feat: add homeassistant integration (#578)

packages/common/src/encryption.ts

@@ -0,0 +1,22 @@
+import crypto from "crypto";
+
+const algorithm = "aes-256-cbc"; //Using AES encryption
+const key = Buffer.from("1d71cceced68159ba59a277d056a66173613052cbeeccbfbd15ab1c909455a4d", "hex"); // TODO: generate with const data = crypto.randomBytes(32).toString('hex')
+
+export function encryptSecret(text: string): `${string}.${string}` {
+  const initializationVector = crypto.randomBytes(16);
+  const cipher = crypto.createCipheriv(algorithm, Buffer.from(key), initializationVector);
+  let encrypted = cipher.update(text);
+  encrypted = Buffer.concat([encrypted, cipher.final()]);
+  return `${encrypted.toString("hex")}.${initializationVector.toString("hex")}`;
+}
+
+export function decryptSecret(value: `${string}.${string}`) {
+  const [data, dataIv] = value.split(".") as [string, string];
+  const initializationVector = Buffer.from(dataIv, "hex");
+  const encryptedText = Buffer.from(data, "hex");
+  const decipher = crypto.createDecipheriv(algorithm, Buffer.from(key), initializationVector);
+  let decrypted = decipher.update(encryptedText);
+  decrypted = Buffer.concat([decrypted, decipher.final()]);
+  return decrypted.toString();
+}