[Dovecot] passwd-file management utility

I'm now putting together tools/documentation to manage/administer the mail server, including, of course, managing users. Round one will be command line tools. In order to avoid re-invention, I was looking around for existing tools. I really cannot find any. So it seems I will be developing them. The first will be the one to manage users in the passwd-file format. So I'm just asking around if anyone has heard of such tools somewhere Google isn't finding (it does find lots of generic pages with the keywords used in other contexts). If not, I'll be building my own (and this will be for passwd-file format for the userdb/passdb),