Hi Tom, Hm.. I am on the receiving end of this TLS Handshake. I am running -release on one and -current on another. Problem and error messages are the same.
Excerpt of the running postfix main.cf: smtpd_tls_mandatory_ciphers = high smtpd_tls_ciphers = high smtp_tls_mandatory_ciphers = high smtp_tls_ciphers = high tls_ssl_options = NO_COMPRESSION, NO_RENEGOTIATION, PRIORITIZE_CHACHA tls_high_cipherlist = HIGH:+aRSA:+SHA384:+SHA256:+DH:+SHA:+kRSA:!eNULL:!aNULL:!PSK:!SRP:!AESCCM:!DSS:!ARIA smtpd_tls_mandatory_protocols = !SSLv2, !SSLv3 smtpd_tls_protocols = !SSLv2, !SSLv3 smtp_tls_mandatory_protocols = !SSLv2, !SSLv3 smtp_tls_protocols = !SSLv2, !SSLv3 smtpd_tls_security_level = maytfix/smtpd[97536]: mout.web.de[212.227.17.12]:52515: TLS cipher list "HIGH:+aRSA:+SHA384:+SHA256:+DH:+SHA:+kRSA:!eNULL:!aNULL:!PSK:!SRP:!AESCCM:!DSS:!ARIA:!aNULL" Set the tls debug level to 2. The output: postfix/smtpd[97536]: SSL_accept error from mout.web.de[212.227.17.12]:52515: -1 postfix/smtpd[97536]: warning: TLS library problem: error:1404A42E:SSL routines:ST_ACCEPT:tlsv1 alert protocol version:/usr/src/lib/libssl/tls13_lib.c:150: postfix/smtpd[97536]: lost connection after STARTTLS from mout.web.de[212.227.17.12]:52515 postfix/smtpd[97536]: disconnect from mout.web.de[212.227.17.12]:52515 ehlo=1 starttls=0/1 commands=1/2 Best regards, Stephan On Wed, Apr 06, 2022 at 11:41:41PM +0100, Tom Smyth wrote: > Hi Stephan, > at a guess I would say that there is no overlap between supported TLS > protool versions and ciphers > available on the client vs the server. > if your system is using a recent version of an Os and you are trying > to relay to an older legacy system, > ideally ask the older system to uprade / enable higher ciphers.... > or you can be more permissive on your tls configuration... > I hope this is helpful > > On Wed, 6 Apr 2022 at 23:32, Stephan Mending <l...@md5collisions.eu> wrote: > > > > Hi *, > > I've noticed on my mail relays, that tls handshake with one certain email > > relay keep failing. I was wondering what the > > reason for that may be. > > > > Following error from postfix: > > > > connect from mout.web.de[ IP ]:44003 > > SSL_accept error from mout.web.de[ IP ]:44003: -1 > > warning: TLS library problem: error:1404A42E:SSL > > routines:ST_ACCEPT:tlsv1 alert protocol > > version:/usr/src/lib/libssl/tls13_lib.c:150: > > lost connection after STARTTLS from mout.web.de > > > > Can anybody with more knowledge of libressl and it's error messages tell by > > this error what is wrong? > > > > Best regards, > > Stephan > > > > > -- > Kindest regards, u Tom Smyth.