bug#41386: 28.0.50; Gnus nnimap OAuth 2.0 support

[Thomas Fitzsimmons]

Richard Stallman <rms@gnu.org> writes:

> [[[ To any NSA and FBI agents reading my email: please consider    ]]]
> [[[ whether defending the US Constitution against all enemies,     ]]]
> [[[ foreign or domestic, requires you to follow Snowden's example. ]]]
>
>   > OK, I'll try to help, but I don't know what Google or Gmail will do in
>   > the future, in general, obviously.
>
> I don't expect you to practice precognition.  But it may be possible
> to deduce something by putting their announcements together with other
> known facts.  Maybe we could figure out questions to ask them.
>
>   > Your question reminded me that Gmail provides "basic HTML view" which
>   > does not require any Javascript whatsoever for sign-in or for the main
>   > interface, and thus is fully useable with Emacs Web Wowser (eww).
>
> That is a significant fact.  It means that using Gmail in the free
> world won't become entirely impossible.  Thanks.
>  
> So I modify the question:
>
>    Will Gmail in the future permit access from the Free World
>    to read mail with a free local MUA in any manner whatsoever?
>    
> And there is another followup question:
>
> Is it possible to log in on basic HTML view
> passing via a proxy that will hide your actual location?

Yes.  Here is the recipe I tested:

   sudo apt install proxychains
   sudo sed 's/#quiet_mode/quiet_mode/' -i /etc/proxychains.conf
   ssh -ND 9050 <host-from-which-to-access-mail> &
   HOME=$(mktemp -d) proxychains emacs -Q -nw
   M-x eww RET https://gmail.com RET
   [Use the usual web-based log-in procedure via Emacs Web Wowser.]

The log-in procedure was successful and I was able to use the basic HTML
view interface.

To confirm the results of the test, I also logged into the same service
via Firefox and a direct connection.  After I did the procedure above,
the Firefox session showed:

"This account is currently being used in 1 other location (<address>)."

Where <address> was the IP address of <host-from-which-to-access-mail>.

The above is just an example, other methods may be superior in various
ways, but I think this proves that Gmail is useable in Emacs Web Wowser
via a proxy.

Thomas

P.S. Prior to installing proxychains, I tried using Emacs's built-in
proxy support in the same way.  There are references to SOCKS in the URL
manual, but I couldn't find an easy way to make EWW use localhost:9050
as a SOCKS proxy.  I debugged until I got to the comment "Should check
for socks" in url-default-find-proxy-for-url.