我为python工作做了一些工作，但大约一个月后我开始收到以下错误：
gc = gspread.authorize(credentials)
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
我已经尝试了我能想到的一切，包括安装一个新的python发行版，但没有任何作用。我在Mac上，我升级了pyOpenSSL并完成了我能想到的一切。有没有人有想法？