implement over-engineered diceroll #479

wagyourtail · 2022-12-19T22:49:08Z

uses a modified diffie-hellman key exchange to prevent cheating

…culated length

xpple · 2022-12-26T10:15:22Z

Sorry if this is a strange request but could you perhaps extract the C2C packet changes to a separate PR?

wagyourtail · 2022-12-28T19:32:50Z

I can't completely remove them from this one or it'll break this one. but I can have them as a seperate branch that this one is based uppon

xpple · 2022-12-28T19:34:19Z

Sure, thanks!

Starmania · 2023-01-07T18:38:24Z

Would it be useful to use 2048 bit keys? A wikipedia article

wagyourtail · 2023-01-08T22:37:09Z

Would it be useful to use 2048 bit keys? A wikipedia article

yes, but they don't fit in a minecraft chat message, xd and for our purposes I don't think that'll be an issue

xpple

I don't understand much of the technical stuff so these are mostly style related changes.

xpple · 2023-07-03T13:21:46Z

src/main/java/net/earthcomputer/clientcommands/c2c/C2CPacket.java

 import net.minecraft.network.PacketByteBuf;

 public interface C2CPacket {
    void write(PacketByteBuf buf);

-    void apply(CCPacketListener listener);
+    void apply(CCPacketListener listener) throws CommandSyntaxException;


I feel like this is out of the scope of command syntax exceptions. Perhaps we should create our own exception class or just return instead of throwing an exception.

xpple · 2023-07-03T13:25:31Z

src/main/java/net/earthcomputer/clientcommands/c2c/packets/DiceRollC2CPackets.java

+    public static void register() {
+        CCPacketHandler.register(DiceRollInitC2CPacket.class, DiceRollInitC2CPacket::new);
+        CCPacketHandler.register(DiceRollAcceptedC2CPacket.class, DiceRollAcceptedC2CPacket::new);
+        CCPacketHandler.register(DiceRollResultC2CPacket.class, DiceRollResultC2CPacket::new);
+    }


Not sure if it's necessary to register them here. I don't know why CCPacketHandler#register wasn't private in the first place.

xpple · 2023-07-03T13:27:35Z

src/main/java/net/earthcomputer/clientcommands/c2c/CCNetworkHandler.java

@@ -4,7 +4,10 @@
 import com.mojang.brigadier.exceptions.DynamicCommandExceptionType;
 import com.mojang.brigadier.exceptions.SimpleCommandExceptionType;
 import com.mojang.logging.LogUtils;
+import io.netty.buffer.Unpooled;


Unused import.

Suggested change

import io.netty.buffer.Unpooled;

xpple · 2023-07-03T13:29:51Z

src/main/java/net/earthcomputer/clientcommands/command/DiceRollCommand.java

+import java.security.SecureRandom;
+import java.util.*;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;


Unused import.

Suggested change

import java.util.concurrent.atomic.AtomicInteger;

xpple · 2023-07-03T13:31:34Z

src/main/java/net/earthcomputer/clientcommands/command/DiceRollCommand.java

+        dispatcher.register(literal("cdiceroll")
+                .executes(ctx -> localDiceroll(ctx.getSource(), 6))
+                .then(argument("sides", integer(2, 100))
+                        .executes(ctx -> localDiceroll(ctx.getSource(), getInteger(ctx, "sides")))
+                        .then(argument("player", gameProfile())
+                            .executes(ctx -> diceroll(ctx.getSource(), getCProfileArgument(ctx, "player"), getInteger(ctx, "sides")))))
+                .then(argument("player", gameProfile())
+                        .executes(ctx -> diceroll(ctx.getSource(), getCProfileArgument(ctx, "player"), 6))));


Inconsistent indentation.

xpple · 2023-07-03T13:33:45Z

src/main/resources/assets/clientcommands/lang/en_us.json

+  "commands.diceroll.diceroll": "dice roll (%s side)",
+  "commands.diceroll.coinflip": "coin flip",
+  "commands.diceroll.sent": "Sent %s request to %s",
+  "commands.diceroll.received": "Received %s request from %s",
+  "commands.diceroll.value": "%s result from %s: %s",
+  "commands.diceroll.heads": "Heads",
+  "commands.diceroll.tails": "Tails",
+  "commands.diceroll.cheater": "I think %s is cheating, they got a different value.",
+  "commands.diceroll.timeout": "Timeout waiting for %s's response to %s request",
+  "commands.diceroll.waitingForResponse": "Waiting for %s's response already",


It should be cdiceroll. Also I think some of these shouldn't be a subkey of commands, but rather of ccpacket.

