diff --git a/src/docker/config.json b/src/docker/config.json
index 253dfd4..8beeaf1 100644
--- a/src/docker/config.json
+++ b/src/docker/config.json
@@ -2,7 +2,11 @@
   "webservice":{
     "host":"0.0.0.0",
     "port":8022,
-    "ssl":false
+      "ssl": false,
+      "cors-relative-origins": [
+          "chrome-extension://[a-p]{32}",
+          "(https|http)://.*"
+      ]
   },
   "application":{
     "authentication":false,
diff --git a/src/main/java/net/zyclonite/nassh/MainVerticle.java b/src/main/java/net/zyclonite/nassh/MainVerticle.java
index bb2e728..bb6763c 100644
--- a/src/main/java/net/zyclonite/nassh/MainVerticle.java
+++ b/src/main/java/net/zyclonite/nassh/MainVerticle.java
@@ -13,6 +13,7 @@
 import io.vertx.core.Promise;
 import io.vertx.core.http.HttpServer;
 import io.vertx.core.http.HttpServerOptions;
+import io.vertx.core.json.JsonArray;
 import io.vertx.core.json.JsonObject;
 import io.vertx.core.net.SelfSignedCertificate;
 import io.vertx.ext.web.Router;
@@ -42,11 +43,12 @@ public void start(final Promise<Void> startPromise) {
         }
         server = vertx.createHttpServer(options);
         final Router router = Router.router(vertx);
-        router.route().handler(CorsHandler
-            .create()
-            .addRelativeOrigin(".*")
-            .allowCredentials(true)
-        );
+        CorsHandler corsHandler = CorsHandler.create().allowCredentials(true);
+        JsonArray relOrigins = webserviceConfig.getJsonArray("cors-relative-origins");
+        for (int i = 0; i < relOrigins.size(); i++) {
+            corsHandler.addRelativeOrigin(relOrigins.getString(i));
+        }
+        router.route().handler(corsHandler);
         router.get("/cookie").handler(new CookieHandler(config().getJsonObject("application").copy().put("auth", config().getJsonObject("google-sso"))));
         router.post("/cookie").handler(new CookiePostHandler(vertx, new JsonObject().put("auth", config().getJsonObject("google-sso"))));
         router.get("/proxy").handler(new ProxyHandler(vertx, config()));
diff --git a/src/main/java/net/zyclonite/nassh/handler/ProxyHandler.java b/src/main/java/net/zyclonite/nassh/handler/ProxyHandler.java
index a19d52b..020781b 100644
--- a/src/main/java/net/zyclonite/nassh/handler/ProxyHandler.java
+++ b/src/main/java/net/zyclonite/nassh/handler/ProxyHandler.java
@@ -14,7 +14,7 @@
 import io.vertx.core.Vertx;
 import io.vertx.core.http.HttpServerRequest;
 import io.vertx.core.http.HttpServerResponse;
-import io.vertx.core.impl.VertxImpl;
+import io.vertx.core.impl.VertxInternal;
 import io.vertx.core.json.JsonArray;
 import io.vertx.core.json.JsonObject;
 import io.vertx.core.net.NetClient;
@@ -39,14 +39,16 @@ public class ProxyHandler implements Handler<RoutingContext> {
     private final LocalMap<String, Session> sessions;
     private final int sessionlimit;
     private final boolean authentication;
-    private final Vertx vertx;
+    private final VertxInternal vertx;
+    private final NetClient client;
     private final JsonObject config;
     private final JsonArray accessList;
     private final JsonArray whiteList;
     private final JsonArray blackList;
 
     public ProxyHandler(final Vertx vertx, final JsonObject config) {
-        this.vertx = vertx;
+        this.vertx = (VertxInternal) vertx;
+        this.client = vertx.createNetClient(new NetClientOptions().setRegisterWriteHandler(true).setReconnectAttempts(10).setReconnectInterval(500));
         this.config = config;
         this.authentication = config.getJsonObject("application").getBoolean("authentication", true);
         this.sessions = vertx.sharedData().getLocalMap(Constants.SESSIONS);
@@ -84,7 +86,7 @@ public void handle(final RoutingContext context) {
                 logger.warn(() -> "ssh session limit of " + sessionlimit + " reached");
                 return;
             }
-            ((VertxImpl) vertx).resolveAddress(host, result -> {
+            vertx.resolveAddress(host, result -> {
                 if (result.succeeded()) {
                     final InetAddress address = result.result();
                     vertx.executeBlocking(() -> AccessHelper.isHostAllowed(accessList, whiteList, blackList, address, authSession), false)
@@ -123,7 +125,6 @@ public void handle(final RoutingContext context) {
 
     private Promise<UUID> connectTcpEndpoint(final UUID sid, final String host, final int port, final String clienthost) {
         final Promise<UUID> promise = Promise.promise();
-        final NetClient client = vertx.createNetClient(new NetClientOptions().setReconnectAttempts(10).setReconnectInterval(500));
         client.connect(port, host, asyncResult -> {
             if (asyncResult.succeeded()) {
                 logger.info(() -> "Connected to ssh server: " + host + ":" + port + " (" + clienthost + ")");