E2EE images sent from pantalaimon are malformed events in Mirage

[BurnyBoi]

Description

I chat with someone who uses Pantalaimon as their Matrix client, and any time they send an image in an E2EE room, it just says they "sent a malformed m.room.message event." The same events show as images in Element Web.

Running Mirage from AUR on Arch.

[mirukana]

Which client is the person using behind Pantalaimon? Could you post the Element decrypted source for one such event?

[BurnyBoi]

Multiple clients were used behind pantalaimon: Gomuks (compiled with E2EE disabled as to work properly with pantalaimon), Fractal, and QuickMedia. A theory on why this happens I was told is that allegedly pantalaimon doesn't encrypt the media itself, whereas mirage tries to decrypt it and possibly fails.

[BurnyBoi]

Also, here is a decrypted source for one which shows as malformed:

{
  "content": {
    "msgtype": "m.image",
    "body": "1604581243123878101.jpg",
    "info": {
      "size": 236222,
      "mimetype": "image/jpeg",
      "w": 1080,
      "h": 775
    },
    "url": "mxc://midov.pl/oKPZaUNoWAXYMgFIkwKrDuKy"
  },
  "type": "m.room.message",
  "room_id": "!oESsRqyaQizmKFpmJL:midov.pl"
}

[mirukana]

Your theory was correct, opened issue at https://github.com/poljar/matrix-nio/issues/224.