On Thu, 6 Oct 2022 11:32:50 -0700
"'Aaron Gable' via [email protected]"
<[email protected]> wrote:

> A client downloading the full collection of CRL shards can check the
> thisUpdate timestamps to ensure it is not receiving old data, and can
> check for duplicate shards to ensure it doesn't receive the same
> shard twice. As long as they download the correct expected number of
> sufficiently-recent shards, there are no duplicates, and all
> signatures validate, they can be confident that none of the shards
> have been replaced.

Could you elaborate on your proposed logic, in particular how a client
would determine whether a shard is "sufficiently-recent"?  Let's say a
client considers anything less than 24 hours old to be
"sufficiently-recent" but a CA reissues CRLs every 12 hours.  Then an
attacker would always be able to replace the shard they want to hide
with an older but still sufficiently-recent version of a different
shard.

Regards,
Andrew

-- 
You received this message because you are subscribed to the Google Groups 
"[email protected]" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To view this discussion on the web visit 
https://groups.google.com/a/mozilla.org/d/msgid/dev-security-policy/20221006151504.fbabd7c122ab960f5d3406a5%40andrewayer.name.

Reply via email to