TS Library src (#8)

ts-lib/package.json

@@ -2,7 +2,7 @@
   "name": "neareth",
   "version": "1.0.0",
   "description": "The smart contract exposes two methods to enable storing and retrieving an encrypted (key, value)",
-  "main": "index.js",
+  "main": "index.ts",
   "scripts": {
     "test": "jest",
     "lint": "eslint && prettier --check .",

ts-lib/src/encryption/base58.ts

@@ -0,0 +1,69 @@
+/**
+ * This Key Manager is based on the cryptography package provided by
+ * @nearfoundation/near-js-encryption-box
+ * It relies on base58 encoding and requires a nonce to decrypt the key!
+ */
+
+import { HDNodeWallet } from "ethers";
+import { KeyContract } from "../keyContract";
+import { EthKeyManager } from "./interface";
+import { NearAccount } from "../types";
+import bs58 from "bs58";
+import { KeyPair } from "near-api-js";
+import { create, open } from "@nearfoundation/near-js-encryption-box";
+
+export class Base58KeyManager implements EthKeyManager {
+  // EthKeyContract connected to account for `nearPrivateKey`.
+  contract: KeyContract;
+
+  constructor(contract: KeyContract) {
+    this.contract = contract;
+  }
+
+  async encryptAndSetKey(
+    ethWallet: HDNodeWallet,
+    encryptionKey: string,
+  ): Promise<string | undefined> {
+    let keyPair = KeyPair.fromString(encryptionKey);
+    let encodedEthKey = this.encodeEthKey(ethWallet.privateKey);
+    const { secret: encryptedKey, nonce } = create(
+      encodedEthKey,
+      keyPair.getPublicKey().toString(),
+      encryptionKey,
+    );
+    console.log("Posting Encrypted Key", encryptedKey, nonce);
+    await this.contract.methods.set_key({ encrypted_key: encryptedKey });
+    return nonce || undefined;
+  }
+
+  async retrieveAndDecryptKey(
+    nearAccount: NearAccount,
+    nonce?: string,
+  ): Promise<string> {
+    const retrievedKey = await this.contract.methods.get_key({
+      account_id: nearAccount.accountId,
+    });
+    let keyPair = KeyPair.fromString(nearAccount.privateKey);
+    const decryptedKey = open(
+      retrievedKey!,
+      keyPair.getPublicKey().toString(),
+      nearAccount.privateKey,
+      nonce!,
+    );
+    if (decryptedKey === null) {
+      throw new Error("Unable to decrypt key!");
+    }
+    return this.decodeEthKey(decryptedKey);
+  }
+
+  private encodeEthKey(key: string): string {
+    const bytes = Buffer.from(key.slice(2), "hex");
+    const encodedKey = bs58.encode(bytes);
+    return encodedKey;
+  }
+
+  private decodeEthKey(key: string): string {
+    const bytes = Buffer.from(bs58.decode(key));
+    return "0x" + bytes.toString("hex");
+  }
+}

ts-lib/src/encryption/interface.ts

@@ -0,0 +1,23 @@
+import { ethers } from "ethers";
+import { NearAccount } from "../types";
+
+export interface EthKeyManager {
+  /**
+   *
+   * @param ethWallet - Ethereum Wallet to be stored on key contract.
+   * @param encryptionKey - Secret key of for encryption.
+   * @returns Nonce if needed decrypt encoded key, otherwise nothing.
+   */
+  encryptAndSetKey(
+    ethWallet: ethers.HDNodeWallet,
+    encryptionKey: string,
+  ): Promise<string | undefined>;
+
+  retrieveAndDecryptKey(
+    nearAccount: NearAccount,
+    nonce?: string,
+  ): Promise<string>;
+
+  // encodeEthKey(key: string): string;
+  // decodeEthKey(key: string): string;
+}

ts-lib/src/index.ts

@@ -0,0 +1,3 @@
+export * from "./encryption/base58";
+export * from "./keyContract";
+export * from "./types";

