first commit

Version 3.x.x

runtime/VMProtect.Runtime/StringManager.cs

@@ -0,0 +1,65 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Runtime.InteropServices;
+
+// ReSharper disable once CheckNamespace
+namespace VMProtect
+{
+	public class StringManager
+	{
+		public StringManager(long instance)
+		{
+			_instance = instance;
+			var key = new byte[8];
+			Marshal.Copy(new IntPtr(_instance + (uint)Faces.KEY_INFO), key, 0, key.Length);
+			_cipher = new CipherRC5(key);
+			_entries = new Dictionary<uint, uint>();
+			_key = BitConverter.ToUInt32(key, 0);
+
+			var startPosition = (uint)Faces.STRING_INFO;
+			// DecryptDirectory
+			var directory = new byte[8];
+			Marshal.Copy(new IntPtr(_instance + startPosition), directory, 0, directory.Length);
+			directory = _cipher.Decrypt(directory);
+			var numberOfEntries = BitConverter.ToUInt32(directory, 0);
+
+			var entry = new byte[16];
+			for (uint i = 0; i < numberOfEntries; i++)
+			{
+				// DecryptEntry
+				uint pos = startPosition + 8 + i * 16;
+				Marshal.Copy(new IntPtr(_instance + pos), entry, 0, 16);
+				entry = _cipher.Decrypt(entry);
+				_entries.Add(BitConverter.ToUInt32(entry, 0), pos);
+			}
+		}
+
+		public string DecryptString(uint stringId)
+		{
+			uint pos;
+			if (_entries.TryGetValue(stringId, out pos))
+			{
+				var entry = new byte[16];
+				Marshal.Copy(new IntPtr(_instance + pos), entry, 0, 16);
+				entry = _cipher.Decrypt(entry);
+
+				var size = BitConverter.ToInt32(entry, 8);
+				var stringData = new byte[size];
+				Marshal.Copy(new IntPtr(_instance + BitConverter.ToUInt32(entry, 4)), stringData, 0, size);
+				for (var c = 0; c < size; c++)
+				{
+					stringData[c] = (byte)(stringData[c] ^ BitRotate.Left(_key, c) + c);
+				}
+				return Encoding.Unicode.GetString(stringData);
+			}
+
+			return null;
+		}
+
+		private readonly long _instance;
+		private readonly CipherRC5 _cipher;
+		private readonly Dictionary<uint, uint> _entries;
+		private readonly uint _key;
+	}
+}