[tbb-dev] significant ESR60 updater changes

[Georg Koppen]

Tom Ritter:
> On 5 April 2018 at 09:39, Mark Smith <mcs at pearlcrescent.com> wrote:
>> The reason Mozilla chose SHA384 over SHA512 is reduced
>> vulnerability to length extension attacks.
> 
> This decision was made without the crypto people at Mozilla being
> involved. We considered it unnecessary and SHA512 would have been
> fine; but whatever we're not going to change it again for vanity.

Reading through the bug it seems crypto people were consulted, no?
Either way, I wonder what
https://bugzilla.mozilla.org/show_bug.cgi?id=1105689#c52 implies

("Keep in mind that the implementation design that was created with the
security team for this required that we use the system provided crypto
instead of NSS if at all possible.")

because three years ago I said at least that we are using NSS on all
platforms. Looking at the changes for SHA-348, though, it seems they
don't change the game for us or am I missing anything?

brade/mcs: please proceed as you see fit taking my two comments above
into account. Having a smaller patch set for the updater related parts,
especially for the crypto related ones, is pretty appealing...

> 
>> 4. "Remove hashFunction and hashValue attributes"
>> https://bugzilla.mozilla.org/show_bug.cgi?id=1373267
>> Mozilla removed support for a hash check of the MAR files that has
>> historically been implemented by including hash values in the update
>> manifest (XML) file that is returned by the update server. Mozilla
>> relies on MAR signatures to verify the integrity of the Firefox MAR
>> files, but in the past we have talked about the value in requiring that
>> two things need to be compromised: the update server as well as a MAR
>> signing key. For that reason, Kathy and I believe we should back out
>> these changes and continue to have our update server return hash values.
> 
> SGTM.

+1

Georg

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