Feature/retrieve registered users (#243)

* add GET /Accounts/:sid/RegisteredSipUsers

* fix vulnerabilities

lib/routes/api/accounts.js

@@ -145,6 +145,21 @@ router.post('/:sid/VoipCarriers', async(req, res) => {
     sysError(logger, res, err);
   }
 });
+router.get('/:sid/RegisteredSipUsers', async(req, res) => {
+  const {logger, registrar} = req.app.locals;
+  try {
+    const account_sid = parseAccountSid(req);
+    await validateRequest(req, account_sid);
+    const result = await Account.retrieve(account_sid);
+    if (!result || result.length === 0) {
+      throw new DbErrorBadRequest(`account not found for sid ${account_sid}`);
+    }
+    const users = await registrar.getRegisteredUsersForRealm(result[0].sip_realm);
+    res.status(200).json(users.map((u) => `${u}@${result[0].sip_realm}`));
+  } catch (err) {
+    sysError(logger, res, err);
+  }
+});
 
 function coerceNumbers(callInfo) {
   if (Array.isArray(callInfo)) {