# attesto/attesto — Homebrew tap

Homebrew tap for [Attesto](https://attesto.eu): the `attesto` verifier CLI and
the `attesto-local-vault` container wrapper. Artifacts are served from the
signed download host [get.attesto.eu](https://get.attesto.eu).

## Install

```sh
brew tap attesto/attesto https://git.attesto.eu/attesto/homebrew-attesto.git
brew trust attesto/attesto
brew install attesto              # the CLI (offline verifier)
brew install attesto-local-vault  # the Local Vault container wrapper
```

## What is signed, and how to verify independently

Every release channel on get.attesto.eu carries a `SHA256SUMS` manifest and a
cosign signature over it (`SHA256SUMS.sig`). The `sha256` stanzas in the
formulas of this tap are copied verbatim from those **signed** manifests —
never computed locally. Homebrew then enforces the same hashes on every
install.

You do not have to trust this tap. Verify the manifests yourself:

```sh
curl -fsSLO https://get.attesto.eu/cosign.pub

# CLI channel
curl -fsSLO https://get.attesto.eu/0.5.0/SHA256SUMS
curl -fsSLO https://get.attesto.eu/0.5.0/SHA256SUMS.sig
cosign verify-blob --key cosign.pub --insecure-ignore-tlog \
  --signature SHA256SUMS.sig SHA256SUMS

# Local Vault channel
curl -fsSLO https://get.attesto.eu/local-vault/2.0.1/SHA256SUMS
curl -fsSLO https://get.attesto.eu/local-vault/2.0.1/SHA256SUMS.sig
cosign verify-blob --key cosign.pub --insecure-ignore-tlog \
  --signature SHA256SUMS.sig SHA256SUMS
```

then compare the listed hashes with the `sha256` values in `Formula/*.rb`.
(`--insecure-ignore-tlog` is required because the release key is a KMS key
and signatures are not uploaded to the Rekor transparency log.)

The Local Vault container image itself is referenced **by digest**, not by a
tag, so the wrapper can only ever run the exact image
`git.attesto.eu/attesto/local-vault@sha256:5799e7f0669c9b42a55a338f4233cfa5afb5aa6a2627c2c50f7545a41bff1551`.

## macOS honesty note

`attesto-local-vault` requires Docker (Docker Desktop on macOS) at runtime —
Homebrew does not install it for you. On macOS the vault and its Linux-only
provider sandbox run **inside Docker Desktop's Linux VM**. Attesto's
isolation claims apply within that VM; a native macOS process would not carry
them, which is exactly why the macOS install is a container wrapper and never
claims native isolation.

## Where this tap comes from

The contents of this repository are mirrored from `ops/get-host/homebrew/` in
the main Attesto repository — that directory is the source of truth; changes
land there first and are synced here at publish time (`sync_tap.sh`). The
behavioral parity between the brew wrapper and the `install.sh` wrapper is
enforced there by `tests/wrapper_sync_check.sh`.