On Thursday 22 April 2010 18:15:18 Phil Howard wrote: [ ... all standard stuff that is well documented ... ]
- Passwords stored encrypted, such as MD5. And it should be a scheme that both Postfix and Dovecot can use so I don't have keep two different encryption schemes.
Postfix doesn't need any password directly. It only authenticates a user with a password in one case: SMTP SASL authentication of submission users, and it uses the dovecot auth service for that and does not read the password database itself.
- I'd prefer not to, but it looks like I will have to copy data from one format to another format so Dovecot can read it and Postfix can read it. I will most likely be using the CDB format (the constant database file format from Dan Bernstein ... which I'd think should be easy enough for a future version of Dovecot to support).
It is not about supporting a certain database library. There is simply a difference in what Dovecot and Postfix need from a user/recipient database. Dovecot needs information like path to mailbox, uid/gid with which to put files into the mailboxes, extra configuration fields ... Therefore it uses a structured multi-value format like the passwd-file. CDB or similar don't work like this, so dovecot can't easily support using the same CDB files as postfix.
Postfix only supports name:value tables, either to use the value (table-style lookup) or to check whether there is an entry for a name (list-style lookup). Therefore it only uses file databases with such a mapping. In the case of valid recipients which will be handed off to dovecot for delivery, it is such a simple list lookup.
(If it interests you: the postfix virtual delivery agent needs very similar information to dovecot, but it uses several key:value maps for the different information, all with the recipient as key.)
- I am wondering if I can trick Postfix into reading virtual user info by running it chrooted where I substitute /etc/passwd and /etc/shadow with stuff I generate from Dovecot files.
If you need to generate the files that postfix uses, you can generate supported lookup table formats as well.
Rainer