於 四，2013-09-26 於 02:27 +0200，Pavel Machek 提到： > On Wed 2013-09-25 15:16:54, James Bottomley wrote: > > On Wed, 2013-09-25 at 17:25 -0400, Alan Stern wrote: > > > On Wed, 25 Sep 2013, David Howells wrote: > > > > > > > I have pushed some keyrings patches that will likely affect this to: > > > > > > > > http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=keys-devel > > > > > > > > I intend to ask James to pull these into his next branch. If he's happy to do > > > > so, I can look at pulling at least your asymmetric keys patch on top of them. > > > > > > This suggests a point that I raised at the Linux Plumbers conference: > > > > > > Why are asymmetric keys used for verifying the hibernation image? It > > > seems that a symmetric key would work just as well. And it would be a > > > lot quicker to generate, because it wouldn't need any high-precision > > > integer computations. > > > > The reason is the desire to validate that the previous kernel created > > something which it passed on to the current kernel (in this case, the > > hibernation image) untampered with. To do that, something must be > > passed to the prior kernel that can be validated but *not* recreated by > > the current kernel. > > I don't get this. Why is it important that current kernel can't > recreate the signature? > > Current kernel is not considered malicious (if it were, you have worse > problems). > Current boot kernel should not malicious especially when UEFI secure boot enabled. > Pavel > > PS: And yes, it would be nice to have > Documentation/power/swsusp-uefi.txt (or something) explaining the > design. > Thanks for your suggestion, I will write the swsusp-uefi.txt to explaining the design in next version. Thanks a lot! Joey Lee -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
