Andy DixonandClaude Opus 5.5
eea16c9076
File bodies are now cut into 4 MiB objects, the last padded to its power-of-two bucket, so every object is 64 KiB to 4 MiB whatever the file size. Object IDs are HMAC'd from a secret per-record seed, so nothing on disk links a file's pieces, and each object still leads with its own ID, binding it to its record and position. Chunks are encrypted and synced by a small worker pool so their fsyncs overlap. records/ and objects/ are sharded into 256 subdirectories by ID prefix, all created at init, with every shard's mtime pinned to the epoch. vault init --filler SIZE writes at least SIZE of filler. Filler entries are now real entries for a throwaway key, of log-uniform random sizes, so they carry multi-chunk files like a real collection. The marker becomes VAULT 2; earlier vaults are not supported. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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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,list,get,mv,rm.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 256xx/subdirectories by ID prefix. Records a key cannot open are skipped, not treated as errors.lock*.go- vault lock onDIR/.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.shvia Tectonic;shots.pyre-shoots screenshots from the real binary). Keep it in step with the CLI.build.sh- cross-compiles everygo tool dist listtarget 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.
- 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.
getpublishes output only after every object has authenticated.- Decoy deniability: both key slots stay the same size and are both always
tried;
initalways 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.