This piggybacks on the existing IMAP support, and uses the same
configuration format (my local testing example has the IMAP and SMTP
lines almost copy-pasted from one another).
It's a little clumsy in that a new token is negotiated for every
`Send()` command, but it's a start...
imaps+oauthbearer://user:token@host?token_endpoint=...
- the config Source password is used as access token if
no token_endpoint parameter is set
- the config Source password is used as refresh token if
token_endpoint parameter is set, and used to exchange
with an access token
The implementation has only been tested with Gmail.
source = imaps+oauthbearer://{username}:{refersh_token}@imap.gmail.com:993? \
client_id=XX&\
client_secret=XX&\
token_endpoint=https%3A%2F%2Faccounts.google.com%2Fo%2Foauth2%2Ftoken
client credentials created with
https://console.developers.google.com/apis/credentials
refresh token created with
https://github.com/google/gmail-oauth2-tools/blob/master/python/oauth2.py
rel: https://todo.sr.ht/~sircmpwn/aerc2/42