Python gspread/httplib2 SSLHandshakeError

我为python编写了gspread，但大约一个月后，我开始出现以下错误：

gc = gspread.authorize(credentials)

文件“/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site packages/gspread-0.3.0-py2.7.egg/gspread/client.py”，第331行 client.login（） 文件“/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site packages/gspread-0.3.0-py2.7.egg/gspread/client.py”，第101行，登录 self.auth.refresh（http） 文件“/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site packages/oauth2client-1.4.12-py2.7.egg/oauth2client/client.py”，第597行，刷新 自我刷新（http.request） 文件“/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site packages/oauth2client-1.4.12-py2.7.egg/oauth2client/client.py”，第768行，在刷新中 self.\u do\u刷新请求（http\u请求） 文件“/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site packages/oauth2client-1.4.12-py2.7.egg/oauth2client/client.py”，第799行，在“刷新”请求中 self.token_uri，method='POST'，body=body，headers=headers） 文件“/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site packages/httplib2-0.8-py2.7.egg/httplib2/__init_uuuuuuuuuuuuu.py”，请求中的第1570行 （响应，内容）=self.\u请求（conn，authority，uri，request\u uri，method，body，header，重定向，cachekey） 文件“/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site packages/httplib2-0.8-py2.7.egg/httplib2/_uinit_uuuuuuuuuuuuuuuuuuu.py”，第1317行，在请求中 （响应，内容）=自连接请求（连接，请求uri，方法，正文，标题） 文件“/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site packages/httplib2-0.8-py2.7.egg/httplib2/__init_uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu 连接 文件“/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site packages/httplib2-0.8-py2.7.egg/httplib2/__init_____;.py”，第1044行，在connect中 升起SSLhandshake错误（e） httplib2.SSLHandshakeError:[Errno 1]\u ssl.c:504:错误：0D0890A1:asn1编码例程：asn1\u验证：未知消息摘要算法 我已经尝试了我所能想到的一切，包括安装一个新的python发行版，但没有任何效果。我在mac电脑上，我升级了pyOpenSSL并做了我能想到的一切。有人有主意吗

File "/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site-packages/gspread-0.3.0-py2.7.egg/gspread/client.py", line 331, in authorize client.login() File "/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site-packages/gspread-0.3.0-py2.7.egg/gspread/client.py", line 101, in login self.auth.refresh(http) File "/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site-packages/oauth2client-1.4.12-py2.7.egg/oauth2client/client.py", line 597, in refresh self._refresh(http.request) File "/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site-packages/oauth2client-1.4.12-py2.7.egg/oauth2client/client.py", line 768, in _refresh self._do_refresh_request(http_request) File "/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site-packages/oauth2client-1.4.12-py2.7.egg/oauth2client/client.py", line 799, in _do_refresh_request self.token_uri, method='POST', body=body, headers=headers) File "/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site-packages/httplib2-0.8-py2.7.egg/httplib2/__init__.py", line 1570, in request (response, content) = self._request(conn, authority, uri, request_uri, method, body, headers, redirections, cachekey) File "/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site-packages/httplib2-0.8-py2.7.egg/httplib2/__init__.py", line 1317, in _request (response, content) = self._conn_request(conn, request_uri, method, body, headers) File "/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site-packages/httplib2-0.8-py2.7.egg/httplib2/__init__.py", line 1252, in _conn_request conn.connect() File "/Library/Frameworks/Python.framework/Versions/7.3/lib/python2.7/site-packages/httplib2-0.8-py2.7.egg/httplib2/__init__.py", line 1044, in connect raise SSLHandshakeError(e) httplib2.SSLHandshakeError: [Errno 1] _ssl.c:504: error:0D0890A1:asn1 encoding routines:ASN1_verify:unknown message digest algorithm