Add online mode fix for legacy versions; minor refactors in legacy

Signed-off-by: TheKodeToad <TheKodeToad@proton.me>

launcher/ui/pages/global/MinecraftPage.ui

@@ -206,7 +206,7 @@
           <item>
            <widget class="QCheckBox" name="onlineFixes">
             <property name="toolTip">
-             <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Emulates usages of old online services which are no longer operating.&lt;/p&gt;&lt;p&gt;This currently allows modern skins to be used.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+             <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Emulates usages of old online services which are no longer operating.&lt;/p&gt;&lt;p&gt;Current fixes include: skin and online mode support.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
             </property>
             <property name="text">
              <string>Enable online fixes (experimental)</string>

launcher/ui/pages/instance/InstanceSettingsPage.ui

@@ -605,7 +605,7 @@
           <item>
            <widget class="QCheckBox" name="onlineFixes">
             <property name="toolTip">
-             <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Emulates usages of old online services which are no longer operating.&lt;/p&gt;&lt;p&gt;This currently allows modern skins to be used.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+             <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Emulates usages of old online services which are no longer operating.&lt;/p&gt;&lt;p&gt;Current fixes include: skin and online mode support.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
             </property>
             <property name="text">
              <string>Enable online fixes (experimental)</string>

libraries/launcher/CMakeLists.txt

@@ -25,13 +25,14 @@ set(LEGACY_SRC
     legacy/org/prismlauncher/legacy/LegacyLauncher.java
     legacy/org/prismlauncher/legacy/fix/online/Handler.java
     legacy/org/prismlauncher/legacy/fix/online/OnlineFixes.java
+    legacy/org/prismlauncher/legacy/fix/online/OnlineModeFix.java
     legacy/org/prismlauncher/legacy/fix/online/SkinFix.java
     legacy/org/prismlauncher/legacy/utils/Base64.java
     legacy/org/prismlauncher/legacy/utils/api/MojangApi.java
     legacy/org/prismlauncher/legacy/utils/api/Texture.java
     legacy/org/prismlauncher/legacy/utils/json/JsonParseException.java
     legacy/org/prismlauncher/legacy/utils/json/JsonParser.java
-    legacy/org/prismlauncher/legacy/utils/url/CustomUrlConnection.java
+    legacy/org/prismlauncher/legacy/utils/url/ByteArrayUrlConnection.java
     legacy/org/prismlauncher/legacy/utils/url/UrlUtils.java
     legacy/net/minecraft/Launcher.java
     legacy/org/prismlauncher/legacy/LegacyProxy.java

libraries/launcher/legacy/org/prismlauncher/legacy/fix/online/Handler.java

@@ -53,11 +53,16 @@ final class Handler extends URLStreamHandler {
     protected URLConnection openConnection(URL address, Proxy proxy) throws IOException {
         URLConnection result;
 
-        // try skin fix
+        // try various fixes...
         result = SkinFix.openConnection(address, proxy);
         if (result != null)
             return result;
 
+        result = OnlineModeFix.openConnection(address, proxy);
+        if (result != null)
+            return result;
+
+        // ...then give up and make the request directly
         return UrlUtils.openConnection(address, proxy);
     }
 }

libraries/launcher/legacy/org/prismlauncher/legacy/fix/online/OnlineFixes.java

@@ -46,6 +46,8 @@ import java.net.URLStreamHandlerFactory;
 
 /**
  * Fixes skins by redirecting to other URLs.
+ * Thanks to MineOnline for the implementation from which this was inspired!
+ * See https://github.com/ahnewark/MineOnline/tree/main/src/main/java/gg/codie/mineonline/protocol.
  *
  * @see {@link Handler}
  * @see {@link UrlUtils}

