小改，无伤大雅

recv/recv.py

@@ -72,6 +72,6 @@ def handleLetter(letter: Letter):
             break
     with open(path, "wb") as f:
         f.write(data)
-        print(f"确认收到来自 {Segwit.encodeSegwit(letter.senderPubKey.encode("utf-8"))} 的文件")
+        print(f"确认收到来自 {Segwit.encodeSegwit(letter.senderPubKey.encode('utf-8'))} 的文件")
         print(f"签名验证有效，已将文件 {newName} 保存至 {download_dir} 下")
     return

recv/test_recv.py

@@ -25,7 +25,7 @@ def test_handleLetter_sm4_ecb(mock_input):
     pass
 
 
-@patch('builtins.input', side_effect=['./public.pem', 'sm4', 'cbc'])
+@patch('builtins.input', side_effect=['./public.pem', 'aes', 'cbc'])
 def test_handleLetter_sm4_cbc(mock_input):
     letter = sender.main()
     recv.handleLetter(letter)

tool/symmetric/AES.py

@@ -10,7 +10,7 @@ from fontTools.misc.eexec import encrypt
 class AESUtils:
     def __init__(self, key: bytes = None):
         """生成一个随机密钥"""
-        self.key = get_random_bytes(32)
+        self.key = get_random_bytes(16)
 
     def encrypt(self, data: str, mode: str = 'ECB') -> (str,str):
         """加密数据"""