Add and use IS-CAB constants

BurnOutSharp.Builders/InstallShieldCabinet.cs

@@ -3,6 +3,7 @@ using System.IO;
 using System.Text;
 using BurnOutSharp.Models.InstallShieldCabinet;
 using BurnOutSharp.Utilities;
+using static BurnOutSharp.Models.InstallShieldCabinet.Constants;
 
 namespace BurnOutSharp.Builders
 {
@@ -328,8 +329,9 @@ namespace BurnOutSharp.Builders
         {
             CommonHeader commonHeader = new CommonHeader();
 
-            commonHeader.Signature = data.ReadUInt32();
-            if (commonHeader.Signature != 0x28635349)
+            byte[] signature = data.ReadBytes(4);
+            commonHeader.Signature = Encoding.ASCII.GetString(signature);
+            if (commonHeader.Signature != SignatureString)
                 return null;
 
             commonHeader.Version = data.ReadUInt32();
@@ -360,15 +362,13 @@ namespace BurnOutSharp.Builders
             cabDescriptor.FileTableOffset2 = data.ReadUInt32();
             cabDescriptor.Reserved3 = data.ReadBytes(0x0E);
 
-            // TODO: Determine how the value "71" was chosen here
-            cabDescriptor.FileGroupOffsets = new uint[71];
+            cabDescriptor.FileGroupOffsets = new uint[MAX_FILE_GROUP_COUNT];
             for (int i = 0; i < cabDescriptor.FileGroupOffsets.Length; i++)
             {
                 cabDescriptor.FileGroupOffsets[i] = data.ReadUInt32();
             }
 
-            // TODO: Determine how the value "71" was chosen here
-            cabDescriptor.ComponentOffsets = new uint[71];
+            cabDescriptor.ComponentOffsets = new uint[MAX_COMPONENT_COUNT];
             for (int i = 0; i < cabDescriptor.ComponentOffsets.Length; i++)
             {
                 cabDescriptor.ComponentOffsets[i] = data.ReadUInt32();

BurnOutSharp.Models/BFPK/Constants.cs

@@ -2,10 +2,10 @@ namespace BurnOutSharp.Models.BFPK
 {
     public static class Constants
     {
-        public const uint SignatureUInt32 = 0x4b504642;
-
         public static readonly byte[] SignatureBytes = new byte[] { 0x42, 0x46, 0x50, 0x4b };
 
         public const string SignatureString = "BFPK";
+
+        public const uint SignatureUInt32 = 0x4b504642;
     }
 }

BurnOutSharp.Models/InstallShieldCabinet/CommonHeader.cs

@@ -3,7 +3,7 @@ namespace BurnOutSharp.Models.InstallShieldCabinet
     /// <see href="https://github.com/twogood/unshield/blob/main/lib/cabfile.h"/>
     public sealed class CommonHeader
     {
-        public uint Signature;
+        public string Signature;
 
         public uint Version;
 

BurnOutSharp.Models/InstallShieldCabinet/Constants.cs

@@ -0,0 +1,17 @@
+namespace BurnOutSharp.Models.InstallShieldCabinet
+{
+    public static class Constants
+    {
+        public static readonly byte[] SignatureBytes = new byte[] { 0x49, 0x53, 0x63, 0x28 };
+
+        public const string SignatureString = "ISc(";
+
+        public const uint SignatureUInt32 = 0x28635349;
+
+        // TODO: Determine how the value "71" was chosen here
+        public const int MAX_FILE_GROUP_COUNT = 71;
+
+        // TODO: Determine how the value "71" was chosen here
+        public const int MAX_COMPONENT_COUNT = 71;
+    }
+}