18.9.11.2.3 Ensure 'Choose how BitLocker-protected operating system drives can be recovered' is set to 'Enabled'

Information

This policy setting allows you to control how BitLocker-protected operating system drives are recovered in the absence of the required startup key information. This policy setting is applied when you turn on BitLocker.

The 'Allow certificate-based data recovery agent' check box is used to specify whether a Data Recovery Agent can be used with BitLocker-protected operating system drives. Before a Data Recovery Agent can be used it must be added from the Public Key Policies item in either the Group Policy Management Console or the Local Group Policy Editor. Consult the BitLocker Drive Encryption Deployment Guide on Microsoft TechNet for more information about adding Data Recovery Agents.

In 'Configure user storage of BitLocker recovery information' select whether users are allowed, required, or not allowed to generate a 48-digit recovery password or a 256-bit recovery key.

Select 'Omit recovery options from the BitLocker setup wizard' to prevent users from specifying recovery options when they enable BitLocker on a drive. This means that you will not be able to specify which recovery option to use when you enable BitLocker, instead BitLocker recovery options for the drive are determined by the policy setting.

In 'Save BitLocker recovery information to Active Directory Domain Services', choose which BitLocker recovery information to store in AD DS for operating system drives. If you select 'Backup recovery password and key package', both the BitLocker recovery password and key package are stored in AD DS. Storing the key package supports recovering data from a drive that has been physically corrupted. If you select 'Backup recovery password only', only the recovery password is stored in AD DS.

Select the 'Do not enable BitLocker until recovery information is stored in AD DS for operating system drives' check box if you want to prevent users from enabling BitLocker unless the computer is connected to the domain and the backup of BitLocker recovery information to AD DS succeeds.

Note: If the 'Do not enable BitLocker until recovery information is stored in AD DS for operating system drives' check box is selected, a recovery password is automatically generated.

The recommended state for this setting is: Enabled.

Rationale:

Should a user lose their primary means for accessing an encrypted OS volume, or should the system not pass its boot time integrity checks, the system will go into recovery mode. If the recovery key has not been backed up to Active Directory, the user would need to have saved the recovery key to another location such as a USB flash drive, or have printed the recovery password, and now have access to one of those in order to recovery the system. If the user is unable to produce the recovery key, then the user will be denied access to the encrypted volume and subsequently any data that is stored there.

Impact:

Users will need to be domain connected to turn on BitLocker. This policy is not FIPS complaint.

Solution

To establish the recommended configuration via GP, set the following UI path to Enabled:

Computer Configuration\Policies\Administrative Templates\Windows Components\BitLocker Drive Encryption\Operating System Drives\Choose how BitLocker-protected operating system drives can be recovered

Note: This Group Policy path may not exist by default. It is provided by the Group Policy template VolumeEncryption.admx/adml that is included with the Microsoft Windows 7 & Server 2008 R2 Administrative Templates (or newer).

Default Value:

Disabled. (The default recovery options are supported for BitLocker recovery - a DRA is allowed, and the recovery options can be specified by the user including the recovery password and recovery key, and recovery information is not backed up to AD DS.)

See Also

https://workbench.cisecurity.org/files/4167

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-28, CSCv7|13.6

Plugin: Windows

Control ID: d113a68c4a7ead166e0358ada4d742b6c00dd28ed47525916b318ba5b42fb1d3