Re: announce-gen and OpenPGP key servers

[Jim Meyering]

On Tue, Aug 3, 2021 at 8:40 AM Simon Josefsson <simon@josefsson.org> wrote:
> Jim Meyering <jim@meyering.net> writes:
>
> > Feel free to make the script generate a full fingerprint and even
> > (though it feels a little like giving up) add a checksum or two.
>
> I think checksums still serve a purpose.
>
> Many announcement e-mails are OpenPGP signed (and sometimes with a
> different key than the release tarballs, thus creating another way to
> verify tarballs).
>
> Checksums also makes it harder to replace the tarball on the server with
> a fake (or, after a key compromise, a genuine) signature.
>
> I don't think it is a either-or situation, but rather a
> belt-and-suspender case.  Ideally, people downloading a release should

Agreed.

> verify both the signature (to know it comes from a trusted origin) and
> checksum (to know it is the intended release, in case multiple signed
> versions co-exists).
>
> The patches below make the maintainer-makefile announcements contain
> SHA1 and B64(SHA256) checksums by default.  The MD5 checksums are
> dropped; they are completely insecure now.  The B64(SHA256) output is
> inspired by OpenSSH which started this practice with release 6.5 in 2014
> and still today prints similar outputs, see:
>
> https://www.openssh.com/txt/release-6.5
> https://www.openssh.com/txt/release-8.6
>
> Unfortunately, 'sha256sum' can't verify these outputs, but I recall
> earlier discussions around 'sha256sum --base64' so I will resume work on
> that.
>
> We could opt to simply use the "standard" sha256sum output instead, if
> people here don't like the base64 output format.

Thanks, Simon! I too am all for B64-formatted checksums.
You may want to coordinate with Pádraig.
I think he is planning a unification of the checksum-generating tools.
Your patches look fine. One nit: please drop the "Please" here :-)

+  print "\nPlease note that the SHA256 checksum is base64 encoded and not\n";