Now an application is connected to a database server in the same LAN and performs selects and inserts.
The database will be moved to a remote location accessible throughout internet. Performance degradation will be addressed reducing the number of operations to the db. It is not possible to use vpn or configure access-in rules based on client IP on the firewall of the net where the database server will be moved. So it seems to me it is necessary to create a database front end in order to protect it. I suppose one way to achieve this goal is to create a web service.
Are there easier alternatives?
I'm new to web services: it should run into Glassfish server while the client would be a c# application.
I read a bit about securing a web service but I'm a confused.
One method I found in internet is to use Glassfish built-in authentication mechanism and configure web.xml limiting the access to the web service URL to a group of users.
It seems an easy approach, are there any drawbacks?
Is it easy to use this type of authentication in the C# client?
Other existing web services wants a parameter key in the request. Then this key is compared with valid ones and if the check is successful the request will be accepted.
Is this approach more secure than the previous one?
Another alternative is to use WSIT but at a first glance it seems over-complicated and all the security mechanisms need a server certificate.
Anyway it looks more secure; does it fit well with JAX-RS and restful web services?
You can use L2TP or PPTP VPN in this case.
Let me show you first Network topology.
Client (accessing firewall with L2TP or PPTP )-----> Firewall (L2TP or PPTP VPN Server)---> Firewall LAN where your Server placed.
In above case all Client come from VPN so its secure and On firewall you have to Configure VPN to LAN rule with client base rule.
Related
Is there a way to securely access a on-prem Sql Server, from an AppService?
The IT guys are nervious about letting an App Service which needs access to our on-premise database.
I am not a networking guy, and am trying to come up with a solution.
The only thing I have thought of is creating a new database (CDS_API). The AppService is then given a connection string to this database. This database would then have access to the primary database (CDS).
If the AppService has only execute permissions to CDS_API, this seems secure to me. Am I missing something?
Is there a better way to do this?
The simple solution is to use an App Service Hybrid Connection
Hybrid Connections can be used to access application resources in any
network that can make outbound calls to Azure over port 443. Hybrid
Connections provides access from your app to a TCP endpoint and does
not enable a new way to access your app. As used in App Service, each
Hybrid Connection correlates to a single TCP host and port
combination. This enables your apps to access resources on any OS,
provided it is a TCP endpoint. The Hybrid Connections feature does not
know or care what the application protocol is, or what you are
accessing. It simply provides network access.
Alternatively, you can Integrate your app with an Azure virtual network which is connected securely to your on-prem networks either with a Site-to-Site VPN or over ExpressRoute.
I am creating simple application where I need get and fetch data to DB. As I find out from Xamarin app is standard using of HTTP request to DB instead of directly connect to DB.
I create Azure SQL DB, I create application with connection to this DB. But I cant really find out how it now should works.
There is no many tutorials or they are not fully described.
I read this one https://learn.microsoft.com/en-us/azure/app-service-mobile/app-service-mobile-xamarin-forms-get-started#download-and-run-the-xamarinforms-solution
I find many references on this one but it seems out of date. Everybody recommended download the project from section
Run the Xamarin.Forms solution
On the settings blade for your Mobile App, click Quickstart (under Deployment) > Xamarin.Forms. Under step 3, click Create a new app if it's not already selected. Next click the Download button.
Under this tab I have only references to next tutorials but not any to Project Download. (screenshot below)
https://imgur.com/THCdUE1
Can you give me some advice if I do something wrong? Or link to updated tutorials? I am little desperate from this
Many Thanks
Azure SQL is not an HTTP/s service-- it runs proprietary SQL Server protocol on port 1433, just like on-premise versions of SQL Server.
If you are trying to connect directly to SQL Server from a Xamarin App, you are almost certainly making a mistake. Doing so would require providing credentials to your Xamarin app that can connect directly to your database, which opens your database up for a malicious user to do pretty much whatever they want to. The reason this kind of 2-tier application is dangerous is because the Xamarin app runs on an untrusted device (your user's mobile device), and a malicious user can intercept any data that your application has in memory, including your database credentials. They can then use those credentials to gain access to your database. Unless you were to use unique database credentials for each user (very impractical) and setup very stringent security roles in SQL Server, it'd be impossible to keep a malicious user from accessing the database for all of your other users (which is very, very bad). The other problem is that many networks block traffic on port 1433, or only allow access via an HTTPS proxy server, so your application would not function on many networks if it tried to connect directly to SQL.
This is the answer to your question, but please don't do this:
If you are certain that you have taken care of the security correctly, you should be able to install the System.Data.SqlClient nuget package and use that to communicate with SQL Server as you would with any .NET application. Here's a code example from Microsoft.
