From 012b1df5d89e017385c5f5ddbae7d15b03d6573a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E2=97=B1=20PixelyIon?= <dhruvmarkcollins@gmail.com>
Date: Thu, 4 Jul 2019 01:25:06 +0530
Subject: [PATCH] NRO Validation

The NRO files are now validated before they're added to the game list.
---
 .../gq/cyuubi/lightswitch/FileAdapter.java    |  2 +-
 .../gq/cyuubi/lightswitch/MainActivity.java   |  4 ++-
 .../java/gq/cyuubi/lightswitch/NroMeta.java   | 33 +++++++++++++++++--
 3 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/app/src/main/java/gq/cyuubi/lightswitch/FileAdapter.java b/app/src/main/java/gq/cyuubi/lightswitch/FileAdapter.java
index ffc88990..cdda9333 100644
--- a/app/src/main/java/gq/cyuubi/lightswitch/FileAdapter.java
+++ b/app/src/main/java/gq/cyuubi/lightswitch/FileAdapter.java
@@ -28,7 +28,7 @@ class GameItem {
     public GameItem(File file) {
         this.file = file;
         index = file.getName().lastIndexOf(".");
-        meta = NroMeta.GetNroTitle(getPath());
+        meta = NroMeta.getTitleEntry(getPath());
     }
 
     public Bitmap getIcon() {
diff --git a/app/src/main/java/gq/cyuubi/lightswitch/MainActivity.java b/app/src/main/java/gq/cyuubi/lightswitch/MainActivity.java
index 617f137e..92497057 100644
--- a/app/src/main/java/gq/cyuubi/lightswitch/MainActivity.java
+++ b/app/src/main/java/gq/cyuubi/lightswitch/MainActivity.java
@@ -51,7 +51,9 @@ public class MainActivity extends AppCompatActivity {
                     try {
                         String file_str = file_i.getName();
                         if (ext.equalsIgnoreCase(file_str.substring(file_str.lastIndexOf(".") + 1))) {
-                            files.add(file_i);
+                            if(NroMeta.verifyFile(file_i.getAbsolutePath())) {
+                                files.add(file_i);
+                            }
                         }
                     } catch (StringIndexOutOfBoundsException e) {
                     }
diff --git a/app/src/main/java/gq/cyuubi/lightswitch/NroMeta.java b/app/src/main/java/gq/cyuubi/lightswitch/NroMeta.java
index b21aecfc..356246cb 100644
--- a/app/src/main/java/gq/cyuubi/lightswitch/NroMeta.java
+++ b/app/src/main/java/gq/cyuubi/lightswitch/NroMeta.java
@@ -32,7 +32,7 @@ final class TitleEntry {
 }
 
 public class NroMeta {
-    public static TitleEntry GetNroTitle(String file) {
+    public static TitleEntry getTitleEntry(String file) {
         try {
             RandomAccessFile f = new RandomAccessFile(file, "r");
             f.seek(0x18); // Skip to NroHeader.size
@@ -41,7 +41,7 @@ public class NroMeta {
             byte[] buffer = new byte[4];
             f.read(buffer);
             if (!(new String(buffer).equals("ASET")))
-                return null;
+                throw new IOException();
 
             f.skipBytes(0x4);
             long iconOffset = Long.reverseBytes(f.readLong());
@@ -57,7 +57,7 @@ public class NroMeta {
             long nacpOffset = Long.reverseBytes(f.readLong());
             long nacpSize = Long.reverseBytes(f.readLong());
             if (nacpOffset == 0 || nacpSize == 0)
-                return null;
+                throw new IOException();
             f.seek(asetOffset + nacpOffset);
             byte[] name = new byte[0x200];
             f.read(name);
@@ -70,4 +70,31 @@ public class NroMeta {
             return null;
         }
     }
+    public static boolean verifyFile(String file) {
+        try {
+            RandomAccessFile f = new RandomAccessFile(file, "r");
+            f.seek(0x18); // Skip to NroHeader.size
+            int asetOffset = Integer.reverseBytes(f.readInt());
+            f.seek(asetOffset); // Skip to the offset specified by NroHeader.size
+            byte[] buffer = new byte[4];
+            f.read(buffer);
+            if (!(new String(buffer).equals("ASET")))
+                return false;
+
+            f.skipBytes(0x4);
+            long iconOffset = Long.reverseBytes(f.readLong());
+            int iconSize = Integer.reverseBytes(f.readInt());
+            if (iconOffset == 0 || iconSize == 0)
+                return false;
+
+            f.seek(asetOffset + 0x18);
+            long nacpOffset = Long.reverseBytes(f.readLong());
+            long nacpSize = Long.reverseBytes(f.readLong());
+            if (nacpOffset == 0 || nacpSize == 0)
+                return false;
+        } catch (IOException e) {
+            return false;
+        }
+        return true;
+    }
 }