<!-- This issue template can be used a great starting point for feature requests. The last section "Release notes" can be used as a summary of the feature and is also required if you want to have your release post blog MR auto generated using the release post item generator: https://about.gitlab.com/handbook/marketing/blog/release-posts/#release-post-item-generator. The remaining sections are the backbone for every feature in GitLab. --> ### Release notes Signing commits just got a lot simpler. [Use SSH keys to sign commits](https://docs.gitlab.com/ee/user/project/repository/ssh_signed_commits/), and provide others with confidence that a Verified commit was authored by you. Previous methods for signing commits required a GPG key or an X.509 certificate, neither of which can be used to sign in to GitLab. Adding support for commit signing with SSH keys now makes it possible to reuse your authentication key pair to also sign your commits. If you already authenticate into GitLab with an SSH key, add three lines of code to your local Git configuration and all your future commits will be signed. By default, all SSH keys currently in your profile can be used for both authentication and signing commits. To use a key for only one of the purposes, upload a new key.  https://docs.gitlab.com/ee/user/project/repository/ssh_signed_commits/ ### Problem to solve <!-- What is the user problem you are trying to solve with this issue? --> As a developer, I don't want to have to manage separate keys for SSH git access and commit signing (or even use GPG at all, if we're being honest). I already have SSH keys set up for git access, and by using the same keys for commit signatures, I can get signed commits :sparkles: for free :sparkles:. ### Context The ability to [sign commits with SSH keys](https://github.com/git/git/pull/1041) is now available in [git 2.34](https://github.com/git/git/blob/abe6bb3905392d5eb6b01fa6e54d7e784e0522aa/Documentation/RelNotes/2.34.0.txt#L81). We should add support for SSH signing for signed commits. ### Intended users Who will use this feature? If known, include any of the following: types of users (e.g. Developer), personas, or specific company roles (e.g. Release Manager). It's okay to write "Unknown" and fill this field in later. Personas are described at https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/ * [Sasha (Software Developer)](https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/#sasha-software-developer) ### Proposal <!-- Use this section to explain the feature and how it will work. It can be helpful to add technical details, design proposals, and links to related epics or issues. --> - Add SSH commit signatures - Allow existing SSH public keys to be used for verifying them ### Related issues - We added support for x509 signatures a year ago in https://gitlab.com/gitlab-org/gitlab/-/issues/29782 <!--- Use the following resources to find the appropriate labels: - https://gitlab.com/gitlab-org/gitlab/-/labels - https://about.gitlab.com/handbook/product/categories/features/ Consider adding related issues and epics to this issue. You can also reference the Feature Proposal Template (https://gitlab.com/gitlab-org/gitlab/-/blob/master/.gitlab/issue_templates/Feature%20proposal%20-%20detailed.md) for additional details to consider adding to this issue. Additionally, as a data oriented organization, when your feature exits planning breakdown, consider adding the `What does success look like, and how can we measure that?` section. Other sections to consider adding: ### User experience goal What is the single user experience workflow this problem addresses? For example, "The user should be able to use the UI/API/.gitlab-ci.yml with GitLab to <perform a specific task>" https://about.gitlab.com/handbook/engineering/ux/ux-research-training/user-story-mapping/ ### Further details Include use cases, benefits, goals, or any other details that will help us understand the problem better. ### Permissions and Security <!-- What permissions are required to perform the described actions? Are they consistent with the existing permissions as documented for users, groups, and projects as appropriate? Is the proposed behavior consistent between the UI, API, and other access methods (e.g. email replies)? Consider adding checkboxes and expectations of users with certain levels of membership https://docs.gitlab.com/ee/user/permissions.html * [ ] Add expected impact to members with no access (0) * [ ] Add expected impact to Guest (10) members * [ ] Add expected impact to Reporter (20) members * [ ] Add expected impact to Developer (30) members * [ ] Add expected impact to Maintainer (40) members * [ ] Add expected impact to Owner (50) members ### Documentation See the Feature Change Documentation Workflow https://docs.gitlab.com/ee/development/documentation/workflow.html#for-a-product-change * Add all known Documentation Requirements in this section. See https://docs.gitlab.com/ee/development/documentation/workflow.html * If this feature requires changing permissions, update the permissions document. See https://docs.gitlab.com/ee/user/permissions.html ### Availability & Testing This section needs to be retained and filled in during the workflow planning breakdown phase of this feature proposal, if not earlier. What risks does this change pose to our availability? How might it affect the quality of the product? What additional test coverage or changes to tests will be needed? Will it require cross-browser testing? Please list the test areas (unit, integration and end-to-end) that needs to be added or updated to ensure that this feature will work as intended. Please use the list below as guidance. * Unit test changes * Integration test changes * End-to-end test change See the test engineering planning process and reach out to your counterpart Software Engineer in Test for assistance: https://about.gitlab.com/handbook/engineering/quality/test-engineering/#test-planning ### What does success look like, and how can we measure that? Define both the success metrics and acceptance criteria. Note that success metrics indicate the desired business outcomes, while acceptance criteria indicate when the solution is working correctly. If there is no way to measure success, link to an issue that will implement a way to measure this. ### What is the type of buyer? What is the buyer persona for this feature? See https://about.gitlab.com/handbook/marketing/product-marketing/roles-personas/buyer-persona/ In which enterprise tier should this feature go? See https://about.gitlab.com/handbook/product/pricing/#three-tiers ### Is this a cross-stage feature? Communicate if this change will affect multiple Stage Groups or product areas. We recommend always start with the assumption that a feature request will have an impact into another Group. Loop in the most relevant PM and Product Designer from that Group to provide strategic support to help align the Group's broader plan and vision, as well as to avoid UX and technical debt. https://about.gitlab.com/handbook/product/#cross-stage-features --> ## Implementation Plan 1. Create a new signature model (`app/models/commit_signatures/ssh_signature.rb`) 1. Update `app/models/key.rb` to be related to an SshSignature. (How to handle key revocation?) 1. Create a new commit type (`lib/gitlab/ssh/commit.rb`) 1. Update the signature methods in `app/models/commit.rb` to handle ssh signatures & commits 1. Update `app/services/git/branch_hooks_service.rb` and `app/workers/create_commit_signature_worker.rb` to process SSH signatures when new commits are pushed <!-- triage-serverless v3 PLEASE DO NOT REMOVE THIS SECTION --> *This page may contain information related to upcoming products, features and functionality. It is important to note that the information presented is for informational purposes only, so please do not rely on the information for purchasing or planning purposes. Just like with all projects, the items mentioned on the page are subject to change or delay, and the development, release, and timing of any products, features, or functionality remain at the sole discretion of GitLab Inc.* <!-- triage-serverless v3 PLEASE DO NOT REMOVE THIS SECTION -->