'hostname "mail.domain.tld" does not match the server certificate' :: SNI サポートは?Discourse コンテナから証明書をクエリする方法は?

I’m getting some kind of a certificate error when accessing the pop3 mail server from another server on our domain. The resultant message is: Job exception: hostname "mail.domain.tld" does not match the server certificate, but does not give the actual hostname mismatch information within the backtrace.

First, SNI is required in this situation and a sysadmin has suggested that Discourse may not be configured properly to use SNI and thus the error message. The certs have tested out and seem to have no problems.

Second, just to make sure I’m on the same page with debug: How should access POP3 (or the cert request and comparison) from within the Discourse container so as to actually get this data that is being compared to indicated a certificate mismatch? I’d like to do a sanity check here to be sure I’m comparing proverbial apples to apples…

「いいね!」 4

I did check in to see if SNI could be disabled on the sever and the reply was that it’s not possible. The sysadmin said:

Please note that there is no supported mechanism for disabling mail SNI, so you will need to work with the Discourse developers to support it. These pages may be of assistance to you in doing that:

ruby - OpenSSL::SSL::SSLContext SNI servername_cb Not Working - Stack Overflow
ruby - OpenSSL::X509::Certificate Showing Certificate for Wrong Domain - Stack Overflow

My recommendation would be to use Straightforward direct-delivery incoming mail rather than pop3.

「いいね!」 2

I’m really glad you pointed that out, I’d not seen this option anywhere and wish I’d known about the this from the get-go. Might be a good idea to add this info to the installation instructions or perhaps even mention it within the app.yaml as something to consider when setting up the email section.

I did ask for some input there as well for some additional clarity given my scenario. Please feel free to chime in.

It’s actually linked in the top post of Set up Reply via Email Support:

:bell: Alternately, if you aren’t comfortable using GMail for this, you can set up your own incoming email service using Straightforward direct-delivery incoming mail

Your original post doesn’t specify which documentation you were following to go down the POP3 rabbit hole, but assuming you were looking at the official guide linked above it has been linked in there since March 28.

I’ve responded to your reply in the other topic to suggest how to structure addresses/domains when using this.

「いいね!」 1

私も参加表明します。また、SNI サポートの実装を心よりお願いいたします。Postfix と Dovecot は過去 1 年間でそれぞれ対応を完了し、私を含め多くの方がすでに移行を完了しています。Discourse は通常、こうした技術には早くから対応しているため、ロードマップからそれが欠落しているのは正直言って驚きました。

「いいね!」 1

SNIが今後の開発の検討事項に含まれているか確認したくてご連絡しました。SafariとOutlookはどちらもSNIをサポートしており、すでに約5年間対応しています。もしSNIを単一のメールサーバーを指す代わりに直接使用できれば、メールサーバーの設定が大幅に簡素化されるのですが。

「いいね!」 1