sender修改了加密，并且进行了优化了输出格式和代码，letter就改了一下格式，AES完成

entity/Letter.py

@@ -1,6 +1,6 @@
 class Letter:
     sign = "计算得到"
-    encryptType = "SM4-GCM"
+    encryptType = "SM4_GCM"
     encryptKey = "计算获得"
     recvPubKey = ""
     senderPubKey = ""

sender/sender.py

@@ -1,7 +1,12 @@
 # 模式，文件，自己的公钥从哪里来，别人的公钥从哪里来
 from entity.Letter import Letter
 from tool.symmetric.AES import AESUtils
+from tool.symmetric.SM4 import encrypt_ecb, decrypt_cbc_with_iv
+from Crypto.Random import get_random_bytes
 
+# 两个变量，记录信封
+letterWay = ""
+letterMode = ""
 
 def main():
     # 用户输入各种数据填充letter字段
@@ -16,33 +21,40 @@ def sendLetter(letter: Letter, target="192.168.195.162:8426"):
     pass
 
 
-# 选择对称加密的方法和模式(aes/sm2)
+# 选择对称加密的方法和模式(aes/sm4)
 def selectSymEncryptionChoice():
+    global letterWay, letterMode
     encryWay = ""
     encryMode = ""
 
     # 选择加密算法
     while True:
-        encryWay = input("Choose the way for encryption (aes/sm2): ").strip().lower()  # 统一转成小写
-        if encryWay in ["aes", "sm2"]:
+        encryWay = input("Choose the way for encryption (aes/sm4): ").strip().lower()  # 统一转成小写
+        if encryWay in ["aes", "sm4"]:
+            letterWay = encryWay
             print(f"You have selected '{encryWay}' encryption.")
             break  # 输入有效后退出循环
         else:
-            print("Invalid choice. Please enter 'aes' or 'sm2'.")
+            print("Invalid choice. Please enter 'aes' or 'sm4'.")
 
     # 选择加密算法的模式
     while True:
         if encryWay == "aes":
             encryMode = input("Choose the encryption mode (ecb/cbc/cfb/ofb): ").strip().lower()
             if encryMode in ["ecb", "cbc", "cfb", "ofb"]:
+                letterMode = encryMode
                 print(f"You have selected '{encryMode}' encryption mode.")
                 break  # 输入有效后退出循环
             else:
                 print("Invalid choice. Please enter ecb/cbc/cfb/ofb")
 
-        elif encryWay == "sm2":
-            print()
-            break  # 输入有效后退出循环
+        elif encryWay == "sm4":
+            encryMode = input("Choose the encryption mode (ecb/cbc): ").strip().lower()
+            if encryMode in ["ecb", "cbc"]:
+                print(f"You have selected '{encryMode}' encryption mode.")
+                break  # 输入有效后退出循环
+            else:
+                print("Invalid choice. Please enter ecb/cbc")
 
     return encryWay, encryMode
 
@@ -54,12 +66,18 @@ def SymEncryption(encryData, key: bytes = None):
 
     if way == "aes":
         aesUtils = AESUtils(key)
-        # tureKey 为 真实返回的Key，如果没有设置初始值，那么key是随机生成
-        encryptedData, tureKey = aesUtils.encrypt(encryData, mode=mode)  # 这里encryData要改为文件内容
-        return encryptedData,tureKey
+        encryptedData, trueKey = aesUtils.encrypt(encryData, mode=mode)  # 这里encryData要改为文件内容
+        return encryptedData,trueKey
+
+    if way == "sm4":
+        key = get_random_bytes(16)
+        if mode == "ecb":
+            encrypted_data = encrypt_ecb(data, key)
+        # mode 为 cbc
+        else:
+            encrypted_data = decrypt_cbc_with_iv(data, key)
 
-    if way == "sm2":
-        pass
+        return encrypted_data, key
 
 
 def getKey():
@@ -69,9 +87,10 @@ def getKey():
 if __name__ == "__main__":
     # 示例数据和密钥
     data = "Hello, AES!"
-    # key = "1234567890abcdef"
-    print(data)
 
-    data,key = SymEncryption(data)
+    data, akey = SymEncryption(data)
+
+    print(data,akey)
 
-    print(data,key)
+    encryptType = f"{letterWay}_{letterMode}".upper()
+    print(encryptType)

tool/symmetric/AES.py

@@ -4,21 +4,27 @@ from Crypto.Cipher import AES
 from Crypto.Util.Padding import pad, unpad
 from Crypto.Random import get_random_bytes
 import base64
+from fontTools.misc.eexec import encrypt
+
 
 class AESUtils:
     def __init__(self, key: bytes = None):
-        """初始化 AES 加密工具，如果没有提供密钥，则生成一个随机密钥"""
-        if key is None:
-            self.key = get_random_bytes(32)  # AES-256
-        else:
-            self.key = key
+        """生成一个随机密钥"""
+        self.key = get_random_bytes(32)
 
     def encrypt(self, data: str, mode: str = 'ECB') -> (str,str):
         """加密数据"""
         cipher = self._get_cipher(mode)
         data = pad(data.encode(), AES.block_size)  # 填充数据
         ciphertext = cipher.encrypt(data)
-        return base64.b64encode(ciphertext).decode(),self.key
+        return base64.b64encode(ciphertext).decode(), self.key
+
+    def decrypt(self, encrypted_data: str, mode: str = 'ECB') -> str:
+        """解密数据"""
+        cipher = self._get_cipher(mode)
+        encrypted_data = base64.b64decode(encrypted_data)
+        plaintext = unpad(cipher.decrypt(encrypted_data), AES.block_size)
+        return plaintext.decode()
 
     def _get_cipher(self, mode: str) -> AES:
         """根据模式返回相应的 AES cipher"""
@@ -33,3 +39,12 @@ class AESUtils:
         else:  # 默认是 ECB
             return AES.new(self.key, AES.MODE_ECB)
 
+if __name__ == "__main__":
+    # 示例数据和密钥
+    data = "Hello, SM4!"
+    key = "1234567890abcdef"
+
+    enData , akey = AESUtils(key)
+
+    print(enData)
+