/// <summary>
/// Encrypts the strings within the given assembly.
/// </summary>
/// <param name="definition">The assembly definition.</param>
private void EncryptStringsInAssembly(AssemblyDefinition definition)
{
//Add an encryption function
MethodReference decryptionMethod = null;
//Generate a new type for decryption
OutputHelper.WriteLine("Generating global decrypt method");
foreach (TypeDefinition td in definition.MainModule.GetAllTypes())
if (td.Name == "<Module>")
{
MethodDefinition md = new MethodDefinition("Decrypt", MethodAttributes.HideBySig | MethodAttributes.Static | MethodAttributes.CompilerControlled, definition.Import(typeof(string)));
//Generate the parameters
md.Parameters.Add(new ParameterDefinition("v", ParameterAttributes.None, definition.Import(typeof(string))));
md.Parameters.Add(new ParameterDefinition("s", ParameterAttributes.None, definition.Import(typeof(int))));
//Add it
td.Methods.Add(md);
//We now need to create a method body
md.Body = new MethodBody(md);
//Output the encryption method body
switch (method)
{
case StringEncryptionMethod.Xor:
GenerateXorDecryptionMethod(definition, md.Body);
break;
default:
throw new ArgumentOutOfRangeException();
}
//Finally get the reference
decryptionMethod = md.GetElementMethod();
}
//Loop through the modules
OutputHelper.WriteLine("Processing modules");
foreach (ModuleDefinition moduleDefinition in definition.Modules)
{
//Go through each type
foreach (TypeDefinition typeDefinition in moduleDefinition.GetAllTypes())
{
//Go through each method
foreach (MethodDefinition methodDefinition in typeDefinition.Methods)
{
if (methodDefinition.HasBody)
{
OutputHelper.WriteMethod(typeDefinition, methodDefinition);
ProcessInstructions(definition, methodDefinition.Body, decryptionMethod);
}
}
}
}
}
/// <summary>
/// Builds the decrypt method.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="assembly">The assembly.</param>
/// <returns></returns>
private static MethodDefinition BuildDecryptMethod(ICloakContext context, AssemblyDefinition assembly)
{
var byteArrayType = assembly.Import(typeof (byte[]));
#if USE_FRIENDLY_NAMING
MethodDefinition method = new MethodDefinition("DecryptData",
MethodAttributes.Private | MethodAttributes.HideBySig |
MethodAttributes.Static, byteArrayType);
#else
MethodDefinition method = new MethodDefinition(context.NameManager.GenerateName(NamingTable.Method),
MethodAttributes.Private | MethodAttributes.HideBySig |
MethodAttributes.Static, assembly.Import(typeof(byte[])));
#endif
method.Body.InitLocals = true;
method.Body.MaxStackSize = 5;
method.Parameters.Add(new ParameterDefinition(byteArrayType));
method.Parameters.Add(new ParameterDefinition(byteArrayType));
method.Parameters.Add(new ParameterDefinition(byteArrayType));
//Declare the locals - first four have quick reference
method.AddLocal(assembly, typeof(Rijndael));
method.AddLocal(assembly, typeof(ICryptoTransform));
method.AddLocal(assembly, typeof(MemoryStream));
method.AddLocal(assembly, typeof(CryptoStream));
var paddedPlain = method.AddLocal(assembly, typeof(byte[]));
var length = method.AddLocal(assembly, typeof(int));
var plain = method.AddLocal(assembly, typeof(byte[]));
var returnArray = method.AddLocal(assembly, typeof(byte[]));
var inferredBool = method.AddLocal(assembly, typeof(bool));
//Add the body
var il = method.Body.GetILProcessor();
//Inject anti reflector code
InjectAntiReflectorCode(il, il.Create(OpCodes.Nop));
//Start the body
var rijndaelCreate = typeof(Rijndael).GetMethod("Create", Type.EmptyTypes);
il.Append(il.Create(OpCodes.Call, assembly.Import(rijndaelCreate)));
il.Append(OpCodes.Stloc_0);
il.Append(OpCodes.Ldloc_0);
il.Append(OpCodes.Ldc_I4_1);
var symmetricAlgMode = typeof(SymmetricAlgorithm).GetProperty("Mode");
il.Append(il.Create(OpCodes.Callvirt, assembly.Import(symmetricAlgMode.GetSetMethod())));
il.Append(OpCodes.Nop);
il.Append(OpCodes.Ldloc_0);
il.Append(OpCodes.Ldarg_1);
il.Append(OpCodes.Ldarg_2);
var createDecryptor = typeof(SymmetricAlgorithm).GetMethod("CreateDecryptor",
new[] { typeof(byte[]), typeof(byte[]) });
il.Append(il.Create(OpCodes.Callvirt, assembly.Import(createDecryptor)));
