Jump to content

Recommended Posts

Posted

Hey, I made a quick explanation of Minecraft UUID auth system implemented in 1.7.

If you're interested in how it works, read further.

 

 

 

> Since 1.7 came out, there's a "GameProfile" assigned to every player now. You can get GameProfile of a player by using EntityPlayer.getGameProfile(). Yeah, with that said, you probably still wonder how does Minecraft UUID system work. Let me start explaining that.

 

>>>>>>>>>>>>>>>>>>>>>>>> DISCLAIMER! <<<<<<<<<<<<<<<<<<<<<<<<

>> 1. English is not my main language, I could make mistakes

>> 2. I could be wrong.

 

1. UUID in Java

> There's a concept of Universally Unique Identifier. If you're not familiar with it, try reading that*. If you have no time (too lazy) to read it, I'm going to cut a long story short here. UUID is an ID made out of 128 bits (16 bytes, 2 longs). It's called "unique" because the random number generator used when doing UUID.randomUUID() is very strong. According to wikipedia "only after generating 1 billion UUIDs every second for the next 100 years, the probability of creating just one duplicate would be about 50%", so yeah, pretty strong. UUIDs can be converted to hexadecimal string and backwards. They can also be generated from any amount of bytes as a random seed(UUID.nameUUIDFromBytes(byte[])), that's what Minecraft uses to get UUIDs from account / nickname.

 

2. Getting UUID from player's account

> There's a UUID assigned with every Minecraft account. When the player enters the game, session id, as well as account UUID, is provided in program arguments. Then it converts into a real UUID by using UUID.fromString(arg). This UUID will be sent to the server when the played connects to it, identificator is also used in constructor of a GameProfile (new GameProfile(UUID, username)).

 

3. Getting UUID from an offline player

> Remember, I mentioned UUID.nameUUIDFromBytes(byte[])? Minecraft generates an offline UUID from bytes of string "OfflinePlayer:<nickname>", in other words: "UUID.nameUUIDFromBytes(("OfflinePlayer:" + getName()).getBytes(Charsets.UTF_8)". That's why when you change "online-mode" in settings.properties, everyone loses their inventories and player infos. UUID is changed, so it leads to another file in "playerdata" folder of your world.

 

That's probably all the explanation of this whole UUID auth system.

 

Source:

> Me researching minecraft sources while I'm modding

 

* https://en.wikipedia.org/wiki/Universally_unique_identifier

 

 

 

Permanent link:

bit.ly/minecraftuuid

  • 4 months later...
Posted

This UUID will be sent to the server when the played connects to it,

 

You said 'played' instead of 'player'. :)

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Unfortunately, your content contains terms that we do not allow. Please edit your content to remove the highlighted words below.
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Announcements



  • Recently Browsing

    • No registered users viewing this page.
  • Posts

    • I want to create block with entity, that will have height of 3 or more(configurable) and I tried to change first VoxelShape by increasing collision box on height I want and for changing block height on visual side i tried to configure BlockModelBuilder:  base.element() .from(0, 0, 0) .to(16f, 48f, 16f) .face(Direction.UP).texture("#top").end() .face(Direction.DOWN).texture("#bottom").end() .face(Direction.NORTH).texture("#side").end() .face(Direction.SOUTH).texture("#side").end() .face(Direction.WEST).texture("#side").end() .face(Direction.EAST).texture("#side").end() .end(); but, getting crash with next error: Position y out of range, must be within [-16, 32]. Found: %d [48.0]; Looks like game wont to block height modified by more than 32. Is there any way to fix that problem?
    • As long as the packets you are sending aren't lost, there's nothing wrong with what you're currently doing. Although, this sounds like something that would benefit from you making your own datapack registry instead of trying to arbitrarily sync static maps. Check out `DataPackRegistryEvent.NewRegistry`.
    • Hey all, I've been working a lot with datapacks lately, and I'm wondering what the most efficient way to get said data from server to client is.  I'm currently using packets, but given that a lot of the data I'm storing involves maps along the lines of Map<ResourceLocation, CustomDataType>, it can easily start to get messy if I need to transmit a lot of that data all at once. Recently I started looking into the ReloadableServerResources class, which is where Minecraft stores its built-ins.  I see you can access it via the server from the server's resources.managers, and it seems like this can be done even from the client to appropriately retrieve data from the server, unless I'm misunderstanding.  However, from what I can tell, this only works via built-in methods such as getRecipeManager() or getLootTables(), etc.  These are all SimpleJsonResourceReloadListeners, just like my datapack entries are, so it seems like it could be possible for me to access my datapack entries similarly?  But I don't see anywhere in ReloadableServerResources that stores loaded modded entries, so either I'm looking in the wrong place or it doesn't seem to be a thing. Are packets really the best way of doing this, or am I missing a method that would let me use ReloadableServerResources or something similar?
    • Hi, everyone! I'm new to minecraft modding stuff and want ask you some questions. 1. I checked forge references and saw there com.mojang and net.minecraft (not net.minecraftforge) and as I understand it's original game packages with all minecraft logic inside including renderers and so on, right? 2. Does it mean that forge has a limited set of instruments which doesn't cover all the aspects of the game? If make my question more specific then does forge provide such instruments that allow me totally change minecraft itself, like base mechanics and etc.? Or I have to use "original game packages" to implement such things? 3. I actively learning basic concepts with forge documentation and tutorials. So in my plans make different inventory system like in diabloids. Is that possible with forge? 4. It is last question related to the second one. So how deeply I can change minecraft with forge? I guess all my questions above because of that I haven't globally understanding what forge is and how it works inside and how it works with minecraft. It would be great if you provide some links or topics about it or explain it by yourself but I guess it's to big to be explained in that post at once. Anyway, thank you all for any help!
    • Im trying add to block a hole in center, just a usual block and in center of it on up side, there is should be a hole. I tried to add it via BlockModelBuilder, but its not working. Problem is that it only can change block size outside. I tried it to do with VoxelShape and its working, but its has been on server side and looks like its just changed collision shape, but for client, there is a texture covering this hole. I tried to use: base.renderType("cutout"); and removed some pixels from texture. I thought its should work, but game optimization makes block inside looks transparent. So, only custom model?
  • Topics

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.