gnutls-cli chat.gnupg.org
Processed 128 CA certificate(s).
Resolving 'chat.gnupg.org:443'...
Connecting to '2a01:4f8:160:91ea::2:443'...
- Certificate type: X.509
- Got a certificate list of 2 certificates.
- Certificate[0] info:
 - subject `CN=chat.gnupg.org', issuer `CN=Let's Encrypt Authority X3,O=Let's Encrypt,C=US', serial 0x03d7f78021a6db9e6ac9160093e2dcfafd35, RSA key 4096 bits, signed using RSA-SHA256, activated `2020-03-08 15:18:18 UTC', expires `2020-06-06 15:18:18 UTC', pin-sha256="NOxpptpyAEO5Fcpe5LGd8Jya40LLr+0Bzb00xOxxgTs="
        Public Key ID:
                sha1:cf3a7b8389b1f753f5be5681e2ffd7d237c6a656
                sha256:34ec69a6da720043b915ca5ee4b19df09c9ae342cbafed01cdbd34c4ec71813b
        Public Key PIN:
                pin-sha256:NOxpptpyAEO5Fcpe5LGd8Jya40LLr+0Bzb00xOxxgTs=

- Certificate[1] info:
 - subject `CN=Let's Encrypt Authority X3,O=Let's Encrypt,C=US', issuer `CN=DST Root CA X3,O=Digital Signature Trust Co.', serial 0x0a0141420000015385736a0b85eca708, RSA key 2048 bits, signed using RSA-SHA256, activated `2016-03-17 16:40:46 UTC', expires `2021-03-17 16:40:46 UTC', pin-sha256="YLh1dUR9y6Kja30RrAn7JKnbQG/uEtLMkBgFF2Fuihg="
- Status: The certificate is NOT trusted. The certificate chain uses expired certificate. 
*** PKI verification of server certificate failed...
*** Fatal error: Error in the certificate.