il.Append(OpCodes.Stloc_1);
var startOfThirdTry = il.Create(OpCodes.Nop);
il.Append(startOfThirdTry);
il.Append(OpCodes.Ldarg_0);
//New memory stream
var memoryStreamCtor = typeof(MemoryStream).GetConstructor(new [] { typeof(byte[]) });
il.Append(il.Create(OpCodes.Newobj, assembly.Import(memoryStreamCtor)));
il.Append(OpCodes.Stloc_2);
var startOfSecondTry = il.Create(OpCodes.Nop);
il.Append(startOfSecondTry);
il.Append(OpCodes.Ldloc_2);
il.Append(OpCodes.Ldloc_1);
il.Append(OpCodes.Ldc_I4_0);
//New crypto stream
var cryptoStreamCtor =
typeof(CryptoStream).GetConstructor(new[]
{
typeof (Stream), typeof (ICryptoTransform),
typeof (CryptoStreamMode)
});
il.Append(il.Create(OpCodes.Newobj, assembly.Import(cryptoStreamCtor)));
il.Append(OpCodes.Stloc_3);
var startOfFirstTry = il.Create(OpCodes.Nop);
il.Append(startOfFirstTry);
il.Append(OpCodes.Ldarg_0);
il.Append(OpCodes.Ldlen);
il.Append(OpCodes.Conv_I4);
il.Append(il.Create(OpCodes.Newarr, assembly.Import(typeof(byte))));
il.Append(il.Create(OpCodes.Stloc_S, paddedPlain));
il.Append(OpCodes.Ldloc_3);
il.Append(il.Create(OpCodes.Ldloc_S, paddedPlain));
il.Append(OpCodes.Ldc_I4_0);
il.Append(il.Create(OpCodes.Ldloc_S, paddedPlain));
il.Append(OpCodes.Ldlen);
il.Append(OpCodes.Conv_I4);
//Get the read method and read into this byte array (full length)
var read = typeof(Stream).GetMethod("Read", new[] { typeof(byte[]), typeof(int), typeof(int) });
il.Append(il.Create(OpCodes.Callvirt, assembly.Import(read)));
il.Append(il.Create(OpCodes.Stloc_S, length));
il.Append(il.Create(OpCodes.Ldloc_S, length));
il.Append(il.Create(OpCodes.Newarr, assembly.Import(typeof(byte))));
il.Append(il.Create(OpCodes.Stloc_S, plain));
il.Append(il.Create(OpCodes.Ldloc_S, paddedPlain));
il.Append(OpCodes.Ldc_I4_0);
il.Append(il.Create(OpCodes.Ldloc_S, plain));
il.Append(OpCodes.Ldc_I4_0);
il.Append(il.Create(OpCodes.Ldloc_S, length));
//Array::Copy
var arrayCopy = typeof(Array).GetMethod("Copy",
new[]
{
typeof (Array), typeof (int), typeof (Array), typeof (int),
typeof (int)
});
il.Append(il.Create(OpCodes.Call, assembly.Import(arrayCopy)));
il.Append(OpCodes.Nop);//padding
il.Append(il.Create(OpCodes.Ldloc_S, plain));
il.Append(il.Create(OpCodes.Stloc_S, returnArray));
//Now it gets a bit confusing as we need to do a few jumps (OO and all...)
var endNop = il.Create(OpCodes.Nop);
il.Append(il.Create(OpCodes.Leave_S, endNop));
//First finally
var firstStartFinally = il.Create(OpCodes.Ldloc_3);
il.Append(firstStartFinally);
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, inferredBool));
il.Append(il.Create(OpCodes.Ldloc_S, inferredBool));
var firstEndFinally = il.Create(OpCodes.Endfinally);
il.Append(il.Create(OpCodes.Brtrue_S, firstEndFinally));
il.Append(OpCodes.Ldloc_3);
//Get the disposable virtual method
var dispose = assembly.Import(typeof(IDisposable).GetMethod("Dispose"));
il.Append(il.Create(OpCodes.Callvirt, dispose));
il.Append(OpCodes.Nop);
il.Append(firstEndFinally);
//Second finally
var secondStartFinally = il.Create(OpCodes.Ldloc_2);
il.Append(secondStartFinally);
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, inferredBool));
il.Append(il.Create(OpCodes.Ldloc_S, inferredBool));
var secondEndFinally = il.Create(OpCodes.Endfinally);
il.Append(il.Create(OpCodes.Brtrue_S, secondEndFinally));
il.Append(OpCodes.Ldloc_2);
il.Append(il.Create(OpCodes.Callvirt, dispose));
il.Append(OpCodes.Nop);
il.Append(secondEndFinally);
//Third finally
var thirdStartFinally = il.Create(OpCodes.Ldloc_1);
il.Append(thirdStartFinally);
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, inferredBool));
il.Append(il.Create(OpCodes.Ldloc_S, inferredBool));
var thirdEndFinally = il.Create(OpCodes.Endfinally);
il.Append(il.Create(OpCodes.Brtrue_S, thirdEndFinally));
il.Append(OpCodes.Ldloc_1);
il.Append(il.Create(OpCodes.Callvirt, dispose));
il.Append(OpCodes.Nop);
il.Append(thirdEndFinally);
//Clean up and return
il.Append(endNop);
il.Append(il.Create(OpCodes.Ldloc_S, returnArray));
il.Append(OpCodes.Ret);
//Add the try/finally handlers
var handler1 = new ExceptionHandler(ExceptionHandlerType.Finally);
handler1.TryStart = startOfFirstTry;
