Validate downloaded mods

Author: 0x0ade

Properties/AssemblyInfo.cs

@@ -34,5 +34,5 @@
 // You can specify all the values or you can default the Build and Revision Numbers 
 // by using the '*' as shown below:
 // [assembly: AssemblyVersion("1.0.*")]
-[assembly: AssemblyVersion("18.05.1.*")]
+[assembly: AssemblyVersion("18.05.2.*")]
 [assembly: AssemblyFileVersion("1.0.0.0")]

src/GameModder.cs

@@ -132,17 +132,32 @@ public void DownloadMod(string url) {
                 Directory.CreateDirectory(modRoot);
 
             string modPath = Path.Combine(modRoot, Path.GetFileName(uri.AbsolutePath));
-            if (File.Exists(modPath))
-                File.Delete(modPath);
 
-            Console.WriteLine($"Downloading: {url}");
+            Console.WriteLine($"Downloading mod");
 
             OnStart?.Invoke();
             try {
 
                 byte[] zipData = _Download(url);
 
+                Console.WriteLine("Verifying");
+
+                using (MemoryStream ms = new MemoryStream(zipData))
+                using (ZipArchive zip = new ZipArchive(ms)) {
+                    string name;
+                    if (!Info.VerifyMod(zip, out name)) {
+                        Console.WriteLine("Error: Invalid mod.");
+                        OnError?.Invoke(null);
+                        return;
+                    }
+                    if (!string.IsNullOrEmpty(name)) {
+                        modPath = Path.Combine(modRoot, name + ".zip");
+                    }
+                }
+
                 Console.WriteLine("Writing data to file");
+                if (File.Exists(modPath))
+                    File.Delete(modPath);
                 File.WriteAllBytes(modPath, zipData);
 
             } catch (Exception e) {

src/Infos/EverestInfo.cs

@@ -11,6 +11,7 @@
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Threading;
+using System.IO.Compression;
 
 namespace MonoMod.Installer.Everest {
     public partial class EverestInfo : GameModInfo {
@@ -247,5 +248,28 @@ private static ModVersion ParseLine(string line, string root) {
             return new ModVersion { Name = name, URL = url, Version = version };
         }
 
+        public override bool VerifyMod(ZipArchive zip, out string name) {
+            name = null;
+            bool valid = false;
+
+            foreach (ZipArchiveEntry entry in zip.Entries) {
+                if (entry.FullName == "everest.yaml" ||
+                    entry.FullName == "everest.yml") {
+                    // Hack: Let's just read the first name.
+                    using (Stream stream = entry.Open())
+                    using (StreamReader reader = new StreamReader(stream))
+                        while (!reader.EndOfStream) {
+                            string line = reader.ReadLine().Trim();
+                            if (line.Contains("Name:") && name == null) {
+                                valid = true;
+                                name = line.Substring(line.IndexOf("Name:") + 5).Trim();
+                            }
+                        }
+                }
+            }
+
+            return valid;
+        }
+
     }
 }

src/Infos/GameModInfo.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.Drawing;
 using System.IO;
+using System.IO.Compression;
 using System.Linq;
 using System.Net;
 using System.Text;
@@ -92,6 +93,11 @@ public virtual string CurrentStatus {
 
         public abstract void Install(Action<float> progress);
 
+        public virtual bool VerifyMod(ZipArchive zip, out string name) {
+            name = null;
+            return false;
+        }
+
         public class ModVersion {
             public string Name;
             public string URL;