Add basic P2PKH address miner

package.json

@@ -32,5 +32,7 @@
     "nyc": "^13.1.0",
     "xo": "^0.23.0"
   },
-  "dependencies": {}
+  "dependencies": {
+    "bitcoinjs-lib": "^5.0.3"
+  }
 }

src/index.js

@@ -1,3 +1,39 @@
-const vanity = () => {};
+const bitcoin = require('bitcoinjs-lib');
 
-module.exports = vanity;
+class Vain {
+	constructor({prefix}) {
+		this.prefix = `1${prefix}`;
+	}
+
+	start() {
+		const startTime = Date.now();
+
+		let found;
+		let attempts = 0;
+		let keyPair;
+		let address;
+
+		while (!found) {
+			attempts++;
+			keyPair = bitcoin.ECPair.makeRandom();
+			({address} = bitcoin.payments.p2pkh({pubkey: keyPair.publicKey}));
+
+			if (address.startsWith(this.prefix)) {
+				found = true;
+			}
+		}
+
+		const endTime = Date.now();
+		const duration = endTime - startTime;
+		const trysPerSecond = Math.floor(attempts / (duration / 1000));
+
+		return {
+			duration,
+			trysPerSecond,
+			address,
+			wif: keyPair.toWIF()
+		};
+	}
+};
+
+module.exports = Vain;