handler1.TryEnd = firstStartFinally;
handler1.HandlerStart = firstStartFinally;
handler1.HandlerEnd = secondStartFinally;
method.Body.ExceptionHandlers.Add(handler1);
var handler2 = new ExceptionHandler(ExceptionHandlerType.Finally);
handler2.TryStart = startOfSecondTry;
handler2.TryEnd = secondStartFinally;
handler2.HandlerStart = secondStartFinally;
handler2.HandlerEnd = thirdStartFinally;
method.Body.ExceptionHandlers.Add(handler2);
var handler3 = new ExceptionHandler(ExceptionHandlerType.Finally);
handler3.TryStart = startOfThirdTry;
handler3.TryEnd = thirdStartFinally;
handler3.HandlerStart = thirdStartFinally;
handler3.HandlerEnd = endNop;
method.Body.ExceptionHandlers.Add(handler3);
return method;
}
/// <summary>
/// Builds the hash method.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="assembly">The assembly.</param>
/// <returns></returns>
private static MethodDefinition BuildHashMethod(ICloakContext context, AssemblyDefinition assembly)
{
#if USE_FRIENDLY_NAMING
MethodDefinition method = new MethodDefinition("Hash",
MethodAttributes.Private | MethodAttributes.HideBySig |
MethodAttributes.Static, assembly.Import(typeof(string)));
#else
MethodDefinition method = new MethodDefinition(context.NameManager.GenerateName(NamingTable.Method),
MethodAttributes.Private | MethodAttributes.HideBySig |
MethodAttributes.Static, assembly.Import(typeof(string)));
#endif
method.Parameters.Add(new ParameterDefinition(assembly.Import(typeof(byte[]))));
method.Body.InitLocals = true;
method.Body.MaxStackSize = 2;
method.AddLocal(assembly, typeof(SHA256));
method.AddLocal(assembly, typeof(string));
//Easy method to output
var il = method.Body.GetILProcessor();
//Inject some anti reflector stuff
InjectAntiReflectorCode(il, il.Create(OpCodes.Nop));
//Create the SHA256 object
var sha256Create = typeof(SHA256).GetMethod("Create", Type.EmptyTypes);
il.Append(il.Create(OpCodes.Call, assembly.Import(sha256Create)));
il.Append(OpCodes.Stloc_0);
il.Append(OpCodes.Ldloc_0);
il.Append(OpCodes.Ldarg_0);
//Call the compute method
var compute = typeof(HashAlgorithm).GetMethod("ComputeHash", new[] { typeof(byte[]) });
il.Append(il.Create(OpCodes.Callvirt, assembly.Import(compute)));
//Finally, convert to base 64
var toBase64 = typeof(Convert).GetMethod("ToBase64String", new[] { typeof(byte[]) });
il.Append(il.Create(OpCodes.Call, assembly.Import(toBase64)));
il.Append(OpCodes.Stloc_1);
var retVar = il.Create(OpCodes.Ldloc_1);
il.Append(il.Create(OpCodes.Br_S, retVar));
il.Append(retVar);
il.Append(OpCodes.Ret);
return method;
}
/// <summary>
/// Builds the load type method.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="assembly">The assembly.</param>
/// <param name="loadAssembly">The load assembly.</param>
/// <returns></returns>
private static MethodDefinition BuildLoadTypeMethod(ICloakContext context, AssemblyDefinition assembly, MethodReference loadAssembly)
{
#if USE_FRIENDLY_NAMING
MethodDefinition method = new MethodDefinition("LoadType",
MethodAttributes.Private | MethodAttributes.HideBySig, assembly.Import(typeof(Type)));
#else
MethodDefinition method = new MethodDefinition(context.NameManager.GenerateName(NamingTable.Method),
MethodAttributes.Private | MethodAttributes.HideBySig, assembly.Import(typeof(Type)));
#endif
//Declare the resource parameter
method.Parameters.Add(new ParameterDefinition(assembly.Import(typeof(string))));
method.Parameters.Add(new ParameterDefinition(assembly.Import(typeof(string))));
method.Body.InitLocals = true;
method.Body.MaxStackSize = 2;
method.AddLocal(assembly, typeof(Assembly)); //Assembly
method.AddLocal(assembly, typeof(Type)); //Temp variable for return type
method.AddLocal(assembly, typeof(bool)); //Temp variable for comparison
//Start with injection
var il = method.Body.GetILProcessor();
InjectAntiReflectorCode(il, il.Create(OpCodes.Nop));
//Start the code
il.Append(OpCodes.Ldarg_0);
il.Append(OpCodes.Ldarg_1);
il.Append(il.Create(OpCodes.Call, loadAssembly));
il.Append(OpCodes.Stloc_0);
il.Append(OpCodes.Ldloc_0);
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
il.Append(OpCodes.Stloc_2);
il.Append(OpCodes.Ldloc_2);
