Mixed Autehtnication and password schemes

[Raymond Sellars]

Hi

Looking for some confirmation/direction on how to achieve the following. 

We have a requirement to support both SASL PLAIN and DIGEST-MD5 authentication (certification reasons). In addition to this we have an application (webmail) that utilises a master password pattern for access, as the contain web portal provides the necessary authentication.

I have access to users passwords in PLAIN text and looking to utilise the dict lookup mechanism for passwords.

Problem #1

https://wiki2.dovecot.org/Authentication/MultipleDatabases - "Currently the fallback works only with the PLAIN authentication mechanism."

The above not suggests I can't use DIGEST-MD5 with master password configuration, if using more than one passdb setup. I don't understand why there would be a restriction as the password validation should just fall through irrespective.

Problem #2 How do I enforce some kind of account access policy

Currently we're backing the authentication with an Identity and Authentication system. I would like to block IMAP access if a user's account is locked out, expired, or inactive. Similarly if there are too many IMAP attempts with the incorrect password I would like the account system wide to be locked out.

With Dict lookup I don't seem a mechanism to keep the IDM system aware of login attempt/failures, since it pulls the plaintext password and validates internally. Is this possible?

As a worse case does Dovecot implement any type of account access policies? Out IT security reviewers are hot on account policies, i.e. lockouts, expiries, and back off attempts.

Thanks
Raymond
Solution Architect - Orion Health