I have a mobile application that communicates with a REST based web-service. The web-service lives behind the firewall and talks to other systems. Currently this web-service requires a firewall port to be opened and a SSL cert generated for each installation. Mobile apps sends login credentials so web-services can login to custom back-end systems.
Recently a customer approached us asking how could we deploy this to 50 offices. As we don't want to say modify every firewall in every office, we're looking for options.. This is a list of possible solutions and my thoughts on each one:
Open firewall port and expose https webservice - This is our current
solution but we dont want to have to contact 50 network admins and explain why we need to do this.
VPN - Too heavy weight, complex and expensive, we only need access
to one server. Does not solve problem as firewall needs to be
modified.
Microsoft Azure Hybrid Connection Manager - This provides a managed
service where the Azure cloud will expose an end point. Azure will
also expect connections from a easy to install application that
lives behind the firewall. When a REST call is made to the cloud
end-point, the request is forward down socket that was initiated by
the software behind the firewall. This does what we want but as its
a Microsoft Solution there might impose other requirements that our
customers might not want. Currently the simple Hybrid Connection Manager is free. But for how long?
Jscape MFT Gateway - Similar to Azure but you can host their server anywhere. Not that expensive but is not opensource.
Netty - A async java library/toolkit where this type of application could easily be build. Client and server apps would need to be build and deployed. Dont know what we dont know about Netty.
MDM, AirWatch, BlackBerry BES - A MDM based solution would work expect that MDM's are centrally managed and are not often in every office where the backend services are located. Airwatch has an AppTunnle but im not sure about the specifics.
At this point the Microsoft and Jscape systems are possible solutions.
But most likely these solutions will require us to modify the mobile software to work around issues such as:
How does the user know which server to login to? A locator service
needs to be built such that, an email address is used to lookup their
office, or they need to select their office location from a list.
While the connection is SSL many company might want some additional protection since network login information will be send down the pipe.
How is load balancing and fail-over managed?
So, at this point i'm looking for more options. The best option would be a commercial product that offers some level of customization. Second, would like a well used open-source product that could be installed in Aws and customized.
Thanks
The best approach we found was to use the PUTTY API and setup a reverse proxy.
Related
It is well documented that Google Apps Script run on Google App Engine servers that would not have access to a company's internal network/server:
https://developers.google.com/apps-script/reference/url-fetch/url-fetch-app
https://cloud.google.com/appengine/kb/#static-ip
https://developers.google.com/apps-script/guides/jdbc#using_jdbcgetconnectionurl
Per the documentation, if you want a Google Apps Script project to have access to an internal network/server then you will have to white-list Google's IPs. But we all know that isn't the safest option. In fact, the documentation even says so:
Note that using static IP address filtering is not considered a safe and effective means of protection. For example, an attacker could set up a malicious App Engine app which could share the same IP address range as your application. Instead, we suggest that you take a defense in depth approach using OAuth and Certs.
The issue is I cannot find any documentation, reference material, or articles on how best an organization should do what it suggests.
So my question is, how can an organization using G-Suite Enterprise securely allow Google Apps Script projects to access the company's internal network?
The documentation made it quite clear, that since App Scripts are ran on shared App Engine instances, it is impossible to restrict with IP, and that also implies the networking capability would be very limited (i.e. no VPC peering or alike). Therefore, as in the highlighted block, they suggest implementing authentication over just IP restriction.
Apart from authentication, App Script also supports encrypting and authenticating the server with SSL (sample code). This should protect the connection from being eavesdropped when sent over the Internet.
Further more, you can implement a "semi IP restriction" mechanism, technically called Port Knocking, which briefly works as follow:
First create a special endpoint, requires authentication, accepts an IP address as input. When requested, you open up your firewall to accept connection from that IP to your internal network for a limited time (e.g. 5min).
In your App Script, use URL Fetch to request that endpoint, so that your scripts instance is temporarily allowed to access your network.
Of course that will not be perfect, since one App Engine instance runs many scripts concurrently and the whitelist is opened for a set time, but still this is considerably better than persistently opening the port to all Google (App Engine) IPs.
Apps Script is a great tool for simplifying tasks when you are using G Suite services, unfortunately, what you are trying to achieve is not available. Also, keep in mind Apps Script is not built on App Engine, it's a completely different product.
Therefore if what it is shown in the documentation can't fulfill the requirements you have, please check other Google alternatives like App Engine or Google Cloud Platform, instead of G Suite.
I have been researching for a couple days and looking at pluralsight courses but I Can't seem to find a decent answer on how to setup a proper Azure infrastructure.
I have a client app, api backend, and a database as a core of my overall application. I know I need 2 different Web App services and an SQL database.
I also have a need to only allow access to all 3 from our company's IP address.
I'm getting lost with all the VNET and VPN talk and I am wondering if that is even required. Is it considered good to do IP restrictions and call it a day? Should I add an Application Gateway infront of the client application none the less?
If VNETs are required, is it a must to do site-to-site? (don't think we have the authority to do that) If not, how do we access the backend services like the database and API if everything is locked down?
Any help is appreciated because there is too much information and I can't seem to make sense of any of it.
Thanks
It depends a lot on both the purpose of your client application, web application and database, as well as the capabilities that currently exist within your organisation. Have you had a look at the references architectures Microsoft has as a starting point ?
