OpenSSL::SSL::SSLSocket#post_connection_check

# File tmp/rubies/ruby-3.0.5/ext/openssl/lib/openssl/ssl.rb, line 390
def post_connection_check(hostname)
  if peer_cert.nil?
    msg = "Peer verification enabled, but no certificate received."
    if using_anon_cipher?
      msg += " Anonymous cipher suite #{cipher[0]} was negotiated. " \
             "Anonymous suites must be disabled to use peer verification."
    end
    raise SSLError, msg
  end

  unless OpenSSL::SSL.verify_certificate_identity(peer_cert, hostname)
    raise SSLError, "hostname \"#{hostname}\" does not match the server certificate"
  end
  return true
end