Accompany .asc and .DIGESTS keys for the ISO

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4 participants
  • bo0od
  • Carlo Zancanaro
  • Leo Famulari
  • Ludovic Courtès
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unassigned
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bo0od
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Leo Famulari wrote on 8 Apr 2021 19:03
(name . bo0od)(address . bo0od@riseup.net)(address . 47634@debbugs.gnu.org)
YG83aEbWP7BZkyUn@jasmine.lan
On Wed, Apr 07, 2021 at 05:42:40AM +0000, bo0od wrote:
Toggle quote (8 lines)
> Hi There,
>
> I see there is only .sig provided:
>
> https://guix.gnu.org/en/download/
>
> Its better to provide more than one way of verification e.g:

Why?
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bo0od wrote on 8 Apr 2021 19:34
(name . Leo Famulari)(address . leo@famulari.name)(address . 47634@debbugs.gnu.org)
d6171b07-515f-58e2-2cff-e6dbd721656b@riseup.net
This is nicely written by Qubes documentation:


Leo Famulari:
Toggle quote (11 lines)
> On Wed, Apr 07, 2021 at 05:42:40AM +0000, bo0od wrote:
>> Hi There,
>>
>> I see there is only .sig provided:
>>
>> https://guix.gnu.org/en/download/
>>
>> Its better to provide more than one way of verification e.g:
>
> Why?
>
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Carlo Zancanaro wrote on 9 Apr 2021 00:57
(address . 47634@debbugs.gnu.org)
8624B91E-1A4F-4455-880A-E5664C27D5B1@zancanaro.id.au
On 9 April 2021 3:34:20 am AEST, bo0od <bo0od@riseup.net> wrote:
Toggle quote (4 lines)
>This is nicely written by Qubes documentation:
>
>https://www.qubes-os.org/security/verifying-signatures/

From that page:

Toggle quote (2 lines)
> If you’ve already verified the signatures on the ISO directly, then verifying digests is not necessary.

Which implies that the signatures are sufficient, right?

What is the benefit to providing the key (.asc) and hashes (.DIGESTS)? The page you linked provides rationale for providing and checking digital signatures, but we already provide them.

Carlo
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(address . 47634@debbugs.gnu.org)
5c01ac9b-74db-42d5-db39-7f287b70255d@riseup.net
Toggle quote (2 lines)
> Which implies that the signatures are sufficient, right?

Well this is simple question but the answer is sorta deeper, So i will
answer with yes and no:

yes signatures are sufficient but signatures with PGP has problems, In
the suggestion above i didnt suggest to diverse the signing methods
(like for example using signify alongside with gpg) but just adding
extra steps better than one (more convenience to say that everything is
going smoothly).

To understand what im talking about i suggest to read:

Why PGP on expiration time:


Discussion which might consider deprecate the usage of PGP by debian:


Whonix already using signify alongside with PGP:


Also there are challenges to the concept itself:




So I hope by complete reading that you will come to the conclusion that
either provide as much as possible from extra verification (like
.asc,DIGESTS,SHA512...etc) or provide alternative verification along
side with the traditional one like using signify or using something like
signify and thats it. (i think providing both methods like pgp/signify
is the best way which suits everybody)




Toggle quote (17 lines)
>
>
> On 9 April 2021 3:34:20 am AEST, bo0od <bo0od@riseup.net> wrote:
>> This is nicely written by Qubes documentation:
>>
>> https://www.qubes-os.org/security/verifying-signatures/
>
> From that page:
>
>> If you’ve already verified the signatures on the ISO directly, then verifying digests is not necessary.
>
> Which implies that the signatures are sufficient, right?
>
> What is the benefit to providing the key (.asc) and hashes (.DIGESTS)? The page you linked provides rationale for providing and checking digital signatures, but we already provide them.
>
> Carlo
>
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Carlo Zancanaro wrote on 10 Apr 2021 04:27
(name . bo0od)(address . bo0od@riseup.net)(address . 47634@debbugs.gnu.org)
87y2dqlvqj.fsf@zancanaro.id.au
Hi bo0od!

On Sat, Apr 10 2021, bo0od wrote:
Toggle quote (8 lines)
>> Which implies that the signatures are sufficient, right?
>
> Well this is simple question but the answer is sorta deeper, So
> i will answer with yes and no:
>
> yes signatures are sufficient but signatures with PGP has
> problems...

I grant that this might be true, but whether or not to use PGP is
a different issue to whether cryptographic signatures are
sufficient to verify downloads. If we compare the projects you've
shown as examples:

- Qubes provides hashes, PGP signatures, and a release signing
key

- Whonix provides hashes, PGP signatures, and a release signing
key

For verification purposes the hashes only provide transport
integrity - they don't provide any mechanism to verify where the
content came from, and because they're stored next to the images
it's likely that any attacker who could manipulate the images
could also manipulate the hashes. The signature provides a better
guarantee that the image contains what the project intends to
distribute (i.e. that nobody has compromised image itself). In
this instance, the hash provides no significant additional value
over the signature.

