Files
vault/CLAUDE.md
T
Andy Dixon 4c1507c463 Add unlock --idle, and packaging/repo.sh for repo.dixon.cx
vault unlock --idle counts the duration from the last command that used
the key rather than from the unlock: the agent resets its timer each
time it hands the key out. The agent loop no longer needs its own
goroutine.

packaging/repo.sh builds the dixon-vault .deb, .rpm and Arch packages
from a release tag (a clean git archive) with nfpm for amd64, arm64,
armv7, 386 and riscv64, then publishes them to the apt, dnf and pacman
repositories at repo.dixon.cx: apt-ftparchive with a signed InRelease,
createrepo_c (in a Fedora container) with signed RPMs and repomd.xml,
and repo-add (in an Arch container) with signed packages and database.
Indexes cover every package in the repository, under a lock, so other
projects publishing with their copy of the script are kept. The package
is dixon-vault because vault is HashiCorp Vault in Arch's [extra] and
HashiCorp's own repositories; it conflicts with vault.

README, guide and CLAUDE.md point at the repository.
2026-10-03 09:44:49 +01:00

3.6 KiB

CLAUDE.md

This file provides guidance to Claude Code when working with this repository.

Overview

vault is a post-quantum encrypted file vault: one package main at the repo root that builds a single vault binary. Module github.com/andydixon/vault.

  • main.go - CLI: genkey, init, add (file, directory or URL), migrate (add, then delete originals), mirror, absorb (tar on stdin, absorb.go), ls (one folder level), list (recursive), get (-r for a folder), mv/cp (files or folders; transfers resolves names like mv(1), copies share objects), rm (-r for a folder, asks unless -f), unlock/lock.
  • agent*.go - vault unlock re-executes itself as a hidden __agent process holding the suite ID and seed (pipe in, mlocked, undumpable) and serving them on a Unix socket in a 0700 per-user dir until a deadline (fixed, or with --idle reset on each use). keyIdentity asks it first unless $VAULT_PASSPHRASE is set.
  • keyfile.go - key file with two passphrase slots (Argon2id + XChaCha20-Poly1305 sealing a suite ID and 32-byte master seed). The second slot is either a decoy identity or random bytes; slot order is random.
  • store.go - on-disk vault: records/ holds fixed-size encrypted catalogue records, objects/ holds file bodies cut into 4 MiB chunks (last one bucket-padded) whose IDs are HMAC'd from a per-record seed. Both are sharded into 256 xx/ subdirectories by ID prefix. Records a key cannot open are skipped, not treated as errors.
  • lock*.go - vault lock on DIR/.lock: fcntl on unix, LockFileEx on Windows, an exclusive lock file elsewhere. Writers lock exclusively, readers shared, taken after the passphrase prompt.
  • docs/guide - LaTeX user guide (build-pdf.sh via Tectonic; shots.py re-shoots screenshots from the real binary). Keep it in step with the CLI.
  • packaging/repo.sh [TAG] - builds dixon-vault .deb/.rpm/Arch packages from a tag with nfpm and publishes them, signed, to the apt/dnf/pacman repo at repo.dixon.cx (same script, other project block, in ../mapsize).
  • build.sh - cross-compiles every go tool dist list target except iOS and android/386, amd64, arm (cgo-only).
  • internal/pqcrypt - file encryption (header + STREAM ChaCha20-Poly1305), suite registry, hybrid FrodoKEM-640 + ML-KEM-768 default suite.
  • internal/format, internal/stream, internal/term - header encoding, chunked payload encryption, terminal passphrase prompts.

Commands

go test ./...
go build .
./build.sh                                  # all platforms, into ./dist
TARGETS="linux/amd64" ./build.sh            # a subset

End-to-end check:

export VAULT_PASSPHRASE=test VAULT_KEY=$PWD/k VAULT_DIR=$PWD/s
./vault genkey && ./vault init && ./vault add README.md docs && ./vault list

Invariants

  • Never write a seed or private key unencrypted (the agent gets it by pipe).
  • Keep suite IDs, stanza tags, HKDF info strings and fileKeySize (32) stable.
  • Every ciphertext's and shard directory's mtime is pinned to the epoch; records stay one fixed size; objects stay at most 4 MiB and bucket-padded. These hide metadata from the storage host.
  • An object's plaintext starts with its own ID, binding it to its record and its position in the file.
  • get publishes output only after every object has authenticated.
  • Decoy deniability: both key slots stay the same size and are both always tried; init always writes filler; foreign records are skipped silently.
  • Every command that changes the vault holds the exclusive lock.
  • Keep dependencies pure Go and CGO_ENABLED=0 builds working.
  • Diagnostics go to standard error, lower-case, no trailing full stops.