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Date:   Fri, 4 Nov 2022 11:41:49 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Evan Green <evgreen@chromium.org>
Cc:     linux-kernel@vger.kernel.org, corbet@lwn.net,
        linux-pm@vger.kernel.org, rjw@rjwysocki.net, gwendal@chromium.org,
        apronin@chromium.org, Pavel Machek <pavel@ucw.cz>,
        Matthew Garrett <mgarrett@aurora.tech>,
        linux-integrity@vger.kernel.org, jejb@linux.ibm.com,
        zohar@linux.ibm.com, dlunev@google.com,
        Eric Biggers <ebiggers@kernel.org>,
        Ben Boeckel <me@benboeckel.net>, jarkko@kernel.org,
        Len Brown <len.brown@intel.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>
Subject: Re: [PATCH v4 08/11] PM: hibernate: Use TPM-backed keys to encrypt
 image
Message-ID: <202211041139.15A90C4EED@keescook>
References: <20221103180120.752659-1-evgreen@chromium.org>
 <20221103105558.v4.8.Ibd067e73916b9fae268a5824c2dd037416426af8@changeid>
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On Thu, Nov 03, 2022 at 11:01:16AM -0700, Evan Green wrote:
> When using encrypted hibernate images, have the TPM create a key for us
> and seal it. By handing back a sealed blob instead of the raw key, we
> prevent usermode from being able to decrypt and tamper with the
> hibernate image on a different machine.
> 
> We'll also go through the motions of having PCR23 set to a known value at
> the time of key creation and unsealing. Currently there's nothing that
> enforces the contents of PCR23 as a condition to unseal the key blob,
> that will come in a later change.
> 
> Sourced-from: Matthew Garrett <mjg59@google.com>

I'd say Suggested-by. "Source-from:" is not a tag that has ever been
used before. :)

Otherwise, looks good.

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook