I have deployed an opnesource public webservice (elasticsearch) on my Ubuntu.
Problem is - no security at all (only if you pay).
I've researched a bit about blocking port only to internal requests while allowing external access only through authentication proxy.
The simplest way was nginx with basic authentication.
But what's the best practice in those cases? What are my other options?
This is question would find a better home on ServerFault, but you're likely going to find that you'll want to use iptables to block all external IPs on all ports, except for the 'authentication proxy'
Related
so I have 0% experience with web programming, and the project I am working on doesn't have anything to do with it, but I hit a small roadblock and need to solve a small port problem.
So we want to build a cluster of GPU machines on Azure for some Deep Learning calculations, and want to install some applications on them and let our scientists use the app' GUIs to launch and monitor their jobs. The problem is that an app A for example runs on port 5050, but our firewall doesn't let us communicate to unusual ports. The problem is easy to fix from the Azure side, but our IT team won't let us modify our security policies.
That's why I need to find a hacky and fast solution to overcome this, I don't want to spend my whole internship doing something complicated for it, just something that does the job.
What I thought about was to have some kind of server running on the machines (let's say Machine A has public IP address ipbA and private IP ipvA) that when we type "http://ipba/app1" on our browser, the server on A will fetch the page "http://ipva:5050" (or "----://ipba/app2" -> "----://ipva:5051") and display it, but does this work if the page needs to be interactive because we would like to launch jobs?
I have no clue how to do this, if you could please just tell me what I should look into, google and read about, or if there is an easier way to handle it, (maybe some VPN stuff, which I don't prefer since we're moving towards a hybrid cloud architecture and I don't think we would want to VPN into all the different cloud platforms) that would be awesome :)
Two common solutions for your problem:
Set-up a reverse proxy on a standard port (such as 80 or 443 if you want some SSL certificates headaches).
All your domain names will point to the reverse proxy (single IP) but the reverse proxy will forward the traffic transparently to the real servers on their special ports.
https://httpd.apache.org/docs/2.4/howto/reverse_proxy.html
https://www.digitalocean.com/community/tutorials/how-to-use-apache-http-server-as-reverse-proxy-using-mod_proxy-extension
For the technical details, in short: you keep in file(s) the configuration for each domain or subdomain and where they should be forwarded.
Chain of events:
User types http://interface-1.company.com
Browser resolves interface-1.company.com (DNS: IP Reverse Proxy)
Browser connects on reverse proxy (port 80)
Reverse proxy reads configuration which says where to forward
Proxy forwards request to realserver.company.com:5050
Realserver relays response to reverse proxy
reverse proxy relays response to browser
I think that is what you are trying to achieve.
Set-up a VPN service which will be connectible through the proxy of your company and provide VPN clients to the end-users. OpenVPN clients can use an HTTPS proxy connection (your company proxy) to establish connexion to a remote VPN.
Once connected on the VPN, everyone uses the VPN's IP address + firewall policy, and are therefore no more restricted by the company's firewalling policy. Any kind of traffic can also be forwarded. This is harder to set up and your security team might not accept it. However, it's a fully functional solution and it can also offer additional security features if implemented properly.
I do not recommend going this way for all the paperwork that would involve.
I have a front end web server running over HTTPS - this is public facing - i.e. port is open.
I also have a backend API server that my webserver makes API requests to - this is public facing and requires authentication - port is open.
These 2 servers run over HTTPS.
Behind the API server, there are lots of other servers. The API server reverse proxies to these servers. Ports for these other servers are not open to incoming traffic. They can only be talked to via the API server.
My Question ... Do the "lots of other servers" need to run over HTTPS or, given that they cannot be accessed externally, can they run over HTTP safely instead?
I thought this would be a common question but I could not find an answer to it. Thanks. If this is a dupe please point me to the right answer.
TL;DR you should encrypt the traffic unless it's on the same host.
You can't trust your network. Malwares in your own network can intercept/modify http requests.
It's not theoretical attacks, but real life example:
Routers (probably hacked) inside the network of some websites injecting ads: https://www.blackhat.com/docs/us-16/materials/us-16-Nakibly-TCP-Injection-Attacks-in-the-Wild-A-Large-Scale-Study-wp.pdf
Indian network sniffing between cloudfare and back-end: https://medium.com/#karthikb351/airtel-is-sniffing-and-censoring-cloudflares-traffic-in-india-and-they-don-t-even-know-it-90935f7f6d98#.hymc3785e
The now famous "SSl Added and removed here :-)" from the NSA
The question is how much do you trust the connection between the public IP and the backend server?
