Re: Making GNUS continue to work with Gmail

[Andrew Cohen <cohen@bu.edu>]

Microsoft has deferred retiring Basic Authentication for existing
customers until the second half of 2021 due to covid-19. New customers,
or those with no recorded usage, will have Basic Authentication disabled
as scheduled, October 2020.

https://developer.microsoft.com/en-us/office/blogs/deferred-end-of-support-date-for-basic-authentication-in-exchange-online/


For what its worth the outlook issues are similar to (or the same as)
gmail: registering a client with MS (or google) and then using a
potentially problematic web page to obtain a refresh-token. Once this is
done it is quite easy (in both gmail and outlook) to use the oauth2.el
library to authenticate.

In case anyone is interested in the details:

1. Refreshing the access-token using the oauth2.el library didn't work
    at first. Turns out MS forbids including the client_secret in the
    params list, while google requires it. I've changed oauth2.el to
    handle this trivial issue.

2. There are a several packages floating around to make this work but I
    realized it can be done with existing mechanisms with one minor
    change to auth-source.el (which I just pushed to master), allowing
    the plstore backend to store a function that retrieves the password
    rather than the password itself. Then setting this slot to the
    function from oauth2.el that refreshes the token
    makes everything just work.

If anyone wants more details let me know.

Best,
Andy