Re: [GIT PULL] Load keys from signed PE binaries

Matthew Garrett
2013-02-28T22:51:27Z

On Thu, Feb 28, 2013 at 11:48:06PM +0100, Jiri Kosina wrote:

> Let me formulate my point more clearly -- Microsoft very likely going to
> sign hello world EFI PE binary, no matter the contents of .keylist
> section, as they don't give a damn about this section, as it has zero
> semantic value to them, right?
>
> They sign the binary. By signing the binary, they are *NOT* establishing
> cryptographic chain of trust to the key stored in .keylist, but your
> patchset seems to imply so.

Mr Evil Blackhat's binary is then a mechanism for circumventing the
Windows trust mechanism, and as such his account is subject to
termination and his binary can be added to dbx. We'd check the binary
hash against dbx and refuse to load it on systems that have received the
update, and Mr Evil Blackhat would have to find a new bunch of identity
documents to create a new account to repeat the process.

--
Matthew Garrett | mjg59@srcf.ucam.org