validate call hook urls (#431)

lib/routes/api/utils.js

@@ -1,4 +1,6 @@
 const { v4: uuid, validate } = require('uuid');
+const URL = require('url').URL;
+const isValidHostname = require('is-valid-hostname');
 const Account = require('../../models/account');
 const {promisePool} = require('../../db');
 const {cancelSubscription, detachPaymentMethod} = require('../../utils/stripe-utils');
@@ -464,6 +466,28 @@ function hasValue(data) {
   }
 }
 
+const isInvalidUrl = async(s) => {
+  const protocols = ['https:', 'http:', 'ws:', 'wss:'];
+  try {
+    const url = new URL(s);
+    if (s.length != s.trim().length) {
+      return 'URL contains leading/trailing whitespace';
+    }
+    else if (!isValidHostname(url.hostname)) {
+      return `URL has invalid hostname ${url.hostname}`;
+    }
+    else if (!protocols.includes(url.protocol)) {
+      return `URL has missing or invalid protocol ${url.protocol}`;
+    }
+    else {
+      return false;
+    }
+  } catch (err) {
+    return 'URL is invalid';
+  }
+};
+
+
 module.exports = {
   setupFreeTrial,
   createTestCdrs,
@@ -486,4 +510,5 @@ module.exports = {
   disableSubspace,
   validatePasswordSettings,
   hasValue,
+  isInvalidUrl
 };