Re: LDAP authentication and authorization using Debian and Active Directory

"denis via Info" <[email protected]>
Newsgroups gmane.mail.imap.cyrus
Message-ID <[email protected]>
Hi Jim,

Thanks a lot for our help and time. 
I managed to encrypt the authentication to windows 2022 AD  few days ago.  The method used is nearly identical to yours with slightly difference.
Similarly to your method:
1.      I created ADCS
2.       Exported CA certificate and copied to the mail server
3.      Update the local CA stores on the mail server using update-ca-certificates command
4.      Configuration of /etc/default/saslauthd :-     MECHANISMS = “ldap”
5.      Configuration of /etc/saslauthd.conf  was nearly identical to your method with the exception of the following keywords
a.      ldap_servers: ldap://{DC name here}  instead of ldap_servers: ldaps://{DC name here}:636
b.      ldap_tls_check_peer: yes  in my case this was removed to avoid compilations.
c.      ldap_start_tls: YES this is different from your method basically it starts TLS encryption before authentication.
6.      Configuration of  /etc/imapd.conf  should include the following keywords
a.      allowplaintext: yes
b.      sasl_mech_list: PLAIN
c.      sasl_pwcheck_method: saslauthd
I checked communication with Wireshark and I could confirm that there were several TLS packets exchanges between the domain server and the mails server. Furthermore, when plain text communication was used that is when ldap_start_tls: was NO Windows server 2022 event viewer recorded an informative error with Event ID 2889. Event ID 2889 states the following:
“the following client performed a SASL (Negotiate/NTLM/Digest) LDAP bind without requesting signing (integrity verification), or performed a simple binding over a clear text (non-SSL/TLS-encrypted) LDAP Connection.”
This informative error was caused because in this case simple binding was used.
In contrast, when ldap_start_tls: was YES no similar informative errors were recorded and cyrus managed authenticate with the server.

Regards

Denis

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Cyrus: Info
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