Dovecot On C7.2 – Secure Internet Access
I have a mail server running on CentOS 7.2 which has been working for my LAN
for a long time.
I’m at the point where I have to make it accessible to the internet. At the moment, access can be insecure but as it’s on my LAN it isn’t an issue.
However, for internet access I wish to force SSL/TLS. Having read the documents I think it’s as simple as changing 10-ssl.conf from
ssl = yes
to
ssl = required remote 10.0.0.0/8 {
ssl = yes
}
Am I right in thinking that this would make the global value now force SSL/TLS
to be required, but for my LAN (10.0.0.0/8) override this with the old value of ‘yes’
Is there a better way to do this?
Have I missed anything?
I believe that this means implies
disable_plaintext_auth = no
for all except my LAN. Is that right?
3 thoughts on - Dovecot On C7.2 – Secure Internet Access
I’ve tried the changes that I put below. Users are still able to log in from the LAN.
However, despite putting the appropriate rule in my firewall allowing port 143
I cannot create a user on a PC outside my network.
I’m using Thunderbird to do the testing. Is there a better way to test my setup? Thunderbird doesn’t give any diagnostic data, it just says it’s failed to test the account.
Am 05.05.2016 um 16:18 schrieb Gary Stainburn:
Connect with:
openssl s_client -connect:143 -starttls imap
Then issue IMAP commands:
01 CAPABILITY
02 LOGIN user password
03 LOGOUT
That should be successful and you should have seen the configured AUTH
mechanisms. Now try without transport layer security:
telnet 143
01 LOGIN user password
That should be forbidden because of LOGINDISABLED.
Regards
Alexander
Thanks for this Alexander.
I tried this from inside my LAN and both the openssl and the telnet sessions worked. I then tried it from outside my LAN and the openssl session worked while the telnet session failed.
Exactly what I wanted. That does beg the question as to why Thunderbird failed.