proxy.stop().await.unwrap();
 }
 
+/// Test that WebSocket upgrade works through terminate-and-reencrypt mode.
+///
+/// Verifies the full chain: client→TLS→proxy terminates→re-encrypts→TLS→backend WebSocket.
+/// The proxy's `handle_websocket_upgrade` checks `upstream.use_tls` and calls
+/// `connect_tls_backend()` when true. This test covers that path.
+#[tokio::test]
+async fn test_terminate_and_reencrypt_websocket() {
+    let backend_port = next_port();
+    let proxy_port = next_port();
+    let domain = "ws.example.com";
+
+    // Frontend cert (client→proxy TLS)
+    let (frontend_cert, frontend_key) = generate_self_signed_cert(domain);
+    // Backend cert (proxy→backend TLS)
+    let (backend_cert, backend_key) = generate_self_signed_cert("localhost");
+
+    // Start TLS WebSocket echo backend
+    let _backend = start_tls_ws_echo_backend(backend_port, &backend_cert, &backend_key).await;
+
+    // Create terminate-and-reencrypt route
+    let mut route = make_tls_terminate_route(
+        proxy_port,
+        domain,
+        "127.0.0.1",
+        backend_port,
+        &frontend_cert,
+        &frontend_key,
+    );
+    route.action.tls.as_mut().unwrap().mode = rustproxy_config::TlsMode::TerminateAndReencrypt;
+
+    let options = RustProxyOptions {
+        routes: vec![route],
+        ..Default::default()
+    };
+
+    let mut proxy = RustProxy::new(options).unwrap();
+    proxy.start().await.unwrap();
+    assert!(wait_for_port(proxy_port, 2000).await);
+
+    let result = with_timeout(
+        async {
+            let _ = rustls::crypto::ring::default_provider().install_default();
+            let tls_config = rustls::ClientConfig::builder()
+                .dangerous()
+                .with_custom_certificate_verifier(std::sync::Arc::new(InsecureVerifier))
+                .with_no_client_auth();
+            let connector =
+                tokio_rustls::TlsConnector::from(std::sync::Arc::new(tls_config));
+
+            let stream = tokio::net::TcpStream::connect(format!("127.0.0.1:{}", proxy_port))
+                .await
+                .unwrap();
+            let server_name =
+                rustls::pki_types::ServerName::try_from(domain.to_string()).unwrap();
+            let mut tls_stream = connector.connect(server_name, stream).await.unwrap();
+
+            // Send WebSocket upgrade request through TLS
+            let request = format!(
+                "GET /ws HTTP/1.1\r\n\
+                 Host: {}\r\n\
+                 Upgrade: websocket\r\n\
+                 Connection: Upgrade\r\n\
+                 Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==\r\n\
+                 Sec-WebSocket-Version: 13\r\n\
+                 \r\n",
+                domain
+            );
+            tls_stream.write_all(request.as_bytes()).await.unwrap();
+
+            // Read the 101 response (byte-by-byte until \r\n\r\n)
+            let mut response_buf = Vec::with_capacity(4096);
+            let mut temp = [0u8; 1];
+            loop {
+                let n = tls_stream.read(&mut temp).await.unwrap();
+                if n == 0 {
+                    break;
+                }
+                response_buf.push(temp[0]);
+                if response_buf.len() >= 4 {
+                    let len = response_buf.len();
+                    if response_buf[len - 4..] == *b"\r\n\r\n" {
+                        break;
+                    }
+                }
+            }
+
+            let response_str = String::from_utf8_lossy(&response_buf).to_string();
+            assert!(
+                response_str.contains("101"),
+                "Expected 101 Switching Protocols, got: {}",
+                response_str
+            );
+            assert!(
+                response_str.to_lowercase().contains("upgrade: websocket"),
+                "Expected Upgrade header, got: {}",
+                response_str
+            );
+
+            // After upgrade, send data and verify echo
+            let test_data = b"Hello TLS WebSocket!";
+            tls_stream.write_all(test_data).await.unwrap();
+
+            // Read echoed data
+            let mut echo_buf = vec![0u8; 256];
+            let n = tls_stream.read(&mut echo_buf).await.unwrap();
+            let echoed = &echo_buf[..n];
+
+            assert_eq!(echoed, test_data, "Expected echo of sent data");
+
+            "ok".to_string()
+        },
+        10,
+    )
+    .await
+    .unwrap();
+
+    assert_eq!(result, "ok");
+    proxy.stop().await.unwrap();
+}
+
 /// Test that the protocol field on route config is accepted and processed.
 #[tokio::test]
 async fn test_protocol_field_in_route_config() {