# VaultZip (CLI prototype)

Password-encrypted archive with built-in checksum verification. Working
prototype of the core engine — see ../plan.md for the full product plan
(the WinUI 3 shell and archive preview are still on the roadmap; this
build is the pack/unpack/verify engine only).

## Build from source

Requires Go 1.24+, no external dependencies.

    go build -o vaultzip .

Cross-compile for another platform:

    GOOS=windows GOARCH=amd64 go build -o vaultzip.exe .
    GOOS=darwin  GOARCH=arm64 go build -o vaultzip .

## Usage

    vaultzip pack   <path> [<path> ...] -o vault.vz --password PASS [--dry-run]
    vaultzip unpack <vault.vz> -o outdir --password PASS
    vaultzip verify <vault.vz> --password PASS

## Looking before you pack

Packing replaces a vault already sitting at the -o path without asking, so
pack takes --dry-run:

    vaultzip pack Records -o Records.vz --password PASS --dry-run

It lists every file that would go into the vault with its size on disk,
totals them, warns you if a vault is already there under that name, and
writes nothing whatsoever — no vault, no partial file, no temporary. Add
the flag to the command you were about to run, read the list, then run the
same command again without it.

The listing comes from the same walk that packing itself uses, so it cannot
drift out of step with what a real pack would store; files the real pack
would have to skip as unreadable are skipped in the dry run too. The dry
run stops short of the key stretching as well as the output file, so it
costs a fraction of a real pack rather than doubling it.

A vault is tar+gzip, then AES-256-GCM encrypted. The key is stretched from
the password via 200,000 rounds of iterated SHA-256 — a dependency-free
stand-in for PBKDF2 (Go's stdlib has no built-in KDF). This has not been
independently audited; treat it as a working prototype of the mechanism,
not a production-grade crypto implementation.

"verify" authenticates the vault and lists its contents (with per-file
SHA-256) without writing anything to disk — a wrong password fails loudly
via AES-GCM authentication rather than silently producing garbage.

## Prebuilt binaries

See ../downloads/ for prebuilt binaries (Windows/macOS/Linux) and
CHECKSUMS.txt for their SHA-256 hashes. These are unsigned indie builds —
Windows SmartScreen and macOS Gatekeeper will warn on first run, which is
expected until a code-signing certificate is in place (see the build
plan's risk section).