libraries/launcher/legacy/org/prismlauncher/legacy/fix/online/OnlineModeFix.java

@@ -0,0 +1,64 @@
+// SPDX-License-Identifier: GPL-3.0-only
+/*
+ *  Prism Launcher - Minecraft Launcher
+ *  Copyright (C) 2023 TheKodeToad <TheKodeToad@proton.me>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  Linking this library statically or dynamically with other modules is
+ *  making a combined work based on this library. Thus, the terms and
+ *  conditions of the GNU General Public License cover the whole
+ *  combination.
+ *
+ *  As a special exception, the copyright holders of this library give
+ *  you permission to link this library with independent modules to
+ *  produce an executable, regardless of the license terms of these
+ *  independent modules, and to copy and distribute the resulting
+ *  executable under terms of your choice, provided that you also meet,
+ *  for each linked independent module, the terms and conditions of the
+ *  license of that module. An independent module is a module which is
+ *  not derived from or based on this library. If you modify this
+ *  library, you may extend this exception to your version of the
+ *  library, but you are not obliged to do so. If you do not wish to do
+ *  so, delete this exception statement from your version.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.prismlauncher.legacy.fix.online;
+
+import java.io.IOException;
+import java.net.MalformedURLException;
+import java.net.Proxy;
+import java.net.URL;
+import java.net.URLConnection;
+
+public final class OnlineModeFix {
+    public static URLConnection openConnection(URL address, Proxy proxy) throws IOException {
+        // we start with "http://www.minecraft.net/game/joinserver.jsp?user=..."
+        if (!(address.getHost().equals("www.minecraft.net") && address.getPath().equals("/game/joinserver.jsp")))
+            return null;
+
+        // change it to "https://session.minecraft.net/game/joinserver.jsp?user=..."
+        // this seems to be the modern version of the same endpoint...
+        // maybe Mojang planned to patch old versions of the game to use it
+        // if it ever disappears this should be changed to use sessionserver.mojang.com/session/minecraft/join
+        // which of course has a different usage requiring JSON serialisation...
+        URL url;
+        try {
+            url = new URL("https", "session.minecraft.net", address.getPort(), address.getFile());
+        } catch (MalformedURLException e) {
+            throw new AssertionError("url should be valid", e);
+        }
+
+        return url.openConnection();
+    }
+}

libraries/launcher/legacy/org/prismlauncher/legacy/fix/online/SkinFix.java

@@ -54,7 +54,7 @@ package org.prismlauncher.legacy.fix.online;
 
 import org.prismlauncher.legacy.utils.api.MojangApi;
 import org.prismlauncher.legacy.utils.api.Texture;
-import org.prismlauncher.legacy.utils.url.CustomUrlConnection;
+import org.prismlauncher.legacy.utils.url.ByteArrayUrlConnection;
 import org.prismlauncher.legacy.utils.url.UrlUtils;
 
 import java.awt.AlphaComposite;
@@ -97,9 +97,9 @@ final class SkinFix {
 
         URLConnection connection = UrlUtils.openConnection(texture.getUrl(), proxy);
         try (InputStream in = connection.getInputStream()) {
-            // thank you craftycodie!
+            // thank you ahnewark!
             // this is heavily based on
-            // https://github.com/craftycodie/MineOnline/blob/4f4f86f9d051e0a6fd7ff0b95b2a05f7437683d7/src/main/java/gg/codie/mineonline/gui/textures/TextureHelper.java#L17
+            // https://github.com/ahnewark/MineOnline/blob/4f4f86f9d051e0a6fd7ff0b95b2a05f7437683d7/src/main/java/gg/codie/mineonline/gui/textures/TextureHelper.java#L17
             BufferedImage image = ImageIO.read(in);
             Graphics2D graphics = image.createGraphics();
             graphics.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));
@@ -131,7 +131,7 @@ final class SkinFix {
             image = image.getSubimage(0, 0, 64, 32);
             ImageIO.write(image, "png", out);
 
-            return new CustomUrlConnection(out.toByteArray());
+            return new ByteArrayUrlConnection(out.toByteArray());
         }
     }
 

libraries/launcher/legacy/org/prismlauncher/legacy/utils/url/ByteArrayUrlConnection.java

@@ -40,16 +40,12 @@ import java.io.IOException;
 import java.io.InputStream;
 import java.net.HttpURLConnection;
 
-public final class CustomUrlConnection extends HttpURLConnection {
+public final class ByteArrayUrlConnection extends HttpURLConnection {
     private final InputStream in;
 
-    public CustomUrlConnection(byte[] data) {
+    public ByteArrayUrlConnection(byte[] data) {
-        this(new ByteArrayInputStream(data));
-    }
-
-    public CustomUrlConnection(InputStream in) {
         super(null);
-        this.in = in;
+        this.in = new ByteArrayInputStream(data);
     }
 
     @Override
@@ -58,12 +54,7 @@ public final class CustomUrlConnection extends HttpURLConnection {
     }
 
     @Override
-    public void disconnect() {
+    public void disconnect() {}
-        try {
-            in.close();
-        } catch (IOException e) {
-        }
-    }
 
     @Override
     public InputStream getInputStream() throws IOException {

libraries/launcher/legacy/org/prismlauncher/legacy/utils/url/UrlUtils.java

@@ -101,7 +101,7 @@ public final class UrlUtils {
         } catch (IOException | Error | RuntimeException e) {
             throw e; // rethrow if possible
         } catch (Throwable e) {
-            throw new AssertionError(e); // oh dear! this isn't meant to happen
+            throw new AssertionError("openConnection should not throw", e); // oh dear! this isn't meant to happen
         }
     }
 }

libraries/launcher/org/prismlauncher/EntryPoint.java

@@ -81,10 +81,9 @@ public final class EntryPoint {
         PreLaunchAction action = PreLaunchAction.PROCEED;
 
         try (BufferedReader reader = new BufferedReader(new InputStreamReader(System.in, StandardCharsets.UTF_8))) {
-            String line;
-
             while (action == PreLaunchAction.PROCEED) {
-                if ((line = reader.readLine()) != null)
+                String line = reader.readLine();
+                if (line != null)
                     action = parseLine(line, params);
                 else
                     action = PreLaunchAction.ABORT;
@@ -105,7 +104,7 @@ public final class EntryPoint {
             return ExitCode.ABORT;
         }
 