If we look at the Tor project (who, I hope you will agree, care
about security), their download page[1] only provides links to PGP
signatures as their sole method of verification.

I'm not convinced there's much value to add anything beyond the
signatures, and I think there is some cost. Having multiple
verification options makes the download page more confusing (by
providing more choices to do the same thing), and may make it less
likely that people do any verification.

I think there may be a larger conversation to have around using
something like Signify rather than PGP/GPG, but I'm not familiar
enough with Signify to have an opinion about that at the moment.

Carlo

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(name . Carlo Zancanaro)(address . carlo@zancanaro.id.au)(address . 47634@debbugs.gnu.org)
efb8d568-f38a-2bbb-db8c-ab215da455f0@riseup.net
Toggle quote (1 lines)
> In this instance, the hash provides no
> significant additional value over the signature.

What you said is true, Only thing i would see it useful when there is an
attack on PGP but not necessary can be produced as well on the same time
on SHA512 like collision attack or so (nothing at the moment discovered
but just theoretical attack)

> If we look at the Tor project (who, I hope you will agree, care about
> security), their download page[1] only provides links to PGP signatures
> as their sole method of verification.

If you tell me what most projects using at the moment i would tell you
straight forward PGP, But on the future bases PGP on the bye bye way so
what im suggesting here is to make it happen now rather than just
waiting for the future to come with its more insecurities. (like what i
referred to debian deprecation of PGP)

> I think there may be a larger conversation to have around using
> something like Signify rather than PGP/GPG, but I'm not familiar enough
> with Signify to have an opinion about that at the moment.

Sure tyt, These stuff doesnt need to be fixed instantly but need to be
looked in for sure.

ThX!

Carlo Zancanaro:
Toggle quote (44 lines)
> Hi bo0od!
>
> On Sat, Apr 10 2021, bo0od wrote:
>>> Which implies that the signatures are sufficient, right?
>>
>> Well this is simple question but the answer is sorta deeper, So i will
>> answer with yes and no:
>>
>> yes signatures are sufficient but signatures with PGP has problems...
>
> I grant that this might be true, but whether or not to use PGP is a
> different issue to whether cryptographic signatures are sufficient to
> verify downloads. If we compare the projects you've shown as examples:
>
> - Qubes provides hashes, PGP signatures, and a release signing key
>
> - Whonix provides hashes, PGP signatures, and a release signing key
>
> For verification purposes the hashes only provide transport integrity -
> they don't provide any mechanism to verify where the content came from,
> and because they're stored next to the images it's likely that any
> attacker who could manipulate the images could also manipulate the
> hashes. The signature provides a better guarantee that the image
> contains what the project intends to distribute (i.e. that nobody has
> compromised image itself). In this instance, the hash provides no
> significant additional value over the signature.
>
> If we look at the Tor project (who, I hope you will agree, care about
> security), their download page[1] only provides links to PGP signatures
> as their sole method of verification.
>
> I'm not convinced there's much value to add anything beyond the
> signatures, and I think there is some cost. Having multiple verification
> options makes the download page more confusing (by providing more
> choices to do the same thing), and may make it less likely that people
> do any verification.
>
> I think there may be a larger conversation to have around using
> something like Signify rather than PGP/GPG, but I'm not familiar enough
> with Signify to have an opinion about that at the moment.
>
> Carlo
>
> [1]: https://www.torproject.org/download/
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Ludovic Courtès wrote on 18 Apr 2021 12:40
(name . Carlo Zancanaro)(address . carlo@zancanaro.id.au)
875z0jlvud.fsf@gnu.org
Hi all,

Carlo Zancanaro <carlo@zancanaro.id.au> skribis:

Toggle quote (6 lines)
> I'm not convinced there's much value to add anything beyond the
> signatures, and I think there is some cost. Having multiple
> verification options makes the download page more confusing (by
> providing more choices to do the same thing), and may make it less
> likely that people do any verification.

Agreed.

Toggle quote (4 lines)
> I think there may be a larger conversation to have around using
> something like Signify rather than PGP/GPG, but I'm not familiar
> enough with Signify to have an opinion about that at the moment.

Right. OpenPGP isn’t great for software signing, but it’s widespread,
and that’s an important criterion if we are to allow users to
authenticate what they download. Tools like Signify are certainly worth
looking at, but I see it as a longer-term option.

I’m closing this issue since it’s not really actionable.

Thanks,
Ludo’.
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Ludovic Courtès wrote on 18 Apr 2021 12:40
control message for bug #47634
(address . control@debbugs.gnu.org)
874kg3lvtv.fsf@gnu.org
tags 47634 wontfix
close 47634
quit
?