Remove age_ts from reference hash calculation

[MichaelKohler]

Signed-off-by: Michael Kohler me@michaelkohler.info

Fixes #1489

Preview: https://pr1536--matrix-spec-previews.netlify.app

[turt2live]

ftr, I'm happy that this does not need an MSC because aside from some random example in unsigned in the appendices, age_ts shows up literally nowhere else.

This implies that it's from an ancient and long-since deprecated version of the spec.

[morguldir]

So my HS discovered a join event in HQ from March 10th 2023 with the age_ts key. If you look above ruma faithfully implemented the change, and now such an event isn't passing auth in Condu(wu)it

Raw Event

{
    "auth_events": [
        "$b_onTjnTaifE1ZhoyuAvBG0-ibtoair17-XL9tDC91s", 
        "$MaPUZG2fNleIE_gUYDmOy-nj0Zom8mQ5FNM7gEAVI6I", 
        "$cqtvWbNUS-f2uwi7Lp6RUbwNnvtorTXDBaH0Qx1-Ej4", 
        "$0QMsU7XVvBu1aJbnq8GZpB47MdbJTvvrWrTM1YaqgHE"
    ], 
    "content": {
        "avatar_url": "mxc://matrix.grainscom.de/fEzcWRPpQWXzRJsvrkpgDlXc", 
        "displayname": "Timo", 
        "membership": "join"
    }, 
    "depth": 551301, 
    "hashes": {
        "sha256": "1UqIuYiF6FzUfe7/SRxUHedH9qLx5PcKYAfg+VSKAlw"
    }, 
    "origin": "matrix.grainscom.de", 
    "origin_server_ts": 1678452391464, 
    "prev_events": [
        "$JIcpQSJrTXaQ0khR3xOKENU50UVbz1tvjNxCXRtSt2k"
    ], 
    "room_id": "!OGEhHVWSdvArJzumhm:matrix.org", 
    "sender": "@fritzi:matrix.grainscom.de", 
    "state_key": "@fritzi:matrix.grainscom.de", 
    "type": "m.room.member", 
    "age_ts": 1678452396191, 
    "signatures": {
        "matrix.grainscom.de": {
            "ed25519:a_pQPq": "bgW0udTENViCidANG3A6nha/DGpgOKfI7MQFgxhbeZAf2ffX4ultFAZt+JJlgLszfvMkKCvPfUHglin7z/uuAg"
        }
    }, 
    "unsigned": {
        "age": 1, 
        "replaces_state": "$b_onTjnTaifE1ZhoyuAvBG0-ibtoair17-XL9tDC91s"
    }
}

homeserver_1  | 2024-04-06T02:58:41.386997Z  WARN ruma_state_res: auth event id for $38b0HozwA-NMcHiA6RV8DA509d98-B9e-oH2gVaursE is missing $6xN8lpeq-QwU5x5SBsav-Rmz0pXFIzCXfM01bGfSNEw
homeserver_1  | 2024-04-06T02:59:14.640150Z  WARN conduit::service::rooms::event_handler: Dropping bad event $38b0HozwA-NMcHiA6RV8DA509d98-B9e-oH2gVaursE: Verification error: Could not verify signature: signature error: Verification equation was not satisfied
homeserver_1  | 2024-04-06T02:59:14.640182Z  WARN conduit::service::rooms::event_handler: Authentication of event $38b0HozwA-NMcHiA6RV8DA509d98-B9e-oH2gVaursE failed: M_INVALID_PARAM: Signature verification failed
homeserver_1  | 2024-04-06T02:59:14.640225Z  WARN conduit::service::rooms::event_handler: Could not find auth event $38b0HozwA-NMcHiA6RV8DA509d98-B9e-oH2gVaursE

How should this be resolved?