If it is not your data center, at least any privileged employee of the ISP could see/change the data. I guess that's not something your customers would like to hear.
If it is your data center, meaning you are a kind of ISP still everybody who has physical access to the data center can potentially sniff the clear text traffic. Or in general, anybody who has access to the wire can see the traffic, it is much harder to implement a strict access control in your company.
I have a windows server 2012 VPS running a web app behind Cloudflare. The app needs to initiate outbound connections based on user actions (eg upload image from URL). The problem is that this 'leaks' my server's IP address and increases risk of DDOS attacks.
So I would like to prevent my server's IP from being discovered by setting up a forward proxy. So far my research has shown that this is no simple task, and would involve setting up another VPS to act as a proxy.
Does this extra forward proxy VPS have to be running windows ? Are their any paid services that could act as a forward proxy for my server (like cloudflare's reverse proxy system)?
Also, it seems that the suggested IIS forward proxy plugin, Application Request Routing, does not work for HTTPS.
Is there a solution for both types of outgoing (HTTPS + HTTP) requests?
I'm really lost here, so any help or suggestions would be appreciated.
You are correct in needing a "Forward Proxy". A good analogy for this is the proxy settings your browser has for outbound requests. In your case, the web application behaves like a desktop browser and can be configured to make the resource request through a proxy.
Often you can control this for individual requests at the application layer. An example of doing so with C#: C# Connecting Through Proxy
As far as the actual proxy server: No, it does not need to run Windows or IIS. Yes, you can use a proxy service. The vast majority of proxy services are targeted towards consumers and are used for personal privacy or to get around network restrictions. As such, I have no direct recommendations.
Cloudflare actually has recommendations regarding this: https://blog.cloudflare.com/ddos-prevention-protecting-the-origin/.
Features like "upload from URL" that allow the user to upload a photo from a given URL should be configured so that the server doing the download is not the website origin server.
This may be a more comfortable risk mitigator, as it wouldn't depend on a third party proxy service. A request for upload could be handled as a web service call to a dedicated "file downloader" server. Keep in mind that if you have a queued process for another server to do the work, and that server is hosted in the same infrastructure, both might be impacted by a DDoS, depending on the type of DDoS.
Your question implies that you may be comfortable using a non-windows server. Many softwares exist that can operate as a proxy(most web servers), but suffer from the same problem as ARR - lack of support for the HTTP "CONNECT" verb, which is used by modern browsers to start an HTTPS connection before issuing a "GET". SQUID is very popular, open source, and supports everything to connect to.. anything. It's not trivial to set up. Apache also has support for this in "mod_proxy_connect", but I have no experience in that and the online documentation isn't very robust. It's Apache, though, so it may be worth the extra investigation.
First a bit of background here. This question is for a server not exposed to the wilds of the internet, a private network with no outside networking. Its for QA testing of a product and needs to be tested, so security is a joke. On with the question:
Is it possible to configure Squid3/Samba to only accept NTLMv1 authentication?
I've already built a Squid3/Samba for NTLMv2. But I'm lost on how to configure Squid3/Samba to accept only NTLMv1.
Current Squid conf:
auth_param ntlm program /usr/bin/ntlm_auth --diagnostics --helper-protocol=squid-2.5-ntlmssp
auth_param ntlm children 25
auth_param ntlm keep_alive on
acl ntlm proxy_auth REQUIRED
It's been a while for this. So I'll post my answer. I had to do a strange filter to the system to deny NTLMv2 requests using a Bluecoat/Packeteer hardware. Not much of an answer, but it will close this.
I have a node application sitting behind a corporate proxy -- McAfee Web Gateway in direct proxy mode (not transparent). I have access to a username/password and domain for authentication but not sure how to use them for this.
For other proxies that use NTLM, I can generally use cntlm and it works well but does not work well in this case. I am also successful when behind an http proxy that just uses "basic" authentication. However, I have never run into this kind of beast before and was wondering where to start.
Thanks!