# Dependency and license review

Reviewed 2026-08-09. The OpenPGP backend decision is complete. The project
license remains intentionally unset pending the full transitive license audit
and packaging review described below.

## License direction

The preferred implementation stack permits IronStorage itself to use
`MIT OR Apache-2.0`. That is the provisional choice, not yet a final license.

The current direct dependencies are:

| Crate | Purpose | License |
| --- | --- | --- |
| [cap-std 4.0](https://crates.io/crates/cap-std/4.0.2), [cap-tempfile 4.0](https://crates.io/crates/cap-tempfile/4.0.2) | Capability-scoped filesystem access and atomic temporary files | Apache-2.0 WITH LLVM-exception OR Apache-2.0 OR MIT |
| [clap 4.6](https://crates.io/crates/clap/4.6.4), [clap_complete 4.6](https://crates.io/crates/clap_complete/4.6.9) | CLI parsing and in-process shell completion generation | MIT OR Apache-2.0 |
| [crossterm 0.29](https://crates.io/crates/crossterm/0.29.0) | Terminal I/O | MIT |
| [Ratatui 0.30](https://crates.io/crates/ratatui/0.30.2) | TUI | MIT |
| [Iced 0.14](https://crates.io/crates/iced/0.14.0) | Desktop UI | MIT |
| [gix 0.86](https://crates.io/crates/gix/0.86.0), [gix-config 0.59](https://crates.io/crates/gix-config/0.59.0) | Embedded Git objects, index, references, fetch, and merge | MIT OR Apache-2.0 |
| [reqwest 0.13](https://crates.io/crates/reqwest/0.13.4) | HTTPS smart-Git transport with Rustls | MIT OR Apache-2.0 |
| [flate2 1.1](https://crates.io/crates/flate2/1.1.9), [sha1 0.10](https://crates.io/crates/sha1/0.10.7) | Git pack compression and checksums | MIT OR Apache-2.0 |
| [pgp 0.20](https://crates.io/crates/pgp/0.20.0) | Embedded OpenPGP key import, encryption, decryption, and signatures | MIT OR Apache-2.0 |
| [rand 0.8](https://crates.io/crates/rand/0.8.7) | Operating-system-backed cryptographic randomness for OpenPGP operations | MIT OR Apache-2.0 |
| [regex 1.13](https://crates.io/crates/regex/1.13.1) | Linear-time byte-oriented decrypted grep matching | MIT OR Apache-2.0 |
| [tempfile 3](https://crates.io/crates/tempfile) | Permission-restricted CLI editor session directories and cleanup | MIT OR Apache-2.0 |
| [Serde 1](https://crates.io/crates/serde), [TOML 0.9](https://crates.io/crates/toml), [shlex 1.3](https://crates.io/crates/shlex), [url 2.5](https://crates.io/crates/url) | Strict configuration and command values | MIT OR Apache-2.0 |
| [UniFFI 0.32](https://crates.io/crates/uniffi/0.32.0) | Swift bridge | MPL-2.0 |
| [zeroize 1.9](https://crates.io/crates/zeroize/1.9.0) | Clear decrypted bytes on drop | MIT OR Apache-2.0 |

The activated transitive graph has no dependency that forces a GPL or LGPL
license choice. UniFFI and its support crates are the only mandatory copyleft
dependencies; MPL-2.0 is file-level copyleft and permits a larger work under a
different license, subject to its notice and source-availability requirements.

`pass` is GPL-2.0-or-later and `pass-otp` is GPL-3.0. Treat their documentation
and observable behavior as compatibility requirements, but do not copy their
source or tests into IronStorage. Any such reuse requires a fresh license
decision.

