edmgutil
edmgutil is a simple wrapper utility to hdiutil to help you work with disposable, encrypted DMGs. It can decompress an encrypted ZIP into a newly mounted encrypted DMG, create empty throwaway DMGs and automatically eject expired ones. This makes transferring and working with data that should only live for a short period of time for debugging purposes to developer machines a more convenient endeavour. The volume is individually encrypted and gets destroyed when ejected.
It also instructs the backup tool to disable backing up the volume in case someone accidentally adds it.
Installation
cargo install --git https://github.com/getsentry/edmgutil --branch main edmgutil
Note that this requires 7z to be installed. If you don't have it:
brew install p7zip
Importing Encrypted Zip Archives
edmgutil import /path/to/encrypted.zip
It will prompt for the password, then create an encrypted volumne with the same password and then extract the zip file into it and then delete the created dmg (unless -k is passed).
Once the DMG is ejected everything is gone again.
When the DMG is created a timestamp is frozen into it (defined by --days, defaults to 7). It's recommended to run edmgutil eject --expired regularly to automatically unmount expired images for instance by putting it into your crontab (see edmgutil cron).
To create an encrypted zip use 7zip:
7za a -tzip -p'the password' -mem=AES256 encrypted.zip folder
Just make sure to use a long password, maybe something like this:
openssl rand -hex 32
Creating Empty DMGs
To create an empty, encrypted DMG use the new command and provide the size of the DMG in megabytes. Alternatively you can provide a descriptive name which will become the volume name:
edmgutil new --size 100 --name "My Stuff"
Listing / Ejecting
To list and eject encrypted DMGs you can use the following commands:
edmgutil list
edmgutil eject --expired
edmgutil eject --all
edmgutil eject /Volumes/EncryptedVolume
Crontab
To ensure that expired images are ejected automatically when possible can can install a crontab which runs ejecting hourly:
edmgutil cron --install
3 Oct 10, 2022
12 Dec 30, 2022
5 Sep 27, 2023
9 Sep 29, 2023
11 Sep 5, 2022
3 Aug 1, 2022
29 Jun 13, 2023
9 Sep 11, 2023
7 Dec 17, 2022
51 Dec 17, 2022
91 Jan 8, 2023
71 Dec 30, 2022
3 Sep 16, 2022
41 Jan 5, 2023
16 Jul 12, 2022
22 Nov 6, 2022
4 Jul 29, 2022
7 Dec 8, 2022
2 Oct 8, 2022