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Is there a ways to check inside a browser (e.g. javascript) if the user is running inside a Remote Desktop session?
If the user is running their browser inside a Remote Desktop (i.e. Terminal Services), i want to disable animations on the web-site.
If this were a native application, as opposed to a web-site, i could perform this checking using:
//Native code
isRemoteSession = GetSystemMetrics( SM_REMOTESESSION );
or
//Managed Code:
isRemoteSession = System.Windows.Forms.SystemInformation.TerminalServerSession;
Is there a similar check that can be done inside the browser?
Note: Assume for the purposes of this discussion that the browser we're talking about is Internet Explorer 8.
Update One: Perhaps something in How can you get the terminal service client machine name from javascript?
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However, RDP was not initially designed with the security and privacy features needed to use it securely over the internet. RDP communicates over the widely known port 3389 making it very easy to discover by criminal threat actors.
First option — use command line to query user /server:SERVERNAME (or quser.exe - same thing). This shows User name, Session name, Session Id, Session state, Idle Time and Logon Time for all logged in users. Second option — use command line to query session /server:SERVERNAME .
No. There is no way to tell who is using the browser on the client-side.
With TeamViewer, you can run these programs on your laptop by using remote desktop for Google Chrome OS to connect to a Windows device. If TeamViewer is installed on both your Chromebook and the remote device you want to access, you can establish a connection between them with just a few clicks.
My solution is to use CSS @media queries for minimum and maximum values of the color media feature. Based on experiment, RDP only seems to have 5 bits per color, rather than the full 8 bits per color of your typical desktop.
This solution is, of course, not perfect, because you'll get lots of false positives from people who aren't on RDP, but just happen to have low color-depth displays. However:
Here is an example that works for me in recent version of Firefox and Chrome. See the screenshot below.
<!DOCTYPE html>
<html>
<head>
<title>Test RDP detection</title>
<style type="text/css">
@media all { li.color { display: none; } }
@media all and (min-color: 1) { li.color.color-depth-1 { display: block; } }
@media all and (min-color: 2) { li.color.color-depth-2 { display: block; } }
@media all and (min-color: 3) { li.color.color-depth-3 { display: block; } }
@media all and (min-color: 4) { li.color.color-depth-4 { display: block; } }
@media all and (min-color: 5) { li.color.color-depth-5 { display: block; } }
@media all and (min-color: 6) { li.color.color-depth-6 { display: block; } }
@media all and (min-color: 7) { li.color.color-depth-7 { display: block; } }
@media all and (min-color: 8) { li.color.color-depth-8 { display: block; } }
/* 5 bits per color seems to be the max for RDP */
@media all and (max-color: 5) {
.not-rdp { display: none; }
}
@media all and (min-color: 6) {
.rdp-only { display: none; }
}
</style>
</head>
<body>
<p>This page uses CSS <tt>@media</tt> queries to detect whether you
are viewing it over RDP—heuristically, by looking at the
color depth of your display.</p>
<ul>
<li class="color color-depth-1">Your display is not monochrome!</li>
<li class="color color-depth-2">Your display has at least 2 bits per color.</li>
<li class="color color-depth-3">Your display has at least 3 bits per color.</li>
<li class="color color-depth-4">Your display has at least 4 bits per color.</li>
<li class="color color-depth-5">Your display has at least 5 bits per color.</li>
<li class="color color-depth-6">Your display has at least 6 bits per color.</li>
<li class="color color-depth-7">Your display has at least 7 bits per color.</li>
<li class="color color-depth-8">Your display has at least 8 bits per color.</li>
</ul>
<p>You are <span class="not-rdp">not</span> using RDP.</p>
<p class="rdp-only">This is only visible over RDP.</p>
</body>
</html>
Yet another approach along these lines is to use javascript to examine the value of the screen.colorDepth variable.
64
You can use the following media query:
@media screen and (prefers-reduced-motion: reduce) { . . . }
This condition can also hold for non-RDP sessions, but as your intention is to disable all animations, this type of query is probably exactly what you're looking for.
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You can probably expose the detection code via an ActiveX or BHO (e.g. assign a property to the window object in BHO) if you use IE.
Otherwise if you are using an ActiveX player to play animation, check the player's documentation to see if it automatically adjust frame rate under remote desktop.
You can always offer a low bandwidth version of your web site and instruct the user choose the web site instead of the regular web site if the video playback is not satisfactory.
For tips in writing a terminal service-aware graphics app, check graphic effects consideration, and the general performance guidelines
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