XO Wallet Integration Part IV

packages/stack/src/wallet/base-wallet.ts

@@ -11,7 +11,15 @@ import { type BlockchainUTXOs } from '../blockchain/index.js';
 import { type Activities, type BaseStore } from '../storage/index.js';
 import { EventEmitter } from '../utils/index.js';
 
-import { type TokenBalances, type Address } from '@xocash/primitives';
+import {
+  type TokenBalances,
+  type Address,
+  Bytes,
+  Hasher,
+  encodeExtendedJson,
+} from '@xocash/primitives';
+
+export type WalletGenesisData = Record<string, unknown>;
 
 export type WalletEvents = {
   shouldMonitorUpdated: boolean;
@@ -33,32 +41,69 @@ export type WalletEvents = {
 export abstract class BaseWallet<
   WalletEventsType extends WalletEvents = WalletEvents,
 > extends EventEmitter<WalletEventsType> {
-  static readonly deriveKey: (keyName: string) => Promise<Uint8Array>;
+  /**
+   * Derive a key to use based on the given Genesis Data.
+   *
+   * @remarks
+   *
+   * These keys can be used for Wallet Id's, Signing Keys, Encryption Keys and for Dapp Samdboxes.
+   */
+  static deriveKey(genesisData: WalletGenesisData, keyName: string) {
+    // Hash the genesis data using Hash256 and the key ("WalletID") for this derivation using Hash256.
+    const genesisDataHashed = Hasher.fromUTF8(
+      encodeExtendedJson(genesisData),
+    ).toHash256Bytes();
+    const keyHashed = Hasher.fromUTF8(keyName).toHash256Bytes();
+
+    // Combine the hashes and do one final hash for good measure.
+    return Hasher.fromBytes(
+      new Uint8Array([...genesisDataHashed, ...keyHashed]),
+    ).toHash256Bytes();
+  }
+
+  static deriveId(genesisData: WalletGenesisData) {
+    return BaseWallet.deriveKey(genesisData, 'walletId');
+  }
 
   // Dependencies.
   abstract readonly activities: Activities;
   abstract readonly blockchain: WalletBlockchain;
   abstract readonly cache: BaseStore;
 
+  // Genesis Data.
+  abstract readonly genesisData: WalletGenesisData;
+
   /**
    * Get the ID for this wallet.
    */
-  abstract getId(): Promise<string>;
-
-  /**
-   * Derive a key using secret data from this wallet.
-   */
-  abstract deriveKey(keyName: string): Promise<Uint8Array>;
+  async getId() {
+    // NOTE: Use the cache to optimize future calls.
+    return Bytes.from(
+      await this.cache.getOrSet('walletId', async () =>
+        BaseWallet.deriveKey(this.genesisData, 'walletId'),
+      ),
+    ).toHex();
+  }
 
   /**
    * Get the encryption key to use for this wallet.
    */
-  abstract getEncryptionKey(): Promise<Uint8Array>;
+  async getEncryptionKey() {
+    // NOTE: Use the cache to optimize future calls.
+    return await this.cache.getOrSet('encryptionKey', async () =>
+      BaseWallet.deriveKey(this.genesisData, 'encryptionKey'),
+    );
+  }
 
   /**
    * Get the signing key to use for this wallet.
    */
-  abstract getSigningKey(): Promise<Uint8Array>;
+  async getSigningKey() {
+    // NOTE: Use the cache to optimize future calls.
+    return this.cache.getOrSet('signingKey', async () =>
+      BaseWallet.deriveKey(this.genesisData, 'signingKey'),
+    );
+  }
 
   /**
    * Start monitoring this wallet for any transaction activity.