imapc and masteruser

[Sami Ketola]

> On 28 Sep 2017, at 23.08, Computerisms Corporation <bob at computerisms.ca> wrote:
> 
> Hi Sami,
> 
> Thank you for your reply.
>> yes you do need to define imapc_user if you want to switch user and master user around for imapc. like:
>> imapc_user = authapps
>> imapc_master_user = %u
>> without imapc_user dovecot would login to the secondary server like A bob.test*bob.test password
> 
> When I add the 'imapc_user = authapps' option to the primary instance running on port 993, it passes the imapc_password as the password for the master user.  here is what the logs on the shared instance show when I log into the primary instance:
> 
> 2017-09-28 12:47:35.361064500 Sep 28 12:47:35 auth: Debug: ldap(bob.test,192.168.120.70,master,<hU/PLUVavLbAqHhG>): Master user lookup for login: authapps
> 2017-09-28 12:47:35.364892500 Sep 28 12:47:35 auth: Info: ldap(bob.test,192.168.120.70,master,<hU/PLUVavLbAqHhG>): invalid credentials (given password: XXXXXXXXX)
> 2017-09-28 12:47:37.367173500 Sep 28 12:47:37 auth: Debug: client passdb out: FAIL	2	user=bob.test
> 
> 
> The given password in the logs is the password supplied as imapc_password.
> 
> if I change the imapc_password to be that of the bob.test user, the imapc login does succeed with bob.test as the master user.
> 
> I followed this before, and it seemed the solution was to set
> 
> imapc_password = %w
> 
> However, dovecot will not start with this configuration.
> 
> In Sven's email, he places the imapc_password = %w as a default_field in the userdb on the primary instance.  If I remove the default field, I get the invalid credentials reported as above.  However, I still think this is correct way to pass %w, because if I remove 'imapc_user = authapps' from the global config *and*  'imapc_password = %w' from the default_fields in the userdb, the logs on the shared instance show that the user password is not being passed in the imapc login:
> 
> 
> 2017-09-28 12:57:10.409884500 Sep 28 12:57:10 auth: Debug: static(bob.test,192.168.120.70,<rvFSUEVaxLfAqHhG>): lookup
> 2017-09-28 12:57:10.409903500 Sep 28 12:57:10 auth: Debug: static(bob.test,192.168.120.70,<rvFSUEVaxLfAqHhG>): username changed bob.test -> authapps
> 2017-09-28 12:57:10.409905500 Sep 28 12:57:10 auth: Info: static(authapps,192.168.120.70,<rvFSUEVaxLfAqHhG>): No password returned (and no nopassword)
> 2017-09-28 12:57:12.412437500 Sep 28 12:57:12 auth: Debug: client passdb out: FAIL	11	user=authapps	original_user=bob.test
> 
> 
> so maybe I am not passing the %w in the correct spot?
> 
> truly appreciate you taking a look at this, thank you.


Now this starts to be a bit complex. Not sure if you can get this working by returning imapc_password = %w from the first passdb. Atleast if it works it will only work with PLAIN auth scheme.
What I would do here is to just trust that the user is already authenticated with the first ldap passdb in the primary server and then switch the imapc connection to both master user and master password.

So just put imapc_password=masterpassword in dovecot.conf of the primary server and on secondary server modify ldap config not to fetch the user password but always return password=masterpassword.

and maybe protect the authentication scheme with allow_nets=127.0.0.1 from external abuse

Sami