Options to communicate to a C# desktop app from a linux server?

The desktop application is being developed with开发者_开发问答 a demo version that is supposed to run for a few minutes and after that would request the user to restart the application to run again (the user has to input their login and password to access it), since I dont know much in this field the way I can think of doing this without the user bypassing it would be having a realtime communication between both or something of the sorts.

After X minutes the server sends a message to the client to close/disable the client requiring the user to restart it, it also limits the daily usage on the demo for the same user.

As I am very inexperienced in this type or communication I would like to consult you guys with what options I have here ?

The desktop application is developed in c# to run mainly on windows OS as for the server we only have linux available and as to what sort of service, if it is possible to make a webapi or session in php or perl to work with it that would be reliable enough would be nice but if that is not possible we are open to hear other options.

PS: If I have'nt given enough information or am missing anything important here please drop me a comment i will update as soon as possible.

I'd give a go to HTTPS with mutual certificate-based authentication as the safest option. The desktop app can poll the server (=ask periodically) and quit in case of no response / no connection / negative reponse.

However, based on the type of app you are developing and the target audience, you can expect an important amount of users to have connectivity problems or have no connectivity at all.

Because of this, at the end of the day, you can come up with a lot simpler solution, like measuring run-time locally without any server involved, and gain pretty much the same effect.

I don't think you need to involve a server to do this.

Just have the desktop application save the date and time when it started. Periodically on a timer you can check the current time, and see if too much time has elapsed for the demo version, and tell the user they have to quit.

It is very unlikely many users will try to get around this. They are more likely to dump your trial software in favour of something that treats them decently!

Checking DateTime.Now could work as Ben stated, but you'd be better off with System.Timers.Timer. Set interval to be your desired interval between auth calls in milliseconds. Attach a handler to the elapsed event that asks for auth info. System.Timers.Timer works in a separate thread so you can take advantage of some parallelism here. Changing the system time shouldn't have any effect on System.Timers.Timer but I am not positive on that point.