basic implementation of XDG base directory for alt folder

src/main/java/net/wurstclient/WurstClient.java

@@ -10,7 +10,6 @@
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
-import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -23,6 +22,7 @@
 import net.minecraft.client.resource.language.I18n;
 import net.minecraft.client.util.InputUtil;
 import net.wurstclient.altmanager.AltManager;
+import net.wurstclient.altmanager.Encryption;
 import net.wurstclient.analytics.WurstAnalytics;
 import net.wurstclient.clickgui.ClickGui;
 import net.wurstclient.command.CmdList;
@@ -145,9 +145,7 @@ public void initialize()
 		problematicPackDetector.start();
 
 		Path altsFile = wurstFolder.resolve("alts.encrypted_json");
-		Path encFolder =
-			Paths.get(System.getProperty("user.home"), ".Wurst encryption")
-				.normalize();
+		Path encFolder = Encryption.chooseEncryptionFolder();
 		altManager = new AltManager(altsFile, encFolder);
 
 		zoomKey = new KeyBinding("key.wurst.zoom", InputUtil.Type.KEYSYM,

src/main/java/net/wurstclient/altmanager/Encryption.java

@@ -8,12 +8,14 @@
 package net.wurstclient.altmanager;
 
 import java.io.BufferedReader;
+import java.io.File;
 import java.io.IOException;
 import java.io.ObjectInputStream;
 import java.io.ObjectOutputStream;
 import java.math.BigInteger;
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.nio.file.StandardOpenOption;
 import java.security.GeneralSecurityException;
 import java.security.KeyFactory;
@@ -39,6 +41,7 @@
 import net.minecraft.util.Util;
 import net.minecraft.util.crash.CrashException;
 import net.minecraft.util.crash.CrashReport;
+import net.minecraft.util.crash.CrashReportSection;
 import net.wurstclient.util.json.JsonException;
 import net.wurstclient.util.json.JsonUtils;
 import net.wurstclient.util.json.WsonArray;
@@ -99,6 +102,57 @@ private Path createEncryptionFolder(Path encFolder) throws IOException
 		return encFolder;
 	}
 
+	public static Path chooseEncryptionFolder()
+	{
+		String userHome = System.getProperty("user.home");
+		String xdgDataHome = System.getenv("XDG_DATA_HOME");
+		String encFolderName = ".Wurst encryption";
+
+		Path homeEncFolder = Paths.get(userHome, encFolderName).normalize();
+		Path encFolder = homeEncFolder;
+		if(xdgDataHome != null && !xdgDataHome.isEmpty())
+		{
+			encFolder = Paths.get(xdgDataHome, encFolderName).normalize();
+
+			if(!Files.exists(encFolder) && Files.isDirectory(homeEncFolder))
+				migrateEncryptionFolder(homeEncFolder, encFolder);
+		}
+
+		return encFolder;
+	}
+
+	public static void migrateEncryptionFolder(Path oldFolder, Path newFolder)
+	{
+		System.out.println("Migrating encryption folder from " + oldFolder
+			+ " to " + newFolder);
+
+		try
+		{
+			Files.createDirectories(newFolder);
+
+			File[] oldFiles = oldFolder.toFile().listFiles();
+			for(File oldFile : oldFiles)
+			{
+				Path fileDestination = newFolder.resolve(oldFile.getName());
+				Files.copy(oldFile.toPath(), fileDestination);
+			}
+
+			for(File oldFile : oldFiles)
+				oldFile.delete();
+
+			Files.deleteIfExists(oldFolder);
+
+		}catch(IOException e)
+		{
+			CrashReport report =
+				CrashReport.create(e, "Migrating Wurst encryption folder");
+			CrashReportSection section = report.addElement("Migration");
+			section.add("Old path", oldFolder);
+			section.add("New path", newFolder);
+			throw new CrashException(report);
+		}
+	}
+
 	public byte[] decrypt(byte[] bytes)
 	{
 		try