On 06.11.2017 13:20, Zbyszek Żółkiewski wrote: > >> Wiadomość napisana przez Aki Tuomi <aki.tu...@dovecot.fi> w dniu 06.11.2017, >> o godz. 08:44: >> >> On 04.11.2017 20:52, Zbyszek Żółkiewski wrote: >>> Hi, >>> >>> I have few questions regarding mail_crypt: >>> >>> 1) Is mail_crypt_global_private_key file read upon dovecot start/restart >>> only or it is/can be read in any other time? I have made few tests by >>> starting dovecot and removing master key for decryption - therefore it is >>> not available on the platform - it only reside in memory, removing one of >>> attack vectors >> It can be given from config file, or from user database. It is read on >> use. You can also encrypt the key using a password, but in the end, the >> password or the key needs to be provided by something. > > yes i am loading it in conf file like: > > mail_crypt_global_private_key = </etc/dovecot/somefile.key > > but then i am removing that file - and it looks like dovecot still is able to > decrypt mails encrypted with that file. So you are saying there might be > situation that this file need to be “re-read” from disk ? Yeah, the file content is loaded into configuration. If you need to re-read it you need to restart dovecot.
> >>> 3) is there any better way to encrypt mails that were sent before enabling >>> mail_crypt ? I have made some simple script to automate and in-place >>> encryption: >>> https://gist.github.com/kolargol/d551d132949068ce6efce7bc85a317cb but maybe >>> there is better way? If someone want to use it, please read code before as >>> it require updating magic(5) local database >>> >>> thanks! >> The Best Practice, supported way, is to move the emails around, so you >> move all your mails from INBOX to FooBox, and then back. This can have >> some side-effects, and you might want to test this. Most notably it will >> consume UIDs, unless you reset the folder by removing indexes. > ok, i was using above script to encrypt hundred of thousands email files and > i did not found any issues, it is also quite fast, do you see any problems > with that ? > > thanks! > > _ > Zbyszek That script looks fine. Aki
