Re: oauth2 support for Emacs email clients

[Andrew Cohen]

>>>>> "LI" == Lars Ingebrigtsen <larsi@gnus.org> writes:

    LI> Andrew Cohen <acohen@ust.hk> writes:
    >> It requires two minor lisp changes (which I haven't yet pushed to
    >> master): one for imap support of xoauth2, the other for smtpmail
    >> support (see below).

    LI> The patch looks good to me -- I can push it to Emacs 28 if you
    LI> want?

Yes please.

Ideally this should come with some documentation updates:) For imap
usage the relevant paragraph in "Customizing the IMAP Connection" should
read:

‘nnimap-authenticator’
     Some IMAP servers allow anonymous logins.  In that case, this
     should be set to ‘anonymous’.  If this variable isn’t set, the
     normal login methods will be used.  If you wish to specify a
     specific login method to be used, you can set this variable to
     either ‘login’ (the traditional IMAP login method), ‘plain’, 
     ‘cram-md5’, or ‘xoauth2’ (to use oauth2). 

For the smtp usage the last paragraph of the SMTP authentication section
needs updating. Actually, I think it is currently mistaken (it says that
it tries various authentication methods in order, but as I recall if one
method fails it doesn't fall through to others). So ideally this whole
paragraph would get rewritten. But a temporary fix is 


   The process by which the SMTP library authenticates you to the server
is known as “Simple Authentication and Security Layer” (SASL). There are
various SASL mechanisms, and this library supports four of them:
CRAM-MD5, PLAIN, LOGIN, and XOAUTH2 where the first uses a form of
encryption to obscure your password, the next two do not, and the fourth
uses the oauth2 protocol.  It tries each of them, in that order, until
one succeeds.  You can override this by assigning a specific
authentication mechanism to a server by including a key ‘smtp-auth’ with
the value of your preferred mechanism in the appropriate ‘~/.authinfo’
entry.

Thanks,
Andy

--