AccessDeny Error

[Muzijiajian]

博主你好，我直接在views里面定义相关的access_id & access_key进行验证oss,控制台输出可以返回一个oss的object，但是想去遍历这个的时候出现报错，如下：
System check identified no issues (0 silenced).
August 30, 2018 - 06:01:08
Django version 1.11, using settings 'mysite.settings'
Starting development server at http://127.0.0.1:8000/
Quit the server with CONTROL-C.
<oss2.api.Bucket object at 0x7f1c675b7d90>
Internal Server Error: /mark_index/
Traceback (most recent call last):
File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/exception.py", line 41, in inner
response = get_response(request)
File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py", line 187, in _get_response
response = self.process_exception_by_middleware(e, request)
File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py", line 185, in _get_response
response = wrapped_callback(request, *callback_args, **callback_kwargs)
File "/home/lord/imooc/mysite/marking/views.py", line 26, in index
for obj in oss2.ObjectIterator(bucket, delimiter='/'):
File "/usr/local/lib/python2.7/dist-packages/oss2/iterators.py", line 43, in next
return self.next()
File "/usr/local/lib/python2.7/dist-packages/oss2/iterators.py", line 40, in next
self.fetch_with_retry()
File "/usr/local/lib/python2.7/dist-packages/oss2/iterators.py", line 48, in fetch_with_retry
self.is_truncated, self.next_marker = self._fetch()
File "/usr/local/lib/python2.7/dist-packages/oss2/iterators.py", line 108, in _fetch
max_keys=self.max_keys)
File "/usr/local/lib/python2.7/dist-packages/oss2/api.py", line 331, in list_objects
'encoding-type': 'url'})
File "/usr/local/lib/python2.7/dist-packages/oss2/api.py", line 1128, in __do_object
return self._do(method, self.bucket_name, key, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/oss2/api.py", line 154, in _do
raise exceptions.make_exception(resp)
AccessDenied: {'status': 403, 'request-id': '5B87882C95F081E9CA6611B4', 'details': {'HostId': 'uncertain.oss-cn-beijing.aliyuncs.com', 'Message': 'OSS authentication requires a valid Date.', 'Code': 'AccessDenied', 'RequestId': '5B87882C95F081E9CA6611B4'}}
ERROR:django.request:Internal Server Error: /mark_index/

view中代码如下:
def index(request):
# 遍历oss云端bucket
auth = oss2.Auth(ACCESS_KEY_ID, ACCESS_KEY_SECRET)
bucket = oss2.Bucket(auth, END_POINT, 'uncertain')
print bucket
for obj in oss2.ObjectIterator(bucket, delimiter='/'):
print('Processing')
welcom = u"这是首页!!"
return render(request, 'marking/index.html', {'welcom': welcom})