refactor: improve API key decryption error handling and logging

Author: ogabrielluiz

src/backend/base/langflow/services/auth/utils.py

@@ -375,13 +375,29 @@ def encrypt_api_key(api_key: str, settings_service: SettingsService):
 
 
 def decrypt_api_key(encrypted_api_key: str, settings_service: SettingsService):
+    """Decrypt the provided encrypted API key using Fernet decryption.
+
+    This function first attempts to decrypt the API key by encoding it,
+    assuming it is a properly encoded string. If that fails, it logs a detailed
+    debug message including the exception information and retries decryption
+    using the original string input.
+
+    Args:
+        encrypted_api_key (str): The encrypted API key.
+        settings_service (SettingsService): Service providing authentication settings.
+
+    Returns:
+        str: The decrypted API key, or an empty string if decryption cannot be performed.
+    """
     fernet = get_fernet(settings_service)
-    decrypted_key = ""
-    # Two-way decryption
     if isinstance(encrypted_api_key, str):
         try:
-            decrypted_key = fernet.decrypt(encrypted_api_key.encode()).decode()
-        except Exception:  # noqa: BLE001
-            logger.debug("Failed to decrypt API key")
-            decrypted_key = fernet.decrypt(encrypted_api_key).decode()
-    return decrypted_key
+            return fernet.decrypt(encrypted_api_key.encode()).decode()
+        except Exception as primary_exception:  # noqa: BLE001
+            logger.debug(
+                "Decryption using UTF-8 encoded API key failed. Error: %s. "
+                "Retrying decryption using the raw string input.",
+                primary_exception,
+            )
+            return fernet.decrypt(encrypted_api_key).decode()
+    return ""