What exactly does "Can't use SSL_get_servername" mean?

[ckcr4lyf]

I am trying to manually connect to a HTTPS server, WITHOUT SNI.

It works, but I would like to understand this "warning message" that comes up:

$ openssl s_client -connect 66.254.114.41:443
CONNECTED(00000003)
Can't use SSL_get_servername
depth=2 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert Global Root CA
verify return:1
depth=1 C = US, O = DigiCert Inc, CN = DigiCert TLS Hybrid ECC SHA384 2020 CA1
verify return:1
depth=0 C = CY, L = Dali, O = MG Freesites Ltd, CN = *.pornhub.com
verify return:1
---
[truncated]

I found #12731 (comment), where matt implies the server did not acknowledge the SNI extension.

However in my case, I never sent the SNI extension, though the server did give it's cert and everything else proceeded as expected:

Just want to understand the meaning of Can't use SSL_get_servername.

Thanks. If you need the pcap or similar I'd be happy to attach it.

[t8m]

It means there is no SNI extension used.

[ckcr4lyf]

Thanks for the clarification.