Rearrange Link Play module

- Try to ensure thread safety by using TCP socket

latest version/linkplay_server/aes.py

@@ -0,0 +1,24 @@
+from os import urandom
+from cryptography.hazmat.primitives.ciphers import (
+    Cipher, algorithms, modes
+)
+
+
+def encrypt(key, plaintext, associated_data):
+    iv = urandom(12)
+    encryptor = Cipher(
+        algorithms.AES(key),
+        modes.GCM(iv, min_tag_length=12),
+    ).encryptor()
+    encryptor.authenticate_additional_data(associated_data)
+    ciphertext = encryptor.update(plaintext) + encryptor.finalize()
+    return (iv, ciphertext, encryptor.tag)
+
+
+def decrypt(key, associated_data, iv, ciphertext, tag):
+    decryptor = Cipher(
+        algorithms.AES(key),
+        modes.GCM(iv, tag, min_tag_length=12),
+    ).decryptor()
+    decryptor.authenticate_additional_data(associated_data)
+    return decryptor.update(ciphertext) + decryptor.finalize()