Interesting.
Assuming your "Kali" tools are in fact up to date to test with newer protocols TLS1.2+, is Dovecot compiled against a recent version of the OpenSSL or GnuTLS library or whatever it uses to support the newer TLS protocols?
Definitely an outdated cipher issue, on Postfix as well as Dovecot....
On July 14, 2021 6:55:19 AM AKDT, Stefan Schumacher s.schumacher@consulting1x1.com wrote:
Hi,
I wish to build a new secure email server. It seems I am on the right way – at least I get no more error messages for Postfix – but Dovecot is still making trouble.
I am using Dovecot 1:2.3.4.1-5+deb10u6 and I am using ISPconfig 3.25 to do the rough configuring and nano and whats left of my brain to do the finer details. Lets start with what I added to conf.d/10-ssl.conf
ssl_cert =
ssl_key =
ssl_cipher_list = EECDH+ECDSA+AESGCM:EECDH+aRSA+AESGCM:EECDH+ECDSA+SHA384:EECDH+ECDSA+SHA256:EECDH+aRSA+SHA384:EECDH+aR$
ssl_protocols = !SSLv2 !SSLv3 !TLSv1 !TLSv1.1
ssl_min_protocol = TLSv1.2
As you can see, I clearly do not want to use TLS before v1.2. I think this is not unreasonable in the year 2021.
Now, after the changes I ran Kali (I use it to verify the results of my experiments)
and - this is a mailing list, so no screenshots:
It says:
SSL/TLS Deprecated TLS v1.0 and TLS v1.1 Detection. I get this for the ports 143, 110, 993 and 995.
I thought I had done everything one could to disable old TLS-Versions. What am I doing wrong?
Yours sincerely
Stefan Schumacher
-- Sent from my Android device with K-9 Mail. Please excuse my brevity.