Of course the aprent post might still be deleted after the reply was
already created, but in this case the reply will still show up as a
reply and be federated as a reply with a reference to the parent post.
If the parent was already deleted before the reply gets created however
it used to be indistinguishable from a root post both in Masto API and
ActivityPub.
From a UX perspective, users likely will like to know if the post
they’re replying to no longer exists by the time they finished writing.
The natural language error will show up in akkoma-fe without clearing
the post form, meaning users can decide to discard the reply or copy it
to post as a new root post. It seems sensibly to for other clients to
behave like this too, but so far no more clients were actually tested.
Furthermore, this used to allow replying to all sorts of activities not
just posts which was rather non-sensical (and after all processsing
steps turned into a reply to the object referenced by the activity).
In particular this allowed replying to an user object by specifying the
db ID of a follow request activity (if the latter was somehow obtained).
Note: empty-string in_reply_to parameters are explicitly ignored since
45ebc8dd9a to workaround one buggy client;
see: https://git.pleroma.social/pleroma/pleroma/-/issues/355.
It’s not clear if this workaround is still necessary,
but it is preserved by this commit.
Resolves: https://akkoma.dev/AkkomaGang/akkoma/issues/522
We now add the htmlMfm key when relevant, store this in the database, and we see it when fetching using e.g.
curl -L -H 'Accept: application/activity+json' "$ap_id"
The `@context` of the Activity Pub message now also contains `htmlMfm: https://w3id.org/fep/c16b#htmlMfm`.
When an incomming post has `htmlMfm: true`, we will not re-parse the content.
FEDERATION.md is adapted to show the `htmlMfm` term is used.
In Mastodon media can only be used by owners and only be associated with
a single post. We currently allow media to be associated with several
posts and until now did not limit their usage in posts to media owners.
However, media update and GET lookup was already limited to owners.
(In accordance with allowing media reuse, we also still allow GET
lookups of media already used in a post unlike Mastodon)
Allowing reuse isn’t problematic per se, but allowing use by non-owners
can be problematic if media ids of private-scoped posts can be guessed
since creating a new post with this media id will reveal the uploaded
file content and alt text.
Given media ids are currently just part of a sequentieal series shared
with some other objects, guessing media ids is with some persistence
indeed feasible.
E.g. sampline some public media ids from a real-world
instance with 112 total and 61 monthly-active users:
17.465.096 at t0
17.472.673 at t1 = t0 + 4h
17.473.248 at t2 = t1 + 20min
This gives about 30 new ids per minute of which most won't be
local media but remote and local posts, poll answers etc.
Assuming the default ratelimit of 15 post actions per 10s, scraping all
media for the 4h interval takes about 84 minutes and scraping the 20min
range mere 6.3 minutes. (Until the preceding commit, post updates were
not rate limited at all, allowing even faster scraping.)
If an attacker can infer (e.g. via reply to a follower-only post not
accessbile to the attacker) some sensitive information was uploaded
during a specific time interval and has some pointers regarding the
nature of the information, identifying the specific upload out of all
scraped media for this timerange is not impossible.
Thus restrict media usage to owners.
Checking ownership just in ActivitDraft would already be sufficient,
since when a scheduled status actually gets posted it goes through
ActivityDraft again, but would erroneously return a success status
when scheduling an illegal post.
Independently discovered and fixed by mint in Pleroma
1afde067b1
See https://akkoma.dev/AkkomaGang/akkoma/pulls/350#issuecomment-6109
When making quotes through Mast-API, they will now have the same context as the quoted post. This also results in them being showed when fetching the thread. I checked Misskey to see how it's there, and they show the quotes there as well, see e.g. <https://mk.toast.cafe/notes/98u1g0tulg>.
An example from Akkoma:
Co-authored-by: ilja <git@ilja.space>
Reviewed-on: https://akkoma.dev/AkkomaGang/akkoma/pulls/379
Reviewed-by: floatingghost <hannah@coffee-and-dreams.uk>
Co-authored-by: ilja <akkoma.dev@ilja.space>
Co-committed-by: ilja <akkoma.dev@ilja.space>
Sometimes people put emoji in the subject, which results in the subject
looking broken if someone replies to it from a server that does not
have the said emoji under the same shortcode. This patch solves the problem
by extending the emoji set available in the summary to that of the parent
post.
