Add CExe detection (#30)

* Add CExe detection

* Optimize check

BurnOutSharp/PackerType/CExe.cs

@@ -0,0 +1,44 @@
+using System.Collections.Generic;
+using System.IO;
+
+namespace BurnOutSharp.PackerType
+{
+    // The official website for CExe also includes the source code (which does have to be retrieved by the Wayback Machine). http://www.scottlu.com/Content/CExe.html
+    public class CExe : IContentCheck, IScannable
+    {
+        /// <inheritdoc/>
+        public bool ShouldScan(byte[] magic) => true;
+
+        /// <inheritdoc/>
+        public string CheckContents(string file, byte[] fileContent, bool includePosition = false)
+        {
+            // "%WoÁa6.’a6.’a6.’a6.’{6.’.).’f6.’‰).’`6.’Ù0.’`6.’"
+            byte?[] check = new byte?[] { 0x25, 0x57, 0x6F, 0xC1, 0x61, 0x36, 0x01, 0x92, 0x61, 0x36, 0x01, 0x92, 0x61, 0x36, 0x01, 0x92, 0x61, 0x36, 0x00, 0x92, 0x7B, 0x36, 0x01, 0x92, 0x03, 0x29, 0x12, 0x92, 0x66, 0x36, 0x01, 0x92, 0x89, 0x29, 0x0A, 0x92, 0x60, 0x36, 0x01, 0x92, 0xD9, 0x30, 0x07, 0x92, 0x60, 0x36, 0x01, 0x92 };
+            if (fileContent.FirstPosition(check, out int position, end: 200))
+            {
+                return "CExe";
+            }
+
+            return null;
+        }
+
+        /// <inheritdoc/>
+        public Dictionary<string, List<string>> Scan(Scanner scanner, string file)
+        {
+            if (!File.Exists(file))
+                return null;
+
+            using (var fs = File.OpenRead(file))
+            {
+                return Scan(scanner, fs, file);
+            }
+        }
+
+        /// <inheritdoc/>
+        // TODO: Add extraction if viable
+        public Dictionary<string, List<string>> Scan(Scanner scanner, Stream stream, string file)
+        {
+            return null;
+        }
+    }
+}

README.md

@@ -89,6 +89,7 @@ Below is a list of the protections that can be detected using this code:
 Below is a list of the executable packers that can be detected using this code:
 
 - Armadillo
+- CExe
 - dotFuscator
 - EXE Stealth
 - Inno Setup