Question: HTTP error 400 when trying do Undo Follow

[zoggy]

Question

Hello,

I hope this is the right place and category to post. I'm developing an activitypub server and tries to interact with exiting ones.

I can send Follow request and receive Accept, for example from https://lemmy.world/c/fediverse .

But when I send an Undo to unfollow this community, I get a HTTP 400 error with no additional error message.

Here is the json that my servers tries to post to https://lemmy.world/c/fediverse/inbox. It send an Undo activity with the previous Follow activity as object:

{
  "@context": [
    "https://www.w3.org/ns/activitystreams",
    "https://w3id.org/security/v1"
  ],
  "to": [
    "https://lemmy.world/c/fediverse"
  ],
  "published": "2023-12-22T10:16:23-00:00",
  "object": {
    "to": [
      "https://lemmy.world/c/fediverse"
    ],
    "published": "2023-12-22T09:05:45-00:00",
    "object": "https://lemmy.world/c/fediverse",
    "actor": "https://taps.good-eris.net/actors/zoggy",
    "type": "Follow",
    "id": "https://taps.good-eris.net/actors/zoggy/outbox/1703235945766700506210"
  },
  "actor": "https://taps.good-eris.net/actors/zoggy",
  "type": "Undo",
  "id": "https://taps.good-eris.net/actors/zoggy/outbox/1703240184381154537201"
}

Am I doing something wrong ?

[Nutomic]

I threw that json into the Lemmy tests and it gets parsed without problems. Your actor also gets fetched without problems. Can you try with an instance on the latest version like voyager.lemmy.ml?

[dessalines]

Will re-open if it can be recreated on 0.19.1

[zoggy]

I tried to follow https://voyager.lemmy.ml/c/test or https://voyager.lemmy.ml/c/test3 as suggested by @Nutomic, but I received no accept until now. Is there some manual accept ? When my follow will be accepted, I can try to unfollow.

[dessalines]

There's no manual accept, it should send an async accept out directly after. Would need @Nutomic to take a look.

[IsaacSchemm]

Here's an activity I'm trying to send to https://lemmy.ml/c/fediverse/inbox:

{
  "@context": [
    "https://w3id.org/security/v1",
    "https://www.w3.org/ns/activitystreams",
    {
      "Hashtag": "as:Hashtag",
      "comments": "as:comments",
      "sensitive": "as:sensitive"
    }
  ],
  "id": "https://microblog.lakora.us/#crowmask-imitator-57435cb4-ee44-447c-a4b1-4c5f3904fa09",
  "type": "Undo",
  "actor": "https://microblog.lakora.us",
  "object": {
    "id": "https://microblog.lakora.us/#crowmask-imitator-aa332465-8987-4dce-852d-985126050ab2",
    "type": "Follow",
    "actor": "https://microblog.lakora.us",
    "object": "https://lemmy.ml/c/fediverse",
    "published": "2024-01-13T17:22:04.1254006+00:00"
  },
  "published": "2024-01-13T17:30:18.7233821+00:00"
}

This returns an HTTP 400 with the response:

{"error":"unknown","message":""}

The original Follow worked (HTTP 200) with the same signing key.

This may be the same as #2106.

[Nutomic]

Is the object.id of your Undo/Follow identical to the id of the original follow? In that case its fixed by https://github.com/LemmyNet/lemmy/pull/4364

#2106 is unrelated.