NodeJS server blocked by certain wifi networks - node.js

We have a NodeJS server running on an AWS EC2 instance to serve an iOS app. The server instance is running behind NGINX. We noticed that several public wifi networks are blocking the connection to the server, and we get no response from the server. This not only happens while using the actual mobile app, but also while attempting to get a server response using other clients (postman).
So far we've came across this on a university public wifi, train station and airport. So there are potentially quite a lot of users we are “losing” by this.
We assume this is due to a local firewall blocking unknown communication.
Does anybody know what are our options in such a case?
What do other apps do? Call each university and request to be added to the trusted connections seems kinda extreme...
Thank you!!

Related

Suggestions for secure WAN/LAN/VPN please - diag included

This has taken me about a year to understand and get to, but I am the limit of my capability so reaching out to a StackOverflow guru please...
I would like to, if possible, secure my network model. The model is as shown in the diagram. To explain:-
All the aspects I have control of, is within the green shaded area. I cannot change anything outside this.
I run a simple application web server which is the VPN IPsec/L2tpd client. Static IP.
My router is ISP provided. It receives a DHCP Dynamic IP from the ISP.
My Digital Ocean Virtual Private Server has a static IP. It runs an NGINX reverse proxy that channels traffic through the VPN tunnel. It also runs the IPsec/L2tpd server.
A IPsec/L2TPD VPN tunnel is established and working.
A working VPN tunnel.
A cellphone that runs an app that communicates with my application server app. My cellphone receives a dynamic IP from my Network Operator.
I have three IP camera feeds served by my application server. Not a great speed but watchable in real-time.
I cannot change my ISP, or bandwidth/download/upload speed.
I cannot install VPN clients on the cellphone and I may want to access my app server through another cellphone provided by work so cannot install apps on it but does have unfettered web access through a browser.
Everything is now working, can't believe I've done it !
Anyway, my question is:-
Is there any way to secure the network so that only traffic from my mobile reaches - or rather is accepted - by my application server.
I accept IPsec/L2tpd is not great, but it is fast and I use this because I have tried OpenVPN, SoftEther and key based OpenSwan. These are waaaay to slow. The camera feeds are unwatchable and update one frame about every 5 seconds.
So with the limitations above, what can I do, what is possible? Please may I respectfully ask that you refrain from suggestions and concerns requiring a change to that which I cannot control, i accept all critique but that is not what I need here. I am asking for advice on how to secure , that which I can influence. Thank you
I cannot install VPN clients on the cellphone and I may want to access
my app server through another cellphone provided by work so cannot
install apps on it but does have unfettered web access through a
browser.
Due to the limitation that at the end, even a phone where you are not allowed to change anything but use the web, i suggest to configure proxy authentication on the nginx reverse proxy. I don't have experience with setting this up with nginx in particular but that's what should do the trick according to the network architecture and description you provided.
An example configuration on how to configure nginx for basic / client certificate auth can be found at: https://www.cloudsavvyit.com/1355/how-to-setup-basic-http-authentication-on-nginx/

Recently having trouble with socket.io connections via a Digitalocean load balancer (400 Error)

I have a DO Load Balancer that has 4 servers behind it, I've been using socket.io with Sticky Sessions enabled in the Load Balancer settings and it had been working just fine for a while.
Recently clients have not been able to connect at all getting a 400 error immediately on connection. I haven't changed anything in the way I connect to the sockets at all. If I do require that the transport be 'websocket' only from the client it does connect successfully, but then I lose out on the polling backup (one of the main benefits of socket.io).
Also, connecting directly to one of the droplets works as expected, so the issue definitely stands with the Load Balancer.
Does anyone have any idea as to any kind of set up that should be in place for this to work with the DO Load Balancers? Anything that might have changed recently?
I'm running socket.io on a NodeJS server with Express if that helps at all.
Edit #1: Added a screenshot of the LB Settings

