tamias

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Security model ​

Tamias moves other people's code onto your machine, so the threat model is supply chain: a malicious or tampered package, a hijacked ref, a poisoned registry. This page explains the layers; SECURITY.md at the repo root is the reporting policy.

Integrity: digests and pins ​

Every install records three things in the store entry: the source ref, the resolved sha (commit sha for git, payload sha256 for tarballs), and the payload digest. tamias verify recomputes the digest and fails on mismatch — tampering with the store is detected.

Prefer pinned refs:

  • …#sha256:<hex> on an http tarball — verified before unpack.
  • git refs resolve to a commit sha up front, so the recorded resolved is immutable even when the branch moves.

Two honest caveats:

  • http:// refs without a #sha256: pin fetch cleartext and warn on stderr. Use https:// or pin the digest.
  • cf: registry installs are TLS-authenticated but not sha-pinned at transport — the registry records a payload directory digest, not the tarball sha256. For end-to-end integrity prefer git: or an http ref with #sha256:.

A package's type: names a driver (tamias-driver-<type>), which tamias executes as a subprocess. Drivers on PATH or in <tamias-home>/drivers/ are trusted host tooling.

A package that ships its own drivers/ dir is different: those binaries are arbitrary code inside the payload. Installing one requires explicit consent:

sh
tamias install --allow-drivers <ref>
# or once per environment:
TAMIAS_ALLOW_DRIVERS=1 tamias install <ref>

Without consent the install fails before anything is registered or run — no partial store entry, no copied driver. The same gate exists in the tamias-serve protocol as "allow_drivers": true.

Missing drivers fail closed ​

Installing a package whose type has no discoverable driver fails the install (for any type other than files) — tamias never silently "installs" content it can't place. tamias doctor lists the drivers it found so you can see what's resolvable.

Secrets are names, never values ​

  • Registry tokens live in env vars — TAMIAS_REGISTRY_TOKEN for http registries, or the env var named by a config token_env field. tamias.yaml / tamias.lock hold refs, names, and digests only.
  • tamias registry serve is an open dev server unless you set TAMIAS_REGISTRY_SERVE_TOKEN (then every request needs Authorization: Bearer …).

Git fetch hardening ​

  • Clone URLs are allowlisted: https, http, ssh, git, file, and scp-style git@host:…. Other schemes are rejected.
  • Revs are validated — no leading -, whitespace, .., or //, so a ref can't smuggle git options. Relative revs (HEAD~2, main^) are allowed.
  • GIT_TERMINAL_PROMPT=0 — a fetch never blocks on a credential prompt; it fails instead.

Reporting ​

Vulnerabilities go to the maintainers via GitHub private advisories — see SECURITY.md. Don't open public issues for security reports.