I believe it is possible though I am not sure if it is without including https://github.com/ruby-ldap/ruby-net-ldap which I think that should go under another plugin for LDAP specific.

If you can give me the output of this in something like an irb session I might be able to help more: https://github.com/sensu-plugins/sensu-plugins-ssl/blob/1.4.0/bin/check-ssl-host.rb#L146 it might end up being quite simple.

Hi, thanks for your help
sorry, i'm not good with ruby... can you explain me how to do the irb session ?

assuming you have ruby setup you just type irb this drops you into an interactive ruby shell, from here you can start copying and pasting code from the plugin and it should spit back results. Basically I just need to see what the socket returns when you try hitting it so we can see if there is something that we can determine if we are ok or if there is an issue.

feel free to join us in the community slack:

• signup: http://sensucommunityslack.herokuapp.com/
• login: https://sensucommunity.slack.com

The manpage for s_client from openssl-1.1.0g-1.fc27.x86_64, which is what fedora 27 is shipping with, lists:

   -starttls protocol
       send the protocol-specific message(s) to switch to TLS for
       communication.  protocol is a keyword for the intended protocol.
       Currently, the only supported keywords are "smtp", "pop3", "imap",
       "ftp", "xmpp", "xmpp-server", and "irc."

So starttls for ldap isn't going to work with 1.1.0g.

It looks like ldap support has been merged into openssl, and includes a manpage update:

openssl/openssl#2293

I don't know if that is part of 1.1.1 or not.

It is part of the 1.1.1 pre releases: openssl/openssl@398b0bb#diff-7f3b79983f6d53c047c90a62813cc11f

ok when there is a stable release we can consider bringing it in but as @jothoma1 we may need to wait until distributions catch up with it.

Considering that EL7/etc. are still largely using 1.0.2, it will likely be awhile. On the other hand, I think 1.1.1 is supposed to include TLS1.3, which is probably a strong selling point.