About commit signature verification
You can sign commits and tags locally, to give other people confidence about the origin of a change you have made. If a commit or tag has a GPG or S/MIME signature that is cryptographically verifiable, GitHub marks the commit or tag "Verified" or "Partially verified."
Commits and tags have the following verification statuses, depending on whether you have enabled vigilant mode. By default vigilant mode is not enabled. For information on how to enable vigilant mode, see "Displaying verification statuses for all of your commits."
Note: Vigilant mode is currently in beta and subject to change.
Default statuses
| Status | Description |
|---|---|
| Verified | The commit is signed and the signature was successfully verified. |
| Unverified | The commit is signed but the signature could not be verified. |
| No verification status | The commit is not signed. |
Statuses with vigilant mode enabled
| Status | Description |
|---|---|
| Verified | The commit is signed, the signature was successfully verified, and the committer is the only author who has enabled vigilant mode. |
| Partially verified | The commit is signed, and the signature was successfully verified, but the commit has an author who: a) is not the committer and b) has enabled vigilant mode. In this case, the commit signature doesn't guarantee the consent of the author, so the commit is only partially verified. |
| Unverified | Any of the following is true: - The commit is signed but the signature could not be verified. - The commit is not signed and the committer has enabled vigilant mode. - The commit is not signed and an author has enabled vigilant mode. |
Repository administrators can enforce required commit signing on a branch to block all commits that are not signed and verified. For more information, see "About protected branches."
You can check the verification status of your signed commits or tags on GitHub and view why your commit signatures might be unverified. For more information, see "Checking your commit and tag signature verification status."
GitHub will automatically use GPG to sign commits you make using the GitHub web interface, except for when you squash and merge a pull request that you are not the author of. Commits signed by GitHub will have a verified status on GitHub. You can verify the signature locally using the public key available at https://github.com/web-flow.gpg. The full fingerprint of the key is 5DE3 E050 9C47 EA3C F04A 42D3 4AEE 18F8 3AFD EB23. You can optionally choose to have GitHub sign commits you make in Codespaces. For more information about enabling GPG verification for your codespaces, see "Managing GPG verification for Codespaces."
GPG commit signature verification
You can use GPG to sign commits with a GPG key that you generate yourself.
GitHub uses OpenPGP libraries to confirm that your locally signed commits and tags are cryptographically verifiable against a public key you have added to your GitHub account.
To sign commits using GPG and have those commits verified on GitHub, follow these steps:
- Check for existing GPG keys
- Generate a new GPG key
- Add a new GPG key to your GitHub account
- Tell Git about your signing key
- Sign commits
- Sign tags
S/MIME commit signature verification
You can use S/MIME to sign commits with an X.509 key issued by your organization.
GitHub uses the Debian ca-certificates package, the same trust store used by Mozilla browsers, to confirm that your locally signed commits and tags are cryptographically verifiable against a public key in a trusted root certificate.
Note: S/MIME signature verification is available in Git 2.19 or later. To update your version of Git, see the Git website.
To sign commits using S/MIME and have those commits verified on GitHub, follow these steps:
You don't need to upload your public key to GitHub.
Signature verification for bots
Organizations and GitHub Apps that require commit signing can use bots to sign commits. If a commit or tag has a bot signature that is cryptographically verifiable, GitHub marks the commit or tag as verified.
Signature verification for bots will only work if the request is verified and authenticated as the GitHub App or bot and contains no custom author information, custom committer information, and no custom signature information, such as Commits API.