Mastodon instances in "secure mode" canot use the relay

[mhamzahkhan]

Mastodon relays that have AUTHORIZED_FETCH or "secure mode" enabled, do not work with the relay (https://docs.joinmastodon.org/admin/config/#authorized_fetch).

Looks like this is because you have to sign the request when fetching the public key here: https://github.com/yukimochi/Activity-Relay/blob/528e801a64c2514b21ae711d635aa96d28fc6ca9/models/models.go#L100

Without it, the request returns a 401 from instances that have secure mode enabled.

[yukimochi]

Mastodon explains that relays do not work properly in secure mode. (Appears when trying to enable relay in secure mode.)

It is unclear whether the relay will work correctly by signing the request during account acquisition. However, I think it's a good idea to use signatures for account acquisition, so I'll incorporate it into my implementation plan.