Add ledger interaction example

ledger/index.js

+const { newElixxirApp } = require('@zondax/ledger-substrate');
+const TransportNodeHid = require("@ledgerhq/hw-transport-node-hid");
+const { ApiPromise, WsProvider } = require('@polkadot/api');
+require('dotenv').config();
+
+const LEDGER = '6WA132Y5Ycgz3cXUt6a6rEhcJ4imhxXAij7x5Gefha5wu83g';
+const ALICE = '6a6XHUGV5mu33rX1vn3iivxxUR4hwoUapsuECGyHpPzfaNtt';
+
+/**
+ * Connect to an xx network node using websocket
+ * @return {Promise} chain api
+ */
+async function connect() {
+    const provider = new WsProvider(process.env.WS_CHAIN);
+    const api = await ApiPromise.create({
+        provider,
+    });
+    await api.isReady;
+    return api;
+}
+
+async function sendAndWait(extrinsic, final) {
+    return new Promise((reject, resolve) => {
+        // Sign and send the extrinsic using our wallet
+        extrinsic.send(({ status }) => {
+            if (status.isInBlock) {
+                console.log(`Transfer included in block ${status.asInBlock}`);
+                if (!final) {
+                    resolve();
+                }
+            }
+            if (status.isFinalized && final) {
+                console.log(`Transfer finalized in block ${status.asFinalized}`);
+                resolve();
+            }
+        });
+    })
+}
+
+async function main () {
+    const transport = await TransportNodeHid.default.create();
+
+    const app = newElixxirApp(transport);
+
+    // Connect to the node
+    const api = await connect();
+
+    // Create a extrinsic, transferring 10 units to Alice (with 9 decimals)
+    const transfer = api.tx.balances.transfer(ALICE, 10_000000000);
+
+    // Get the current nonce for the sending account
+    const nonce = await api.rpc.system.accountNextIndex(LEDGER);
+
+    // Create the signing payload
+    // These options are for an immortal extrinsic
+    const signPayload = api.registry.createTypeUnsafe('SignerPayload', [
+        {
+            genesisHash: api.genesisHash,
+            blockHash: api.genesisHash,
+            runtimeVersion: api.runtimeVersion,
+            signedExtensions: api.registry.signedExtensions,
+            version: 4,
+            specVersion: api.runtimeVersion.specVersion,
+            transactionVersion: api.runtimeVersion.transactionVersion,
+            nonce: nonce,
+            address: LEDGER,
+            method: transfer.method,
+            blockNumber: 0,
+        }
+    ]);
+
+    const txData = signPayload.toRaw().data.substring(2);
+    const txBlob = Buffer.from(txData, 'hex');
+
+    const signature = await app.sign(0x80000000, 0x80000000, 0x80000000, txBlob);
+
+    // Add signature
+    transfer.addSignature(
+        LEDGER,
+        signature.signature,
+        signPayload.toPayload()
+    );
+
+    await sendAndWait(transfer, true);
+}
+
+main().catch(console.error).finally(() => process.exit());

ledger/package.json

+{
+  "name": "ledger",
+  "version": "1.0.0",
+  "description": "Ledger integration",
+  "main": "index.js",
+  "repository": "github.com/xx-labs/scripts/ledger",
+  "author": "xx labs",
+  "license": "MIT",
+  "scripts": {
+    "start": "node index.js"
+  },
+  "dependencies": {
+    "@ledgerhq/hw-transport-node-hid": "^6.24.1",
+    "@polkadot/api": "^7.15.1",
+    "@zondax/ledger-substrate": "^0.24.0",
+    "dotenv": "^16.0.0"
+  }
+}