hash checking for module's jarfile

assets/mods/basegame/metadata.properties

@@ -25,6 +25,9 @@ version=0.3.0
 # Due to security reasons, loading an arbitrary JAR is not allowed.
 jar=
 
+# Sha256sum of the External JAR, if any
+jarhash=
+
 # Modules that must be pre-installed, separate multiple by semicolon (;)
 # Dependency syntax: "module's identification name (aka folder name) spaces allowed versionnumber"
 # Version number:

assets/mods/dwarventech/metadata.properties

@@ -6,4 +6,5 @@ entrypoint=net.torvald.terrarum.modulecomputers.EntryPoint
 releasedate=2021-12-03
 version=0.3.0
 jar=ModuleComputers.jar
+jarhash=b2d50cc10693885f060a5825a4fb2be2993b461bae2e58b4a4900fa169ec898f
 dependency=basegame 0.3.0

src/net/torvald/terrarum/ModMgr.kt

@@ -11,8 +11,10 @@ import net.torvald.terrarum.gameitems.ItemID
 import net.torvald.terrarum.itemproperties.ItemCodex
 import net.torvald.terrarum.itemproperties.MaterialCodex
 import net.torvald.terrarum.langpack.Lang
+import net.torvald.terrarum.serialise.Common
 import net.torvald.terrarum.utils.CSVFetcher
 import net.torvald.terrarum.utils.JsonFetcher
+import org.apache.commons.codec.digest.DigestUtils
 import org.apache.commons.csv.CSVFormat
 import org.apache.commons.csv.CSVParser
 import org.apache.commons.csv.CSVRecord
@@ -100,6 +102,8 @@ object ModMgr {
         errorLogs.add(ModuleErrorInfo(type, moduleName, cause))
     }
 
+    private val digester = DigestUtils.getSha256Digest()
+
     /**
      * Try to create an instance of a "titlescreen" from the current load order set.
      */
@@ -162,6 +166,7 @@ object ModMgr {
                     val releaseDate = modMetadata.getProperty("releasedate")
                     val version = modMetadata.getProperty("version")
                     val jar = modMetadata.getProperty("jar")
+                    val jarHash = modMetadata.getProperty("jarhash").uppercase()
                     val dependency = modMetadata.getProperty("dependency").split(Regex(""";[ ]*""")).filter { it.isNotEmpty() }.toTypedArray()
                     val isDir = FileSystems.getDefault().getPath("$modDir/$moduleName").toFile().isDirectory
 
@@ -203,10 +208,20 @@ object ModMgr {
                             if (jar.isNotBlank()) {
                                 val urls = arrayOf<URL>()
 
+                                val jarFilePath = "${File(modDir).absolutePath}/$moduleName/$jar"
                                 val cl = JarFileLoader(urls)
-                                cl.addFile("${File(modDir).absolutePath}/$moduleName/$jar")
+                                cl.addFile(jarFilePath)
                                 moduleClassloader[moduleName] = cl
 
+                                // check for hash
+                                digester.reset()
+                                val hash = digester.digest(File(jarFilePath).readBytes()).joinToString("","","") { it.toInt().and(255).toString(16).uppercase().padStart(2,'0') }
+
+                                if (jarHash != hash) {
+                                    println("Hash expected: $jarHash, got: $hash")
+                                    throw IllegalStateException("Module Jarfile hash mismatch")
+                                }
+
                                 // check for module-info.java
                                 val moduleInfoPath = cl.getResources("module-info.class").toList().filter { it.toString().contains("$moduleName/$jar!/module-info.class") && it.toString().endsWith("module-info.class")}
                                 if (moduleInfoPath.size == 0) {

src/net/torvald/terrarum/ui/UIItemModuleInfoCell.kt

@@ -6,10 +6,7 @@ import com.badlogic.gdx.graphics.Texture
 import com.badlogic.gdx.graphics.g2d.SpriteBatch
 import com.badlogic.gdx.graphics.g2d.TextureRegion
 import com.badlogic.gdx.utils.GdxRuntimeException
-import net.torvald.terrarum.App
-import net.torvald.terrarum.CommonResourcePool
-import net.torvald.terrarum.ModMgr
-import net.torvald.terrarum.blendNormal
+import net.torvald.terrarum.*
 import net.torvald.terrarum.modulebasegame.ui.MODULEINFO_CELL_HEIGHT
 import net.torvald.terrarum.modulebasegame.ui.MODULEINFO_CELL_WIDTH
 
@@ -27,6 +24,7 @@ class UIItemModuleInfoCell(
 
     private val modProp = ModMgr.moduleInfo[modName] ?: ModMgr.moduleInfoErrored[modName]!!
 
+    private val modErrors = ModMgr.errorLogs.filter { it.moduleName == modName }
     private val modErrored = (ModMgr.moduleInfo[modName] == null)
 
     private val modIcon = try {
@@ -88,7 +86,10 @@ class UIItemModuleInfoCell(
         batch.shader = null
         batch.color = Color.WHITE
         App.fontGame.draw(batch, "$ccZero${modName.toUpperCase()}$ccNum $modVer", initialX + 86f + 3f, initialY + 2f)
-        App.fontGame.draw(batch, "$ccDesc$modDesc", initialX + 86f + 3f, initialY + 26f)
+        if (modErrored)
+            App.fontGame.draw(batch, "$emphRed${modErrors.first().cause?.message}", initialX + 86f + 3f, initialY + 26f)
+        else
+            App.fontGame.draw(batch, "$ccDesc$modDesc", initialX + 86f + 3f, initialY + 26f)
         App.fontGame.draw(batch, "$ccZero2$modAuthor$ccNum2 $modDate", initialX + 86f + 3f, initialY + 50f)
 
         if (modErrored) {