xpple · 2023-07-03T13:34:41Z

src/main/java/net/earthcomputer/clientcommands/command/DiceRollCommand.java

+        try {
+            md = MessageDigest.getInstance("SHA-1");
+        }
+        catch(NoSuchAlgorithmException e) {


Suggested change

catch(NoSuchAlgorithmException e) {

catch (NoSuchAlgorithmException e) {

xpple · 2023-07-03T13:39:37Z

src/main/java/net/earthcomputer/clientcommands/command/DiceRollCommand.java

+            System.out.println("expected: " + byteArrayToHexString(opponentHash.get(packet.sender)));
+            System.out.println("actual: " + byteArrayToHexString(toSHA1(B.toByteArray())));


This should probably be removed.

xpple · 2023-07-03T13:42:37Z

src/main/java/net/earthcomputer/clientcommands/command/DiceRollCommand.java

+
+public class DiceRollCommand {
+    private static final Logger LOGGER = LogUtils.getLogger();
+    private static final SimpleCommandExceptionType PLAYER_NOT_FOUND_EXCEPTION = new SimpleCommandExceptionType(Text.translatable("commands.cwe.playerNotFound"));


Perhaps it's an idea to add a few common exceptions for c2c related stuff to a certain class, I don't like the commands.cwe translation key being used here.

RealRTTV · 2024-07-16T13:01:38Z

might i ask: how does this work, can't i just generate these values on my client over and over until i get the one i want, then send it?

Semisol · 2024-10-08T10:33:13Z

A simpler solution for fairness could be implemented:

Initiator generates s_i, sends H(s_i) (commit)
Receiver saves H(s_i), generates s_r, sends H(s_r) (commit)
Initiator saves H(s_r), sends s_i (reveal)
Receiver verifies H(s_i received) = H(s_i) saved, calculates xor s_i ^ s_r = s, sends s_r, shows dice roll result (reveal)
Initiator verifies H(s_r received) = H(s_r) saved, calculates xor s_i ^ s_r = s, shows dice roll result

This is secure, as:

the committed value cannot be changed after the fact, and no values are revealed before commit is complete, so you cannot bias your value to get an expected xor output
xoring two values that are not correlated can only increase entropy (correlated being generated from the same source as the other value, or generated with knowledge of the other value to intentionally bias the xor)
there is an attack where receiver can withhold revealing, but this should result in a big warning

wagyourtail added 6 commits December 19, 2022 15:44

implement over-engineered coinflip

1ea760b

exchange hashes first so player2 cant easily cheat via guess/check

d818e3c

fix self coinflip and multi coinflips with new method

186fba9

generalize to dice rolling

99fd970

fix function names

8cde399

bump to 1024 bytes, add timeout safety. make message too long say cal…

46d4223

…culated length

wagyourtail changed the title ~~implement over-engineered coinflip~~ implement over-engineered diceroll Dec 20, 2022

wagyourtail added 3 commits December 20, 2022 12:51

forgot to make dynamic change on decrypt

7ec2e3d

missed a spot

b0e6c37

fix timeout breaking things

f00d2da

wagyourtail added 3 commits February 8, 2023 08:27

Merge branch 'fabric' into ccoinflip

fb0fe94

Merge branch 'fabric' into ccoinflip

9858c62

update

b9fba3e

xpple requested changes Jul 3, 2023

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xpple added the enhancement New feature or request label Jul 3, 2023

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implement over-engineered diceroll #479

implement over-engineered diceroll #479

wagyourtail commented Dec 19, 2022 •

edited

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xpple commented Dec 26, 2022

wagyourtail commented Dec 28, 2022

xpple commented Dec 28, 2022

Starmania commented Jan 7, 2023

wagyourtail commented Jan 8, 2023

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RealRTTV commented Jul 16, 2024

Semisol commented Oct 8, 2024

	catch(NoSuchAlgorithmException e) {
	catch (NoSuchAlgorithmException e) {

		System.out.println("expected: " + byteArrayToHexString(opponentHash.get(packet.sender)));
		System.out.println("actual: " + byteArrayToHexString(toSHA1(B.toByteArray())));

implement over-engineered diceroll #479

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implement over-engineered diceroll #479

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wagyourtail commented Dec 19, 2022 • edited Loading

xpple commented Dec 26, 2022

wagyourtail commented Dec 28, 2022

xpple commented Dec 28, 2022

Starmania commented Jan 7, 2023

wagyourtail commented Jan 8, 2023

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RealRTTV commented Jul 16, 2024

Semisol commented Oct 8, 2024

wagyourtail commented Dec 19, 2022 •

edited

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