hc_seed_bundle 0.0.7

SeedBundle parsing and generation library.
Documentation
#![deny(missing_docs)]
#![deny(unsafe_code)]
#![deny(warnings)]
//! [![License: Apache-2.0](https://img.shields.io/badge/License-Apache%202.0-blue.svg)](https://www.apache.org/licenses/LICENSE-2.0)
//!
//! SeedBundle parsing and generation library.
//!
//! ### Links
//!
//! - [Git Repo - https://github.com/holochain/lair](https://github.com/holochain/lair)
//! - [API Documentation - https://docs.rs/hc_seed_bundle](https://docs.rs/hc_seed_bundle)
//! - [Javascript Implementation - https://holochain.github.io/hcSeedBundle/](https://holochain.github.io/hcSeedBundle/)
//!
//! ### Rationale
//!
//! - Applications like Holochain have different requirements than classic blockchain system in terms of key management. Namely there is no need for read-only or hardened wallets (Holochain handles these concepts through capabilities and membranes).
//! - Applications like Holochain still have need of hierarchy and determinism in key (or in this case seed) derivation.
//! - Since we're using libsodium for hashing, signature, and encryption algorithms, let's use it for derivation as well.
//! - To be psychologically compatible with the [Bitcoin "HD Wallet" spec](https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki), we will do away with the "context" part of sodium KDF by always setting it to `b"SeedBndl"` and focusing on the `subkey_id` and can declare a chain of subsequent derivations of a 32 byte seed in the form `m/68/1/65/8` where we apply `subkey_id`s 68, 1, 65, then 8 in turn.
//!
//! ### hcSeedBundle Encoding Spec
//!
//! Encoded in [MSGPACK](https://msgpack.org/index.html) binary format.
//!
//! To better facilitate rust/javascript interoperability, the rust library will treat msgpack "ext" types as binary data.
//!
//! #### SeedBundle
//!
//! ```javascript
//! // seed_bundle is a top-level array
//! 'seed_bundle':array [
//!   // literal 'hcsb0' version / heuristic marker
//!   'id_ver':str,
//!   // list of SeedCiphers define how to decrypt
//!   'cipher_list':array [
//!     'cipher_1':SeedCipher,
//!     'cipher_2':SeedCipher,
//!     // ..
//!     'cipher_N':SeedCipher,
//!   ],
//!   // additional second-level encoding app data
//!   'app_data':bin,
//! ]
//! ```
//!
//! #### SeedCipher::PwHash
//!
//! ```javascript
//! // the PwHash type SeedCipher defines a straight-forward
//! // pwhash secret that is use to secretstream encrypt a seed
//! 'seed_cipher':array [
//!   // for the pw hash cipher, this is a literal 'pw'
//!   'type':str,
//!   // argon2id 16 byte salt
//!   'salt':bin,
//!   // argon2id mem limit capped to u32 for js compatibility
//!   'mem_limit':int,
//!   // argon2id ops limit capped to u32 for js compatibility
//!   'ops_limit':int,
//!   // secretstream 24 byte header
//!   'header':bin,
//!   // secretstream 49 byte cipher
//!   'cipher':bin,
//! ]
//! ```
//!
//! #### SeedCipher::SecurityQuestions
//!
//! ```javascript
//! // Security Questions SeedCipher defines a pwhash cipher
//! // based on concatonating 3 answers that are lcased/trimmed
//! 'seed_cipher':array [
//!   // for the pw hash cipher, this is a literal 'qa'
//!   'type':str,
//!   // argon2id 16 byte salt
//!   'salt':bin,
//!   // argon2id mem limit capped to u32 for js compatibility
//!   'mem_limit':int,
//!   // argon2id ops limit capped to u32 for js compatibility
//!   'ops_limit':int,
//!   // the first security question to be answered
//!   'question_1':str,
//!   // the second security question to be answered
//!   'question_2':str,
//!   // the third security question to be answered
//!   'question_3':str,
//!   // secretstream 24 byte header
//!   'header':bin,
//!   // secretstream 49 byte cipher
//!   'cipher':bin,
//! ]
//! ```
//!
//!### Algorithms
//!
//! - `sodium_kdf32` - seed derivation
//!   - set to output 32 bytes (`[32 byte sub-seed]`)
//!   - context bytes - fixed `b"SeedBndl"`
//!   - subkey_id clamped to u32 to better support javascript
//! - `argon2id32` - generates secret for seed secretstream encryption
//!   - set to output 32 bytes (`[32 secret bytes]`)
//!   - salt: `[16 salt bytes from bundle]`
//!   - mem_limit: default `MODERATE`
//!   - ops_limit: default `MODERATE`
//!   - passphrase: user-supplied
//! - `secretstream_xchacha20poly1305`
//!   - single `push_final/pull_final` with entire contents

mod seed_cipher;
pub use seed_cipher::*;

mod unlocked_seed_bundle;
pub use unlocked_seed_bundle::*;