Add BOS gcf output (#413)

BinaryObjectScanner/FileType/GCF.cs

@@ -0,0 +1,34 @@
+using System.IO;
+
+namespace BinaryObjectScanner.FileType
+{
+    /// <summary>
+    /// Game Cache File (GCF)
+    /// </summary>
+    public class GCF : DetectableBase<SabreTools.Serialization.Wrappers.GCF>
+    {
+        /// <inheritdoc/>
+        public GCF(SabreTools.Serialization.Wrappers.GCF wrapper) : base(wrapper) { }
+
+        /// <inheritdoc/>
+        public override string? Detect(Stream stream, string file, bool includeDebug)
+        {
+            // Filename is worth reporting, since it's descriptive and has to match the Steam2 CDN in order to work.
+            string fileName = Path.GetFileName(file);
+            uint depotId = _wrapper.Model.Header.CacheID;
+            uint manifestVersion = _wrapper.Model.Header.LastVersionPlayed;
+
+            // At the moment, all samples of GCF files on redump are unencrypted. Combined with being uncertain about
+            // whether this is the best way to check whether the GCF is encrypted, this block will be left commented
+            // out until further research is done.
+            /*bool encrypted = false;
+            if (_wrapper.Files != null && _wrapper.Files.Length > 0)
+                encrypted = _wrapper.Files[0].Encrypted;
+
+            string encryptedString = encrypted ? "encrypted" : "unencrypted";
+            string returnString = $"{fileName} - {depotId} (v{manifestVersion}, {encryptedString})";*/
+            string returnString = $"{fileName} - {depotId} (v{manifestVersion})";
+            return returnString;
+        }
+    }
+}

BinaryObjectScanner/Scanner.cs

@@ -493,6 +493,7 @@ namespace BinaryObjectScanner
             {
                 AACSMediaKeyBlock obj => new FileType.AACSMediaKeyBlock(obj),
                 BDPlusSVM obj => new FileType.BDPlusSVM(obj),
+                GCF obj => new FileType.GCF(obj),
                 ISO9660 obj => new FileType.ISO9660(obj),
                 LDSCRYPT obj => new FileType.LDSCRYPT(obj),
                 LinearExecutable obj => new FileType.LinearExecutable(obj),