//Get type
var getType = il.Create(OpCodes.Ldloc_0);
il.Append(il.Create(OpCodes.Brtrue_S, getType));
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Stloc_1);
//Prepare to return the temp type
var returnType = il.Create(OpCodes.Ldloc_1);
//Jump to it
il.Append(il.Create(OpCodes.Br_S, returnType));
il.Append(getType);
il.Append(OpCodes.Ldarg_2);
var getTypeMethod = typeof (Assembly).GetMethod("GetType", new[] {typeof (string)});
il.Append(il.Create(OpCodes.Callvirt, assembly.Import(getTypeMethod)));
il.Append(OpCodes.Stloc_1);
il.Append(il.Create(OpCodes.Br_S, returnType));
il.Append(returnType);
il.Append(OpCodes.Ret);
return method;
}
/// <summary>
/// Builds the load assembly method.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="assembly">The assembly.</param>
/// <param name="loadedAssemblies">The loaded assemblies.</param>
/// <param name="executingAssembly">The executing assembly.</param>
/// <param name="decryptData">The decrypt data.</param>
/// <param name="hashData">The hash data.</param>
/// <param name="passwordKey">The password key.</param>
/// <param name="salt">The salt.</param>
/// <returns></returns>
private static MethodDefinition BuildLoadAssemblyMethod(ICloakContext context, AssemblyDefinition assembly, FieldReference loadedAssemblies, FieldReference executingAssembly, MethodReference decryptData, MethodReference hashData, string passwordKey, Guid salt)
{
#if USE_FRIENDLY_NAMING
MethodDefinition method = new MethodDefinition("LoadAssembly",
MethodAttributes.Private | MethodAttributes.HideBySig, assembly.Import(typeof(Assembly)));
#else
MethodDefinition method = new MethodDefinition(context.NameManager.GenerateName(NamingTable.Method),
MethodAttributes.Private | MethodAttributes.HideBySig, assembly.Import(typeof(Assembly)));
#endif
//Declare the resource parameter
method.Parameters.Add(new ParameterDefinition(assembly.Import(typeof(string))));
method.Body.InitLocals = true;
method.Body.MaxStackSize = 4;
method.AddLocal(assembly, typeof(string)); //Hash
method.AddLocal(assembly, typeof(Stream)); //Stream for loading
method.AddLocal(assembly, typeof(byte[])); //Hash data
method.AddLocal(assembly, typeof(byte[])); //Data
var password = method.AddLocal(assembly, typeof(Rfc2898DeriveBytes)); //Password
var keyBytes = method.AddLocal(assembly, typeof(byte[])); //Key bytes
var initVector = method.AddLocal(assembly, typeof(byte[])); //Init vector
var rawAssembly = method.AddLocal(assembly, typeof(byte[])); //Assembly raw bytes
var actualAssembly = method.AddLocal(assembly, typeof(Assembly)); //Actual Assembly
var tempAssembly = method.AddLocal(assembly, typeof(Assembly)); //Temp Assembly
var tempBool = method.AddLocal(assembly, typeof(bool)); //Temp bool
//Build the body
var il = method.Body.GetILProcessor();
InjectAntiReflectorCode(il, il.Create(OpCodes.Nop));
#if VERBOSE_OUTPUT
DebugLine(assembly, il, "Loading ", il.Create(OpCodes.Ldarg_1));
#endif
//Check the cache first
il.Append(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Ldfld, loadedAssemblies));
il.Append(OpCodes.Ldarg_1);
var containsKey = typeof (Dictionary<string, Assembly>).GetMethod("ContainsKey");
il.Append(il.Create(OpCodes.Callvirt, assembly.Import(containsKey)));
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
//Jump if we don't have it, other wise return it
var startFindType = il.Create(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Brtrue_S, startFindType));
//Otherwise return the cached assembly
il.Append(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Ldfld, loadedAssemblies));
il.Append(OpCodes.Ldarg_1);
//We are retrieving the name item
var getItem = typeof (Dictionary<string, Assembly>).GetProperty("Item");
il.Append(il.Create(OpCodes.Callvirt, assembly.Import(getItem.GetGetMethod())));
//Store the variable in our return arg
il.Append(il.Create(OpCodes.Stloc_S, tempAssembly));
//Branch to our return routine
var returnSequence = il.Create(OpCodes.Nop);
il.Append(il.Create(OpCodes.Br, returnSequence));
//Back to finding our type
//Let's check the hash first
il.Append(startFindType);
il.Append(il.Create(OpCodes.Ldfld, executingAssembly));
