add Pilz.Gaming.Minecraft (generate offline player uuid)

Pilz.Gaming.Minecraft/Pilz.Gaming.Minecraft.csproj

@@ -0,0 +1,15 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
+    <IncrementVersionOnBuild>1.yyyy.Mdd.Hmm</IncrementVersionOnBuild>
+    <Version>1.2023.1120.1110</Version>
+  </PropertyGroup>
+
+</Project>

Pilz.Gaming.Minecraft/Utils.cs

@@ -0,0 +1,43 @@
+using System.Security.Cryptography;
+using System.Text;
+
+namespace Pilz.Gaming.Minecraft
+{
+    public static class Utils
+    {
+        public static string GetUUID(string value)
+        {
+            using var md5 = MD5.Create();
+
+            //extracted from the java code:
+            //new GameProfile(UUID.nameUUIDFromBytes(("OfflinePlayer:" + name).getBytes(Charsets.UTF_8)), name));
+            byte[] data = md5.ComputeHash(Encoding.ASCII.GetBytes(value));
+            //set the version to 3 -> Name based md5 hash
+            data[6] = Convert.ToByte(data[6] & 0x0f | 0x30);
+            //IETF variant
+            data[8] = Convert.ToByte(data[8] & 0x3f | 0x80);
+
+            //example: 069a79f4-44e9-4726-a5be-fca90e38aaf5
+            var striped = Convert.ToHexString(data);
+            var components = new string[] {
+                striped[..].Remove(8),
+                striped[8..].Remove(4),
+                striped[12..].Remove(4),
+                striped[16..].Remove(4),
+                striped[20..]
+            };
+
+            return string.Join('-', components).ToLower();
+        }
+
+        public static string GetPlayerUUID(string username, bool offlineMode)
+        {
+            using var md5 = MD5.Create();
+
+            if (!offlineMode)
+                throw new NotSupportedException("Getting player's online UUID via the Mojang API is not supported at this time.");
+
+            return GetUUID("OfflinePlayer:" + username);
+        }
+    }
+}