add get_pass and confirm_pass utilities

pass.js

@@ -0,0 +1,32 @@
+const readline = require('readline');
+const stream = require('stream');
+const devnull = new stream.Writable({ write: (chunk, encoding, cb) => cb() });
+
+function get_pass(prompt) {
+	process.stdout.write(prompt);
+	return new Promise((res, rej) => {
+		const rl = readline
+			.createInterface({ input: process.stdin, output: devnull, terminal: true })
+			.once('line', (line) => {
+				res(line);
+				rl.close();
+			})
+			.once('close', () => {
+				process.stdout.write('\n');
+				rej();
+			});
+	});
+}
+
+async function confirm_pass(prompt1, prompt2, error) {
+	for (;;) {
+		const pass1 = await get_pass(prompt1);
+		const pass2 = await get_pass(prompt2);
+		if (pass1 === pass2) {
+			return pass1;
+		}
+		process.stdout.write(error + '\n');
+	}
+}
+
+module.exports = { get_pass, confirm_pass };