Add virus scanner

VoidCat/Model/VirusScanResult.cs

@@ -0,0 +1,10 @@
+namespace VoidCat.Model;
+
+public sealed class VirusScanResult
+{
+    public DateTimeOffset ScanTime { get; init; } = DateTimeOffset.UtcNow;
+    
+    public bool IsVirus { get; init; }
+
+    public List<string> VirusNames { get; init; } = new();
+}

VoidCat/Model/VoidFile.cs

@@ -30,6 +30,11 @@ namespace VoidCat.Model
         /// Traffic stats for this file
         /// </summary>
         public Bandwidth? Bandwidth { get; init; }
+        
+        /// <summary>
+        /// Virus scanner results
+        /// </summary>
+        public VirusScanResult? VirusScan { get; init; }
     }
 
     public sealed record PublicVoidFile : VoidFile<VoidFileMeta>

VoidCat/Model/VoidSettings.cs

@@ -19,6 +19,8 @@ namespace VoidCat.Model
         public List<Uri> CorsOrigins { get; init; } = new();
         
         public CloudStorageSettings? CloudStorage { get; init; }
+        
+        public VirusScannerSettings? VirusScanner { get; init; }
     }
 
     public sealed record TorSettings(Uri TorControl, string PrivateKey, string ControlPassword);
@@ -46,4 +48,9 @@ namespace VoidCat.Model
         public string? Region { get; init; }
         public string? BucketName { get; init; } = "void-cat";
     }
+
+    public sealed record VirusScannerSettings
+    {
+        public Uri? ClamAV { get; init; } 
+    }
 }

VoidCat/Services/Abstractions/IFileInfoManager.cs

@@ -2,6 +2,10 @@ using VoidCat.Model;
 
 namespace VoidCat.Services.Abstractions;
 
+/// <summary>
+/// Main interface for getting file info to serve to clients.
+/// This interface should wrap all stores and return the combined result
+/// </summary>
 public interface IFileInfoManager
 {
     ValueTask<PublicVoidFile?> Get(Guid id);

VoidCat/Services/Abstractions/IVirusScanStore.cs

@@ -0,0 +1,7 @@
+using VoidCat.Model;
+
+namespace VoidCat.Services.Abstractions;
+
+public interface IVirusScanStore : IBasicStore<VirusScanResult>
+{
+}

VoidCat/Services/Abstractions/IVirusScanner.cs

@@ -0,0 +1,8 @@
+using VoidCat.Model;
+
+namespace VoidCat.Services.Abstractions;
+
+public interface IVirusScanner
+{
+    ValueTask<VirusScanResult> ScanFile(Guid id, CancellationToken cts);
+}

VoidCat/Services/Background/VirusScannerService.cs

@@ -0,0 +1,56 @@
+using VoidCat.Services.Abstractions;
+
+namespace VoidCat.Services.Background;
+
+public class VirusScannerService : BackgroundService
+{
+    private readonly ILogger<VirusScannerService> _logger;
+    private readonly IVirusScanner _scanner;
+    private readonly IFileStore _fileStore;
+    private readonly IVirusScanStore _scanStore;
+
+    public VirusScannerService(ILogger<VirusScannerService> logger, IVirusScanner scanner, IVirusScanStore scanStore,
+        IFileStore fileStore)
+    {
+        _scanner = scanner;
+        _logger = logger;
+        _scanStore = scanStore;
+        _fileStore = fileStore;
+    }
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        _logger.LogInformation("Virus scanner background service starting..");
+
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            var page = 0;
+            while (true)
+            {
+                var files = await _fileStore.ListFiles(new(page, 10));
+                if (files.Pages < page) break;
+                page++;
+
+                await foreach (var file in files.Results.WithCancellation(stoppingToken))
+                {
+                    // check for scans
+                    var scan = await _scanStore.Get(file.Id);
+                    if (scan == default)
+                    {
+                        try
+                        {
+                            var result = await _scanner.ScanFile(file.Id, stoppingToken);
+                            await _scanStore.Set(file.Id, result);
+                        }
+                        catch (Exception ex)
+                        {
+                            _logger.LogError(ex, "Failed to scan file {Id} error={Message}", file.Id, ex.Message);
+                        }
+                    }
+                }
+            }
+
+            await Task.Delay(TimeSpan.FromMinutes(5), stoppingToken);
+        }
+    }
+}

