diff --git a/res/job.py b/res/job.py
index dea993616..1ddf0faa5 100755
--- a/res/job.py
+++ b/res/job.py
@@ -37,7 +37,7 @@ def create(task_name, file_path=None):
                 headers=HEADERS,
                 files=files,
             )
-    return response.json()
+    return get_json(response)
 
 
 def upload_file(task_id, file_path):
@@ -46,12 +46,12 @@ def upload_file(task_id, file_path):
         response = requests.post(
             f"{BASE_URL}/tasks/{task_id}/files", headers=HEADERS, files=files
         )
-    return response.json()
+    return get_json(response)
 
 
 def get_status(task_id):
     response = requests.get(f"{BASE_URL}/tasks/{task_id}/status", headers=HEADERS)
-    return response.json()
+    return get_json(response)
 
 
 def download_files(task_id, output_dir, fn=None):
@@ -88,7 +88,7 @@ def download_one_file(task_id, file_id, output_dir):
 
 def fetch():
     response = requests.get(f"{BASE_URL}/tasks/fetch_task", headers=HEADERS)
-    return response.json()
+    return get_json(response)
 
 
 def update_status(task_id, status):
@@ -97,7 +97,7 @@ def update_status(task_id, status):
         headers=HEADERS,
         json=status,
     )
-    return response.json()
+    return get_json(response)
 
 
 def delete_task(task_id):
@@ -105,7 +105,7 @@ def delete_task(task_id):
         f"{BASE_URL}/tasks/{task_id}",
         headers=HEADERS,
     )
-    return response.json()
+    return get_json(response)
 
 
 def sign(file_path):
@@ -152,6 +152,13 @@ def sign_one_file(file_path):
     return False
 
 
+def get_json(response):
+    try:
+        return response.json()
+    except Exception as e:
+        raise Exception(response.text)
+
+
 SIGN_EXTENSIONS = [
     ".dll",
     ".exe",
@@ -170,11 +177,18 @@ SIGN_EXTENSIONS = [
 ]
 
 
-def sign_files(dir_path):
+def sign_files(dir_path, only_ext=None):
+    if only_ext:
+        only_ext = only_ext.split(",")
+        for i in range(len(only_ext)):
+            if not only_ext[i].startswith("."):
+                only_ext[i] = "." + only_ext[i]
     for root, dirs, files in os.walk(dir_path):
         for file in files:
             file_path = os.path.join(root, file)
             _, ext = os.path.splitext(file_path)
+            if only_ext and ext not in only_ext:
+                continue
             if ext in SIGN_EXTENSIONS:
                 if not sign_one_file(file_path):
                     logging.error(f"Failed to sign {file_path}")
@@ -200,6 +214,9 @@ def main():
     sign_files_parser.add_argument(
         "dir_path", help="The path of the directory containing the files to sign."
     )
+    sign_files_parser.add_argument(
+        "only_ext", help="The file extension to sign.", default=None, nargs="?"
+    )
 
     # Create a parser for the "fetch" command
     fetch_parser = subparsers.add_parser("fetch", help="Fetch a task.")
@@ -258,7 +275,7 @@ def main():
     if args.command == "sign_one_file":
         sign_one_file(args.file_path)
     elif args.command == "sign_files":
-        sign_files(args.dir_path)
+        sign_files(args.dir_path, args.only_ext)
     elif args.command == "fetch":
         print(fetch())
     elif args.command == "update_status":