theseus/bundled-addons/bchwallet/lib/sia/keys.js

// Key tree for the Sia wallet: index i -> ed25519 key via walletd's
// KeyFromSeed(root, i), address = standard unlock hash of the public key.
// Private keys stay inside this module; sign() is the only way out.
module.exports = function makeKeys({ sia }) {
  class WalletKeys {
    constructor(root32) {
      this._root = Uint8Array.from(root32);
      this._cache = new Map();
    }
    entry(index) {
      let e = this._cache.get(index);
      if (!e) {
        const k = sia.keyFromSeed(this._root, index);
        e = { index, pub: k.pub, address32: k.address32, address: k.address, _priv: k.priv };
        this._cache.set(index, e);
      }
      return e;
    }
    sign(entry, msg) { return sia.sign(entry._priv, msg); }
    // Revealed only on explicit user action in Settings.
    get seedHex() { return sia.toHex(this._root); }
    wipe() {
      for (const e of this._cache.values()) e._priv.fill(0);
      this._cache.clear();
      this._root.fill(0);
    }
  }
  return { WalletKeys };
};