This is my opinion on what you should do instead:
The correct way for most Xamarin applications to communicate with Azure SQL database would be via an intermediary application server.
If your application access data specific to a user, should have per-user credentials in it (username and password that get exchanged for an authorization token when the user logs in is a common technique). The Xamarin app would then use HTTPS to make requests to your application server using those user credentials. The application server would validate the user credentials (authenticate that they are legitimate and authorize the data being requested based on who the user is) and make requests to Azure SQL.
If your application only access public data anonymously, then you can make unauthenticated requests to your application server which will blindly request that data from Azure SQL and return it to your client (though it would also return the same data to any attacker on the internet, so be sure if you use this approach you intend all data served to be public to the world).
In both cases, your application server would be the only piece that communicates with Azure SQL. For a .NET application this would typically be done via System.Data.SqlClient or perhaps indirectly through an ORM like Entity Framreworks. The advantage to this 3-tier approach is that the untrusted client tier does not have unrestricted access to your database tier. Only the middle application server tier has the credentials for SQL Server, and it is trusted and runs in a secure environment (a server you manage, not an end-user's mobile device). This means that an attacker cannot intercept the database credentials and misuse them. It also means that your application only requires HTTPS data access to function, so your application will work on almost any network.
This is probably not the answer you are looking for, since it involves authoring an entire application server that has to be hosted by you (Azure App Service would be my recommendation, if you are already using Azure SQL). It also requires you to implement an API on the server, and then write an API client for your Xamarin application. This is no small amount of work.
Is there way to make the vb6 desktop application which is not on client network to communicate with sql server which is in the client premises?
A far better option (a necessity if the app is for general distribution) is to use an intermediary service, either over web/HTTP or some other (possibly custom) protocol.
If you app is specific to your company/employer for their internal use, then you will need to use a VPN or similar to allow it to work as if it was on the same internal network.
Note that opening up a database server to the wider internet is asking for trouble and should be avoided at all costs.
Easiest would be to use port forwarding on border router to SQL server.
Better would be to encrypt traffic to/from SQL Server like this: IPSec through NAT: Securing SQL Server remote connections
I am trying to secure online transaction between application server and database. One-way is SSL, but is there any other way of securing transaction between them. I am trying to reduce the overhead in securing the line. Are there any tool or api's which I can integrate with the application server or deploy on it.
/SR
Sure, but it requires a thoughtful review of your architecture. If you have a dedicated line between your application and your database, the connection could be encrypted at the network layer.
I'm a bit surprised that your application server and your database are not within the same trust boundary. Is this an app in the cloud?
SSL is by far the best way, its extremely secure and absolutely free. If your database or another application doesn't support SSL then you can use a free SSL VPN such as OpenVPN. This will create a secure transport layer connection between 2 machines.
If you are connecting to a database on the local machine then there is no point in a secure transport layer connection. However you should firewall off the database port, for instance MySQL uses tcp 3306.
I need to transfer data daily from SQL Server (2008) to SQL Server (2005). One of the servers is located at our web host so the data will be transferred over the Internet. On the same network I would use SSIS to transfer the data, but over the Internet this is not a secure option. Is there a secure way of achieving this?
You can use SSL with SQL Server (2000/2005 Instructions / 2008 Instructions) and then force protocol encryption on the connection between both machines. You don't have to use a purchased SSL certificate either, you can use Windows Server Certificate Services to generate one - however if you do so then the CRL must be on a machine that both servers can connect to. An easy way to do this is install Certificate Services on a stand alone machine, perhaps just a VM and the configure it to embed a public DNS name for it's CRL. This doesn't have to be a machine running Certificate Services, just something you own and can upload to. Then you can generate the certificates and publish the CRL and tada, all done.
You will need to ensure the service account SQL is running as has access to the private key of the certificate it is using.
Generally it isn't recommended to have your SQL Servers exposed to the Internet, although that may be out of your control in this case. In your position I would investigate developing some separate Web Services that would perform the transfer of the data. These can then be secured using a variety of methods, such as SSL and WS-Security and other custom user permissions. If that isn't possible then blowdart's answer seems like the way to go.
You can use Service Broker:
Built into SLQ Server engine itself, no need for external process to drive communication.
Compatible protocol SQL 2005 and SQL 2008 communicate over Service Broker out-of-the box.
No need to expose either server to the internet. Through Message Forwarding you can expose
just a SQL Express, with no data on it, to the internet to act as a gateway that lets messages into the back end target.
Communication is encrypted.
Speed, the sample in the link shows how you can exchange over 5000 1k payload messages per second between commodity machines.
Unlike SSIS or replication Service Broker is a general communication framework so it won't provide support to extract the changes and to apply the changes, with conflict resolution and the like. You would have to code that part yourself.