Ask Slashdot: Establishing Procurement Policies Regarding Secure Boot?

New submitter Firx writes: My university department has a tradition of selling its used computers and/or repurposing them with Linux for graduate students and science computer labs. With Windows no longer requiring one be able to disable secure boot, my department is writing up a procurement policy to ensure future machines we buy will still have this feature. Part of the draft motion reads: "Be it resolved that computers running or intending to run Microsoft Windows purchased by the department which boot using the Unified Extensible Firmware Interface (UEFI) have the ability to disable the Secure Boot features for both local hard drive and network booting." Is there something further we should be including here and what is the best way to explain the need for this policy to colleagues less technically literate?

Comments

Add a test

[gweihir]

Require it, for example, to be installable with Linux with the "current version of the stable Debian installer" at the time of purchase. For an individual contract, that version needs to be specified, of course. This way you have at least somebody to blame if it later turns out this does not work.

Re:Add a test

[mattventura]

You don't have to do it for every single PC purchase, just once for each model.

Re:Expalnation

[fahrbot-bot]

what is the best way to explain the need for this policy to colleagues less technically literate?

We bought the computers, we should be able to use them as we see fit.

Would you want a car that only accepts fuel from one gas station company?

Linux can UEFI Boot

[Zombie Ryushu]

Linux can UEFI Boot with and without Secure Boot. With Secure Boot you have to be able to install keys or use a Grub Shim, but I have seen both Toshiba and HP Laptops boot Mageia and RedHat in UEFI and CSM modes.

Re:Linux can UEFI Boot

[wolrahnaes]

Then, how do I recompile a custom kernel and with UEFI Boot and Secure Boot run it?

Depends on how your distro of choice has implemented Secure Boot.

All of the distros with official support are using a shim derived from Red Hat's. That shim is a very simple bootloader which maintains compliance with Secure Boot by only chaining on to verified binaries, but it allows the use of an additional public key which has been compiled in to the binary. Anyone who finds it worth the $99 can have their build signed by Microsoft and will then be able to boot anything signed with the associated private key on top of anything signed with the Microsoft keys the system has built in. It also provides a method to pass the public key down the chain so the next stage bootloader, kernel, and beyond can verify with it as well.

Fedora and Ubuntu stop here. Fedora signs GRUB2 with their key which then verifies the kernel, which then verifies the modules. ( http://mjg59.dreamwidth.org/12... ) Ubuntu jumped on a loophole in the wording of the Secure Boot spec to just use their key to sign a bootloader which will then happily launch an unsigned kernel. ( https://lists.ubuntu.com/archi... )

Suse took things a step further and expanded the shim to support a local key list in the UEFI configuration area. ( https://www.suse.com/communiti... ). Now even a system that lacks the ability to add keys to the firmware's verification process can run a fully signed boot process with custom keys.

Finally one of the main original developers on the shim who has since left Red Hat took Suse's key management code, mixed it with his own continued tinkering, and added a user interface that comes up if you attempt to boot a signed binary that doesn't match an approved key, allowing the user to browse for a key on any accessible storage and add it to the system. ( http://mjg59.dreamwidth.org/20... )

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So the answer depends on your distro. If you're running Ubuntu, you just compile your new kernel and go have fun because Ubuntu's not yet verifying the kernel (this is apparently becoming optional in 16.04). If you're running Suse, you use whatever tool they offer to add a key to their shim's list. If you're running Fedora, you replace their shim with one of the other variants and either add a key of your own or just go Ubuntu-style and drop it at the kernel.

Of course this is all assuming your system doesn't allow you to change the keys, which I know is a valid theoretical possibility but I still haven't encountered in the real world.

Not all computers have UEFI

[Anonymous Coward]

You are both over-specifying the mechanism, and scope.

Not all computers you can buy to run Windows have UEFI, and some otherwise useful devices can't disable it.

2 examples that would be excluded from purchase by how you have phrased this :

- Macs (do not have UEFI, but an Apple fork of EFI)
- iPads (locked boot loader)
- Many Windows 10 tablets/hybrids/ultrabooks e.g. Surface (locked boot loader)
- Windows Phone (locked boot loader)
- Sony Playstation (sometimes used as GPU clusters, but have a locked boot loader )

Now if you want to ban those other device types , thats really up to you. It depends on do you consider a tablet to be a computer or a phone to be a computer, but heck. Increasingly , the number of computers that function as you describe are going to go down, and more and more locked down devices like tablets and hybrids will become the norm in the market.

Why not frame it in terms of why :

"The department believes that it is essential to generate long term utility from computers it buys, and that they shouldn't simply be disposable. We believe that long term use requires flexibility in the operating system used on a computer. We believe that long term use can be achieved in multiple ways - such as reselling used devices to other entities that have need for them, re-purposing computers for graduate students and laboratories, or converting computers for use in instrumentation. This means that wherever possible, computers should be purchased ensuring they have the capability to be unlocked from only running Windows, and running other operating systems such as Linux. This ensures maximum flexibility for our department in generating value from the money we invest in our IT hardware. Exceptions to this need to present a business case and be approved by XXXX"

The committee approving the exceptions is the mechanism to handle your other options.

Why mention Windows?

[bws111]

Other than pure FUD, why mention Windows or Microsoft at all? We have hundreds of servers running Linux that have Secure Boot enabled, and our requirements for the next gen of servers is that the Secure Boot can not be disabled. So don't pretend it is just a 'Windows' thing.

Dragging MS into it is really childish. A manufacturer that gets a Windows 10 cert has the choice of allowing Secure Boot to be disabled or not. Are you trying to claim that a manufacturer who DOESN'T get an MS certification is somehow prevented from that option?

Re:Why mention Windows?

[bws111]

Who signed it? We did. And anyone who has the passwords required to access the UEFI does not have physical access to the servers without accompanied.

Re:Why mention Windows?

[Anonymous Coward]

False. The reason why MS has the keys is that to have your product certified to run on Windows, this is a must. Same with TPM + TCG 2.0. It was only due to good negotiators on RedHat's part that MS allows their OS to boot, -period- on Secure UEFI computers.

Re:Tablets?

[Anonymous Coward]

You are able to disable Secure boot on the x86 Surface tablets, I have it disabled on my first gen Surface Pro. Even the newest ones apparently support disabling it according to Microsoft's documentation on them.

No such luck for the ARM Surface tablets.