Unexpected config results with local_name + multiple SSL certs

25 Feb 2018

      Working with SSL on fresh install of latest Ubuntu Artful + Dovecot
seems broken somehow.
Application is Dovecot listening for many SSL sites...
Likely I've missed adding something simple to the config, related
to local_name usage.
Be great if someone can point out what I've missed, to setup
multiple SSL certs for different host.domain entries in config.
Thanks.

This works as expected... where the SNI server name is returned...
#local_name imap.cydec.com {
ssl_cert = 
service dovecot restart && echo QUIT | openssl s_client -connect imap.cydec.com:993 -servername imap.cydec.com 2>&1 | egrep ^subject
subject=/CN=imap.cydec.com

This fails...
local_name imap.cydec.com {
ssl_cert = 
service dovecot restart && echo QUIT | openssl s_client -connect imap.cydec.com:993 -servername imap.cydec.com 2>&1 | egrep ^subject
# Empty, so no servername match

Full openssl output shows no cert being returned...
service dovecot restart && echo QUIT | openssl s_client -connect imap.cydec.com:993 -servername imap.cydec.com
CONNECTED(00000004)
write:errno=104
no peer certificate available
No client certificate CA names sent
SSL handshake has read 0 bytes and written 199 bytes
Verification: OK
New, (NONE), Cipher is (NONE)
Secure Renegotiation IS NOT supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
Protocol  : TLSv1.2
Cipher    : 0000
Session-ID:
Session-ID-ctx:
Master-Key:
PSK identity: None
PSK identity hint: None
SRP username: None
Start Time: 1519576210
Timeout   : 7200 (sec)
Verify return code: 0 (ok)
Extended master secret: no

Config seems correct, with local_name uncommented...
dovecot -n
# 2.2.27 (c0f36b0): /etc/dovecot/dovecot.conf
# Pigeonhole version 0.4.16 (fed8554)
# OS: Linux 4.13.0-36-generic x86_64 Ubuntu 17.10
auth_debug = yes
auth_debug_passwords = yes
auth_verbose = yes
debug_log_path = /var/log/dovecot.log
disable_plaintext_auth = no
info_log_path = /var/log/dovecot.log
log_path = /var/log/dovecot.log
mail_debug = yes
mail_location = mbox:~/mail:INBOX=/var/mail/%u
namespace inbox {
inbox = yes
location =
mailbox Drafts {
special_use = \Drafts
}
mailbox Junk {
special_use = \Junk
}
mailbox Sent {
special_use = \Sent
}
mailbox "Sent Messages" {
special_use = \Sent
}
mailbox Trash {
special_use = \Trash
}
prefix =
}
passdb {
args = dovecot
driver = pam
}
protocols = " imap pop3"
service imap-login {
inet_listener imap {
port = 0
}
inet_listener imaps {
port = 993
ssl = yes
}
}
service pop3-login {
inet_listener pop3 {
port = 0
}
inet_listener pop3s {
port = 995
ssl = yes
}
}
userdb {
driver = passwd
}
local_name imap.cydec.com {
ssl_cert = 

Unexpected config results with local_name + multiple SSL certs

David Favor

service dovecot restart && echo QUIT | openssl s_client -connect imap.cydec.com:993 -servername imap.cydec.com CONNECTED(00000004) write:errno=104

no peer certificate available

No client certificate CA names sent

SSL handshake has read 0 bytes and written 199 bytes Verification: OK