date: "2019-08-17T10:20:00+01:00" title: "GPG Commit Signatures" slug: "signing" weight: 20 toc: false draft: false menu: sidebar: parent: "advanced" name: "GPG Commit Signatures" weight: 20

identifier: "signing"

GPG Commit Signatures

Table of Contents

Gitea will verify GPG commit signatures in the provided tree by checking if the commits are signed by a key within the Gitea database, or if the commit matches the default key for Git.

Keys are not checked to determine if they have expired or revoked. Keys are also not checked with keyservers.

A commit will be marked with a grey unlocked icon if no key can be found to verify it. If a commit is marked with a red unlocked icon, it is reported to be signed with a key with an id.

Please note: The signer of a commit does not have to be an author or committer of a commit.

This functionality requires Git >= 1.7.9 but for full functionality this requires Git >= 2.0.0.

Automatic Signing

There are a number of places where Gitea will generate commits itself:

Repository Initialisation
Wiki Changes
CRUD actions using the editor or the API
Merges from Pull Requests

Depending on configuration and server trust you may want Gitea to sign these commits.

Installing and generating a GPG key for Gitea

It is up to a server administrator to determine how best to install a signing key. Gitea generates all its commits using the server git command at present - and therefore the server gpg will be used for signing (if configured.) Administrators should review best-practices for GPG - in particular it is probably advisable to only install a signing secret subkey without the master signing and certifying secret key.

General Configuration

Gitea's configuration for signing can be found with the [repository.signing] section of app.ini:

...
[repository.signing]
SIGNING_KEY = default
SIGNING_NAME =
SIGNING_EMAIL =
INITIAL_COMMIT = always
CRUD_ACTIONS = pubkey, twofa, parentsigned
WIKI = never
MERGES = pubkey, twofa, basesigned, commitssigned

...

`SIGNING_KEY`

The first option to discuss is the SIGNING_KEY. There are three main options:

none - this prevents Gitea from signing any commits
default - Gitea will default to the key configured within git config
KEYID - Gitea will sign commits with the gpg key with the ID KEYID. In this case you should provide a SIGNING_NAME and SIGNING_EMAIL to be displayed for this key.

The default option will interrogate git config for commit.gpgsign option - if this is set, then it will use the results of the user.signingkey, user.name and user.email as appropriate.

Please note: by adjusting Git's config file within Gitea's repositories, SIGNING_KEY=default could be used to provide different signing keys on a per-repository basis. However, this is clearly not an ideal UI and therefore subject to change.

`INITIAL_COMMIT`

This option determines whether Gitea should sign the initial commit when creating a repository. The possible values are:

never: Never sign
pubkey: Only sign if the user has a public key
twofa: Only sign if the user logs in with two factor authentication
always: Always sign

Options other than never and always can be combined as a comma separated list. The commit will be signed if all selected options are true.

`WIKI`

This options determines if Gitea should sign commits to the Wiki. The possible values are:

never: Never sign
pubkey: Only sign if the user has a public key
twofa: Only sign if the user logs in with two factor authentication
parentsigned: Only sign if the parent commit is signed.
always: Always sign

Options other than never and always can be combined as a comma separated list. The commit will be signed if all selected options are true.

`CRUD_ACTIONS`

This option determines if Gitea should sign commits from the web editor or API CRUD actions. The possible values are:

never: Never sign
pubkey: Only sign if the user has a public key
twofa: Only sign if the user logs in with two factor authentication
parentsigned: Only sign if the parent commit is signed.
always: Always sign

Options other than never and always can be combined as a comma separated list. The change will be signed if all selected options are true.

`MERGES`

This option determines if Gitea should sign merge commits from PRs. The possible options are:

never: Never sign
pubkey: Only sign if the user has a public key
twofa: Only sign if the user logs in with two factor authentication
basesigned: Only sign if the parent commit in the base repo is signed.
headsigned: Only sign if the head commit in the head branch is signed.
commitssigned: Only sign if all the commits in the head branch to the merge point are signed.
approved: Only sign approved merges to a protected branch.
always: Always sign

Options other than never and always can be combined as a comma separated list. The merge will be signed if all selected options are true.

Obtaining the Public Key of the Signing Key

The public key used to sign Gitea's commits can be obtained from the API at:

/api/v1/signing-key.gpg

In cases where there is a repository specific key this can be obtained from:

/api/v1/repos/:username/:reponame/signing-key.gpg