From 53024dfdab2f621ad707cec29302a207c1f700e1 Mon Sep 17 00:00:00 2001
From: Dorian Niemiec <dorian.niemiec@svrjs.org>
Date: Fri, 23 Aug 2024 22:13:58 +0200
Subject: [PATCH] Added redirects middleware.

---
 src/index.js                |  3 ++-
 src/middleware/redirects.js | 52 +++++++++++++++++++++++++++++++++++++
 2 files changed, 54 insertions(+), 1 deletion(-)
 create mode 100644 src/middleware/redirects.js

diff --git a/src/index.js b/src/index.js
index b7c8ae0..91b14a8 100644
--- a/src/index.js
+++ b/src/index.js
@@ -101,7 +101,8 @@ const serverconsole = serverconsoleConstructor(configJSON.enableLogging);
 
 let middleware = [
   require("./middleware/core.js"),
-  require("./middleware/urlSanitizer.js")
+  require("./middleware/urlSanitizer.js"),
+  require("./middleware/redirects.js")
 ];
 
 function addMiddleware(mw) {
diff --git a/src/middleware/redirects.js b/src/middleware/redirects.js
new file mode 100644
index 0000000..9bc6e48
--- /dev/null
+++ b/src/middleware/redirects.js
@@ -0,0 +1,52 @@
+module.exports = (req, res, logFacilities, config, next) => {
+  // Estimate fromMain from SVR.JS 3.x
+  let fromMain = !(config.secure && !req.socket.encrypted);
+
+  // Handle redirects to HTTPS
+  if (config.secure && !fromMain && !config.disableNonEncryptedServer && !config.disableToHTTPSRedirect) {
+    var hostx = req.headers.host;
+    if (hostx === undefined) {
+      serverconsole.errmessage("Host header is missing.");
+      callServerError(400);
+      return;
+    }
+
+    if (req.isProxy) {
+      callServerError(501);
+      serverconsole.errmessage("This server will never be a proxy.");
+      return;
+    }
+
+    var isPublicServer = !(req.socket.realRemoteAddress ? req.socket.realRemoteAddress : req.socket.remoteAddress).match(/^(?:localhost$|::1$|f[c-d][0-9a-f]{2}:|(?:::ffff:)?(?:(?:127|10)\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}|192\.168\.[0-9]{1,3}\.[0-9]{1,3}|172\.(?:1[6-9]|2[0-9]|3[0-1])\.[0-9]{1,3}\.[0-9]{1,3})$)/i);
+
+    var destinationPort = 0;
+
+    var parsedHostx = hostx.match(/(\[[^\]]*\]|[^:]*)(?::([0-9]+))?/);
+    var hostname = parsedHostx[1];
+    var hostPort = parsedHostx[2] ? parseInt(parsedHostx[2]) : 80;
+    if (isNaN(hostPort)) hostPort = 80;
+
+    if (hostPort == config.port || (config.port == config.pubport && !isPublicServer)) {
+      destinationPort = config.sport;
+    } else {
+      destinationPort = config.spubport;
+    }
+
+    redirect("https://" + hostname + (destinationPort == 443 ? "" : (":" + destinationPort)) + req.url);
+    return;
+  }
+
+  // Handle redirects to addresses with "www." prefix
+  if (config.wwwredirect) {
+    let hostname = req.headers.host.split(":");
+    let hostport = null;
+    if (hostname.length > 1 && (hostname[0] != "[" || hostname[hostname.length - 1] != "]")) hostport = hostname.pop();
+    hostname = hostname.join(":");
+    if (hostname == domain && hostname.indexOf("www.") != 0) {
+      res.redirect((req.socket.encrypted ? "https" : "http") + "://www." + hostname + (hostport ? ":" + hostport : "") + req.url.replace(/\/+/g, "/"));
+      return;
+    }
+  }
+
+  next();
+}
\ No newline at end of file