il.Append(OpCodes.Ldarg_1);
il.Append(il.Create(OpCodes.Ldstr, ".v0"));
//Concat the arg1 (resourceName) and v0
var concat = assembly.Import(typeof (String).GetMethod("Concat", new[] {typeof (string), typeof (string)}));
il.Append(il.Create(OpCodes.Call, concat));
//Now get this from the manifest
var getManifest = assembly.Import(typeof (Assembly).GetMethod("GetManifestResourceStream", new[] {typeof (string)}));
il.Append(il.Create(OpCodes.Callvirt, getManifest));
//Store the result in our temp local
il.Append(OpCodes.Stloc_1);
var try1Start = il.Create(OpCodes.Nop);
il.Append(try1Start);
//Make sure it's not null
il.Append(OpCodes.Ldloc_1);
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
//Return null if it is
var startDeclareArray = il.Create(OpCodes.Ldloc_1);
il.Append(il.Create(OpCodes.Brtrue_S, startDeclareArray));
//Load null into our return variable
il.Append(OpCodes.Ldnull);
il.Append(il.Create(OpCodes.Stloc_S, tempAssembly));
//Jump to the return routine
il.Append(il.Create(OpCodes.Leave, returnSequence)); //Leave as in try
//Carry on and declare a buffer
il.Append(startDeclareArray);
var getLength = assembly.Import(typeof (Stream).GetProperty("Length").GetGetMethod());
il.Append(il.Create(OpCodes.Callvirt, getLength));
il.Append(OpCodes.Conv_Ovf_I);
il.Append(il.Create(OpCodes.Newarr, assembly.Import(typeof(byte))));
//Now read it in
il.Append(OpCodes.Stloc_2);
il.Append(OpCodes.Ldloc_1);
il.Append(OpCodes.Ldloc_2);
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ldloc_2);
il.Append(OpCodes.Ldlen);
il.Append(OpCodes.Conv_I4);
var readMethod =
assembly.Import(typeof (Stream).GetMethod("Read", new[] {typeof (byte[]), typeof (int), typeof (int)}));
il.Append(il.Create(OpCodes.Callvirt, readMethod));
//Get the result
il.Append(OpCodes.Pop);
il.Append(OpCodes.Ldloc_2);
//Convert it to base 64
var base64String = assembly.Import(typeof (Convert).GetMethod("ToBase64String", new[] {typeof (byte[])}));
il.Append(il.Create(OpCodes.Call, base64String));
//Get the result
il.Append(OpCodes.Stloc_0);
il.Append(OpCodes.Nop);
//Read the assembly
var startReadAssembly = il.Create(OpCodes.Nop);
il.Append(il.Create(OpCodes.Leave_S, startReadAssembly));
//Dispose of appropriately
var try1End = il.Create(OpCodes.Ldloc_1);
il.Append(try1End);
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
var endFinally1 = il.Create(OpCodes.Endfinally);
il.Append(il.Create(OpCodes.Brtrue_S, endFinally1));
il.Append(OpCodes.Ldloc_1);
//Dispose
var disposeMethod = assembly.Import(typeof (IDisposable).GetMethod("Dispose"));
il.Append(il.Create(OpCodes.Callvirt, disposeMethod));
il.Append(OpCodes.Nop);
il.Append(endFinally1);
//Start the read assembly
il.Append(startReadAssembly);
il.Append(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Ldfld, executingAssembly));
il.Append(OpCodes.Ldarg_1);
il.Append(il.Create(OpCodes.Callvirt, getManifest));
il.Append(OpCodes.Stloc_1);
var try2Start = il.Create(OpCodes.Nop);
il.Append(try2Start);
il.Append(OpCodes.Ldloc_1);
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
//Check if it is null
var startReadAssembly2 = il.Create(OpCodes.Ldloc_1);
il.Append(il.Create(OpCodes.Brtrue_S, startReadAssembly2));
il.Append(OpCodes.Ldnull);
il.Append(il.Create(OpCodes.Stloc_S, tempAssembly));
il.Append(il.Create(OpCodes.Leave, returnSequence)); //Leave as in try
//Read the assembly
il.Append(startReadAssembly2);
il.Append(il.Create(OpCodes.Callvirt, getLength));
il.Append(OpCodes.Conv_Ovf_I);
il.Append(il.Create(OpCodes.Newarr, assembly.Import(typeof(byte))));
//Now read it in
il.Append(OpCodes.Stloc_3);
il.Append(OpCodes.Ldloc_1);
il.Append(OpCodes.Ldloc_3);
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ldloc_3);
il.Append(OpCodes.Ldlen);
il.Append(OpCodes.Conv_I4);
il.Append(il.Create(OpCodes.Callvirt, readMethod));
//Get the result and clean up
il.Append(OpCodes.Pop);
il.Append(OpCodes.Nop);
var startCheck = il.Create(OpCodes.Nop);
il.Append(il.Create(OpCodes.Leave_S, startCheck));
var try2End = il.Create(OpCodes.Ldloc_1);
il.Append(try2End);
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
var endFinally2 = il.Create(OpCodes.Endfinally);
