GNU Privacy Guard-encrypted git remote
Remote helper programs are invoked by git to handle network transport. This helper handles gcrypt:: URLs that will access a remote repository encrypted with GPG, using our custom format.
Supported locations are local, rsync:// and sftp://, where the repository is stored as a set of files, or instead any <giturl> where gcrypt will store the same representation in a git repository, bridged over arbitrary git transport.
The aim is to provide confidential, authenticated git storage and collaboration using typical untrusted file hosts or services. PLEASE help us evaluate how well we meet this design goal!
This is a development version -- Repository format MAY CHANGE.
git-remote-gcryptby running the supplied
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:
Space-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
gcrypt-participantssetting on the remote takes precedence over the repository variable
- (From regular git configuration) The key to use for signing. You
user.signingkeyif your default signing key is not part of the participant list.
- This environment variable forces 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::firstname.lastname@example.org:repo#next git push gitcrypt master
The URL fragment (#next here) indicates which backend branch is used.
- 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.
sftp: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.
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 :<hashtype>:<hash> <key>
- Packfile hash (Hi) and corresponding symmetric key (Ki).
keep :<hashtype>:<hash> <generation>
- Packfile hash and its repack generation
- The remote id
extn <name> ...
- Extension field, preserved but unused.
This document and git-remote-gcrypt are licensed under identical terms, GPL-3 (or 2+), see the git-remote-gcrypt file.