Can you think of any linux command-line method for saving the certificate presented by a HTTPS server? Something along the lines of having curl/wget/openssl make a SSL connection and save the cert rather than the HTTP response content.

The gui equivalent to what I'm looking for would be to browse to the HTTPS site, double-click on the browser "secure site" icon, and export the cert. Except the goal here is to do it non-interactively.

Thanks, Jim


Something like:

openssl s_client -servername remote.server.net -connect remote.server.net:443 </dev/null | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' >/path/to/certificate.pem

That's what I use with fetchmail to retrieve the certificate of an SSL capable IMAP or POP3 server (except obviously I don't use port 443)

(Note that "redundant" -servername parameter is necessary to make openssl do a request with SNI support.)

  • 1
    Any way to get the full chain? – Collin Anderson Nov 10 '17 at 17:35

From http://www.madboa.com/geek/openssl/#cert-retrieve

# usage: retrieve-cert.sh remote.host.name [port]

echo |\
openssl s_client -connect ${REMHOST}:${REMPORT} 2>&1 |\

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.