il.Append(il.Create(OpCodes.Brtrue_S, endFinally2));
il.Append(OpCodes.Ldloc_1);
//Dispose
il.Append(il.Create(OpCodes.Callvirt, disposeMethod));
il.Append(OpCodes.Nop);
il.Append(endFinally2);
il.Append(startCheck);
//We need to load in both the salt, and the password key
il.Append(il.Create(OpCodes.Ldstr, passwordKey));
il.Append(il.Create(OpCodes.Ldstr, Convert.ToBase64String(salt.ToByteArray())));
var fromBase64String = assembly.Import(typeof (Convert).GetMethod("FromBase64String"));
il.Append(il.Create(OpCodes.Call, fromBase64String));
//Set these into an rfc 2898 object
il.Append(OpCodes.Ldc_I4_2);
//RFC2898 ctor
var rfcCtor =
assembly.Import(
typeof (Rfc2898DeriveBytes).GetConstructor(new[] {typeof (string), typeof (byte[]), typeof (int)}));
il.Append(il.Create(OpCodes.Newobj, rfcCtor));
//Store this object
il.Append(il.Create(OpCodes.Stloc_S, password));
//Get the key bytes
il.Append(il.Create(OpCodes.Ldloc_S, password));
il.Append(il.Create(OpCodes.Ldc_I4_S, (sbyte)0x20));
var getBytes = assembly.Import(typeof (DeriveBytes).GetMethod("GetBytes", new[] {typeof (int)}));
il.Append(il.Create(OpCodes.Callvirt, getBytes));
il.Append(il.Create(OpCodes.Stloc_S, keyBytes));
//Init vector
il.Append(il.Create(OpCodes.Ldloc_S, password));
il.Append(il.Create(OpCodes.Ldc_I4_S, (sbyte)0x10));
il.Append(il.Create(OpCodes.Callvirt, getBytes));
il.Append(il.Create(OpCodes.Stloc_S, initVector));
//Now decrypt the data
il.Append(OpCodes.Ldloc_3);
il.Append(il.Create(OpCodes.Ldloc_S, keyBytes));
il.Append(il.Create(OpCodes.Ldloc_S, initVector));
il.Append(il.Create(OpCodes.Call, decryptData));
il.Append(il.Create(OpCodes.Stloc_S, rawAssembly));
//Get the "real" hash
il.Append(OpCodes.Ldloc_0);
il.Append(il.Create(OpCodes.Ldloc_S, rawAssembly));
il.Append(il.Create(OpCodes.Call, hashData));
//Run the inequality operator
var inequality =
assembly.Import(typeof (String).GetMethod("op_Inequality", new[] {typeof (string), typeof (string)}));
il.Append(il.Create(OpCodes.Call, inequality));
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
//Return null if it's not a match
var startLoadAssembly = il.Create(OpCodes.Ldloc_S, rawAssembly);
il.Append(il.Create(OpCodes.Brtrue_S, startLoadAssembly));
il.Append(OpCodes.Ldnull);
il.Append(il.Create(OpCodes.Stloc_S, tempAssembly));
il.Append(il.Create(OpCodes.Br_S, returnSequence));
il.Append(startLoadAssembly);
var assemblyLoad = assembly.Import(typeof (Assembly).GetMethod("Load", new[] {typeof (byte[])}));
il.Append(il.Create(OpCodes.Call, assemblyLoad));
il.Append(il.Create(OpCodes.Stloc_S, actualAssembly));
//Check if it is null
il.Append(il.Create(OpCodes.Ldloc_S, actualAssembly));
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
var startCache = il.Create(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Brtrue_S, startCache));
il.Append(OpCodes.Ldnull);
il.Append(il.Create(OpCodes.Stloc_S, tempAssembly));
il.Append(il.Create(OpCodes.Br_S, returnSequence));
//Cache before returning
il.Append(startCache);
il.Append(il.Create(OpCodes.Ldfld, loadedAssemblies));
il.Append(OpCodes.Ldarg_1);
il.Append(il.Create(OpCodes.Ldloc_S, actualAssembly));
var addMethod = assembly.Import(typeof (Dictionary<string, Assembly>).GetMethod("Add"));
il.Append(il.Create(OpCodes.Callvirt, addMethod));
il.Append(OpCodes.Nop);
//Move it to our temp return var
il.Append(il.Create(OpCodes.Ldloc_S, actualAssembly));
il.Append(il.Create(OpCodes.Stloc_S, tempAssembly));
il.Append(il.Create(OpCodes.Br_S, returnSequence)); //Need this?
//Return sequence
il.Append(returnSequence);
#if VERBOSE_OUTPUT
DebugLine(assembly, il, "Successfully loaded");
#endif
/*
il.Append(il.Create(OpCodes.Ldstr, "Load assembly "));
il.Append(OpCodes.Ldarg_1);
il.Append(il.Create(OpCodes.Call, concat));
il.Append(OpCodes.Stloc_0);
il.Append(OpCodes.Ldloc_0);
var wl = assembly.Import(typeof(Console).GetMethod("WriteLine", new[] { typeof(string) }));
il.Append(il.Create(OpCodes.Call, wl));
*/
il.Append(il.Create(OpCodes.Ldloc_S, tempAssembly));
il.Append(OpCodes.Ret);
//Last but not least, add our try/finally's (i.e. usings)
ExceptionHandler finally1 = new ExceptionHandler(ExceptionHandlerType.Finally);