beginner webrtc/nodejs issue connecting remote clients

I'm trying to develop a web application in nodejs. I'm using an npm package called "simple-peer" but i don't think this issue is related to that. I was able to use this package and get it working when integrating it with a laravel application using an apache server as the back end. I could access the host machine through it's IP:PORT on the network and connect a separate client to the host successfully with a peer-to-peer connection. However, I'm now trying to develop this specifically in node without an apache back end. I have my express server up and running on port 3000, I can access the index page from a remote client on the same network through IP:3000. But when I try to connect through webrtc, I get a "Connection failed" error. If I connect two different browser instances on the same localhost device, the connection succeeds.
For reference: i'm just using the copy/pasted code from this usage demo. I have the "simplepeer.min.js" included and referenced in the correct directory.
So my main questions are: is there a setting or some webRTC protocol that could be blocking the remote clients from connecting? What would I need to change to meet this requirement? Why would it work in a laravel/webpack app with apache and not with express?
If your remote clients can not get icecandidates, you need TURN server.
When WebRTC Peer behind NAT, firewall or using Cellular Network(like smartphone), P2P Connection will fail.
At that time, for fallback, TURN server will work as a relay server.
I recommend coTURN.
Here is an simple implementation of simple-peer with nodejs backend for multi-user video/audio chat. You can find the client code in /public/js/main.js. Github Project and the Demo.
And just like #JinhoJang said. You do need a turn server to pass the information. Here is a list of public stun/turn servers.

Use Electron-App (displaying an online Website) as a secure proxy to the local network

I've build a Web-App that is displayed in an Electron-App with Nativefier. That already works great, but now i need to send requests from the website to the local network to talk with some local devices which are (with it's ip-address) configured in the Web-App.
I had the idea to use the Electron-App as a "proxy" to the local network by using a javascript callback from the Website to the Electron-App (don't know if this is possible, just an idea), which then makes the local request because it's running on a computer in the same network.
The reason for this post is that i need ideas/tips to secure this and prevent allowing to talk to other than the desired Web-App (available under a certain domain) by developing something protective like checking or validating the Server, validating the request by sending it's hash back to the server or other methods.
So my questions are: is it generally a good idea to do something like this or is this a huge security problem and have anyone any tips to secure the communication and only allowing the communication to in the web-app configured devices in the local network?

node js send html to network rather than only localhost server

I'm using node js trying to send my web-page to my network, I successfully call localhost:port in my computer using express as server, the webpage loads fine trigger my webcam which I used to streaming in the webpage, and then im working to make a simple app in my phone to directly access my server, so my questions:
1.How do I able to access my server from different devices in the same wireless-network? by calling ip + port ?192.168.1.104:9001 ? cause i've tried and it didnt work.
2.I've found https with .pem something like that, is that the answer ? is there also any other way ?
3.maybe any advice before i work to make my web-app to devices? using koa? i don't even really know what is that, but i'm happily take any advices.
EDIT: i've read How could others, on a local network, access my NodeJS app while it's running on my machine?
let's say I simply using random router, so i can't configure my router-port, my server in my pc and my phone join in the same network, trying to access the server in my phone
1.How do I able to access my server from different devices in the same wireless-network?
All you need to do is find your server's IP address in this same wireless-network, and find the Node.js application's port. Then access the following URL in other devices:
http://{server_IP}:{port}
However, there are some points need to check:
Need to check firewall and confirm the port is not blocked, server IP is not blocked by test device, and test device IP is not blocked by server.
Need to check whether there is any Proxy setting in server and test device. If there is any, disable the proxy.
A computer may have many IP addresses at the same time, you need to find the correct one in the same wireless-network. For example, If you install a virtual machine software such as VMware and run a virtual system inside, your real computer will get IP address as 192.168.*.* -- this IP address looks like an intranet IP in wireless-network, but it is not, and can never be accessed by test device.
2.I've found https with .pem something like that, is that the answer?
No, HTTPS has nothing to do with this problem. HTTPS just add security (based on HTTP layer), it does not impact any HTTP connectivity. Actually, to minify the problem, it is better to only use HTTP in your scenario.
There is only one very special case that may bring your problem by HTTPS -- the test machine is configured and will block any non-HTTPS connection for security.
3.maybe any advice before i work to make my web-app to devices? using koa?
My suggestion is: As there is an HTTP connectivity issue, the first step is trying to find the root cause of that issue. Thus, it is better to make a simplest HTTP server using native Node.js, no Koa, no Express. In this way, the complexity of server will be reduced, which makes root cause investigation easier.
After the HTTP connectivity issue is fixed, you can pick up Koa or Express or any other mature Node.js web framework to help the web-app work.
4.let's say I simply using random router, so i can't...
Do you mean your server get dynamic IP address by DHCP? As long as the IP is not blocked by test device, it does not matter.

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