Improve library

src/messages/basic.ts

@@ -1,4 +1,4 @@
-import { encrypt } from "romulus-js";
+import { encrypt, decrypt } from "romulus-js";
 import { DEFAULT_KEY, MessageTypes } from "../common";
 import { numberToUint16BE } from "../utilities/number";
 import { packOutgoingPacket } from "./packet";
@@ -28,9 +28,17 @@ export function packBasicMessage(
 
 /**
  * Unpack the data section of an incoming basic message (0x0001) message.
- * @param data The data section of an incoming basic message (0x0001) message.
- * @returns An encrypted unpacked basic message (0x0001) message.
+ * @param data The encrypted data section of an incoming basic message (0x0001) message.
+ * @param key The key to decrypt the data with.
+ * @returns The decrypted plaintext message.
  */
-export function unpackBasicMessage(data: Uint8Array): Uint8Array {
-  return data;
+export function unpackBasicMessage(
+  data: Uint8Array,
+  key: Uint8Array = DEFAULT_KEY,
+): Uint8Array {
+  const result = decrypt(data, MESSAGE_TYPE, key);
+  if (result.success) {
+    return result.plaintext;
+  }
+  throw new Error("Failed to decrypt basic message");
 }