Security

What cadenas guarantees

• Without the password, the contents of an encrypted file are unreadable.
• Any modification, truncation, or reordering of the encrypted file is detected during decryption: cadenas never returns altered content.

Limitations

• The .cadenas format has not been audited by independent specialists. It only assembles proven primitives (Argon2id, HKDF-SHA256, HMAC-SHA256, XChaCha20-Poly1305) from audited libraries, following a construction documented in docs/FORMAT.md. If you need an audited format, use the age format, which cadenas can produce and read.
• Security depends on the password. Argon2id strongly slows down brute-force attacks, but does not protect a short or common password. Prefer a passphrase of 4 to 5 random words, or at least 12 random characters.
• The file name and its approximate size are not hidden.
• A forgotten password is permanently lost: there is no way to recover the contents.

Verify what you download

All versions are built and published by GitHub Actions from this repository, never from a personal machine, and come with verifiable proof (Sigstore).

npm package — provenance attached to every release:

npm install cadenas
npm audit signatures

Docker image — keylessly signed by the publication workflow:

cosign verify ghcr.io/pierreebele/cadenas:latest \
  --certificate-identity-regexp '^https://github.com/PierreEbele/cadenas/\.github/workflows/docker\.yml@refs/tags/v' \
  --certificate-oidc-issuer https://token.actions.githubusercontent.com

The image also embeds an SBOM (a list of its components) and a provenance attestation: docker buildx imagetools inspect ghcr.io/pierreebele/cadenas:latest --format '{{ json .SBOM }}'.

GitHub release files (site archive, standalone executables) — checksums in SHA256SUMS and provenance attestation:

sha256sum -c SHA256SUMS --ignore-missing
gh attestation verify cadenas-site-vX.Y.Z.zip --repo PierreEbele/cadenas

Starting with version 1.4.0, signed provenance is also attached to every release (cadenas-vX.Y.Z.sigstore.json, and cadenas-vX.Y.Z.intoto.jsonl in SLSA format): gh attestation verify <file> --repo PierreEbele/cadenas --bundle cadenas-vX.Y.Z.sigstore.json verifies it without querying GitHub.

Version tags — starting with version 1.4.0, each tag is signed with a maintainer SSH key ("Verified" badge on GitHub). To verify it yourself in a clone of the repository:

node scripts/verify-tag.js vX.Y.Z

The script fetches the signing keys published on the GitHub account PierreEbele and runs git verify-tag.

The site matches the source code — the site build is reproducible: built from the same tag, on any system, it produces bit-for-bit identical files (CI verifies this on Linux, Windows, and macOS, with Node.js 22 and 24). To verify it yourself:

git checkout vX.Y.Z
npm ci
npm run build
node scripts/site-hashes.js | diff - site-files.sha256

(site-files.sha256 is the one from the release; no output: identical.)

A self-hosted site — site-files.sha256 lists the checksum of every site file: compare them with the files served by your instance.

Reporting a vulnerability

Please do not open a public issue. Use GitHub's private vulnerability reporting, or, without a GitHub account, write to security@getcadenas.com: the maintainer then opens the private security advisory and invites you to it. The same contact is published in /.well-known/security.txt (RFC 9116).

Handling of reports

1. Acknowledgment within 7 days, in the private security advisory opened by your report.
2. Analysis: the maintainer reproduces the issue, assesses its severity (CVSS), and keeps you informed at least every two weeks.
3. Fix prepared privately in the GitHub security advisory, with a test that reproduces the issue. Target: less than 60 days after the report, and as soon as possible for a critical vulnerability.
4. Publication: new version, public security advisory with a CVE identifier requested via GitHub, and a mention in the CHANGELOG ("Security" section).
5. Credit: the person who reported the vulnerability is thanked by name in the advisory and the CHANGELOG, unless they prefer to remain anonymous.

Only the latest version receives security fixes.

Why cadenas meets its security requirements (threat model, trust boundaries, countermeasures): docs/ASSURANCE.md.

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Source of this page: SECURITY.md