ts-lib/src/keyContract.ts

@@ -0,0 +1,27 @@
+import { Account, Contract } from "near-api-js";
+
+export interface IKeyContract {
+  set_key: (args: { encrypted_key: string }) => Promise<void>;
+  get_key: (args: { account_id: string }) => Promise<string | null>;
+}
+
+export class KeyContract {
+  // Contract method interface
+  methods: IKeyContract;
+  // Connected Account
+  account: Account;
+
+  /**
+   * Constructs an instance of a connected KeyContract
+   * @param contractId - Account ID of deployed contract.
+   * @param account - Near Account to sign change method transactions.
+   */
+  constructor(contractId: string, account: Account) {
+    this.account = account;
+    this.methods = new Contract(account, contractId, {
+      viewMethods: ["get_key"],
+      changeMethods: ["set_key"],
+      useLocalViewExecution: false,
+    }) as unknown as IKeyContract;
+  }
+}

ts-lib/src/types.ts

@@ -0,0 +1,4 @@
+export interface NearAccount {
+  accountId: string;
+  privateKey: string;
+}

ts-lib/tests/contract.test.ts

@@ -2,20 +2,13 @@ import { connect, Contract, KeyPair, keyStores, utils } from "near-api-js";
 import { ethers } from "ethers";
 import * as dotenv from "dotenv";
 import * as path from "path";
-// @ts-ignore
-import { create, open } from "@nearfoundation/near-js-encryption-box";
-import bs58 from "bs58";
+import { Base58KeyManager, KeyContract } from "../src";
 
 dotenv.config({
   path: path.resolve(__dirname, "../../neardev/dev-account.env"),
 });
 jest.setTimeout(30000);
 
-interface EthKeysContract {
-  set_key: (args: { encrypted_key: string }) => Promise<void>;
-  get_key: (args: { account_id: string }) => Promise<string | null>;
-}
-
 const contractName = process.env.CONTRACT_NAME as string;
 if (!contractName) {
   throw new Error("CONTRACT_NAME not found in environment");
@@ -30,7 +23,7 @@ const keyStore = new keyStores.InMemoryKeyStore();
 let keyPair = KeyPair.fromString(privateKey);
 const accountId = process.env.TEST_ACCOUNT_ID!;
 
-async function initContract(): Promise<EthKeysContract> {
+async function initContract(): Promise<KeyContract> {
   await keyStore.setKey("testnet", accountId, keyPair);
 
   const config = {
@@ -45,51 +38,31 @@ async function initContract(): Promise<EthKeysContract> {
   const near = await connect(config);
   const account = await near.account(accountId);
 
-  const contract = new Contract(account, contractName, {
-    viewMethods: ["get_key"],
-    changeMethods: ["set_key"],
-    useLocalViewExecution: false,
-  }) as unknown as EthKeysContract;
+  const contract = new KeyContract(contractName, account);
 
   return contract;
 }
 
-function encodeEthKey(key: string): string {
-  const bytes = Buffer.from(key.slice(2), "hex");
-  const encodedKey = bs58.encode(bytes);
-  return encodedKey;
-}
-
-function decodeEthKey(key: string): string {
-  const bytes = Buffer.from(bs58.decode(key));
-  return "0x" + bytes.toString("hex");
-}
-
 describe("EthKeys contract tests", () => {
-  let contract: EthKeysContract;
+  let contract: KeyContract;
 
   beforeAll(async () => {
     contract = await initContract();
   });
 
-  it("should generate ethWallet, encode and encrypt private key, set value on contract, retrieve, decrypt and match", async () => {
+  it("Base58 RoundTrip", async () => {
+    const keyManager = new Base58KeyManager(contract);
+
     // TODO - can we create not random?
-    let ethWallet = ethers.Wallet.createRandom();
-    let encodedEthKey = encodeEthKey(ethWallet.privateKey);
-    const { secret: encryptedKey, nonce } = create(
-      encodedEthKey,
-      keyPair.getPublicKey().toString(),
-      privateKey,
-    );
-    console.log("Encrypted Key", encryptedKey, nonce);
-    await contract.set_key({ encrypted_key: encryptedKey });
-    const retrievedKey = await contract.get_key({ account_id: accountId });
-    const decryptedKey = open(
-      retrievedKey!,
-      keyPair.getPublicKey().toString(),
-      privateKey,
+    const ethWallet = ethers.Wallet.createRandom();
+
+    // TODO - include nonce on contract so we don't have to remember it.
+    const nonce = await keyManager.encryptAndSetKey(ethWallet, privateKey);
+
+    const decryptedKey = await keyManager.retrieveAndDecryptKey(
+      { accountId, privateKey },
       nonce,
     );
-    expect(decodeEthKey(decryptedKey!)).toBe(ethWallet.privateKey);
+    expect(decryptedKey).toBe(ethWallet.privateKey);
   });
 });