PGP-encrypted git remotes
:Manual section: 1
git-remote-gcrypt is a git remote helper to push and pull from repositories encrypted with GnuPG, using a custom format. This remote helper handles URIs prefixed with
Supported backends are
sftp://, where the repository is stored as a set of files, or instead any where gcrypt will store the same representation in a git repository, bridged over arbitrary git transport. See "Performance" below for backends comparison.
There is also an experimental
rclone://backend for early adoptors only (you have been warned).
The aim is to provide confidential, authenticated git storage and collaboration using typical untrusted file hosts or services.
use your GNU/Linux distribution's package manager -- Debian, Ubuntu, Fedora, Arch and some smaller distros are known to have packages
run the supplied
install.shscript on other systems
Create an encrypted remote by pushing to it::
git remote add cryptremote gcrypt::rsync://example.com:repo git push cryptremote master > gcrypt: Setting up new repository > gcrypt: Remote ID is :id:7VigUnLVYVtZx8oir34R > [ more lines .. ] > To gcrypt::[...] > * [new branch] master -> master
git-config(1)variables are supported:
gcrypt.participantsSpace-separated list of GPG key identifiers. The remote is encrypted to these participants and only signatures from these are accepted.
gpg -klists all public keys you know.
If this option is not set, we encrypt to your default key and accept any valid signature. This behavior can also be requested explicitly by setting participants to ``simple``.
gcrypt-participantssetting on the remote takes precedence over the repository variable
gcrypt.publish-participantsBy default, the gpg key ids of the participants are obscured by encrypting using
gpg -R. Setting this option to
truedisables that security measure.
The problem with using ``gpg -R`` is that to decrypt, gpg tries each available secret key in turn until it finds a usable key. This can result in unnecessary passphrase prompts.
gcrypt.gpg-argsThe contents of this setting are passed as arguments to gpg. E.g.
user.signingkey(The latter from regular git configuration) The key to use for signing. You should set
user.signingkeyif your default signing key is not part of the participant list. You may use the per-remote version to sign different remotes using different keys.
gcrypt.rsync-put-flagsFlags to be passed to
rsyncwhen uploading to a remote using the
rsync://backend. If the flags are set to a specific remote, the global flags, if also set, will not be applied for that remote.
gcrypt.require-explicit-force-pushA longstanding bug is that every git push effectively has a
If this flag is set to ``true``, git-remote-gcrypt will refuse to push, unless ``--force`` is passed, or refspecs are prefixed with ``+``.
GCRYPTFULLREPACK When set (to anything), this environment variable forces a full repack when pushing.
How to set up a remote for two participants::
git remote add cryptremote gcrypt::rsync://example.com:repo git config remote.cryptremote.gcrypt-participants "KEY1 KEY2" git push cryptremote master
How to use a git backend::
# notice that the target git repo must already exist and its # `next` branch will be overwritten! git remote add gitcrypt gcrypt::[email protected]:repo#next git push gitcrypt master
The URL fragment (
#nexthere) indicates which backend branch is used.
Collaboration The encryption of the manifest is updated for each push to match the participant configuration. Each pushing user must have the public keys of all collaborators and correct participant config.
rclone:respectively. The main executable requires a POSIX-compliant shell that supports
GNU Privacy Guard Both GPG 1.4 and 2 are supported. You need a personal GPG key. GPG configuration applies to algorithm choices for public-key encryption, symmetric encryption, and signing. See
man gpgfor more information.
Remote ID The Remote ID is not secret; it only ensures that two repositories signed by the same user can be distinguished. You will see a warning if the Remote ID changes, which should only happen if the remote was re-created.
Performance Using an arbitraryor an
sftp://URI requires uploading the entire repository history with each push. If your repository history is large or you are pushing over a slow link, consider using the
rsync://transport, which performs incremental pushes. Note that the latter won't work with a repository hosting service like Gitolite, GitHub or GitLab.
rsync URIs Note that the URI format for the rsync backend is, regretably, non-standard. git-remote-gcrypt uses
rsync://[email protected]:pathwhereas plain rsync uses either
rclone backend In addition to adding the rclone backend as a remote with URI like
gcrypt::rclone://remote:subdir, you must add the remote to the rclone configuration too. This is typically done by executing
rclone config. See rclone(1).
The rclone backend is considered experimental and is for early adoptors only. You have been warned.
Repository format .................
EncSign(X):Sign and Encrypt to GPG key holder |
Encrypt(K,X):Encrypt using symmetric-key algorithm |
Hash(X):SHA-2/256 | |
B:branch list |
L:list of the hash (
Hi) and key (
Ki) for each packfile |
R:Remote ID | | To write the repository: | | Store each packfile
Kiis a new random string and
EncSign(B || L || R)in the manifest | | To read the repository: | | Get manifest, decrypt and verify using GPG keyring →
(B, L, R)| Warn if
Rdoes not match previously seen Remote ID | for each
L: | Get file
Hifrom the server →
Manifest file .............
Example manifest file (with ellipsis for brevity)::
$ gpg -d 91bd0c092128cf2e60e1a608c31e92caf1f9c1595f83f2890ef17c0e4881aa0a 542051c7cd152644e4995bda63cc3ddffd635958 refs/heads/next 3c9e76484c7596eff70b21cbe58408b2774bedad refs/heads/master pack :SHA256:f2ad50316...cd4ba67092dc4 z8YoAnFpMlW...3PkI2mND49P1qm pack :SHA256:a6e17bb4c...426492f379584 82+k2cbiUn7...dgXfyX6wXGpvVa keep :SHA256:f2ad50316...cd4ba67092dc4 1 repo :id:OYiSleGirtLubEVqJpFF
Each item extends until newline, and matches one of the following:
Git object id and its ref
pack ::Packfile hash (
Hi) and corresponding symmetric key (
keep ::Packfile hash and its repack generation
repoThe remote id
extn ...Extension field, preserved but unused.
To detect if a git url is a gcrypt repo, use:
git-remote-gcrypt --check urlExit status is 0 if the repo exists and can be decrypted, 1 if the repo uses gcrypt but could not be decrypted, and 100 if the repo is not encrypted with gcrypt (or could not be accessed).
Note that this has to fetch the repo contents into the local git repository, the same as is done when using a gcrypt repo.
Every git push effectively has
--force. Be sure to pull before pushing.
git-remote-gcrypt can decide to repack the remote without warning, which means that your push can suddenly take significantly longer than you were expecting, as your whole history has to be reuploaded. This push might fail over a poor link.
git-remote-gcrypt might report a repository as "not found" when the repository does in fact exist, but git-remote-gcrypt is having authentication, port, or network connectivity issues.
The original author of git-remote-gcrypt was GitHub user bluss.
The de facto maintainer in 2013 and 2014 was Joey Hess.
The current maintainer, since 2016, is Sean Whitton [email protected].
This document and git-remote-gcrypt are licensed under identical terms, GPL-3 (or 2+); see the git-remote-gcrypt file.
.. this document generates a man page with rst2man .. vim: ft=rst tw=72 sts=4