trailofbits/open-sourcing

Open-Sourcing a Repository

Prepare a repository for public release so that an outsider with no prior context can build, use, and contribute to it — and so that nothing sensitive ships with it. Work through the steps in order; the secrets audit comes first because its outcome (keeping vs. recreating the repository) affects everything after it.

When to Use

• Making a private repository public
• Auditing an existing public repository for release quality ("make it official")
• Choosing a license for a project
• Setting up packaging, versioning, or release automation ahead of a public launch

When NOT to Use

• Routine development on an already-released project (no release event)
• Auditing third-party code for vulnerabilities (use a security-review skill)
• Publishing a package from a repository that will stay private — only the release-management steps apply; skip the rest

Workflow

Step 1: Detect the organization profile

bash {baseDir}/scripts/detect_org.sh

The script inspects git remotes and recent committer emails, and prints a profile name. If it prints trailofbits, read references/trailofbits.md now and apply its license policy, publishing accounts, and process notes throughout the remaining steps. If it prints generic, proceed with the generic guidance alone. If the user says the detection is wrong, trust the user.

Step 2: Audit for secrets — before anything else

A repository that has ever contained secrets (API keys, credentials, client data) should not be flipped public. History rewriting is error-prone and does not reach forks, caches, or CI artifacts. The reliable fix is a fresh repository: copy the current tree over, commit, and archive the old repository privately.

1. Ask whether the project ever handled secrets or client-confidential material. For a security consultancy's tooling, also ask whether test fixtures or example data came from client engagements.
2. Scan the full history with a dedicated tool if available — gitleaks git . or trufflehog git file://. — rather than eyeballing.
3. Check beyond the git tree: GitHub Actions logs and artifacts, old releases, issue and PR history, and the repository wiki all become public with the repository.
4. After going public, enable GitHub secret scanning and push protection in the repository settings.

Reject these rationalizations — this is the one step that cannot be fixed after publication:

• "The key was revoked, so the history is fine." Revoked credentials still leak infrastructure names, internal URLs, and patterns attackers use for targeting.
• "We'll rewrite history with git-filter-repo." Rewrites miss forks, clones, caches, and CI artifacts; the fresh-repository approach does not.
• "It's only test data." Fixtures derived from client engagements or production systems are confidential regardless of how they are labeled.

Step 3: Run the readiness check

bash {baseDir}/scripts/check_readiness.sh

The script prints a checklist of presence indicators (README, LICENSE, CONTRIBUTING, SECURITY.md, CI, tests, semver tags, ...) and warns about tracked files that commonly contain secrets. Treat unchecked items as discussion prompts, not hard failures — a research prototype does not need everything a flagship library needs. Walk through the gaps with the user and fix the ones that matter for this project.

Step 4: Documentation

The README is the project's front door. Confirm it explains:

• What the project is and what problem it solves (first paragraph)
• How to install it — package manager, container image, or build from source; a fresh-clone build must work using only what is in the repository
• How to use it — at least one concrete, copy-pasteable example
• How to contribute — inline or via CONTRIBUTING.md
• The license — a short section naming it

Also add:

• SECURITY.md with vulnerability-reporting instructions (a contact address or GitHub private vulnerability reporting). For security tooling this is table stakes.
• API documentation, built and hosted (GitHub Pages via CI is the usual route), linked from the README and the repository website field. See the language references below for per-ecosystem doc tooling.
• A code of conduct if the project expects outside contributors.

Step 5: Licensing

No license means not open source, regardless of visibility. Read references/licensing.md for selection criteria and mechanics. The short version:

1. Apply the organization's policy if one was detected in Step 1.
2. Otherwise: Apache 2.0 as the permissive default, AGPLv3 when private modification by competitors is a real concern, Creative Commons for non-code artifacts.
3. Add the LICENSE file, set SPDX identifiers in package metadata, state the license in the README, and verify all three agree.

Step 6: Tests and CI

• Confirm the test suite exists and passes; a public repository with a failing default branch signals abandonment.
• Ensure CI runs the tests on every PR, across the supported language-version and platform matrix.
• Enforce formatting and linting in CI (per-language tooling in the references below), so style debates never reach review.
• Respect existing tooling. Do not replace a working formatter, linter, or type checker as part of open-sourcing. If it lags the current generation (the language references name the current tools), warn the maintainer and let them decide; only when a category is missing entirely — no type checker, no formatter — add the current default.
• Consider a coverage gate that fails CI when coverage drops.
• Harden the workflows themselves before they become public attack surface:
  • Pin third-party actions to full commit SHAs; enable Dependabot for github-actions so pins stay current.
  • Set least-privilege permissions: blocks (start from permissions: {}).
  • Audit with zizmor .github/workflows/ and lint with actionlint.

Step 7: Repository settings

• Branch protection on the default branch: no force pushes, PRs required. Prefer rulesets for new repositories; classic branch protection remains supported.
• Merge protection: required status checks so PRs cannot merge with failing tests.
• Dependabot or Renovate for dependency and Actions updates. Group updates to cut PR noise, and set a cooldown window (e.g., 7 days) so freshly published — and occasionally hijacked — versions age before adoption.
• .editorconfig so contributors' editors agree on whitespace basics.
• Labels: create them as soon as more than one issue or PR needs one; prefixes for facets scale well (C: component, P: platform). See blight's labels for a worked example.

Step 8: Releases and versioning

• Tag every release vX.Y.Z, following semver; use -rc.N / -pre.N suffixes for release candidates and prereleases.
• Make releases CI-driven: pushing a tag (or publishing a GitHub Release) triggers build, packaging, and upload with no manual steps. A release should be git tag vX.Y.Z && git push origin vX.Y.Z.
• Publish packages under an organization-owned account, not a personal one, and use trusted publishing (OIDC) instead of long-lived tokens wherever the index supports it.

Step 9: Language-specific practices

Identify the project's languages from its marker files and read the matching reference for packaging, publishing, and quality tooling:

| Marker file | Reference | |-------------|-----------| | pyproject.toml, setup.py | references/python.md — defers to the modern-python skill for tooling | | CMakeLists.txt, Makefile (C/C++) | references/c-cpp.md | | Cargo.toml | references/rust.md | | go.mod | references/go.md | | package.json | references/javascript.md | | Gemfile, *.gemspec | references/ruby.md |

For other ecosystems, apply the cross-cutting principles: reproducible builds from a fresh clone, CI-driven releases, trusted publishing or organization-owned accounts, and license metadata in the package manifest.

Final Review

Before the visibility switch is flipped, verify from an outsider's perspective:

1. Clone into a clean directory and follow the README's build instructions verbatim — do they work with no tribal knowledge?
2. Re-run {baseDir}/scripts/check_readiness.sh and confirm the remaining gaps are deliberate choices, stated to the user.
3. Confirm the secrets audit (Step 2) actually happened; it is the one step that cannot be fixed after publication.

Making the repository public is then a repository-settings change. Pair the release with an announcement where the organization has a process for one.

Additional Resources

Reference Files

• references/licensing.md — license selection criteria, SPDX metadata, forks and relicensing
• references/trailofbits.md — Trail of Bits policy overlay (loaded only when detected in Step 1)
• references/python.md, references/c-cpp.md, references/rust.md, references/go.md, references/javascript.md, references/ruby.md — per-language packaging, publishing, and quality tooling

Scripts

• scripts/detect_org.sh — prints the organization profile (trailofbits or generic) from git remotes and committer emails
• scripts/check_readiness.sh — prints presence indicators for release-readiness files and flags tracked files that commonly hold secrets