Add sample script to init and call the secure owner API from node.js (m…

…imblewimble#335)

* add sample script to init and call the secure owner API from node

* fix xiaojay's name.. thanks xiaojay!

doc/samples/v3_api_node/package.json

@@ -0,0 +1,14 @@
+{
+  "name": "node-sample",
+  "version": "0.0.1",
+  "description": "Sample of connecting to the secure OwnerAPI via node",
+  "main": "src/index.js",
+  "scripts": {
+    "test": "npm test"
+  },
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "jayson": "^3.2.0"
+  }
+}

doc/samples/v3_api_node/readme.md

@@ -0,0 +1,28 @@
+# Connecting to the wallet's V3 Owner API from Node
+
+This is a small sample with code that demonstrates how to initialize the Wallet V3's Secure API and call API functions through it.
+
+To run this sample:
+
+First run the Owner API:
+
+```.sh
+grin-wallet owner_api
+```
+
+This sample doesn't use the authentication specified in the wallet's `.api_secret`, so before running the owner_api please ensure api authentication is commented out in `grin-wallet.toml`. Including the authentication token as part of the request is a function of your json-rpc client library of choice, so it's not included in the sample to make setup a bit simpler.
+
+ensure the client url in `src\index.js` is set correctly:
+
+```.sh
+const client = jayson.client.http('http://localhost:3420/v3/owner');
+```
+
+Then (assuming node.js and npm are installed on the system):
+
+```.sh
+npm install
+node src/index.json
+```
+
+Feel free to play around with the sample, modifying it to call whatever functions you'd like to see in operation!

doc/samples/v3_api_node/src/index.js

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+/* Sample Code for connecting to the V3 Secure API via Node
+ *
+ * With thanks to xiaojay of Niffler Wallet:
+ * https://github.com/grinfans/Niffler/blob/gw3/src/shared/walletv3.js
+ *
+ */
+
+const jayson = require('jayson/promise');
+const crypto = require('crypto');
+
+const client = jayson.client.http('http://localhost:3420/v3/owner');
+
+// Demo implementation of using `aes-256-gcm` with node.js's `crypto` lib.
+const aes256gcm = (shared_secret) => {
+	const ALGO = 'aes-256-gcm';
+
+	// encrypt returns base64-encoded ciphertext
+	const encrypt = (str, nonce) => {
+		let key = Buffer.from(shared_secret, 'hex')
+		const cipher = crypto.createCipheriv(ALGO, key, nonce)
+		const enc = Buffer.concat([cipher.update(str, 'utf8'), cipher.final()])
+		const tag = cipher.getAuthTag()
+		return Buffer.concat([enc, tag]).toString('base64')
+	};
+
+	// decrypt decodes base64-encoded ciphertext into a utf8-encoded string
+	const decrypt = (enc, nonce) => {
+		//key,nonce is all buffer type; data is base64-encoded string
+		let key = Buffer.from(shared_secret, 'hex')
+		const data_ = Buffer.from(enc, 'base64')
+		const decipher = crypto.createDecipheriv(ALGO, key, nonce)
+		const len = data_.length
+		const tag = data_.slice(len-16, len)
+		const text = data_.slice(0, len-16)
+		decipher.setAuthTag(tag)
+		const dec = decipher.update(text, 'binary', 'utf8') + decipher.final('utf8');
+		return dec
+	};
+
+	return {
+		encrypt,
+		decrypt,
+	};
+};
+
+class JSONRequestEncrypted {
+	constructor(id, method, params) {
+		this.jsonrpc = '2.0'
+		this.method = method
+		this.id = id
+		this.params = params
+	}
+
+	async send(key){
+		const aesCipher = aes256gcm(key);
+		const nonce = new Buffer.from(crypto.randomBytes(12));
+		let enc = aesCipher.encrypt(JSON.stringify(this), nonce);
+		console.log("Encrypted: " + enc)
+		let params = {
+			'nonce': nonce.toString('hex'),
+			'body_enc': enc,
+		}
+		let response = await client.request('encrypted_request_v3', params);
+
+		if (response.err) {
+			throw response.err
+		}
+
+		const nonce2 = Buffer.from(response.result.Ok.nonce, 'hex');
+		const data = Buffer.from(response.result.Ok.body_enc, 'base64');
+
+		let dec = aesCipher.decrypt(data, nonce2)
+		return dec
+	}
+}
+
+async function initSecure() {
+	let ecdh = crypto.createECDH('secp256k1')
+	ecdh.generateKeys()
+	let publicKey = ecdh.getPublicKey('hex', 'compressed')
+	const params = {
+		'ecdh_pubkey': publicKey
+	}	
+	let response = await client.request('init_secure_api', params);
+	if (response.err) {
+		throw response.err
+	}
+
+	return ecdh.computeSecret(response.result.Ok, 'hex', 'hex')
+}
+
+function sleep(ms) {
+	return new Promise(resolve => setTimeout(resolve, ms));
+}
+
+async function main() {
+	let shared_key = await initSecure();
+
+	let response = await new JSONRequestEncrypted(1, 'open_wallet', {
+		"name": null,
+		"password": "",
+	}).send(shared_key);
+
+	let token = JSON.parse(response).result.Ok;
+
+	let iterations = 1;
+
+	for (i=0; i<iterations*2; i+=2)  {
+		let info_response = await new JSONRequestEncrypted(i, 'retrieve_summary_info', {
+			"token": token,
+			"refresh_from_node": true,
+			"minimum_confirmations": 1,
+		}).send(shared_key)
+
+		console.log("Info Response: ", info_response);
+		await sleep(2000)
+
+		let txs_response = await new JSONRequestEncrypted(i+1, 'retrieve_txs', {
+			"token": token,
+			"refresh_from_node": true,
+			"tx_id": null,
+			"tx_slate_id": null,
+		}).send(shared_key)
+
+		console.log("Txs Response: ", txs_response);
+		await sleep(2000)
+	}
+}
+
+
+
+main();
+
+