Archive

Archive for the ‘macOS Recovery’ Category

macOS, hyperthreading and Microarchitectural Data Sampling vulnerabilities

May 16, 2019 Leave a comment

In 2018, vulnerabilities were publicly disclosed in computer processor architecture which affected the vast majority of desktops, laptops, mobile devices and servers. These vulnerabilities are referred to as Meltdown and Spectre. There is a lot of information available online about these vulnerabilities, but the cartoon below provides a decent summary of the issue:

Meltdown and spectre

On May 14th, 2019, additional Spectre vulnerabilities were disclosed using the name Microarchitectural Data Sampling (MDS). These vulnerabilities apply to desktop and laptop computers which use Intel processors. These processors are used by all modern Macs, but not by iOS or Apple Watch devices. These devices do not use Intel processors and instead use Apple’s own processors. For an excellent round-up of information on this developing issue, please see @zoocoup‘s post available via the link below:

https://mrmacintosh.com/mds-vulnerabilities-summary-for-macadmins-by-jason-broccardo

How to remediate this problem? For the details, please see below the jump.

Read more…

Re-syncing local account passwords and Secure Token on FileVault-encrypted Macs running macOS Mojave

February 10, 2019 5 comments

As part of FileVault on Apple File System, Apple introduced a new account attribute called Secure Token. As mentioned in a previous post, Secure Token can present some interesting problems for Mac admins who work with FileVault-encrypted laptops. Among the potential complications are these scenarios:

  • “I changed the password for my local account, but only the old password is being taken at the FileVault login screen.”
  • “We’ve lost the password to the only local user account with a Secure Token, so now we can’t enable any other accounts on this Mac for FileVault.”

Usually, this happens because the local account password in question was changed outside of the Users & Groups preference pane in System Preferences and now Secure Token and the account password are out of sync with each other.

Up until the past few days, the only fix I knew of for that situation was to back up the data and wipe the drive. However, it looks like there is a workaround for encrypted Macs which fixes the password problem and sorts out Secure Token in these scenarios. In both cases, a personal recovery key will be needed as the way to authorize the needed changes. For more details, please see below the jump.

Read more…

Unable to enable FileVault on macOS Mojave

February 8, 2019 4 comments

As part of FileVault on Apple File System, Apple introduced a new account attribute called Secure Token. Secure Token can present some interesting complications for Mac admins and among them is this scenario:

“The laptop is decrypted, but we can’t re-enable FileVault now.”

Usually, this happens because the account password was changed outside of the Users & Groups preference pane in System Preferences and now Secure Token and the account password are out of sync with each other.

Up until today, the only fix I knew of for that situation was to back up the data and wipe the drive. However, it looks like there is a workaround that fixes the password problem and sorts out the Secure Token attribute for the account on a decrypted laptop. For more details, please see below the jump.

Read more…

Unlock or decrypt your FileVault-encrypted boot drive from the command line on macOS Mojave

January 15, 2019 7 comments

As part of working with FileVault on macOS Mojave, it may be necessary to decrypt an encrypted boot drive in order to fix a problem. On Mojave all boot volumes will use Apple File System (APFS), so to unlock or decrypt an encrypted boot drive from the command line, you will need to do the following:

  1. Identify the relevant encrypted APFS volume
  2. Unlock the encrypted APFS volume
  3. If needed, decrypt the encrypted APFS volume

For more details, see below the jump.

Read more…

The T2 Macs, the end of NetBoot and deploying from macOS Recovery

August 15, 2018 16 comments

In late 2017, Apple released the iMac Pro. Along with the new Secure Enclave protection provided by Apple’s T2 chip, the iMac Pro brought another notable development: It did not support booting from a network volume, otherwise known as NetBoot.

The one exception was Apple’s Internet Recovery, where Apple is providing a NetBoot-like service to provide access to macOS Recovery. The iMac Pro is still able to boot to Internet Recovery, which provides a way to repair the Mac or reinstall the operating system in situations where the Mac’s own Recovery volume is missing or not working properly.

With NetBoot not being available for the iMac Pro but still available for other models, it wasn’t yet clear if NetBoot-based workflows for setting up new Macs or rebuilding existing ones were on the way out. However, Apple’s release of of T2-equipped MacBook Pros in July 2018 which also could not use NetBoot has made Apple’s direction clear. As Apple releases new Mac models equipped with T2 chips and Secure Enclave, it is unlikely that these future Mac releases will be supporting NetBoot.

Screen Shot 2018 08 15 at 10 23 19 AM

For Mac admins using NetBoot-based workflows to set up their Macs, what are the alternatives? Apple has been encouraging the use of Apple’s Device Enrollment Program, which leverages a company, school or institutions’ mobile device management (MDM) service. In this case, you would need to arrange with Apple or an Apple reseller to purchase Macs that are enrolled in your organization’s DEP.

When a DEP-enrolled Mac is started for the first time (or started after an OS reinstall), it is automatically configured to use your organizations’ MDM service and the device checks in with the MDM service. The MDM service then configures the Mac as desired with your organization’s software and configuration settings. A good example of what this process may look like can be seen here.

What if you don’t have DEP, or you don’t have MDM? In that case, you may still be able to leverage Recovery-based deployment methods, which would allow you install the desired software and configuration settings onto the Mac’s existing OS, or install a new OS along with software and configuration settings. For more details on these methods, please see below the jump.

Read more…

%d bloggers like this: