From 5fbf5598b4b7e1a4dbc465ed2aa5ac3469483ca6 Mon Sep 17 00:00:00 2001
From: Henry Le Grys <henry@legrys.info>
Date: Fri, 10 Dec 2021 13:55:23 +0000
Subject: [PATCH] Support downloading logging config files from the version
 manifest

This update is required to mitigate the log4j2 vulnerability
---
 .../com/skcraft/launcher/launch/Runner.java   | 11 +++++++++++
 .../model/minecraft/VersionManifest.java      | 10 ++++++++++
 .../skcraft/launcher/update/BaseUpdater.java  | 19 ++++++++++++++++++-
 3 files changed, 39 insertions(+), 1 deletion(-)

diff --git a/launcher/src/main/java/com/skcraft/launcher/launch/Runner.java b/launcher/src/main/java/com/skcraft/launcher/launch/Runner.java
index 588a365..0fcbd87 100644
--- a/launcher/src/main/java/com/skcraft/launcher/launch/Runner.java
+++ b/launcher/src/main/java/com/skcraft/launcher/launch/Runner.java
@@ -9,6 +9,7 @@ package com.skcraft.launcher.launch;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.common.base.Strings;
+import com.google.common.collect.ImmutableMap;
 import com.google.common.io.Files;
 import com.skcraft.concurrency.DefaultProgress;
 import com.skcraft.concurrency.ProgressObservable;
@@ -279,6 +280,16 @@ public class Runner implements Callable<Process>, ProgressObservable {
                 }
             }
         }
+
+        if (versionManifest.getLogging() != null) {
+            log.info("Logging config present, log4j2 bug likely mitigated");
+
+            VersionManifest.LoggingConfig config = versionManifest.getLogging().getClient();
+            File configFile = new File(launcher.getLibrariesDir(), config.getFile().getId());
+            StrSubstitutor loggingSub = new StrSubstitutor(ImmutableMap.of("path", configFile.getAbsolutePath()));
+
+            flags.add(loggingSub.replace(config.getArgument()));
+        }
     }
 
     /**
diff --git a/launcher/src/main/java/com/skcraft/launcher/model/minecraft/VersionManifest.java b/launcher/src/main/java/com/skcraft/launcher/model/minecraft/VersionManifest.java
index f270ca4..dd3cf63 100644
--- a/launcher/src/main/java/com/skcraft/launcher/model/minecraft/VersionManifest.java
+++ b/launcher/src/main/java/com/skcraft/launcher/model/minecraft/VersionManifest.java
@@ -9,6 +9,7 @@ package com.skcraft.launcher.model.minecraft;
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.google.common.base.Splitter;
+import com.skcraft.launcher.model.loader.SidedData;
 import lombok.Data;
 
 import java.util.*;
@@ -28,6 +29,7 @@ public class VersionManifest {
     private int minimumLauncherVersion;
     private LinkedHashSet<Library> libraries;
     private JavaVersion javaVersion;
+    private SidedData<LoggingConfig> logging;
     private Map<String, Artifact> downloads = new HashMap<String, Artifact>();
 
     public String getAssetId() {
@@ -61,6 +63,7 @@ public class VersionManifest {
     @Data
     @JsonIgnoreProperties(ignoreUnknown = true)
     public static class Artifact {
+        private String id;
         private String url;
         private int size;
 
@@ -74,4 +77,11 @@ public class VersionManifest {
         private String id;
         private String url;
     }
+
+    @Data
+    @JsonIgnoreProperties(ignoreUnknown = true)
+    public static class LoggingConfig {
+        private String argument;
+        private Artifact file;
+    }
 }
diff --git a/launcher/src/main/java/com/skcraft/launcher/update/BaseUpdater.java b/launcher/src/main/java/com/skcraft/launcher/update/BaseUpdater.java
index cfb3d4f..fac401d 100644
--- a/launcher/src/main/java/com/skcraft/launcher/update/BaseUpdater.java
+++ b/launcher/src/main/java/com/skcraft/launcher/update/BaseUpdater.java
@@ -25,6 +25,7 @@ import com.skcraft.launcher.model.modpack.Manifest;
 import com.skcraft.launcher.model.modpack.ManifestEntry;
 import com.skcraft.launcher.persistence.Persistence;
 import com.skcraft.launcher.util.Environment;
+import com.skcraft.launcher.util.FileUtils;
 import com.skcraft.launcher.util.HttpRequest;
 import com.skcraft.launcher.util.SharedLocale;
 import lombok.NonNull;
@@ -40,6 +41,7 @@ import java.util.logging.Level;
 
 import static com.skcraft.launcher.LauncherUtils.checkInterrupted;
 import static com.skcraft.launcher.LauncherUtils.concat;
+import static com.skcraft.launcher.util.HttpRequest.url;
 
 /**
  * The base implementation of the various routines involved in downloading
@@ -231,7 +233,7 @@ public abstract class BaseUpdater {
     protected void installLibraries(@NonNull Installer installer,
                                     @NonNull Manifest manifest,
                                     @NonNull File librariesDir,
-                                    @NonNull List<URL> sources) throws InterruptedException {
+                                    @NonNull List<URL> sources) throws InterruptedException, IOException {
         VersionManifest versionManifest = manifest.getVersionManifest();
 
         Iterable<Library> allLibraries = versionManifest.getLibraries();
@@ -271,6 +273,21 @@ public abstract class BaseUpdater {
                 }
             }
         }
+
+        // Fetch logging config
+        if (versionManifest.getLogging() != null) {
+            VersionManifest.LoggingConfig config = versionManifest.getLogging().getClient();
+
+            VersionManifest.Artifact file = config.getFile();
+            File targetFile = new File(librariesDir, file.getId());
+
+            if (!targetFile.exists() || !Objects.equals(config.getFile().getHash(), FileUtils.getShaHash(targetFile))) {
+                File tempFile = installer.getDownloader().download(url(file.getUrl()), file.getHash(), file.getSize(), file.getId());
+
+                log.info("Downloading logging config " + file.getId() + " from " + file.getUrl());
+                installer.queue(new FileMover(tempFile, targetFile));
+            }
+        }
     }
 
     private static void writeDataFile(File path, Object object) {