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---
stage: Create
group: Source Code
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://handbook.gitlab.com/handbook/product/ux/technical-writing/#assignments
description: "Sign commits in your GitLab repository with SSH keys."
---
# Sign commits with SSH keys
DETAILS:
**Tier:** Free, Premium, Ultimate
**Offering:** GitLab.com, Self-managed, GitLab Dedicated
> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/343879) in GitLab 15.7 [with a flag](../../../../administration/feature_flags.md) named `ssh_commit_signatures`. Enabled by default.
> - [Generally available](https://gitlab.com/gitlab-org/gitlab/-/issues/384202) in GitLab 15.8. Feature flag `ssh_commit_signatures` removed.
When you sign commits with SSH keys, GitLab uses the SSH public keys associated
with your GitLab account to cryptographically verify the commit signature.
If successful, GitLab displays a **Verified** label on the commit.
You may use the same SSH keys for `git+ssh` authentication to GitLab
and signing commit signatures as long as their usage type is **Authentication & Signing**.
It can be verified on the page for [adding an SSH key to your GitLab account](../../../ssh.md#add-an-ssh-key-to-your-gitlab-account).
For more information about managing the SSH keys associated with your GitLab account, see
[Use SSH keys to communicate with GitLab](../../../ssh.md).
## Configure Git to sign commits with your SSH key
After you [create an SSH key](../../../ssh.md#generate-an-ssh-key-pair) and
[add it to your GitLab account](../../../ssh.md#add-an-ssh-key-to-your-gitlab-account)
or [generate it using a password manager](../../../ssh.md#generate-an-ssh-key-pair-with-a-password-manager),
configure Git to begin using the key.
Prerequisites:
- Git 2.34.0 or newer.
- OpenSSH 8.1 or newer.
NOTE:
OpenSSH 8.7 has broken signing functionality. If you are on OpenSSH 8.7, upgrade to OpenSSH 8.8.
- A SSH key with the usage type of either **Authentication & Signing** or **Signing**.
The SSH key must be one of these types:
- [ED25519](../../../ssh.md#ed25519-ssh-keys) (recommended)
- [RSA](../../../ssh.md#rsa-ssh-keys)
To configure Git to use your key:
1. Configure Git to use SSH for commit signing:
```shell
git config --global gpg.format ssh
```
1. Specify which public SSH key to use as the signing key and change the filename (`~/.ssh/examplekey.pub`) to the location of your key. The filename might
differ, depending on how you generated your key:
```shell
git config --global user.signingkey ~/.ssh/examplekey.pub
```
## Sign commits with your SSH key
Prerequisites:
- You've [created an SSH key](../../../ssh.md#generate-an-ssh-key-pair).
- You've [added the key](../../../ssh.md#add-an-ssh-key-to-your-gitlab-account) to your GitLab account.
- You've [configured Git to sign commits](#configure-git-to-sign-commits-with-your-ssh-key) with your SSH key.
To sign a commit:
1. Use the `-S` flag when signing your commits:
```shell
git commit -S -m "My commit msg"
```
1. Optional. If you don't want to type the `-S` flag every time you commit, tell
Git to sign your commits automatically:
```shell
git config --global commit.gpgsign true
```
1. If your SSH key is protected, Git prompts you to enter your passphrase.
1. Push to GitLab.
1. Check that your commits [are verified](#verify-commits).
Signature verification uses the `allowed_signers` file to associate emails and SSH keys.
For help configuring this file, read [Verify commits locally](#verify-commits-locally).
## Verify commits
You can verify all types of signed commits
[in the GitLab UI](../signed_commits/index.md#verify-commits). Commits signed
with an SSH key can also be verified locally.
### Verify commits locally
To verify commits locally, create an
[allowed signers file](https://man7.org/linux/man-pages/man1/ssh-keygen.1.html#ALLOWED_SIGNERS)
for Git to associate SSH public keys with users:
1. Create an allowed signers file:
```shell
touch allowed_signers
```
1. Configure the `allowed_signers` file in Git:
```shell
git config gpg.ssh.allowedSignersFile "$(pwd)/allowed_signers"
```
1. Add your entry to the allowed signers file. Use this command to add your
email address and public SSH key to the `allowed_signers` file. Replace `<MY_KEY>`
with the name of your key, and `~/.ssh/allowed_signers`
with the location of your project's `allowed_signers` file:
```shell
# Modify this line to meet your needs.
# Declaring the `git` namespace helps prevent cross-protocol attacks.
echo "$(git config --get user.email) namespaces=\"git\" $(cat ~/.ssh/<MY_KEY>.pub)" >> ~/.ssh/allowed_signers
```
The resulting entry in the `allowed_signers` file contains your email address, key type,
and key contents, like this:
```plaintext
example@gitlab.com namespaces="git" ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAmaTS47vRmsKyLyK1jlIFJn/i8wdGQ3J49LYyIYJ2hv
```
1. Repeat the previous step for each user who you want to verify signatures for.
Consider checking this file in to your Git repository if you want to locally
verify signatures for many different contributors.
1. Use `git log --show-signature` to view the signature status for the commits:
```shell
$ git log --show-signature
commit e2406b6cd8ebe146835ceab67ff4a5a116e09154 (HEAD -> main, origin/main, origin/HEAD)
Good "git" signature for johndoe@example.com with ED25519 key SHA256:Ar44iySGgxic+U6Dph4Z9Rp+KDaix5SFGFawovZLAcc
Author: John Doe <johndoe@example.com>
Date: Tue Nov 29 06:54:15 2022 -0600
SSH signed commit
```
## Revoke an SSH key for signing commits
> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/merge_requests/108344) in GitLab 15.9.
If an SSH key becomes compromised, revoke it. Revoking a key changes both future and past commits:
- Past commits signed by this key are marked as unverified.
- Future commits signed by this key are marked as unverified.
Revoking an SSH key removes it from your account.
SSH keys that are only used for authentication do not have the option to be revoked.
To revoke an SSH key:
1. On the left sidebar, select your avatar.
1. Select **Edit profile**.
1. On the left sidebar, select **SSH Keys** (**{key}**).
1. Next to the SSH key you want to revoke, select **Revoke**.
1. Optional. [Delete the SSH key.](../../../ssh.md#delete-an-ssh-key)
## Related topics
- [Sign commits and tags with X.509 certificates](../signed_commits/x509.md)
- [Sign commits with GPG](gpg.md)
- [Commits API](../../../../api/commits.md)
|
