On Tue, 2013-03-19 at 18:50 +0000, Matthew Garrett wrote: > On Tue, Mar 19, 2013 at 06:40:56PM +0000, James Bottomley wrote: > > On Tue, 2013-03-19 at 18:28 +0000, Matthew Garrett wrote: > > > It requires the key to survive the system being entirely powered down, > > > which means it needs to be BS+NV. It shouldn't be possible for userspace > > > to access this key. > > > > It requires the *public* key to survive power down, certainly. The > > private key can be thrown away once the hibernate image is signed. I > > think the scheme can be constructed so the private key is never in NV > > storage ... that also makes it more secure against tampering. > > Well, that somewhat complicates implementation - we'd be encrypting the > entire contents of memory except for the key that we're using to encrypt > memory. Keeping the public key away from userspace avoids having to care > about that. I don't quite understand what you're getting at: the principle of public key cryptography is that you can make the public key, well public. You only need to guard the private key. James -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html