RE: Certificate and showing a sign-cert not there

9 Feb 2022 · *clients*


      You shouldn't need a root in the full chain, because the client already has to have the root cert, but you do need all the links in the chain up to the root.
On February 8, 2022 4:13:06 PM AKST, Wayne Spivak WSpivak@SBANetWeb.com wrote:
...
Justina,
The vendor I have, which is having the difficulty is still saying he gets a self-signed cert… but as I showed in my last email after I added Intermediate to the certificate, everything was ok.
So ServerCert, Intermediate, Root in same file should solve this?
Wayne
From: dovecot dovecot-bounces@dovecot.org On Behalf Of justina colmena ~biz
Sent: Tuesday, February 8, 2022 2:44 PM
To: dovecot@dovecot.org
Subject: Re: Certificate and showing a sign-cert not there
In general:
Lots of mail servers out in the wild do not require TLS or even bother to verifying TLS certificates when connecting to a remote server on port 25.
However, desktop and mobile email *clients* tend to be much stricter about verifying server certificates when connecting via SSL or TLS, mainly to protect user passwords.
Sometimes the server certificate needs to be presented with a "full chain" appended to it for verification. That has been an issue before when I've used some certs, particularly StartSSL before Letsencrypt started offering free certs.
On February 8, 2022 5:53:34 AM AKST, Wayne Spivak mailto:WSpivak@SBANetWeb.com > wrote:
Hi –
I am running Postfix 3.6.4 with Dovecot 2.3.17.1 (476cd46418).
I have a multi-signed cert from Entrust.
The cert works fine on port 25.
However, on Port 587 I get an error: c
[root@mcq wbs]# openssl s_client -connect mcq.sbanetweb.com:993 -servername mcq.sbanetweb.com
CONNECTED(00000003)
depth=0 C = US, ST = New York, L = Bellmore, O = SBA  Consulting LTD, CN = mcq.sbanetweb.com
verify error:num=20:unable to get local issuer certificate
verify return:1
depth=0 C = US, ST = New York, L = Bellmore, O = SBA  Consulting LTD, CN = mcq.sbanetweb.com
verify error:num=21:unable to verify the first certificate
verify return:1
depth=0 C = US, ST = New York, L = Bellmore, O = SBA  Consulting LTD, CN = mcq.sbanetweb.com
verify return:1

Certificate chain
0 s:C = US, ST = New York, L = Bellmore, O = SBA  Consulting LTD, CN = mcq.sbanetweb.com
i:C = US, O = "Entrust, Inc.", OU = See www.entrust.net/legal-terms http://www.entrust.net/legal-terms , OU = "(c) 2012 Entrust, Inc. - for authorized use only", CN = Entrust Certification Authority - L1K
[root@mcq wbs]# dovecot -n
# 2.3.17.1 (476cd46418): /etc/dovecot/dovecot.conf
# OS: Linux 5.16.5-200.fc35.x86_64 x86_64 Fedora release 35 (Thirty Five)
# Hostname: mcq.sbanetweb.com
auth_mechanisms = plain login
disable_plaintext_auth = no
mbox_write_locks = fcntl
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 {
unix_listener /var/spool/postfix/private/auth {
group = postfix
mode = 0666
user = postfix
}
unix_listener auth-userdb {
group = postfix
mode = 0666
user = postfix
}
}
service imap-login {
inet_listener imap {
port = 143
}
inet_listener imaps {
port = 993
ssl = yes
}
}
service submission-login {
inet_listener submission {
port = 587
}
}
ssl = required
ssl_cert = 
ssl_cipher_list = ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:AES128-GCM-SHA256:AES256-GCM-SHA384:AES128-SHA256:AES256-SHA256:AES128-SHA:AES256-SHA:AES:CAMELLIA:DES-CBC3-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!MD5:!PSK:!aECDH:!EDH-DSS-DES-CBC3-SHA:!EDH-RSA-DES-CBC3-SHA:!KRB5-DES-CBC3-SHA
ssl_client_ca_dir = /etc/postfix/tls/
ssl_client_ca_file = ChainBundle.pem
ssl_dh = # hidden, use -P to show it
ssl_key = # hidden, use -P to show it
ssl_prefer_server_ciphers = yes
userdb {
driver = passwd
}
protocol imap {
mail_max_userip_connections = 15
}
Any ideas?
Wayne Spivak
SBANETWEB.com
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.
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Sent from my Android device with K-9 Mail. Please excuse my brevity.