diff --git a/index.js b/index.js
index 7da7291..7ff95e5 100644
--- a/index.js
+++ b/index.js
@@ -481,5 +481,34 @@ Greenlock.create = function (gl) {
     gl.middleware = gl.middleware.create(gl);
   }
 
+  //var SERVERNAME_RE = /^[a-z0-9\.\-_]+$/;
+  var SERVERNAME_G = /[^a-z0-9\.\-_]/;
+  gl.middleware.sanitizeHost = function (req, res, next) {
+    // Get the host:port combo, if it exists
+    var host = (req.headers.host||'').split(':');
+
+    // if not, move along
+    if (!host[0]) { next(req, res); return; }
+
+    // if so, remove non-allowed characters
+    var safehost = host[0].replace(SERVERNAME_G, '');
+
+    // if there were unallowed characters, complain
+    if (!gl.__sni_allow_dangerous_name && safehost.length !== host[0].length) {
+      res.statusCode = 400;
+      res.end("Malformed HTTP Header: 'Host: " + host[0] + "'");
+      return;
+    }
+
+    // make lowercase
+    if (!gl.__sni_preserve_case) {
+      host[0] = host[0].toLowerCase();
+      req.headers.host = host.join(':');
+    }
+
+    // carry on
+    next(req, res);
+  };
+
   return gl;
 };
diff --git a/package.json b/package.json
index dc557dc..5d948e6 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "greenlock",
-  "version": "2.3.9",
+  "version": "2.3.10",
   "description": "Let's Encrypt for node.js on npm",
   "main": "index.js",
   "files": [
@@ -18,25 +18,12 @@
     "letsencrypt",
     "ACME",
     "v2",
-    "v02",
-    "draft-11",
-    "draft-12",
     "auto-sni",
-    "draft",
-    "11",
-    "12",
     "Free SSL",
     "Automated HTTPS",
     "tls",
     "https",
-    "Greenlock",
-    "letsencrypt.org",
-    "le",
-    "le.js",
-    "node",
-    "nodejs",
-    "node.js",
-    "client"
+    "Greenlock"
   ],
   "author": "AJ ONeal <coolaj86@gmail.com> (https://coolaj86.com/)",
   "license": "(MIT OR Apache-2.0)",
@@ -55,13 +42,10 @@
   "dependencies": {
     "acme": "^1.0.6",
     "acme-v2": "^1.2.0",
-    "asn1js": "^1.2.12",
-    "certpem": "^1.0.0",
+    "certpem": "^1.1.0",
     "le-challenge-fs": "^2.0.2",
     "le-sni-auto": "^2.1.3",
     "le-store-certbot": "^2.1.7",
-    "node.extend": "^1.1.5",
-    "pkijs": "^1.3.27",
     "rsa-compat": "^1.5.0"
   },
   "engines": {