finally1.TryStart = try1Start;
finally1.TryEnd = try1End;
finally1.HandlerStart = try1End;
finally1.HandlerEnd = startReadAssembly;
method.Body.ExceptionHandlers.Add(finally1);
ExceptionHandler finally2 = new ExceptionHandler(ExceptionHandlerType.Finally);
finally2.TryStart = try2Start;
finally2.TryEnd = try2End;
finally2.HandlerStart = try2End;
finally2.HandlerEnd = startCheck;
method.Body.ExceptionHandlers.Add(finally2);
return method;
}
/// <summary>
/// Builds the load assemblies method.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="assembly">The assembly.</param>
/// <param name="executingAssembly">The executing assembly.</param>
/// <param name="loadAssembly">The load assembly.</param>
/// <returns></returns>
private static MethodDefinition BuildLoadAssembliesMethod(ICloakContext context, AssemblyDefinition assembly, FieldReference executingAssembly, MethodReference loadAssembly)
{
#if USE_FRIENDLY_NAMING
MethodDefinition method = new MethodDefinition("LoadAssemblies",
MethodAttributes.Private | MethodAttributes.HideBySig, assembly.Import(typeof(void)));
#else
MethodDefinition method = new MethodDefinition(context.NameManager.GenerateName(NamingTable.Method),
MethodAttributes.Private | MethodAttributes.HideBySig, assembly.Import(typeof(void)));
#endif
method.Body.InitLocals = true;
method.Body.MaxStackSize = 2;
method.AddLocal(assembly, typeof (string)); //Resource name
method.AddLocal(assembly, typeof (string[])); //Foreach temp
method.AddLocal(assembly, typeof (int)); //Loop counter
method.AddLocal(assembly, typeof(bool));
//Build the body
var il = method.Body.GetILProcessor();
InjectAntiReflectorCode(il, il.Create(OpCodes.Nop));
il.Append(OpCodes.Nop);
il.Append(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Ldfld, executingAssembly));
//Get the resources - foreach get's converted to a standard loop
var resourcesMethod = typeof (Assembly).GetMethod("GetManifestResourceNames");
il.Append(il.Create(OpCodes.Callvirt, assembly.Import(resourcesMethod)));
il.Append(OpCodes.Stloc_1);
//Initialise the loop counter
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Stloc_2);
//For loop comparison (well create somewhere to jump to)
var loopComparisonStart = il.Create(OpCodes.Ldloc_2);
//Check the comparison now
il.Append(il.Create(OpCodes.Br_S, loopComparisonStart));
var startCode = il.Create(OpCodes.Ldloc_1);
il.Append(startCode);
il.Append(OpCodes.Ldloc_2);
il.Append(OpCodes.Ldelem_Ref);
il.Append(OpCodes.Stloc_0);
il.Append(OpCodes.Nop);
il.Append(OpCodes.Ldloc_0);
//Make sure it doesn't end with .v0 or .e
il.Append(il.Create(OpCodes.Ldstr, ".v0"));
var endsWith = assembly.Import(typeof (String).GetMethod("EndsWith", new[] {typeof (string)}));
il.Append(il.Create(OpCodes.Callvirt, endsWith));
//Jump out as need be
var load0 = il.Create(OpCodes.Ldc_I4_0);
il.Append(il.Create(OpCodes.Brtrue_S, load0));
il.Append(OpCodes.Ldloc_0);
//Check the .e
il.Append(il.Create(OpCodes.Ldstr, ".e"));
il.Append(il.Create(OpCodes.Callvirt, endsWith));
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
var storeTempBool = il.Create(OpCodes.Stloc_3);
il.Append(il.Create(OpCodes.Br_S, storeTempBool));
il.Append(load0);
il.Append(storeTempBool);
il.Append(OpCodes.Ldloc_3);
var loadArg0 = il.Create(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Brtrue_S, loadArg0));
var loadLoopCounter = il.Create(OpCodes.Ldloc_2);
il.Append(il.Create(OpCodes.Br_S, loadLoopCounter));
il.Append(loadArg0);
il.Append(OpCodes.Ldloc_0);
//Finally load the assembly
il.Append(il.Create(OpCodes.Call, loadAssembly));
il.Append(OpCodes.Pop);
il.Append(OpCodes.Nop);
//Loop counter
il.Append(loadLoopCounter);
il.Append(OpCodes.Ldc_I4_1);
il.Append(OpCodes.Add);
il.Append(OpCodes.Stloc_2);
//Loop comparison
il.Append(loopComparisonStart);
il.Append(OpCodes.Ldloc_1);
il.Append(OpCodes.Ldlen);
il.Append(OpCodes.Conv_I4);
il.Append(OpCodes.Clt);
//Store the result
il.Append(OpCodes.Stloc_3);
//Load it and compare
il.Append(OpCodes.Ldloc_3);
il.Append(il.Create(OpCodes.Brtrue_S, startCode));
il.Append(OpCodes.Ret);
return method;
}
/// <summary>
/// Builds the main method.
