Unable to decrypt from Giom

[weeman1337]

Steps to reproduce

1. Received some messages from Giom this morning

(Rageshakes sent directly from both sides when this occurred)

Outcome

What did you expect?

Can read the messages

What happened instead?

Unable to decrypt :(

Message contents on receiver side incl. event-IDs and timestamps

{
  "content": {
    "algorithm": "m.megolm.v1.aes-sha2",
    "ciphertext": "AwgAEpACHBAMOZIu9XYTc99k8BjUltKdeIUs+536svCS6aVbvJXNGfA8OHFAiUR742G2mVG8tWUJBdlzTeSeRgpb7Q8y1tnaz4D2khWxoKTeM2ie6zKvyOpJiS66dT8gCfHFZwLbcy9pMoMJyV1YW1zC5HaCgfRS1nTms8Clw3biYjjy/10lqMPAxOwLEb753rXurtIsYUeYUdBVQYhV2cUPhgWIx0DVwOoiMlZ1BdR01aTGyy6obQytiRu2tm/mv32l2YcM7gOhW6Nd/TAmBWLFDFN1W+dQQKIdlkMt1Z2eUiDCj4jWDzA3PZxvnCFSM/lLVTXGyx2gf1BRbuBmSGZF7yIa9kEpNmmvDa9dOIZVDKM54oPd1fJAMg0ajTOgxsh3U+RK2qTNiGQeKZ+D71mNDqAvBpDpw01fWxxPg/ujMiv28JEOO4me2w6YH/c6CGZBXCJNH/f3CZZI+A4",
    "device_id": "PPHZWLBEEY",
    "sender_key": "QPMnlZBMmojydh6ipL2WA08Quar6T2JCraTxrbyPKlY",
    "session_id": "3ggtLulINgdt3zc9FFpA/bPDKfKRaeMyBFVk3DQbw9M"
  },
  "origin_server_ts": 1669104726432,
  "sender": "@Giom:matrix.org",
  "type": "m.room.encrypted",
  "unsigned": {},
  "event_id": "$RQKAkgqstzD__9CbkmEaHNWitnFU37p4cpdoZRlqPzI",
  "room_id": "!eWqkwQILiyGNMQtFnL:element.io"
}

{
  "content": {
    "algorithm": "m.megolm.v1.aes-sha2",
    "ciphertext": "AwgBEuABhy48gaGIJKD9CiTfK95BLlIU7QVw9R9AF8eh3rLuZlfhOogICrU8q/CycI+APmH47YKXdxgjjhmXsOXcDMpna326cUHxeEVkjPD+c+mRc/pg8IlRi+PLnXZ4d25d2yIS205gdW58qQBuTPw6Wp2AM4+mt8tmsmxwuewosmLxEKJ7GmfQgWoHGSNNVp1fNJriMQ5W4kgPeaAOxd/mRDrodlNq6SSnZdKMnN+kfz5q+elk9NqIoRT2/tSufT3GZ5A8v+4LX7PmccaY7dRteuzIiYemMQYdRRVF6ZZjOqn8/1pja7WRSyPY3qq9I0HK09sdVYk+MS3r8OeoVHjSLWzoZ78HUYY3OzfCw9fHAeuhY9Vasq1X7doq02YCg05HM6MMppKxCZOaBgE",
    "device_id": "PPHZWLBEEY",
    "sender_key": "QPMnlZBMmojydh6ipL2WA08Quar6T2JCraTxrbyPKlY",
    "session_id": "3ggtLulINgdt3zc9FFpA/bPDKfKRaeMyBFVk3DQbw9M"
  },
  "origin_server_ts": 1669104729350,
  "sender": "@Giom:matrix.org",
  "type": "m.room.encrypted",
  "unsigned": {},
  "event_id": "$abkvefFTPHDzTE2Wyd8Jymyd0Qpg3YZqWbi4-rlkCZI",
  "room_id": "!eWqkwQILiyGNMQtFnL:element.io"
}

{
  "content": {
    "algorithm": "m.megolm.v1.aes-sha2",
    "ciphertext": "AwgCEvAB2KS8NA7vfvcquTgAz1D+37rMow3tzdHQxwAfQMYVtp9Z8Oi0Fq5jKmHNiLauO8VlK+jf2H8zgQ2Hmo1M0Pr8K/ZtWCnODSHgAenJSAv3kJcXisePN7SXTKqydg76v0hYaRBJ88xLdvs2pwj8BnFssE0M1qEvYaRxhN/f9zDCQdSJB7bxI8mDXbC0P8zA+8DU5ie9w7e1t43DV24R1mKNp0hFgoOBZWCT2+w5I9rT2qJHphIyFzv0ink/CEnSmybgfgG5a9uGR0NeuhWAgX6S1AxFohnkl+neB59XEZa69Bdzgz2jGNxSpGPiqM4Bs7niLLFHFfzU7i1frcJHZBtDPKFnaHoGbcDwzFd1rlJawpfsn1JTg4T9TO0FurpVZewB8uAl18TZIRXR6a/mphNE2hmDWxXcSB0I",
    "device_id": "PPHZWLBEEY",
    "sender_key": "QPMnlZBMmojydh6ipL2WA08Quar6T2JCraTxrbyPKlY",
    "session_id": "3ggtLulINgdt3zc9FFpA/bPDKfKRaeMyBFVk3DQbw9M"
  },
  "origin_server_ts": 1669104744600,
  "sender": "@Giom:matrix.org",
  "type": "m.room.encrypted",
  "unsigned": {},
  "event_id": "$YnUPDG8Ft0MVSE0STFDMHgB1sVQ1MZBB8J_yLUSMPDI",
  "room_id": "!eWqkwQILiyGNMQtFnL:element.io"
}

Operating system

Ubuntu 22.04.1 LTS

Application version

Element Nightly version: 2022111601 Olm version: 3.2.12

How did you install the app?

https://packages.element.io/debian/

Homeserver

https://element.ems.host

Will you send logs?

Yes

[weeman1337]

Today's event ids:

• $qUHwgI6HYNz6s3Zp-sBVDNgIYlczMid6H6m2b2sPL1g
• $hfdvcFab7ycQL2RFGhtHnoEEZ4OgLYtxdNBOrlfjlVM

[Friskygote]

I've been seeing this issue a lot in DM with specific person and it started only recently (first occurrences 25th of November). I'm not really a crypto expert, however since this issue on receiving end does occur in more clients than just Element (seeing "There is no key to unlock this message." for those messages in Nheko, currently using 3 different clients and all of them report this or other error on encryption), could the source of this issue be in devices sending the messages rather than receiving?

Note: the only workaround that works for this seems to be /discardsession sent from device sending messages. /discardsession does not work when used by myself. This issue also does not affect other encrypted rooms which I share with that "problematic" person.

[weeman1337]

@Friskygote please read element-hq/element-meta#245 about how to report „unable to decrypt issues“.