running dovecot 2.3.18 (current)

can do connection test

# openssl s_client -connect localhost:993 -tls1             
CONNECTED(00000003)
write:errno=0
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 104 bytes
Verification: OK
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
    Protocol  : TLSv1
    Cipher    : 0000
    Session-ID:
    Session-ID-ctx:
    Master-Key:
    PSK identity: None
    PSK identity hint: None
    SRP username: None
    Start Time: 1649941141
    Timeout   : 7200 (sec)
    Verify return code: 0 (ok)
    Extended master secret: no
---

and worked ok

currently i hve the min version remmed out?

ssl = yes
verbose_ssl = yes
ssl_dh =</usr/local/etc/dovecot/dh-4096.pem
ssl_prefer_server_ciphers = yes


#ssl_min_protocol = TLSv1.2





On 4/12/2022 3:32 PM, Myriam Luce wrote:

Hi, I'm trying to enable TLS1.0 support for an old client. Per dovecot -n

# 2.3.7.2 (3c910f64b): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.5.7.2 ()



# OS: Linux 5.4.0-107-generic x86_64 Ubuntu 20.04.4 LTS ext4
# Hostname:

In 10-ssl.conf, I have set

ssl_min_protocol = TLSv1

(It doesn't show in dovecot -n, I suspect because it's equal to default value?) I restarted dovecot with systemctl. Then, from another machine,

openssl s_client -connect zeserver.com:993 -tls1

fails with this output:

CONNECTED(00000003)
140166917489984:error:141E70BF:SSL routines:tls_construct_client_hello:no protocols available:../ssl/statem/statem_clnt.c:1112:
---
no peer certificate available
---
No client certificate CA names sent
---
SSL handshake has read 0 bytes and written 7 bytes
Verification: OK
---
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
Early data was not sent
Verify return code: 0 (ok)
---

The same command with -tls1_2 works as intended (certificate printing, imap prompt).

Am I forgetting something somewhere, or is this an actual bug?