Port 143 is no SSL; no client auth; plain password auth. But port 993 is SSL; client cert auth.

[UK Universal Support Limited]

I am experiencing the error
"Error: BUG: Authentication client sent unknown handshake command:"

My goal is
Port 143: no SSL; no client auth; plain password auth.
Port 993: SSL; client cert auth.

I found the archive
http://www.dovecot.org/list/dovecot/2016-February/103067.html


and followed it, but does not work, I see the following log in /var/log/maillog

Aug 21 15:36:42 vps0 dovecot: master: Dovecot v2.2.25 (7be1766) starting up for 
imap (core dumps disabled)
Aug 21 15:37:51 vps0 dovecot: auth: Error: BUG: Authentication client sent 
unknown handshake command: 
REQUEST?1997012993?3734?1?e067999d43eebcecf0c9d44a1c108d75?session_pid=3741?r...
Aug 21 15:37:51 vps0 dovecot: imap: Error: Authentication server didn't send 
valid SPID as expected: MECH#011PLAIN#011plaintext
Aug 21 15:37:51 vps0 dovecot: imap: Error: Disconnected from auth server, 
aborting (client-pid=3734 client-id=1)
Aug 21 15:37:51 vps0 dovecot: imap-login: Internal login failure (pid=3734 id=1) (internal 
failure, 1 successful auths): user=<contact>, method=PLAIN, rip=212.104.147.161, 
lip=46.30.14.36, mpid=3741, TLS, session=<UkXhtpY6W8XUaJOh>
Aug 21 15:37:51 vps0 dovecot: imap-login: Disconnected (no auth attempts in 0 secs): 
user=<>, rip=212.104.147.161, lip=46.30.14.36, TLS handshaking: SSL_accept() failed: 
error:140D9115:SSL routines:SSL_GET_PREV_SESSION:session id context uninitialized, 
session=<nkrktpY6XMXUaJOh>


Can anyone advice any solution?


Dovecot version: 2.2.25 (7be1766)
Operating system:CentOS 7, 64bit, selinux is off.
CPU architecture: Intel x86 64bit.
Filesystem: xfs


# /usr/local/bin/doveconf -n
# 2.2.25 (7be1766): /usr/local/etc/dovecot/dovecot.conf
# OS: Linux 3.10.0-327.28.2.el7.x86_64 x86_64 CentOS Linux release 7.2.1511 
(Core)
auth_mechanisms = plain login
auth_ssl_username_from_cert = yes
disable_plaintext_auth = no
mail_location = maildir:~/Maildir
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 {
  driver = pam
}
protocols = imap
service auth-ssl {
  executable = auth -o auth_ssl_require_client_cert=yes
  unix_listener auth-master-ssl {
    mode = 0666
  }
  unix_listener login/login-ssl {
    mode = 0666
  }
}
service imap-login-ssl {
  chroot = login
  executable = imap-login -l imap-ssl login-ssl
  inet_listener imaps {
    port = 993
    ssl = yes
  }
  user = $default_login_user
}
service imap-login {
  inet_listener imaps {
    port = 0
  }
}
service imap-ssl {
  executable = imap -a auth-master-ssl
  unix_listener login/imap-ssl {
    user = $default_login_user
  }
}
ssl_ca = </etc/SslCert/dovecot/2016080505CAcert.WithCrl.pem
ssl_cert = </etc/SslCert/dovecot/2016080506cert.pem
ssl_key = </etc/SslCert/dovecot/2016080506PrivateKey.NoPassPhrase.pem
userdb {
  driver = passwd
}
protocol imap {
  auth_ssl_require_client_cert = no
  ssl_require_crl = no
  ssl_verify_client_cert = no
}
protocol imaps {
  auth_ssl_require_client_cert = yes
  ssl_require_crl = yes
  ssl_verify_client_cert = yes
}
#