Genshin Impact Private Server

[Hibiol]

Honestly, I think the better idea would be an offline version of Genshin Impact. A private server might get shut down due to legal reasons, and the multiplayer is very limited as it stands. An offline option where I can just edit my resin, mora and primogems might be the better route. Maybe not as fun to some, but its better than spending $1000s on gacha.

That would take way more time than just emulating the server, if is not impossible, bc it would require recode a lot of stuff in the game, there's no need to make a private server, an open source emulator can be done so everyone can host its own server on its own machine

[nuocda]

i hope have offline play, game offline content to much, no need private server first :(

[blasti99]

KuroSaru have you figured out what the server name is that is used for UDP ? I did not see any IP being transmitted in the JSON content before it connects. So I wonder where this comes from. Also I noticed that the port number is not always the same.

[plumcakes]

That would take way more time than just emulating the server, if is not impossible, bc it would require recode a lot of stuff in the game, there's no need to make a private server, an open source emulator can be done so everyone can host its own server on its own machine

You're 100% right. I guess I should've explained myself better but that was the same concept I was thinking just poor wording. Having people emulate their own server would be the best route imo. I would hate to see someone put in a ton of work for a multiplayer private server only to be hit with DMCAs and/or potential lawsuits. Maybe a potential feature to have people connect to your server so you can do multiplayer with only people you want to join.

[KuroSaru]

So after all the data transfer via HTTPS has taken place the last transfer contains a BASE64 encoded data chunk. Within this base64 encoded data blob is the IP and port for the UDP traffic and for the game to connect to. There are other aspects that take place here after this point. Spending time looking at traffic game has support for TLS over UDP but not seen proof it is enabled yet.

Here is example of data decoded from the BASE64 packet, you can see the IP and port (hex number, not ascii)


I have been off and on looking into the game, current plan is to redirect login to a simply server I control in a more sensible way, modifying windows HOSTS file feels unreasonable. I have no plan to make a private server but am interested/planning on a local simulation to allow offline playing.

[Crashbash]

@Kuro,We have a team working at decrypting the release client and the lots for just that, will PM the discord if you are interested in joining and pool skills / ideas.Cheers.

[plumcakes]

I have been off and on looking into the game, current plan is to redirect login to a simply server I control in a more sensible way, modifying windows HOSTS file feels unreasonable. I have no plan to make a private server but am interested/planning on a local simulation to allow offline playing.

Do you think the local simulation would allow modifying resin, primogems, etc?

[Spidpex]

Reason for saying XOR is based on the gameloop that takes place when spawning (you join the world).

very detailed information, holy smokes o,o

[samuellucy96]

So after all the data transfer via HTTPS has taken place the last transfer contains a BASE64 encoded data chunk. Within this base64 encoded data blob is the IP and port for the UDP traffic and for the game to connect to. There are other aspects that take place here after this point. Spending time looking at traffic game has support for TLS over UDP but not seen proof it is enabled yet.

Here is example of data decoded from the BASE64 packet, you can see the IP and port (hex number, not ascii)


I have been off and on looking into the game, current plan is to redirect login to a simply server I control in a more sensible way, modifying windows HOSTS file feels unreasonable. I have no plan to make a private server but am interested/planning on a local simulation to allow offline playing.

If you really serious to reverse engineer this game , you should create a way so people could support you like a patreon or something more crypted like a bitcoin/monero address to avoid legal action in the future if it successful . Create a discord server so we could follow this stuff privately and get more people technical on board. Just an idea you know.

[ThorsNextKroban]

During the days I had the idea why not build a proxy for Genshin, 1. easier to sniff the packets, 2. easier to redirect the connection to the localserver (soonTM), 3. maybe ppl will learn some things from it.

(there are already other projects out there about how proxy's for games. https://github.com/tera-proxy/tera-proxy here is an example for a other game , i would do something with this but never did something before with UDP & idk how to decrypt the packets correctly currently.)

~

[FluffyWuffyKins]

Just came here today to say I really hope we get an offline/private version where we can fiddle with it ourselves. Mihoyo's management of the game is atrocious and I'm looking for a nice alternative so I can enjoy the game to its fullest.

[OniZero]

I hope this doesn't make Mihoyo abandon the global server or Genshin Impact all-together, it would be neat if all the content, features events, etc. planned were implemented since it is a single player experience, after all that, people would have a lot of things to do in the game, plus the possibility to mod it far down the line.

[blasti99]

I don't think that the UDP traffic is encrypted at all.
They seem to use a variation of RakNet library for the UDP transmission.

The packet structure itself is not too complicated:

64bit Session-ID
64bit packet type and probably a checksum ... when it starts with 0x51 it is a data packet, when it starts with 0x52 then it is an ACK for a received 0x51 packet
32bit packet sequence count (sent)
32bit packet sequence count (received)
32bit data size in bytes
xxx bytes data

there can be multiple data packets in one UDP packet

I have not yet analysed the data bitstream format yet, but they probably did not change it from the public sources that can be found on https://github.com/facebookarchive/RakNet

[Agnosia]

You are close to being correct on the packet structure - but this is nothing more than another transport layer. The actual protocol is what is being carried in data sections - and it does not seem to be RakNet.

This forum is not a good place for fast-paced discussion. If you are in Discord, PM me your contact information.

[Shenfan]

I have been off and on looking into the game, current plan is to redirect login to a simply server I control in a more sensible way, modifying windows HOSTS file feels unreasonable. I have no plan to make a private server but am interested/planning on a local simulation to allow offline playing.

Oh my god, if you can achieve that, you will be the hero for thousands people. Playing this wonderful game offline, without restriction is a dream.