# Dependencies

Every external crate has a row here. `scripts/check-dep-docs.sh` enforces it.

| Crate | Version | Used by | Why |
|---|---|---|---|
| `serde` | 1.0.229 | `proto`, `brokerd`, `toolkit`, `gatewayd` | Derives serialization for every shared type. MIT OR Apache-2.0. |
| `serde_json` | 1.0.151 | `proto`, `brokerd`, `toolkit`, `gatewayd` | JSON for frames and log files. MIT OR Apache-2.0. |
| `humantime` | 2.4.0 | `proto` | RFC 3339 timestamps. No dependencies of its own. MIT OR Apache-2.0. |
| `toml` | 1.1.6 | `proto` tests; `brokerd` and `bxctl` from M3, `gatewayd` from M4a | Parses grant files. MIT OR Apache-2.0. |
| `emsha` | 1.0.4 | `proto` | SHA-256. Written by the owner; no dependencies, no `unsafe`. Checked against `sha256sum` on 3,204 inputs. |
| `rustls` | 0.23.45 | `gatewayd` | TLS to Mattermost over the tailnet (M4a, owner's decision). `default-features = false` with `ring`, `std`, `tls12`. With its dependencies on Linux: `ring` (Apache-2.0 AND ISC; builds C and assembly), `rustls-webpki` and `untrusted` (ISC), `rustls-pki-types`, `subtle` (BSD-3-Clause), `zeroize`, `once_cell`, `getrandom`, `libc`, `cfg-if`. Apache-2.0 OR ISC OR MIT. |
| `rustls-native-certs` | 0.8.4 | `gatewayd` | The host's trusted certificates, so a CA installed on the host is trusted too; adds `openssl-probe`. Apache-2.0 OR ISC OR MIT. |
| `zeroize` | 1.9.0 | `gatewayd` | Wipes a secret's memory when it is dropped (`Secret`). Already a dependency of `rustls`. Apache-2.0 OR MIT. |