Added some -v to see if that might give some clues to why it is working for me. Letsencrypt recently upgraded their middle keys so the older one might be cached/installed somewhere?
[smooge@xanadu ~]$ LANG=C curl -vvv -I
https://koji.mbox.centos.org* Rebuilt URL to:
https://koji.mbox.centos.org/* Trying 8.43.84.206...
* TCP_NODELAY set
* Connected to
koji.mbox.centos.org (8.43.84.206) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* successfully set certificate verify locations:
* CAfile: /etc/pki/tls/certs/ca-bundle.crt
CApath: none
* TLSv1.3 (OUT), TLS handshake, Client hello (1):
* TLSv1.3 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-AES256-GCM-SHA384
* ALPN, server did not agree to a protocol
* Server certificate:
* subject: CN=
koji.mbox.centos.org* start date: Jan 4 06:56:29 2021 GMT
* expire date: Apr 4 06:56:29 2021 GMT
* subjectAltName: host "
koji.mbox.centos.org" matched cert's "
koji.mbox.centos.org"
* issuer: C=US; O=Let's Encrypt; CN=R3
* SSL certificate verify ok.
> HEAD / HTTP/1.1
> Host:
koji.mbox.centos.org> User-Agent: curl/7.61.1
> Accept: */*
>
< HTTP/1.1 302 Found
HTTP/1.1 302 Found
< Date: Wed, 06 Jan 2021 20:31:21 GMT
Date: Wed, 06 Jan 2021 20:31:21 GMT
< Server: Apache/2.4.39 (Fedora) mod_wsgi/4.6.4 Python/2.7 OpenSSL/1.1.1b
Server: Apache/2.4.39 (Fedora) mod_wsgi/4.6.4 Python/2.7 OpenSSL/1.1.1b
< Location:
https://koji.mbox.centos.org/koji/Location:
https://koji.mbox.centos.org/koji/< Connection: close
Connection: close
< Content-Type: text/html; charset=iso-8859-1
Content-Type: text/html; charset=iso-8859-1
<
* Closing connection 0
* TLSv1.2 (OUT), TLS alert, close notify (256):