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    SubjectRe: [GIT PULL] Load keys from signed PE binaries
    On Thu, 28 Feb 2013, Matthew Garrett wrote:

    > > But the real harm is being done by the i_own_your_ring0.ko module, which
    > > can be modprobed on all the systems where the signed "hello world" binary
    > > has been keyctl-ed before it was blacklisted.
    >
    > Sure, if you've been infected before the revocation, you'll still be
    > infected. There's not really any good way around that.

    Which is a very substantial difference to normal X509 chain of trust,
    isn't it?

    This security model seems to be quite seriously flawed to me (in a sense
    that it has nothing to do with chain of trust as mandated by X509 even
    though it tries to pretend the opposite)

    And frankly, Linus' proposal at [1] doesn't really make it any better in
    principle, it just keeps the whole thing out of kernel.

    [1] https://lkml.org/lkml/2013/2/21/228

    > > In other words -- you blacklist the population of the key on systems by
    > > blakclisting the key-carrying binary, but the key remains trusted on
    > > whatever system the binary has been processed by keyctl before. Right?
    >
    > You have to re-load it on every boot, it's not a permanent thing.

    That unfortunately seems to be very weak security measure as well.

    Thanks,

    --
    Jiri Kosina
    SUSE Labs


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