-        setProperties(params);
+        SystemProperties.apply(params);
 
         String launcherType = params.getString("launcher");
 
@@ -141,43 +140,10 @@ public final class EntryPoint {
         }
     }
 
-    private static void setProperties(Parameters params) {
-        String launcherBrand = params.getString("launcherBrand", null);
-        String launcherVersion = params.getString("launcherVersion", null);
-        String name = params.getString("instanceName", null);
-        String iconId = params.getString("instanceIconKey", null);
-        String iconPath = params.getString("instanceIconPath", null);
-        String windowTitle = params.getString("windowTitle", null);
-        String windowDimensions = params.getString("windowParams", null);
-
-        if (launcherBrand != null)
-            System.setProperty("minecraft.launcher.brand", launcherBrand);
-        if (launcherVersion != null)
-            System.setProperty("minecraft.launcher.version", launcherVersion);
-
-        // set useful properties for mods
-        if (name != null)
-            System.setProperty("org.prismlauncher.instance.name", name);
-        if (iconId != null)
-            System.setProperty("org.prismlauncher.instance.icon.id", iconId);
-        if (iconPath != null)
-            System.setProperty("org.prismlauncher.instance.icon.path", iconPath);
-        if (windowTitle != null)
-            System.setProperty("org.prismlauncher.window.title", windowTitle);
-        if (windowDimensions != null)
-            System.setProperty("org.prismlauncher.window.dimensions", windowDimensions);
-
-        // set multimc properties for compatibility
-        if (name != null)
-            System.setProperty("multimc.instance.title", name);
-        if (iconId != null)
-            System.setProperty("multimc.instance.icon", iconId);
-    }
-
     private static PreLaunchAction parseLine(String input, Parameters params) throws ParseException {
         switch (input) {
             case "":
-                break;
+                return PreLaunchAction.PROCEED;
 
             case "launch":
                 return PreLaunchAction.LAUNCH;
@@ -192,10 +158,10 @@ public final class EntryPoint {
                     throw new ParseException(input, "[key] [value]");
 
                 params.add(pair[0], pair[1]);
-        }
 
                 return PreLaunchAction.PROCEED;
         }
+    }
 
     private enum PreLaunchAction { PROCEED, LAUNCH, ABORT }
 

libraries/launcher/org/prismlauncher/SystemProperties.java

@@ -0,0 +1,38 @@
+package org.prismlauncher;
+
+import org.prismlauncher.utils.Parameters;
+
+public final class SystemProperties {
+    public static void apply(Parameters params) {
+        String launcherBrand = params.getString("launcherBrand", null);
+        String launcherVersion = params.getString("launcherVersion", null);
+        String name = params.getString("instanceName", null);
+        String iconId = params.getString("instanceIconKey", null);
+        String iconPath = params.getString("instanceIconPath", null);
+        String windowTitle = params.getString("windowTitle", null);
+        String windowDimensions = params.getString("windowParams", null);
+
+        if (launcherBrand != null)
+            System.setProperty("minecraft.launcher.brand", launcherBrand);
+        if (launcherVersion != null)
+            System.setProperty("minecraft.launcher.version", launcherVersion);
+
+        // set useful properties for mods
+        if (name != null)
+            System.setProperty("org.prismlauncher.instance.name", name);
+        if (iconId != null)
+            System.setProperty("org.prismlauncher.instance.icon.id", iconId);
+        if (iconPath != null)
+            System.setProperty("org.prismlauncher.instance.icon.path", iconPath);
+        if (windowTitle != null)
+            System.setProperty("org.prismlauncher.window.title", windowTitle);
+        if (windowDimensions != null)
+            System.setProperty("org.prismlauncher.window.dimensions", windowDimensions);
+
+        // set multimc properties for compatibility
+        if (name != null)
+            System.setProperty("multimc.instance.title", name);
+        if (iconId != null)
+            System.setProperty("multimc.instance.icon", iconId);
+    }
+}

libraries/launcher/org/prismlauncher/utils/ReflectionUtils.java

@@ -54,15 +54,9 @@
 
 package org.prismlauncher.utils;
 
-import org.prismlauncher.utils.logging.Log;
-
-import java.applet.Applet;
-import java.io.File;
 import java.lang.invoke.MethodHandle;
 import java.lang.invoke.MethodHandles;
 import java.lang.invoke.MethodType;
-import java.lang.reflect.Field;
-import java.lang.reflect.Modifier;
 
 public final class ReflectionUtils {
     private static final MethodHandles.Lookup LOOKUP = MethodHandles.lookup();