sefy

Every way of storing secrets announces itself. A .kdbx file says "password database". age and gpg write a header. VeraCrypt wants a container and a mount. Whoever looks at your disk, your backup drive or your cloud folder can tell exactly where the interesting file is.

sefy is a secret store whose file looks like nothing. Notes, logins, cards, ssh keys and files live in an encrypted SQLite database sealed into a single blob with no magic bytes, no header and no extension convention. Call it notes.bak, leave it among your other backups, and there is nothing to notice.

$ head -c 32 notes.bak | xxd
00000000: 65b0 1375 a933 361d 89e2 9338 1b8d cb76  e..u.36....8...v
00000010: 0749 7515 ad12 dd40 1c3e 3e93 9282 4b5a  .Iu....@.>>...KZ

Threat model, honestly

• Protects against: a passing glance, a curious file listing, a cloud-side scanner looking for known formats, anyone who does not already know the file is a vault.
• Does not protect against: forensic analysis - a high-entropy headerless file is recognizable as some container to an examiner - or anyone who can compel you to give up the password.

sefy is inconspicuous, not deniable, and it will not pretend otherwise.

A day with it

Point sefy at a file. There is no default location: a vault at a predictable path would undo the whole point.

$ export SEFY_VAULT=~/backups/notes.bak

$ sefy init
Master password:
created /home/you/backups/notes.bak

Put things in. Notes, logins, cards, ssh keys, and files kept byte for byte.

$ sefy add note "bank card" --text "PIN 4815" --tag money
added "bank card" as 1

$ sefy add login mail --login [email protected] --url https://mail.example.com --tag mail
Password for this item:
added "mail" as 2

$ sefy add file ~/.ssh/id_ed25519 --tag keys
added "id_ed25519" as 3

Look around.

$ sefy ls
3  id_ed25519  file        [keys]
2  mail        login       [mail]
1  bank card   note        [money]

$ sefy show mail
id:       2
title:    mail
kind:     login
tags:     mail
login:    [email protected]
password: <hidden — use sefy get>
url:      https://mail.example.com

Take a secret out. It goes to the clipboard and is taken back off after 45 seconds - sefy clears it only if the secret is still what is sitting there, so anything you copied meanwhile is left alone.

$ sefy get mail
copied password of "mail" to the clipboard; clearing in 45s
clipboard cleared

$ sefy get "bank card" --stdout
PIN 4815

Items are addressed by title, by an exact id, or by text to search for. When your words could mean more than one thing, sefy shows what they could mean instead of guessing:

$ sefy get ma
error: 2 items match "ma":
     4  mailing list                    note
     2  mail                            login
narrow the text, or use an id

Several machines? sefy sync carries the vault through a transport and folds what comes back into this one:

$ sefy sync
Master password:
synced "vault" through github
merged: 2 added, 0 updated, 14 unchanged

Or fold in a copy you carried across by hand. Either way, where the two disagree about the same item, sefy keeps both versions rather than letting a timestamp decide which password you get to keep:

$ sefy merge ~/from-laptop.bak
Password for /home/you/from-laptop.bak:
merged: 1 added, 1 updated, 1 unchanged

1 item changed on both sides and could not be resolved here.
This vault's version was kept; the incoming one is beside it:
  "mail" → also kept as "mail (conflicted copy)"
Compare them, keep the right one, and remove the other.

A vault is never a trap. sefy export writes everything back out as plain JSON - which is exactly as sensitive as the vault and protects nothing, so the command makes you say so out loud:

$ sefy export -o backup.json
error: export writes every secret in this vault in the clear
the resulting file protects nothing — encrypt it, or delete it when done
pass --i-know-this-writes-plaintext to go ahead

Full command reference: lacodda.github.io/sefy.

Transports

Carrying a vault to another machine is the job of a plugin: any executable named sefy-plugin-*, found in sefy's data directory or on PATH. sefy knows nothing about git, FTP or any cloud drive - it asks a plugin what it can do and what happened.

Two transports ship alongside the CLI, and neither stores a credential of its own - each authenticates the way the machine already does:

• github keeps the vault in a git repository. Point SEFY_GITHUB_REPO at one; version history comes free with it.
• sftp keeps it on a server you control, over OpenSSH. Point SEFY_SFTP_DESTINATION at you@server:/path; nothing lands there but the blob.

