The Linux Foundation is temporarily supporting a Microsoft security policy to ensure Linux isn’t blocked from running on PCs installed with Windows 8.
The Foundation plans to obtain a Microsoft key to sign a pre-bootloader from core Linux kernel maintainer James Bottomley. Together, the key and pre-bootloader will allow users to start up and run Linux as an authorised piece of software on Windows 8 PCs – it would otherwise have been barred by the machine as potential malware.
The pre-bootloader will allow you to install Linux from CD, DVD or via download and will be made available from the Linux Foundation’s website once it has a Microsoft signature.
A Microsoft-authorised key is a stop-gap measure until Linux distros devise their own ways to work with the Windows 8 Unified Extensible Firmware Interface (UEFI) secure boot.
Bottomley announced the key and pre-bootloader here and here, saying: "The pre-bootloader it [The Linux Foundation] is releasing as a stop-gap measure that will give all distributions time to come up with plans that take advantage of UEFI secure boot.”
He said the Foundation also welcomes the work of Fedora, SuSE and Ubuntu towards allowing Linux to boot on Windows 8 PCs via Microsoft’s UEFI secure boot.
Tech blogger Matthew Garrett first discovered UEFI secure boot would block Linux on Windows 8 PCs back in 2011. Professor Ross Anderson of the Cambridge University Computer Laboratory and a security and privacy commenter blogged that UEFI secure boot was worse than previous attempts to push Digital Rights Management on Windows users and warned it could extend Microsoft's operating system monopoly.
Demonstrating how seriously Windows and Windows Live president Steven Sinofsky took the growing concern, he issued a rare blog response denying UEFI secure boot would prevent Linux from installing by "locking out" operating system loaders. He tried said consumers would retain complete control over their machines.
The fact is, though, that Microsoft will only give PC makers access to the Windows 8 OS if their PCs' UEFI firmware uses Secure Boot. This mechanism will only recognise code that has been signed with a digital key recognised by the motherboard's firmware.
Software which tries to modify the start-up process, is not recognised or which tries to bypass the key, won’t be allowed to install – in theory, at least.
The idea is to stop the installation of malware – but inevitably means that Penguins will need to install a distro which ALSO has a key that is recognised through the UEFI boot.
Microsoft is permitting user-generated keys on x86 PCs but on ARM systems, customised keys are forbidden and only a limited set of keys will be recognised.
According to Bottomley, here, the Foundation’s pre-bootloader works on x86 but should work on ARM, too.
Canonical will generate its own private key for signing code that loads Ubuntu while Fedora is using the GRand Unified Bootloader 2 (GRUB2) from the GPL – its boot-loader key will be signed by Microsoft under a service from Verisign. ®