bug#55858: 28.1; process-async-https-with-delay failure

[Robert Pluim]

>>>>> On Thu, 09 Jun 2022 08:26:50 +0300, Eli Zaretskii <eliz@gnu.org> said:
    >> There are two issues here.  First, there's obviously something I should
    >> do on my system so that the TLS certificate for elpa.gnu.org is
    >> trusted.  I know nothing about TLS certificates and would appreciate
    >> help here.

    Eli> Not sure about Cygwin, but in general on MS-Windows GnuTLS uses the
    Eli> system certificate store to verify certificates.  The particular
    Eli> problem above should be solved by upgrading GnuTLS and perhaps also
    Eli> updating the system certificate store (which should be in general
    Eli> always up to date, but I don't know how that system is maintained).

This might be the Let's Encrypt cross-signing certificate expiry
issue, which is fixed in GnuTLS >= 3.6.14 See eg
<https://blog.germancoding.com/2021/04/16/lets-encrypt-and-expired-root-certificates/>

    Eli> OTOH, if Cygwin GnuTLS uses the Posix mechanism of certificate stores
    Eli> on disk files, then upgrading the certificate files.

If Iʼm right, itʼs a problem in GnuTLS, not an issue with the
certificate store.

Alternatively, we could just let-bind `network-security-level' to 'low
in that test, which effectively disables the checking.

Robert
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