- added mini app content archive checksum validation

- added relative url resolving for remote app content and app icon
- fixed fetched mini app newline parsing issue

Author: firestorm40

Spixi/MiniApps/MiniApp.cs

@@ -1,5 +1,4 @@
 using IXICore;
-using System.Linq;
 using System.Text;
 
 namespace SPIXI.MiniApps
@@ -30,7 +29,7 @@ public class MiniApp
         public byte[] signature = null;      
         public Dictionary<MiniAppCapabilities, bool> capabilities = null;
 
-        public MiniApp(string[] app_info)
+        public MiniApp(string[] app_info, string? app_url = null)
         {
             foreach (string command in app_info)
             {
@@ -110,6 +109,31 @@ public MiniApp(string[] app_info)
                         break;
                 }
             }
+
+            // If an app url is provided, this app metadata is likely from a remote source
+            if (app_url != null)
+            {
+                // Attempt to resolve relative URLs
+                if (!contentUrl.StartsWith("http", StringComparison.OrdinalIgnoreCase))
+                {
+                    int last_index = app_url.LastIndexOf('/');
+                    if (last_index != -1)
+                    {
+                        contentUrl = app_url.Substring(0, last_index + 1) + contentUrl;
+                    }
+                    
+                }
+
+                if (!image.StartsWith("http", StringComparison.OrdinalIgnoreCase))
+                {
+                    int last_index = app_url.LastIndexOf('/');
+                    if (last_index != -1)
+                    {
+                        image = app_url.Substring(0, last_index + 1) + image;
+                    }                  
+                }
+            }
+
         }
 
         private Dictionary<MiniAppCapabilities, bool> parseCapabilities(string value)

Spixi/MiniApps/MiniAppManager.cs

@@ -104,9 +104,9 @@ public void stop()
                 }
 
                 string content = Encoding.UTF8.GetString(data);
-                string[] app_info = content.Split(new[] { Environment.NewLine }, StringSplitOptions.None);
+                string[] app_info = content.Replace("\r\n", "\n").Split('\n');
 
-                return new MiniApp(app_info);
+                return new MiniApp(app_info, url);
             }
             catch (HttpRequestException e)
             {
@@ -138,6 +138,12 @@ public string install(MiniApp fetchedAppInfo)
                 {
                     File.WriteAllBytes(source_app_file_path, client.GetByteArrayAsync(fetchedAppInfo.contentUrl).Result);
                     fetchedAppInfo.contentSize = new FileInfo(source_app_file_path).Length;
+                    string file_checksum = Crypto.sha256(source_app_file_path);
+
+                    if (file_checksum != fetchedAppInfo.checksum)
+                    {
+                        throw new InvalidOperationException($"Checksum mismatch for downloaded app file. Expected {fetchedAppInfo.checksum} got {file_checksum}");
+                    }
                 }
                 catch (Exception e)
                 {