Contributing

KeyHog is open source. The repo is at github.com/santhreal/keyhog. Bug reports, feature requests, detector additions, and PRs are all welcome.

Quick paths

Repo layout

keyhog/
  crates/
    core/             # Detector spec, raw match types, severity, embed
    scanner/          # The scanner engine itself
    sources/          # Filesystem, git, web, docker, S3/GCS/Azure Blob, hosted-git backends
    verifier/         # Live credential verification
    cli/              # The `keyhog` binary, subcommand dispatch
  detectors/          # Embedded detector TOMLs: one secret type per file
  crates/cli/data/
    suppressions/     # Test-fixture suppression list, baked into the binary
  docs/               # This documentation (mdBook source)
  install.sh          # Linux/macOS install script
  install.ps1         # Windows install script

The Rust workspace is at the root; each crates/ member is a standalone crate with its own Cargo.toml. See Architecture for crate ownership and the end-to-end scan flow before moving code across boundaries.

Building

git clone https://github.com/santhreal/keyhog
cd keyhog
cargo build --release -p keyhog
./target/release/keyhog --version

For development:

cargo build               # debug build
cargo test -p keyhog-scanner --lib

Adding a detector

Detector truth has two layers. The compact positive/negative pair lives beside the detector policy and protects every TOML edit. The separate contract adds multiple envelopes, evasions, performance, and scale coverage. Both are required; neither substitutes for the other.

1. Write the detector TOML at detectors/<service>-<thing>.toml. Use an existing detector as a template; the schema is documented in Detectors.

2. Add the inline truth pair in that same TOML:

   [[detector.tests]]
   test_positive = "SERVICE_API_KEY=<valid-shaped-test-value>"
   test_negative = "SERVICE_API_KEY=YOUR_API_KEY_HERE"
   

   Use synthetic or vendor-published test material, never a live credential. The positive must emit this detector’s exact ID; the negative must remain silent through the production scan path.

3. Write the adversarial contract at crates/scanner/tests/contracts/<id>.toml. At minimum, include:

   • 2 positives (env-var shape, quoted shape)
   • 2 negatives (placeholder, EXAMPLE token in the body)
   • 2 evasions (real-world shapes you’ve seen in actual leaks: Bearer header, JSON body, URL query param, multi-line config)
   • A perf block with fixture_bytes + max_microseconds
   • A scale block with fixture_bytes + min_findings + max_seconds

4. Run the detector truth gates locally:

   cargo test -p keyhog-scanner --test detector_inline_test_truth
   cargo test -p keyhog-scanner --test contracts_runner
   

   Must pass before you push. CI re-runs it with strict env vars set, which exercise more aggressive adversarial corpus.

5. Open a PR. A maintainer reviews the detector for:

   • Service is real and not duplicated by an existing detector.
   • Keywords are short, distinctive, and unlikely to FP.
   • Regex captures the right group and rejects obvious placeholders.
   • Verify endpoint (if present) is read-only and won’t trigger side-effects on the upstream service.

Adding a suppression filter

If you find an FP cluster of 5+ findings that all share a shape, the right fix is a new shape filter rather than 5 individual suppressions. The flow:

1. Reproduce. Get the FPs into a .envseal-sealed corpus or a public sanitized fixture you can commit.

2. Find the existing owner. Search crates/scanner/src/suppression/shape/ for the same operation before adding a helper. Extend the narrowest existing shape module; path, prose, public-identifier, canonical-shape, and randomness policy already have separate owners.

3. Wire it through the shared policy boundary. suppression/api.rs exposes the composed shape decisions and adjudicate/ owns the final suppression verdict. Do not add an emission-path-only looks_like_* check: CPU, SIMD, GPU, generic, entropy, and fast-prefix paths must reach the same decision.

4. Add a unit test. Inputs that should trip the filter (5+ variants), inputs that should not (3+ legitimate credentials).

5. Run the contract gate. New filters must not break any contract evasion. If they do, the contract is right and the filter is wrong. Tighten the filter.

Style

• Rust edition 2021, MSRV 1.89.
• Run cargo +stable fmt -- --check and the relevant package’s clippy target. Treat lints as bug leads; avoid behavior-free contortions for style-only findings.
• Split modules by responsibility, ownership, readability, and testability. File length is a prompt to inspect cohesion, not an architecture rule by itself.
• No #[ignore] on tests. A flaky test gets fixed or deleted, not silenced.
• No todo!() / unimplemented!() / panic!("not implemented") in shipped code paths.
• Comments explain WHY, not WHAT. Names carry WHAT.

Tests

cargo test -p keyhog-core --lib          # detector spec / embed
cargo test -p keyhog-scanner --lib       # engine
cargo test -p keyhog --lib               # CLI / orchestrator
cargo test -p keyhog --test e2e_binary   # full-binary end-to-end
cargo test -p keyhog-scanner --test contracts_runner   # per-detector contract gate
cargo test -p keyhog-scanner property::scanner_fuzz    # proptest

Run the narrowest behavioral gate that proves the change, then the affected package suite. Runtime depends on build profile, host, corpus, enabled features, and cache warmth; command output is the timing evidence for that run.

License

License: MIT OR Apache-2.0.

By contributing, you agree that your contributions use this license. Read the MIT terms and Apache-2.0 terms.