README.md

Seed Keeper Core

Seed Keeper Core is a small Rust library for deriving and encrypting keys and seeds.

Uses Argon2, AES Key Encryption Keys,

• Derive a key from username & password (salt & passphrase).
• Generate a random seed that zeroizes memory by default.
• Encrypt the seed with the key, and decrypt.

Roundtrip Usage

use seed_keeper_core::{derive_key}; // the main purpose of this library
use seed_keeper_core::wrap::{encrypt, decrypt}; // utils to encrypt and decrypt the seed
use seed_keeper_core::seed::{Seed, rand_seed}; // utils to generate a random seed
use seed_keeper_core::Zeroizing;

// Generate a secure random seed of 32 bytes:
let seed = rand_seed();
assert_eq!(seed.len(), 32);

// Derive key material from a username (salt) and password:

let password = "some random words that you made up, for sure!".to_string();
let salt = b"[email protected]"; // Salt should be unique per password

let key = derive_key(&password, salt).unwrap();

assert_eq!(
    key.as_ref(),
    [
         164, 103, 254, 113, 126, 241, 57, 240, 100, 56, 243, 125, 155, 224, 40, 242, 178,
         136, 222, 133, 220, 141, 127, 10, 88, 199, 181, 11, 241, 91, 149, 249
     ]
);

// Protect your new seed by encrypting it with the password and salt key:

let encrypted = encrypt(key.clone(), seed.clone()).unwrap();
let decrypted = decrypt(key.clone(), &encrypted).unwrap();
assert_eq!(*seed, *decrypted.as_slice());

Full Credentials and Storage

The inputs for Aegon2 must be at least 8 characters long strings, so seed-keeper exports helpers to help ensure that your users input the minimum length bytes, and give helpful errors when they don't. To use these helpers, just use the credentials module.

use seed_keeper_core::error;
use seed_keeper_core::credentials::{MinString, Credentials, Wallet};

fn it_works() -> Result<(), error::Error> {
    // Create a new wallet
    // [Credentials] supports Deserialization, so you can use it with serde_json from JavaScript
    let credentials = Credentials {
        username: MinString::new("username")?,
        password: MinString::new("password")?,
        encrypted_seed: None,
    };

    let wallet = Wallet::new(credentials)?;

    // Encrypt the seed
    let encrypted_seed = wallet.encrypted_seed()?;

    // Create a new wallet with the encrypted seed
    let credentials = Credentials {
        username: MinString::new("username")?,
        password: MinString::new("password")?,
        encrypted_seed: Some(encrypted_seed.clone()),
    };

    let wallet = Wallet::new(credentials)?;

    // Encrypt the seed
    let encrypted_seed_2 = wallet.encrypted_seed()?;

    assert!(!encrypted_seed_2.is_empty());

    // Should match
    assert_eq!(encrypted_seed, encrypted_seed_2);

    Ok(())
}