Nov 09 2018 04:27 AM
Nov 09 2018 04:27 AM
According to the What's new in Windows 10 1809 the following functionality is available.
You can choose which encryption algorithm to apply automatic BitLocker encryption to capable devices, rather than automatically having those devices encrypt themselves with the default algorithm. This allows the encryption algorithm (and other BitLocker policies that must be applied prior to encryption), to be delivered before automatic BitLocker encryption begins.
For example, you can choose the XTS-AES 256 encryption algorithm, and have it applied to devices that would normally encrypt themselves automatically with the default XTS-AES 128 algorithm during OOBE.
I have worked through implementing this functionality with both the 1809 (17763)and 1903 (18277) builds and it does not work. The system drive automatically encrypts but the drive gets encrypted with the default XTS-AES-128 encryption.
I have the following setup.
Screenshots of the policy, the Intune errors and the BitLocker settings attached.
I have a support call logged but suggestions are welcome.
Nov 26 2018 07:10 AM - edited Nov 26 2018 07:11 AMSolution
After a great deal of experimentation and a blog post from Per Larson; I tracked down the cause of the issue.
The encryption section of the EndPoint Protection policy does not correctly apply to AAD Joined devices capable of HSTI if the policy is set to Encrypt Device: Require.
I was able to successfully encrypt a device during AutoPilot with AES 256 under the following circumstances.
The policy settings that I used are attached.
Apr 23 2019 09:00 PM
@Andrew Matthews Hi Andrew, quick question you have two policies attached. I would like to know how you are assigning each policy. I gather the first one is to an autopilot group that only contains devices and these settings will be applied during the OOBE/Autopilot process (Enrolment Status page). How are you applying the second policy is it to the same group and also is the does the second policy exclude the settings you have in the first ? Are you applying both policies to the same autopilot group but the settings cannot be combined in a single profile ?
Apr 30 2019 03:31 AM
I found that most Device Restriction and Endpoint Protection settings can be applied to a user group but some settings have to be applied to a device group.
My current deployments apply BitLocker settings using a separate Endpoint Protection policy that is a assigned to an Azure AD group containing devices. I use the ZtdId trick to create a dynamic group that targets all AutoPilot devices.
May 01 2019 02:56 PM
@Andrew Matthews Thanks for your quick reply Andrew. As per your Policy 1 image, I have the same settings applying to a Dynamic group and assigned to new devices for autopilot. I was curious as to how you are assigning your second policy with the additional encryption settings. Is this to a wider device or user group that would apply after the ESP page ?
I have a ticket logged with MS at the moment and been working on it for nearly a month and they too are struggling and acknowledged there is a bug with the ESP page and BitLocker for 1809.