Lemonade Vault — Source Audit Module

This repository is the complete, verbatim source of the Vault feature in Lemonade: the local-only encrypted store that holds a user's API keys and injects them into agent terminal sessions.

It exists so that anyone can audit the code that touches their secrets, rather than take our word for it.

What's here

File	Role
src/vault.rs	The entire Vault backend: encryption, storage, PIN gate, all 12 IPC commands, and the two egress routes. 927 lines including tests.
src/redact.rs	The terminal-output redactor that masks vault values in the PTY stream before they reach the UI. 355 lines including tests.
WHITEPAPER.md	The security design document: architecture, threat model, and an honest account of what the Vault does not protect against.

Provenance

• Extracted verbatim, unmodified from the Lemonade application source as shipped in v2.5.1 (Vault first shipped in v2.5.0).
• Source commit: 53a6ea951e808be0f58a7573de08cd19f5b6b6be (private repo lemonade-app; paths src-tauri/src/commands/vault.rs and src-tauri/src/pty/redact.rs).
• These files will be re-published on any release that changes them, with the new commit hash noted here.

The one-sentence claim being audited

Secret values enter the app once, are sealed with AES-256-GCM under a key held in the OS credential store, and leave by exactly two Rust-side routes (child-process environment variables and the OS clipboard). No IPC command ever returns a secret value to the frontend.

Read WHITEPAPER.md for the full design, then verify the claim against the code: every #[tauri::command] in vault.rs is the complete IPC surface of the feature, and none of their return types carries a value field.

Compilation notes

This is an audit copy, not a standalone crate. The files compile inside the Lemonade Tauri application, and two things are external to what is published here:

1. use super::license::require_license; refers to Lemonade's licensing module. Its signature is pub fn require_license() -> Result<(), String>; it gates every command to licensed installs and touches no vault data. Stub it as Ok(()) if you want to type-check the file in isolation.
2. redaction_secrets() and injectable_env() are consumed by the PTY manager (pty/manager.rs), which is out of scope for this audit but is described in the whitepaper's egress section.

Relevant dependency versions (from the application's Cargo.toml):

tauri   = "2"
aes-gcm = "0.10"
keyring = { version = "3", features = ["windows-native", "apple-native"] }
argon2  = "0.5"
zeroize = { version = "1", features = ["derive"] }
base64  = "0.22"
uuid    = { version = "1", features = ["v4"] }
serde   = { version = "1", features = ["derive"] }

Verify it empirically (no source required)

You can check the main claims against the installed app directly:

1. Ciphertext at rest. Open %APPDATA%\dev.getlemonade.lemonade\vault.enc (Windows) or ~/Library/Application Support/dev.getlemonade.lemonade/vault.enc (macOS). It is a small JSON envelope {v, nonce, data} whose payload is base64 AES-256-GCM ciphertext. Your keys do not appear in it.
2. The key lives in your OS credential store. Windows: Credential Manager, entry Lemonade Vault / user dek. macOS: Keychain Access, item Lemonade Vault.
3. Nothing phones home. Run Wireshark, Little Snitch, or netstat while adding, listing, and injecting vault keys. Vault operations perform no network I/O; the only network activity in the app is license validation, the updater, usage meters, and any providers you configure yourself.
4. The frontend never sees a value. Open the WebView devtools and observe the IPC responses: vault_list returns metadata with a masked preview (…3456), and vault_copy_secret returns only an integer (the clipboard clear delay).

Reporting a vulnerability

If you find a flaw in this code, email drew.devteam@gmail.com with the details. Please do not open a public issue for an unpatched vulnerability.

License

The contents of this repository are published under the MIT License (see LICENSE). This covers the published module for audit and reuse; the Lemonade application as a whole remains proprietary.