v9.2.0 error when negotiating with Blessing Skin auth server

[TechnoSparks]

Operating System

Windows

Version of Fjord Launcher

v9.2.0

Version of Qt

v6.7.3

Description of bug

When launching an instance using an account of a Blessing Skin instance, the game fails to launch with this error:

Upon checking the logs, i get this: (true domain name is removed to prevent unwanted to request to my server)

0.586 D | [launcher.task.net.upload]: "{e8a0d3c0-4f61-4925-aeaa-04b27ead0034}" Runninng  "https://example.com/api/yggdrasil/authserver/refresh"
0.597 D | Dir changed: "C:/Users/TechnoSparks/AppData/Roaming/FjordLauncher/translations"
0.677 D | Dir changed: "C:/Users/TechnoSparks/AppData/Roaming/FjordLauncher/translations"
0.678 D | Got translations index!
0.931 C | [launcher.task.net.upload]: "{e8a0d3c0-4f61-4925-aeaa-04b27ead0034}" Failed "https://example.com/api/yggdrasil/authserver/refresh" with reason QNetworkReply::ProtocolInvalidOperationError
0.931 C | [launcher.task.net.upload]: "{e8a0d3c0-4f61-4925-aeaa-04b27ead0034}" HTTP Status 400 ;error "Error transferring https://example.com/api/yggdrasil/authserver/refresh - server replied: Bad Request"
0.931 D | [launcher.task.net.upload]: "{e8a0d3c0-4f61-4925-aeaa-04b27ead0034}" Request failed in previous step: "https://example.com/api/yggdrasil/authserver/refresh"
0.931 D | Yggdrasil request done
0.931 D | RefreshSchedule: Background account refresh failed:  "Authentication operation failed due to a network error: Error transferring https://example.com/api/yggdrasil/authserver/refresh - server replied: Bad Request (302)"

• This does not happen when I revert to 9.1.0 means my blessing skin auth server is not the underlying cause.
• I tried removing and readding the account.
  • Addition succeeds, with column "Status" saying "Ready". See log [2] below
  • But when I hit button "Refresh", "Status" turns into "Errored"

LOG 2

699.017 D | [launcher.task.net.upload]: "{be4b7ca0-027d-425e-8611-b45868c27ff4}" Runninng  "https://example.com/api/yggdrasil"
699.317 D | [launcher.task.net.upload]: "{be4b7ca0-027d-425e-8611-b45868c27ff4}" Request succeeded: "https://example.com/api/yggdrasil"
699.317 D | AuthFlow: "Logging in with Yggdrasil."
699.317 D | [launcher.task.net.upload]: "{3b10bd5e-531d-49ae-997a-1ec22ae2e0dd}" Runninng  "https://example.com/api/yggdrasil/authserver/authenticate"
699.662 D | [launcher.task.net.upload]: "{3b10bd5e-531d-49ae-997a-1ec22ae2e0dd}" Request succeeded: "https://example.com/api/yggdrasil/authserver/authenticate"
699.662 D | Yggdrasil request done
699.662 D | Getting access token.
699.662 D | AuthFlow: "Fetching the Minecraft profile."

Steps to reproduce

• Set a drasl server account as default
• Launch an instance
• Observe error dialog
• Check logs

Suspected cause

Possible bad/malformed URI request when Fjord Launcher contact the /request API endpoint

This issue is unique

• I have searched the issue tracker and did not find an issue describing my bug.

[evan-goode]

Strange, I couldn't reproduce it just now on 9.2.0 with an account on https://skin.prinzeugen.net. Does your BS account have multiple players?

I tried on another public Blessing Skin server, https://skin.meowserver.cn, and neither Fjord Launcher 9.1.0 nor 9.2.0 successfully refreshed after logging in. The server replied with code 400 and:

{
    "error": "IllegalArgumentException",
    "errorMessage": "The player requested doesn't match with that token."
}

so this could be a Blessing Skin bug.

I didn't notice anything different about the /refresh request between 9.1.0 and 9.2.0, and Ely.by and Drasl authenticate and refresh correctly on 9.2.0.

If it is indeed a regression, this could be the fault of #41. Could you double-check removing and re-adding the account on 9.1.0 and see if you get the same error?

If you are able, could you try man-in-the-middling the /authenticate and /refresh HTTP requests using mitmproxy or similar, and posting the request and response bodies?

[evan-goode]

OK, this might be caused by sending selectedProfile in /refresh when we don't need to, I'll prepare a PR to fix that.

[TechnoSparks]

Strange, I couldn't reproduce it just now on 9.2.0 with an account on https://skin.prinzeugen.net. Does your BS account have multiple players?

You had just unlocked a forgotten memory! Initially when i set up the private auth server, yes, but due to some sporadic error when adding an account, I manage to nail down the problem to having multiple players. The error was basically I couldn't authenticate myself sometimes despite having the correct player name. Using email directly bypass this problem altogether, but the user will have no choice in which player to play. I cannot recall how BS choose which player if we use email login. To solve that I used "Single Player Limitation" plugin on my BS server and everything work well. So now the answer is no. Each account can only have 1 player.

Unfortunately I am unable to recall which version of Fjord Launcher i was using when I encountered this problem. I will test having multiple players again when I have the chance.

If it is indeed a regression, this could be the fault of #41. Could you double-check removing and re-adding the account on 9.1.0 and see if you get the same error?

I tried it just now and no I do not get any error. 9.1.0 works flawlessly.

If you are able, could you try man-in-the-middling the /authenticate and /refresh HTTP requests using mitmproxy or similar, and posting the request and response bodies?

I am not familiar with mitmproxy, so I will need some time to learn it and will report back to you.

[evan-goode]

Can you see whether #51 fixes this for you? I think there will be Windows builds with the patch available at https://github.com/unmojang/FjordLauncher/actions/runs/12740359805?pr=51 when the automated CI job finishes.

[evan-goode]

Using email directly bypass this problem altogether, but the user will have no choice in which player to play.

By the way, this is fixed as of Fjord Launcher 9.2.0. There is now a dialog to select a player when there are multiple available players. (That same patchset is probably what broke Blessing Skin)