Fiddling with windows 10 telemetry & spying

[David]

While playing around with windows 10 and looking for ways to ensure it will Shut the F*** up and break up with M$ I noticed that the various privacy violating services seam to respect the proxy configuration in the internet options.

So I installed fiddler on my test VM and enabled SSL decryption.

For some requests like windows update that seamed to work just fine,

but for the interesting telemetry once, it fails with error 408, for example requests to watson.telemetry.microsoft.com

The textView window says "The request body did not contain the specified number of bytes. Got 0, expected 1.359"

So I think its a bug with fiddler (or the lack of support for some protocol version) rather than M$ cooking up their own super secret SSL replacement.

 

So it would be great if the makers of fiddler could fiddle around a bit with this issue and solve it please :)

[Lajos]

Hi David, did you receive a reply to this question?

[David]

no unfortunately not, but from what I managed to find out it seams the Telemetry component uses certificat pinning, so that's one issue, but I don't know if its the only one.

[Lajos]

Thanks David!

[Wayne]

This is still happening. Was there every a workaround posted somewhere or setting to keep this from happening and noising up the fiddler trace?

[Nick Iliev]

Hi Wayne,

Could you let us know what exactly is the issue that is still happening?

David talked about that some requests made from Microsoft telemetry services are not successful through Fiddler. As pointed, that is most likely because the service is handling sensitive information, which is likely why Microsoft is using certificate pinning. Unless you have the certificate generated by the server, then there are not practical solutions for going around the certificate pinning - its sole purpose is to prevent man-in-the-middle proxy, which is precisely what Fiddler is doing.

Regards,
Nick Iliev
Progress Telerik

[Wayne]

Same error as originally reported: 408 - "The request body did not contain the specified number of bytes. Got 0, expected..."

The last comment mentioned certificate pinning, whatever that is, but wasn't clear that that was the cause of the error, or if anything could be done about it. I take it from your response now that this is the case. 

Are you as to detect certificate pinning? If so, it would make more sense to at least give us a setting to ignore or at least not treat these like an error and use a dimmer, less alerting color. T he big red error rows are noisy and distract from looking at the rest of the information. 

Or, have an option to bypass the proxy when certificate pinning is being used. That's actually what I ended up doing, putting the telemetry url in the bypass list. Does the trick. I figured that out after I had posted. 

Thanks

Wayne