[git-remote-gcrypt](https://spwhitton.name/tech/code/git-remote-gcrypt/)
adds support for encrypted remotes to git. The git-annex 
[[gcrypt special remote|special_remotes/gcrypt]] allows git-annex to
also store its files in such repositories. Naturally, git-annex encrypts
the files it stores too, so everything stored on the remote is encrypted.

Here are some ways you can use this awesome stuff..

[[!toc ]]

This page will show how to set it up at the command line, but the git-annex
[[assistant]] can also be used to help you set up encrypted git
repositories.

## prerequisites

* Install [git-remote-gcrypt](https://spwhitton.name/tech/code/git-remote-gcrypt/)
* Install git-annex version 4.20130909 or newer.

## encrypted backup drive

Let's make a USB drive into an encrypted backup repository. It will contain
both the full contents of your git repository, and all the files you
instruct git-annex to store on it, and everything will be encrypted so that
only you can see it.

First, you need to set up a gpg key. You might consider generating a
special purpose key just for this use case, since you may end up wanting to
put the key on multiple machines that you would not trust with your
main gpg key.

You need to tell git-annex the keyid of the key when setting up the
encrypted repository:

	git init --bare /mnt/encryptedbackup
	git annex initremote encryptedbackup type=gcrypt gitrepo=/mnt/encryptedbackup keyid=$mykey
	git annex sync encryptedbackup

Now you can copy (or even move) files to the repository. After
sending files to it, you'll probably want to do a sync, which pushes
the git repository changes to it as well.

	git annex copy --to encryptedbackup ...
	git annex sync encryptedbackup

Note that if you lose your gpg key, it will be *impossible* to get the
data out of your encrypted backup. You need to find a secure way to store a
backup of your gpg key. Printing it out and storing it in a safe deposit box,
for example.

You can actually specifiy keyid= as many times as you like to allow any one
of a set of gpg keys to access this repository. So you could add a friend's
key, or another gpg key you have.

To restore from the backup, just plug the drive into any machine that has
the gpg key used to encrypt it, and then:

	git clone gcrypt::/mnt/encryptedbackup restored
	cd restored
	git annex enableremote encryptedbackup gitrepo=/mnt/encryptedbackup
	git annex get --from encryptedbackup

## encrypted git-annex repository on a ssh server

If you have a ssh server that has rsync installed, you can set up an
encrypted repository there. Works just like the encrypted drive except
without the cable.

First, on the server, run:

	git init --bare encryptedrepo

(Also, install git-annex on the server if it's possible & easy to do so.
While this will work without git-annex being installed on the server, it
is recommended to have it installed.)

Now, in your existing git-annex repository, set up the encrypted remote:

	git annex initremote encryptedrepo type=gcrypt gitrepo=ssh://my.server/home/me/encryptedrepo keyid=$mykey
	git annex sync encryptedrepo

If you're going to be sharing this repository with others, be sure to also
include their keyids, by specifying keyid= repeatedly.

Now you can copy (or even move) files to the repository. After
sending files to it, you'll probably want to do a sync, which pushes
the git repository changes to it as well.

	git annex copy --to encryptedrepo ...
	git annex sync encryptedbackup

Anyone who has access to the repo it and has one of the keys
used to encrypt it can check it out:

	git clone gcrypt::ssh://my.server/home/me/encryptedrepo myrepo
	cd myrepo
	git annex enableremote encryptedrepo gitrepo=ssh://my.server/home/me/encryptedrepo
	git annex get --from encryptedrepo

## private encrypted git remote on hosting site

You can use gcrypt to store your git repository in encrypted form on any
hosting site that supports git. Only you can decrypt its contents.
Using it this way, git-annex does not store large files on the hosting site; it's
only used to store your git repository itself.

	git remote add encrypted gcrypt::ssh://hostingsite/myrepo.git
	git push encrypted master git-annex

Now you can carry on using git-annex with your new repository. For example,
`git annex sync` will sync with it.

To check out the repository from the hosting site, use the same gcrypt::
url you used when setting it up:

	git clone gcrypt::ssh://hostingsite/myrepo.git

## multiuser encrypted git remote on hosting site

Suppose two users want to share an encrypted git remote. Both of you
need to set up the remote, and configure gcrypt to encrypt it so that both
of you can see it.
	
	git remote add sharedencrypted gcrypt::ssh://hostingsite/myrepo.git
	git config remote.sharedencrypted.gcryt-participants "$mykey $friendkey"
	git push sharedencrypted master git-annex
