feat: add example for createDescriptorWalletWithWalletPassphrase

Issue: BTC-0

examples/ts/create-descriptor-wallet.ts

@@ -0,0 +1,79 @@
+/**
+ * Create a multi-sig wallet at BitGo.
+ * This makes use of the convenience function generateWallet
+ *
+ * This tool will help you see how to use the BitGo API to easily create a wallet.
+ * In this form, it creates 2 keys on the host which runs this example.
+ * It is HIGHLY RECOMMENDED that you GENERATE THE KEYS ON SEPARATE MACHINES for real money wallets!
+ *
+ * To perform more advanced features, such as encrypting keys yourself, please look at createWalletAdvanced.js
+ *
+ * Copyright 2022, BitGo, Inc.  All Rights Reserved.
+ */
+
+/**
+ * Add Low Fee webhook to a wallet.
+ *
+ * Copyright 2022 BitGo, Inc.  All Rights Reserved.
+ */
+
+import { BitGoAPI } from '@bitgo/sdk-api';
+import { Tbtc } from '@bitgo/sdk-coin-btc'; // Replace with your given coin (e.g. Ltc, Tltc)
+import { AbstractUtxoCoin, descriptor } from '@bitgo/abstract-utxo';
+require('dotenv').config({ path: '../../.env' });
+
+const bitgo = new BitGoAPI({
+  accessToken: process.env.TESTNET_ACCESS_TOKEN,
+  env: 'test', // Change this to env: 'production' when you are ready for production
+});
+
+// Set the coin name to match the blockchain and network
+// btc = bitcoin, tbtc = testnet bitcoin
+const coin = 'tbtc';
+bitgo.register(coin, Tbtc.createInstance);
+
+// TODO: set a label for your new wallet here
+const label = 'Example Descriptor Wallet';
+
+// TODO: set your passphrase for your new wallet here
+const passphrase = 'test_wallet_passphrase';
+
+// TODO: set your enterprise ID for your new wallet here
+const enterprise = 'your_enterprise_id';
+
+async function main() {
+  console.log(
+    // this wrapper creates three keys: userKey, backupKey, and bitgoKey
+    // at the moment, this is a somewhat artificial requirement from wallet platform
+    // in the future, we will allow for more flexible key generation
+    await descriptor.createWallet.createDescriptorWalletWithWalletPassphrase(
+      bitgo,
+      bitgo.coin(coin) as AbstractUtxoCoin,
+      {
+        label,
+        walletPassphrase: passphrase,
+        enterprise,
+        descriptorsFromKeys(userKey, cosigners) {
+          // userKey is backed up at BitGo with the wallet passphrase
+          // cosigners are backup key and BitGo key
+          const xpubs = [userKey, ...cosigners].map((key) => key.neutered().toBase58());
+
+          return [
+            // here is a single-sig descriptor for the user key
+            descriptor.createNamedDescriptorWithSignature('SingleSigWpkh', `wpkh(${xpubs[0]}/*)`, userKey),
+            // here is a 2of3 multisig descriptor for the backup key and BitGo key
+            descriptor.createNamedDescriptorWithSignature(
+              'MultiSigWsh',
+              `wsh(multi(2,${xpubs.map((xpub) => `${xpub}/*`).join(',')})`,
+              userKey
+            ),
+            // equivalent to the above, but returns two descriptors (external and internal)
+            ...descriptor.createWallet.DefaultWsh2Of3(userKey, cosigners),
+          ];
+        },
+      }
+    )
+  );
+}
+
+main().catch((e) => console.log(e));

modules/abstract-utxo/src/descriptor/NamedDescriptor.ts

@@ -24,9 +24,12 @@ export type NamedDescriptor<T = string> = {
 
 export function createNamedDescriptorWithSignature(
   name: string,
-  descriptor: Descriptor,
+  descriptor: string | Descriptor,
   signingKey: BIP32Interface
 ): NamedDescriptor {
+  if (typeof descriptor === 'string') {
+    descriptor = Descriptor.fromString(descriptor, 'derivable');
+  }
   const value = descriptor.toString();
   const signature = signMessage(value, signingKey, networks.bitcoin).toString('hex');
   return { name, value, signatures: [signature] };

modules/abstract-utxo/src/descriptor/index.ts

@@ -1,6 +1,6 @@
 export { Miniscript, Descriptor } from '@bitgo/wasm-miniscript';
 export { assertDescriptorWalletAddress } from './assertDescriptorWalletAddress';
-export { NamedDescriptor } from './NamedDescriptor';
+export { NamedDescriptor, createNamedDescriptorWithSignature, hasValidSignature } from './NamedDescriptor';
 export { isDescriptorWallet, getDescriptorMapFromWallet } from './descriptorWallet';
 export { getPolicyForEnv } from './validatePolicy';
 export * as createWallet from './createWallet';