Backing up per user keys for mailcrypt

[Ben Burk]

I am wondering how I can back up keys for mail users in their 
password-protected form, without exporting them from `doveadm mailbox 
cryptokey export`, which requires a password. The goal here is to 
perform routine backups to keep keys current. Relevant config is as follows:


mail_attribute_dict = file:%h/Maildir/dovecot-attributes
mail_plugins = $mail_plugins mail_crypt

plugin {
   mail_crypt_curve = secp521r1
   mail_crypt_save_version = 2
   mail_crypt_require_encrypted_user_key = yes
}


Am i correct in assuming I should back up the dovecot-attributes file? 
Are there any ancillary files that need to be backed up as well, such as 
indexes, to properly read and handle this file?

I have viewed the file and it appears there are several keys at play for 
a single mail user. Do different folders in a users imap space have 
different encryption keys? Are all of these keys populated in this 
dovecot-attributes file?

Is there any established procedure for restoring keys? Is it as simple 
as placing the dovecot-attributes file, if that is infact what needs to 
be backed up beforehand to perform a restore.


-- 
Ben Burk
BURK.TECH System Administrator