I found the solution. Unfortunately it is much harder than I anticipated.
In fact you have to hack the security policy of WM5 in order to be able to install you own certificate. To accomplish this task you need two programs:
RegeditSTG.exe the trusted version of regedit from HTC.
SDA_ApplicationUnlock.zip a program to application unlock the SDA and alike smartphones.
Now use the following procedure:
- Copy Regedit.zip to an internal folder of the phone and unpack Regedit.exe. It does not seem to work when it is copied to SD.
- Start Regedit.exe and change the following registry keys:
HKLM\Security\Policies\Policies0001001 = 2 => 1 (RAPI)HKLM\Security\Policies\Policies0001005 = 16 => 40 (Cert)HKLM\Security\Policies\Policies0001017 = 128 => 144 (?)
- Now start SDA_ApplicationUnlock.exe on the PC with the phone attached to the USB port and click Unlock in the application.
- Restart the phone
- Now you can install your own root CA certificates by double clicking the .cer file
I think this patch opens up some more functionality that I don’t know of yet. We shall see what happens next.