$ sefy plugin list
future  9.0.0     unusable: it speaks protocol 99 and this build speaks 1
github  0.7.0     pull, push
sftp    0.7.0     pull, push

With more than one installed, sefy asks which rather than choosing where your vault goes: sefy sync --transport sftp, or SEFY_TRANSPORT=sftp once.

A transport is handed the path of the sealed file and nothing else - no master password, no key, no item. What it carries is what anyone would find on your disk: a blob it cannot read. That is also why a plugin cannot merge: it moves the other copy to a file, and sefy folds the two together itself, where both sides can actually be read.

Broken plugins are listed with the reason rather than skipped: an omitted line would look exactly like a plugin that was never installed.

The protocol is small enough to implement in a shell script - manifest on --manifest, one JSON request on stdin for run. Writing one: plugin reference · ADR-0002.

How it works

• The master password is stretched into a key with Argon2id.
• The whole SQLite database is sealed with XChaCha20-Poly1305 (AEAD).
• The file on disk is salt ‖ nonce ‖ ciphertext. Salt and nonce are fresh on every save, so two saves of identical content share no prefix - and the format version lives inside the ciphertext, because a version byte in the clear would be the signature the format exists to avoid.
• The decrypted database exists only in memory. SQLite is never given a path, so no page, journal or temporary file lands on disk.
• Saves are atomic: ciphertext goes to a temporary file, is synced, and is renamed over the vault. A crash leaves either the old vault or the new one, and never plaintext.

Details and rationale: ADR-0001.

Install

One-line installers. Windows (PowerShell):

irm https://raw.githubusercontent.com/lacodda/sefy/main/tools/install.ps1 | iex

macOS / Linux:

curl -fsSL https://raw.githubusercontent.com/lacodda/sefy/main/tools/install.sh | sh

On Windows use the PowerShell line above: install.sh carries the macOS and Linux builds only, and run from Git Bash it stops with a pointer back here.

cargo - cargo install sefy, plus cargo install sefy-plugin-github or sefy-plugin-sftp for a transport

npm - npm install -g sefy-cli

Binary releases - grab the archive for your platform from Releases (Windows x86_64, Linux x86_64, macOS arm64), unpack and put sefy on your PATH.

Both installers take the newest release by default; set SEFY_VERSION to a tag to pin one, and SEFY_INSTALL_DIR to choose where the binary lands. They also place any transport the archive carries into sefy's plugins directory, so sefy plugin list finds it without a second step.

Shell completions: sefy completions bash (also zsh, fish, powershell, elvish).

Stability

The vault file format is stable at version 1. Files written by this release will stay readable: any future change to the format arrives as version 2, able to read version 1 and migrate it. The Argon2 parameters are part of that promise, not a tuning knob.

The database inside the ciphertext is versioned separately, and it does move: 0.2.0 added an identity to items so two copies of a vault can be merged, and 0.7.0 replaced the credential table with named fields so that a kind of record costs a template rather than a table. A vault from an earlier release opens and is migrated on the way in; the file on disk does not change shape.

What an older build makes of it afterwards depends on the change. The 0.2.0 migration left everything readable by 0.1.x. The 0.7.0 one does not: a login is now a kind 0.6.0 has never heard of, so that build lists it, exports it and syncs it while saying to upgrade before reading it. That is the forward-compatibility contract from 0.6.0 doing its job rather than a break - nothing is lost, and the newer build reads everything - but it is why the rename happened before 1.0 rather than after.

The plugin protocol is at version 1 as of 0.3.0. 0.4.0 put it to work and 0.5.0 added a second transport of a different shape without changing a field of it, which is the evidence that it was not built around the first one. Optional fields may be added to the manifest without breaking a plugin that predates them; changing what an existing field means would arrive as version 2, with both accepted for a time.

Released versions and what landed in each: CHANGELOG on the Releases page.

Building

cargo build --release   # workspace: sefy-core (library) + sefy (CLI)
cargo test              # unit, integration and doc tests

Use a release build for daily work: Argon2id is deliberately expensive, and an unoptimized build makes it several times slower still.

The library is published separately as sefy-core if you want vaults from your own code. The documentation site lives in docs/; architecture decision records are in docs/adr/.

License

MIT