## Storage implementation candidates

| Slice | Candidate | License | Decision |
| --- | --- | --- | --- |
| GPG-compatible packets, encryption, and transferable keys | [`pgp` 0.20](https://crates.io/crates/pgp/0.20.0) | MIT OR Apache-2.0 | Selected with default features disabled. The fixture harness proves armored/binary protected key import, packet validation, GPG-compatible decryption, multi-recipient encryption, and detached signatures without native libraries or processes. |
| Alternative GPG implementation | [`sequoia-openpgp` 2.4](https://crates.io/crates/sequoia-openpgp/2.4.1) | LGPL-2.0-or-later | Hold in reserve. Its default Nettle backend is native; its Rust backend exists, but the LGPL adds distribution work we can avoid. |
| GnuPG integration | [`gpgme` 0.11](https://crates.io/crates/gpgme/0.11.0) | LGPL-2.1 | Reject: native GPGME/GnuPG integration and GPG engine processes violate the portability and no-process requirements. |
| Local Git plus HTTPS fetch/push | [`gix` 0.86](https://crates.io/crates/gix/0.86.0) | MIT OR Apache-2.0 | Selected with default features off and `blocking-http-transport-reqwest-rust-tls`; accept HTTPS remotes only, supply credentials directly, and use the storage-owned receive-pack implementation for push. |
| Git FFI fallback | [`git2` 0.21](https://crates.io/crates/git2/0.21.0) | MIT OR Apache-2.0 | Reject for now; it links libgit2 and is unnecessary for the HTTPS-only scope. |
| Server/application credentials | [`keyring-core` 1.0](https://crates.io/crates/keyring-core/1.0.0), [`apple-native-keyring-store` 1.0](https://crates.io/crates/apple-native-keyring-store/1.0.2), [`windows-native-keyring-store` 1.1](https://crates.io/crates/windows-native-keyring-store/1.1.0), [`zbus-secret-service-keyring-store` 1.0](https://crates.io/crates/zbus-secret-service-keyring-store/1.0.0) | MIT OR Apache-2.0 | Selected behind target-specific dependencies. Apple supports legacy Keychain plus protected-data user presence, Windows uses Credential Manager, and Linux uses Secret Service with the Tokio/Rust-crypto feature. |
| Secret values in memory | [`secrecy` 0.10](https://crates.io/crates/secrecy/0.10.3), [`zeroize` 1.9](https://crates.io/crates/zeroize/1.9.0) | MIT OR Apache-2.0 | `zeroize` selected for the storage-owned redacted byte type; consider `secrecy` only when typed exposure controls add value. |
| Password generation | [`rand`](https://crates.io/crates/rand) | MIT OR Apache-2.0 | Preferred using the operating-system CSPRNG. |
| TOTP and HOTP | [`hmac` 0.12](https://crates.io/crates/hmac/0.12.1), [`sha1` 0.10](https://crates.io/crates/sha1/0.10.7), [`sha2` 0.10](https://crates.io/crates/sha2/0.10.9), [`data-encoding` 2.11](https://crates.io/crates/data-encoding/2.11.1) | MIT or MIT OR Apache-2.0 | Selected for a small storage-owned implementation with RFC 4226/6238 vectors. Handled URIs retain exact bytes while decoded secrets zeroize; `totp-rs` rejects HOTP URIs and cannot cover all of `pass-otp`. |
| Native desktop clipboard | [`arboard` 3.6](https://crates.io/crates/arboard/3.6.1) | MIT OR Apache-2.0 | Selected with image support disabled and Wayland data-control enabled. Storage owns timeout, cleanup, and newer-content race policy; the safe adapter provides macOS, Windows, X11, and Wayland text access without helper processes. |
| CLI cancellation | [`ctrlc` 3.5](https://crates.io/crates/ctrlc/3.5.2) | MIT OR Apache-2.0 | Selected for cross-platform interruption of the blocking clipboard lease. Ctrl-C requests storage cleanup before the CLI returns cancellation. |
| Hidden CLI input | [`rpassword` 7.5](https://crates.io/crates/rpassword/7.5.4) | Apache-2.0 | Selected for portable terminal input with echo disabled. The CLI immediately moves returned strings into storage-owned zeroizing OTP input objects; it does not own validation or confirmation policy. |
| QR output and desktop image input | [`qrcode` 0.14](https://crates.io/crates/qrcode/0.14.1), [`rqrr` 0.10](https://crates.io/crates/rqrr/0.10.1) | MIT OR Apache-2.0; second crate also includes ISC | `qrcode` selected without image features for storage-owned matrices and terminal rendering. `rqrr` is test-only round-trip verification. Apple camera scanning should use AVFoundation and pass only decoded bytes to Rust. |
| Atomic file replacement and scoped filesystem access | [`cap-std` 4.0](https://crates.io/crates/cap-std/4.0.2), [`cap-tempfile` 4.0](https://crates.io/crates/cap-tempfile/4.0.2) | Apache-2.0 WITH LLVM-exception OR Apache-2.0 OR MIT | Selected. Directory capabilities prevent vault escape; temporary files are anonymous where supported and are synced before atomic replacement. |

With this path, the central crate needs no third-party native GPG, Git, OTP, or
QR library. Apple Security/LocalAuthentication, Windows Credential Manager,
Linux Secret Service, and Apple camera APIs remain operating-system boundaries.

## Release gate

Before choosing and adding the project license:

1. Lock the storage dependencies and run a full transitive license audit.
2. Confirm the required notices/source offers for MPL-2.0 dependencies in every
   distributed app package.

The checked-in compatibility suite completes the earlier OpenPGP backend gate:
`pgp` imports protected armored and binary exports, decrypts every GnuPG-audited
fixture, emits independently decryptable single- and multi-recipient messages,
and verifies the detached recipient signatures.