初始提交

shierfeng-fastapi-backend/utils/crypto_util.py

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+import base64
+import hashlib
+
+from cryptography.fernet import Fernet
+
+from config.env import JwtConfig
+from exceptions.exception import ServiceException
+
+
+class CryptoUtil:
+    """
+    加解密工具类
+    """
+
+    _cipher_suite = None
+
+    @classmethod
+    def _get_cipher_suite(cls) -> Fernet:
+        if cls._cipher_suite is None:
+            # 使用 JWT secret key 派生 Fernet key
+            # SHA256 hash (32 bytes) -> Base64 encoded (44 bytes) -> Fernet key
+            key = base64.urlsafe_b64encode(hashlib.sha256(JwtConfig.jwt_secret_key.encode()).digest())
+            cls._cipher_suite = Fernet(key)
+        return cls._cipher_suite
+
+    @classmethod
+    def encrypt(cls, data: str) -> str:
+        """
+        加密字符串
+
+        :param data: 明文
+        :return: 密文
+        """
+        if not data:
+            return data
+        try:
+            cipher_suite = cls._get_cipher_suite()
+            encrypted_bytes = cipher_suite.encrypt(data.encode('utf-8'))
+            return encrypted_bytes.decode('utf-8')
+        except Exception as e:
+            raise ServiceException('加密失败') from e
+
+    @classmethod
+    def decrypt(cls, token: str) -> str:
+        """
+        解密字符串
+
+        :param token: 密文
+        :return: 明文
+        """
+        if not token:
+            return token
+        try:
+            cipher_suite = cls._get_cipher_suite()
+            decrypted_bytes = cipher_suite.decrypt(token.encode('utf-8'))
+            return decrypted_bytes.decode('utf-8')
+        except Exception as e:
+            raise ServiceException('解密失败') from e