Hello,

my reading is that you want to force sendmail to issue STARTTLS, when 
connecting to the remove LMTP mailer.

In the documentation for M(ailer) I cound not find how to do this.

The third parameter to your A= is the port to connect to.

You can try to use the access database and put there Try_TLS:<hostname><TAB>OK. 
Don’t ask for details, I touch sendmail very rarely and each time I do  so I 
have to rediscover how things work.

The problem might be, that sendmail (acting as client) does not recognize the 
certificate of the LMTP server.

Your sendmail might be compiled without STARTTLS support.

You can try to start sendmail under strace and see what exactly does it send to 
the LMTP client.

You could also run stunnel on both sides - one accepts plain text connection, 
encrypts it using TLS, the other stunnel receives that TLS traffic and forwards 
it as plain text to the local system.  Not efficient, but effective. 

Greetings
  Дилян

-----Original Message-----
From: rvan...@netassemble.com
Reply-To: Info <info@cyrus.topicbox.com>
To: Info <info@cyrus.topicbox.com>
Subject: cyrusv2 (lmtp) broken with tls enabled?
Date: 19/07/24 19:36:17

Hi,

 I cannot get sendmail with the cyrusv2 mailer to send messages over lmtp with 
tls enabled on the cyrus imap server.

I have a public smtp server running sendmail that is configured to forward 
received items to a second server running cyrus imapd version 3.4.3. if I 
disable tls on the second server the items are received with no issues, even if 
I am using mech: DIGEST-MD5 for authentication. I think the issue is that the 
public server with cyrusv2 mailer is not using starttls:

:inittls: Loading hard-coded DH parameters
: Set client CA list: Client cert requested, not required
: SSL_accept() incomplete -> wait
: SSL_accept() incomplete -> wait
: Doing a peer verify
: verify error:num=30:authority and subject key identifier mismatch
: certificate verify failed in SSL_accept() -> fail

I believe the "verify error:num=30:authority and subject key identifier 
mismatch" is caused when a non ssl connection is trying to connect to an port 
that has ssl enabled.

if I run  lmtptest from the public server it connects with out issue:

lmtptest -t "" -p 24 -m DIGEST-MD5 -a cy...@example.com  -w mypassword 
imap.example.com

: inittls: Loading hard-coded DH parameters
: Set client CA list: Client cert requested, not required
: SSL_accept() incomplete -> wait
: SSL_accept() incomplete -> wait
: SSL_accept() succeeded -> done
: starttls: TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits new) no 
authentication
: login: imap.example.com [x.x.x.x] cy...@example.com DIGEST-MD5+TLS User 
logged in

Here is my Mailer config in the sendmail.cf file:

Mcyrusv2,       P=[IPC], F=lsDFMnqXzA@/:|m,
                S=EnvFromSMTP/HdrFromL, R=EnvToL/HdrToL, E=\r\n,
                T=DNS/RFC822/SMTP,
                A=TCP imap.example.com lmtps

I also tried:
             A=TCP imap.example.com lmtp

lmtp\lmtps is configured to use port 24 in /etc/services

Is there a option needed to tell the cyrusv2 mailer to use starttls for lmtp 
connections? The public server with cyrusv2 is cyrus-imapd 3.6.0-1. Both 
servers are using openssl 3.0

Disabling tls from imapd.conf on the imap (second) server does allow the items 
to be received. but I would prefer to have tls running. 

Thank You




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