Not logged in
Log in now
Create an account
Subscribe to LWN
LWN.net Weekly Edition for June 20, 2013
Pencil, Pencil, and Pencil
Dividing the Linux desktop
LWN.net Weekly Edition for June 13, 2013
A report from pgCon 2013
Of course, what applies to common people may not apply to Microsoft or Canonical.
No signed kernel, just a signed boot loader
Posted Jun 25, 2012 17:01 UTC (Mon) by gioele (subscriber, #61675)
I suppose that there are a lot of other things that must happen at the same time before you jail someone. Otherwise every borked update to Debian sid or Rawhide would send quite a bit of people in prison.
Posted Jun 25, 2012 18:26 UTC (Mon) by pboddie (subscriber, #50784)
But as I noted, such schemes are mostly used to erode the rights of users in the name of something else so that people don't question such schemes until after they have been introduced, and thus any argument about how a dominant vendor has managed to obliterate the competition can be waved away many years after the fact with excuses like "it's what the market expected" and "nobody demanded anything else".
Posted Jun 25, 2012 18:39 UTC (Mon) by raven667 (subscriber, #5198)
That is hyperbole and is not what secure boot on x86 does. It'd be great if we could stick to a discussion based on the facts.
Posted Jun 25, 2012 21:28 UTC (Mon) by pboddie (subscriber, #50784)
And I'm sure it's not beyond the skills of the vendors to make installing one's own keys a near impossibility and then claiming it was an accident for as long as it takes before they can then claim that the product is no longer supported.
So in practical terms, it is all about control. We can discuss technical workarounds as much as we like and deny that the technology imposes any particular restrictions, but the combination of one company's continuous strategy of pushing the regulatory envelope and that technology results in a shoring up of that company's position.
Why else are the distributions jumping through hoops? Because they like a challenge? The practical effect of the misuse of such a technology is as much a fact as any aspect of the "it's OK - I can still boot my kernel" technical discussion.
Posted Jun 25, 2012 21:40 UTC (Mon) by raven667 (subscriber, #5198)
So we agree on the substance of the matter. I can't comment on the rest of your post because I can't find any facts or point, just a lot of rhetorical flailing about.
Posted Jun 26, 2012 11:03 UTC (Tue) by pboddie (subscriber, #50784)
Posted Jun 26, 2012 18:10 UTC (Tue) by marcH (subscriber, #57642)
> > you can sign your own payloads and install your own keys
> So we agree on the substance of the matter. I can't comment on the rest of your post because I can't find any facts or point, just a lot of rhetorical flailing about.
Too bad things are not that obvious to Fedora and Canonical. They should have hired you and saved a lot of effort.
Posted Jun 26, 2012 19:14 UTC (Tue) by raven667 (subscriber, #5198)
Foolish on my part I suppose. http://xkcd.com/386/
Posted Jun 25, 2012 18:56 UTC (Mon) by jspaleta (subscriber, #50639)
Secureboot as a concept is not a bad thing. The policy surrounding how to enable secureboot for consumer devices needs some iteration however. There is absolutely nothing wrong with an off-by-default secureboot even with the current specification and limitations. On-by-default, has some definite challenges, and MS's certification process requirements brings these challenged directly into the forefront of the discussion.
Even with an on-by-default scheme, if users can disable secureboot to regain access to a system that has been impacted by a key revocation I really don't see a fundamental problem. As long as users are not locked out of the firmware config screens to disable secureboot on the hardware they purchased, a 3rd party revocation process is best described as a very stringent notification about a potential system compromise. If users can disable secureboot they do not lose access to their systems even after a key that their current configuration requires has been revoked.
In fact I'd wager that once the security benefit is digested more widely large institutions like the US Department of Defense and the State Department and even municipal power companies will be making heavy use of secureboot with their own signing keys on a lot of critical infrastructure and even desktops and laptops...so they don't even have to implicitly trust any Vendor (including Microsoft). They'll use the firmware reconfiguration to the fullest to load their own keys on their hardware and then self-sign binaries and to control the revocation process from end-to-end.
Posted Jun 25, 2012 19:13 UTC (Mon) by raven667 (subscriber, #5198)
I'm not sure that's true, you can have many vendor and user keys loaded into the firmware but to get your key pre-loaded would require some relationship with the vendor so your hardware coverage is likely to be less than 100%, whereas all the vendors want to be able to run MS so that key is virtually guaranteed to be loaded by default.
Actual binaries can be signed by only one key though so to boot and reduce the number of boot media spins required forces you to choose which key you are going to use to sign your initial boot loader and the MS key wins on convenience there.
> Even with an on-by-default scheme, if users can disable secureboot to regain access to a system that has been impacted by a key revocation I really don't see a fundamental problem
Which is exactly the case now for x86. Win8 ARM hosts are boot locked but that's its own separate issue at this time, I don't think any Linux vendor is going to fool around with them. Just don't buy them an expect to run anything else on them (not much different that the rest of the ARM market anyway).
> companies will be making heavy use of secureboot with their own signing keys
Thats probably something they will want to do but it depends on how to sign or re-sign boot binaries. Is it possible to re-sign the Windows 8 boot loader for example and have the system not broken? Certainly this will be do-able, maybe even common, with Linux systems.
Posted Jun 26, 2012 7:27 UTC (Tue) by ssmith32 (subscriber, #72404)
Unfortunately, regardless of the "should", there are plenty of examples to the contrary.
Whatever the original intent, in reality, UEFI's largest impact so far has been to impose a significant cost on open-source software, with the to-be-determined security benefits still vaporware..
Posted Jun 25, 2012 21:33 UTC (Mon) by dlang (✭ supporter ✭, #313)
Posted Jun 26, 2012 7:41 UTC (Tue) by micka (subscriber, #38720)
> Of course, what applies to common people may not apply to Microsoft or Canonical.
or Sony. The "Microsoft or Canonical" was not meant to be exhaustive.
Of course I'm exagerating. Even the individual cracker that bricks _one_ computer would not go to jail... t1he first time, unless they go against a police or big corporate computer.
The second time would be very different, though.
Copyright © 2013, Eklektix, Inc.
Comments and public postings are copyrighted by their creators.
Linux is a registered trademark of Linus Torvalds