If you are looking at a fairly simple application, deployed to Azure with minimal internal only use, then use something like this reference architecture: https://learn.microsoft.com/en-us/azure/architecture/reference-architectures/hybrid-networking/vpn. You can actually simplify that a little further by removing the load balancers etc if you think traffic will be generally low.
If you are looking for an external application that can only be managed internally, you should adopt something similar to this reference architecture: https://learn.microsoft.com/en-us/azure/architecture/reference-architectures/n-tier/n-tier-sql-server. Maybe even add a VPN component to the management jump box similar to this architecture: https://learn.microsoft.com/en-us/azure/architecture/reference-architectures/hybrid-networking/vpn.
Even this, however may be too complicated for your use case. If your application is pretty basic, is secured using username/password or identity federation, and has low risk data associated with it, then just the basic web application architecture would do fine, just read through the various considerations here: https://learn.microsoft.com/en-us/azure/architecture/reference-architectures/app-service-web-app/basic-web-app
I'm building a service that allows to enter activation keys in a desktop application, which will then call a web service to check the key and return a license. This call does not require authorization.
The web application is running as Azure "App Service". I'm afraid someone will be trying to "guess" activation keys and slow down my service. (I'm not afraid they will be able to correctly guess, they are long enough).
Do Azure WebApps have some kind of automatic rate-limiting or DOS-protection, or do I need to configure/code this myself?
If I have to do it myself, can you point me into the right direction?
As far as I know, we could use Dynamic IP Restrictions in web app.
The Dynamic IP Restrictions Extension for IIS provides IT Professionals and Hosters a configurable module that helps mitigate or block Denial of Service Attacks or cracking of passwords through Brute-force by temporarily blocking Internet Protocol (IP) addresses of HTTP clients who follow a pattern that could be conducive to one of such attacks. This module can be configured such that the analysis and blocking could be done at the Web Server or the Web Site level.
About how to config this feature. We could remote connect to the azure web app IIS and set it.
About how to remote connect web app IIS, you could refer to this article.
More details, you could also refer to this blog.
Does azure not have a native transactional email service which we can make use of? Currently all aspects of my platform are hosted within azure. Just feels silly going off to a 3rd party for such a simple task.
The problem with the email software in the cloud that it there can be the sitation when the Azure security perimeter will block the traffic or mark it as a spam or many other situations. Especially when you do not have the dedicated IP address (in Azure, btw, you can).
I know about three options - i tested first two, and it works:
1) SendGrid partner offering has 25 000 free emails/month. Tutorial. Simplest way.
2) Less simple is to use external SMTP provider and something like System.Net.Mail. It works, but again, should be tested. It is not guaranteed that your server will not be blocked.
3) Set up the mail server and set up the reverse DNS.
I heard that some folks set up the IIS SMTP service. Did not do it by myself, but i expect that it will involve some extra infrastructure efforts.
I would highly recommend you to not place SMTP server inside of the cloud, but instead of that use some external one. But it can be set up and should work.
We integrate with a third-party service where we can run queries which is right now secured using HTTPS encryption and username/password. We send our queries from a service running on the Windows Azure cloud.
The third-party provider wants to migrate towards better security and they have asked us to either
Setup a VPN - which is problematic because for we'd need to use Azure Connect and they'd have to install the client endpoint service on their part.
Provide some IP address where the queries will come from so they can filter out anyone else at the firewall level - which is problematic because AFAIK you cannot fix the IP addresses of the Windows Azure Compute nodes.
Suggest another secure alternative - the only thing I could think of is to set up the VPN with them on a non-Azure server and then tunnel the requests through using Azure Connect - which is obviously extra work for us and also defeats the point of hosting the service on a cloud if it depends on a non-cloud service.
Any ideas?
Can they install the Azure Connect endpoint on another server on their DMZ network? i.e. not the actual server which hosts their service?
Can we somehow provide them with static IPs for incoming queries?
Any other solution that is scalable?
Thanks
If I understand the scenario correctly, your Azure service is a client to a 3rd party service. This scenario may be solved through the use of the Windows Azure AppFabric Service Bus. You would need to install a proxy app in the 3rd party's datacenter that would be responsible for establishing the connection to the service bus. The connection comes from inside the 3rd party's datacenter, so no new incoming holes in the firewall. The connection can handle WCF connections with all its security strengths, and users can be authenticated with ACS.
Here is a starting point: http://msdn.microsoft.com/en-us/library/ee732537.aspx
There is a hands on lab in the Windows Azure Platform Training Kit that explains most of the details that you'll need.
IMHO, HTTPS is already very good; and I don't exactly see how a VPN would make the system any more secure. In particular, VPN is no silver bullet, if your VM is compromised then the VPN connection is compromised too (same for HTTPS). On the other hand, the IP restriction would indeed reduce the attack surface.
Then, using a server outside the cloud is a poor idea indeed. Not only it defeats most of the benefits of the cloud (been there, done that and suffered a lot), but also it also makes the whole thing less secure with more complexity and more attack surface.
Windows Azure does not provide anything that look like a static IP at this point. In our experience, IP addresses for a given service change once in a while even if the service is only upgraded (and never deleted). Static IP addresses have been an important feature request for a long time, Microsoft will probably provide it at some point, but it might still take many months.