ADD file via upload

verify_digital_signature.py

@@ -0,0 +1,49 @@
+from cryptography.hazmat.primitives import serialization
+from cryptography.hazmat.backends import default_backend
+from cryptography.hazmat.primitives import hashes
+from cryptography.hazmat.primitives.asymmetric import padding
+from cryptography.hazmat.primitives.asymmetric import utils
+import os
+
+def verify_digital_signature():
+    # 获取当前脚本所在目录
+    current_directory = os.path.dirname(__file__)
+
+    # 读取A的公钥
+    public_key_path = os.path.join(current_directory, 'A_public.txt')
+    with open(public_key_path, 'r') as file:
+        public_key_data = file.read()
+        public_key = serialization.load_pem_public_key(
+            public_key_data.encode(),
+            backend=default_backend()
+        )
+
+    # 读取解密后的文件
+    decrypted_file_path = os.path.join(current_directory, 'file.txt_decrypted.txt')
+    with open(decrypted_file_path, 'rb') as file:
+        decrypted_message = file.read()
+
+    # 计算摘要
+    hash_object = hashes.Hash(hashes.SHA256(), backend=default_backend())
+    hash_object.update(decrypted_message)
+    hash_value = hash_object.finalize()
+
+    # 读取数字签名
+    signature_path = os.path.join(current_directory, 'signature.txt')
+    with open(signature_path, 'rb') as file:
+        signature = file.read()
+
+    # 使用公钥验证签名
+    try:
+        public_key.verify(
+            signature,
+            hash_value,
+            padding.PSS(
+                mgf=padding.MGF1(hashes.SHA256()),
+                salt_length=padding.PSS.MAX_LENGTH
+            ),
+            utils.Prehashed(hashes.SHA256())
+        )
+        print("数字签名验证成功！")
+    except Exception as e:
+        print(f"数字签名验证失败: {e}")