VoidCat/Services/Files/FileInfoManager.cs

@@ -9,14 +9,16 @@ public class FileInfoManager : IFileInfoManager
     private readonly IPaywallStore _paywallStore;
     private readonly IStatsReporter _statsReporter;
     private readonly IUserStore _userStore;
+    private readonly IVirusScanStore _virusScanStore;
 
     public FileInfoManager(IFileMetadataStore metadataStore, IPaywallStore paywallStore, IStatsReporter statsReporter,
-        IUserStore userStore)
+        IUserStore userStore, IVirusScanStore virusScanStore)
     {
         _metadataStore = metadataStore;
         _paywallStore = paywallStore;
         _statsReporter = statsReporter;
         _userStore = userStore;
+        _virusScanStore = virusScanStore;
     }
 
     public async ValueTask<PublicVoidFile?> Get(Guid id)
@@ -24,7 +26,8 @@ public class FileInfoManager : IFileInfoManager
         var meta = _metadataStore.Get<VoidFileMeta>(id);
         var paywall = _paywallStore.Get(id);
         var bandwidth = _statsReporter.GetBandwidth(id);
-        await Task.WhenAll(meta.AsTask(), paywall.AsTask(), bandwidth.AsTask());
+        var virusScan = _virusScanStore.Get(id);
+        await Task.WhenAll(meta.AsTask(), paywall.AsTask(), bandwidth.AsTask(), virusScan.AsTask());
 
         if (meta.Result == default) return default;
         
@@ -37,7 +40,8 @@ public class FileInfoManager : IFileInfoManager
             Metadata = meta.Result,
             Paywall = paywall.Result,
             Bandwidth = bandwidth.Result,
-            Uploader = user?.Flags.HasFlag(VoidUserFlags.PublicProfile) == true ? user : null
+            Uploader = user?.Flags.HasFlag(VoidUserFlags.PublicProfile) == true ? user : null,
+            VirusScan = virusScan.Result
         };
     }
 
@@ -46,5 +50,6 @@ public class FileInfoManager : IFileInfoManager
         await _metadataStore.Delete(id);
         await _paywallStore.Delete(id);
         await _statsReporter.Delete(id);
+        await _virusScanStore.Delete(id);
     }
 }

VoidCat/Services/VirusScanner/ClamAvScanner.cs

@@ -0,0 +1,38 @@
+using nClam;
+using VoidCat.Model;
+using VoidCat.Services.Abstractions;
+
+namespace VoidCat.Services.VirusScanner;
+
+public class ClamAvScanner : IVirusScanner
+{
+    private readonly ILogger<ClamAvScanner> _logger;
+    private readonly IClamClient _clam;
+    private readonly IFileStore _store;
+
+    public ClamAvScanner(ILogger<ClamAvScanner> logger, IClamClient clam, IFileStore store)
+    {
+        _logger = logger;
+        _clam = clam;
+        _store = store;
+    }
+
+    public async ValueTask<VirusScanResult> ScanFile(Guid id, CancellationToken cts)
+    {
+        _logger.LogInformation("Starting scan of {Filename}", id);
+
+        await using var fs = await _store.Open(new(id, Enumerable.Empty<RangeRequest>()), cts);
+        var result = await _clam.SendAndScanFileAsync(fs, cts);
+
+        if (result.Result == ClamScanResults.Error)
+        {
+            _logger.LogError("Failed to scan file {File}", id);
+        }
+
+        return new()
+        {
+            IsVirus = result.Result == ClamScanResults.VirusDetected,
+            VirusNames = result.InfectedFiles?.Select(a => a.VirusName.Trim()).ToList() ?? new()
+        };
+    }
+}

VoidCat/Services/VirusScanner/VirusScanStore.cs

@@ -0,0 +1,14 @@
+using VoidCat.Model;
+using VoidCat.Services.Abstractions;
+
+namespace VoidCat.Services.VirusScanner;
+
+public class VirusScanStore : BasicCacheStore<VirusScanResult>, IVirusScanStore
+{
+    public VirusScanStore(ICache cache) : base(cache)
+    {
+    }
+
+    public override string MapKey(Guid id)
+        => $"virus-scan:{id}";
+}

VoidCat/Services/VirusScanner/VirusScannerStartup.cs

@@ -0,0 +1,27 @@
+using nClam;
+using VoidCat.Model;
+using VoidCat.Services.Abstractions;
+
+namespace VoidCat.Services.VirusScanner;
+
+public static class VirusScannerStartup
+{
+    public static void AddVirusScanner(this IServiceCollection services, VoidSettings settings)
+    {
+        services.AddTransient<IVirusScanStore, VirusScanStore>();
+        
+        var avSettings = settings.VirusScanner;
+        if (avSettings != default)
+        {
+            services.AddHostedService<Background.VirusScannerService>();
+            
+            // load ClamAV scanner
+            if (avSettings.ClamAV != default)
+            {
+                services.AddTransient<IClamClient>((_) =>
+                    new ClamClient(avSettings.ClamAV.Host, avSettings.ClamAV.Port));
+                services.AddTransient<IVirusScanner, ClamAvScanner>();
+            }
+        }
+    }
+}

VoidCat/VoidCat.csproj

@@ -17,6 +17,7 @@
 		<PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="6.0.1" />
 		<PackageReference Include="Microsoft.VisualStudio.Azure.Containers.Tools.Targets" Version="1.14.0" />
 		<PackageReference Include="NBitcoin" Version="6.0.19" />
+		<PackageReference Include="nClam" Version="7.0.0" />
 		<PackageReference Include="prometheus-net.AspNetCore" Version="5.0.2" />
 		<PackageReference Include="Seq.Extensions.Logging" Version="6.0.0" />
 		<PackageReference Include="StackExchange.Redis" Version="2.5.27-prerelease" />