Added new example for how to retrieve a Google token, following
the best case, non-browser, workflow. Other thirdparty auth
mechs (Facebook, MSN) follow a similar pattern of using an
access token.
This is mainly just useful for authenticating without using TLS.
If an access token is not provided, an attempt will be made to
retrieve one from Google.
This requires an extra credential for SASL authentication:
xmpp = ClientXMPP('user@chat.facebook.com', '...access_token...')
xmpp.credentials['api_key'] = '...api_key...'
The mechanism name was being correctly de-plussed, but then we used the
original, -PLUS, name to extract the hash, finding SHA-1-PLUS and therefore
finding no match.
Test-Information:
Tested with Sleek against an Isode M-Link with SCRAM-SHA-1-PLUS available.
Author: dwd