/// </summary>
/// <param name="assembly">The assembly.</param>
/// <param name="context">The context.</param>
/// <param name="programType">Type of the program.</param>
/// <param name="getExecutingAssembly">The get executing assembly.</param>
/// <param name="currentDomain">The current domain.</param>
/// <param name="eventHandler">The event handler.</param>
/// <param name="assemblyResolve">The assembly resolve.</param>
/// <param name="resolveMethod">The resolve method.</param>
/// <param name="startMethod">The start method.</param>
/// <returns></returns>
private static MethodDefinition BuildMainMethod(AssemblyDefinition assembly, ICloakContext context, TypeDefinition programType, MethodReference getExecutingAssembly, MethodReference currentDomain, MethodReference eventHandler, MethodReference assemblyResolve, MethodReference resolveMethod, MethodReference startMethod)
{
#if USE_FRIENDLY_NAMING
MethodDefinition entryPoint =
new MethodDefinition("Main",
MethodAttributes.Private | MethodAttributes.Static |
MethodAttributes.HideBySig, assembly.Import(typeof(void)));
#else
MethodDefinition entryPoint =
new MethodDefinition(context.NameManager.GenerateName(NamingTable.Method),
MethodAttributes.Private | MethodAttributes.Static |
MethodAttributes.HideBySig, assembly.Import(typeof(void)));
#endif
entryPoint.Body.InitLocals = true;
entryPoint.Body.MaxStackSize = 4;
#if USE_APPDOMAIN
//Initialise some locals
entryPoint.AddLocal(assembly, typeof(AppDomain));
entryPoint.AddLocal(assembly, typeof(Assembly));
#endif
VariableDefinition result = new VariableDefinition(programType);
entryPoint.Body.Variables.Add(result);
//Add the method
assembly.EntryPoint = entryPoint;
//Declare the il to build the code
ILProcessor il = entryPoint.Body.GetILProcessor();
//First of all add the anti reflector code
InjectAntiReflectorCode(il, il.Create(OpCodes.Nop));
//Now output the code - essentially:
/*
AppDomain domain = AppDomain.CreateDomain("App");
Assembly executingAssembly = Assembly.GetExecutingAssembly();
ProgramRunner runner = (ProgramRunner)domain.CreateInstanceAndUnwrap(executingAssembly.FullName, "TestBootstrapper.ProgramRunner");
AppDomain.CurrentDomain.AssemblyResolve += runner.ResolveAssembly;
runner.Start();
*/
#if USE_APPDOMAIN
#if USE_FRIENDLY_NAMING
il.Append(il.Create(OpCodes.Ldstr, "AppDomainName"));
#else
il.Append(il.Create(OpCodes.Ldstr, context.NameManager.GenerateName(NamingTable.Type)));
#endif
//Get the AppDomain::Create(string) method
var appDomainCreate = assembly.Import(typeof(AppDomain).GetMethod("CreateDomain", new[] { typeof(string) }));
il.Append(il.Create(OpCodes.Call, appDomainCreate));
il.Append(OpCodes.Stloc_0);
//Get the Assembly::GetExecutingAssembly() method
il.Append(il.Create(OpCodes.Call, getExecutingAssembly));
il.Append(OpCodes.Stloc_1);
il.Append(OpCodes.Ldloc_0);
il.Append(OpCodes.Ldloc_1);
//Assembly::get_FullName()
var getFullName = typeof(Assembly).GetProperty("FullName");
il.Append(il.Create(OpCodes.Callvirt, assembly.Import(getFullName.GetGetMethod())));
il.Append(il.Create(OpCodes.Ldstr,
String.Format("{0}.{1}", programType.Namespace, programType.Name)));
//AppDomain::CreateInstanceAndUnwrap(string, string)
var createInstanceAndUnwrap = typeof(AppDomain).GetMethod("CreateInstanceAndUnwrap",
new[]
{
typeof (string), typeof (string)
});
il.Append(il.Create(OpCodes.Callvirt, assembly.Import(createInstanceAndUnwrap)));
il.Append(il.Create(OpCodes.Castclass, programType));
il.Append(OpCodes.Stloc_2);
//AppDomain::get_CurrentDomain
il.Append(il.Create(OpCodes.Call, currentDomain));
il.Append(OpCodes.Ldloc_2);
//Get the function
il.Append(il.Create(OpCodes.Ldftn, resolveMethod));
il.Append(il.Create(OpCodes.Newobj, eventHandler));
il.Append(il.Create(OpCodes.Callvirt, assemblyResolve));
il.Append(OpCodes.Nop);
il.Append(OpCodes.Ldloc_2);
#else
il.Append(il.Create(OpCodes.Newobj, programType.Constructors[0]));
il.Append(OpCodes.Stloc_0);
il.Append(OpCodes.Ldloc_0);
#endif
//Start the program
il.Append(il.Create(OpCodes.Callvirt, startMethod));
il.Append(OpCodes.Nop);
il.Append(OpCodes.Ret);
return entryPoint;
}
/// <summary>
/// Builds the program constructor.
/// </summary>
/// <param name="assembly">The assembly.</param>
/// <param name="programType">Type of the program.</param>
/// <param name="assemblyLock">The assembly lock.</param>
/// <param name="executingAssembly">The executing assembly.</param>
/// <param name="loadedAssemblies">The loaded assemblies.</param>
/// <param name="currentDomain">The current domain.</param>
/// <param name="eventHandler">The event handler.</param>
/// <param name="assemblyResolve">The assembly resolve.</param>
/// <param name="getExecutingAssembly">The get executing assembly.</param>
/// <param name="resolveMethod">The resolve method.</param>
private static void BuildProgramConstructor(AssemblyDefinition assembly, TypeDefinition programType, FieldReference assemblyLock, FieldReference executingAssembly, FieldReference loadedAssemblies, MethodReference currentDomain, MethodReference eventHandler, MethodReference assemblyResolve, MethodReference getExecutingAssembly, MethodReference resolveMethod)
{
var body = assembly.CreateDefaultConstructor(programType);
body.MaxStackSize = 4;
body.InitLocals = true;
body.Variables.Add(new VariableDefinition(assembly.Import(typeof(AppDomain))));
var il = body.GetILProcessor();
//Inject anti reflector code
InjectAntiReflectorCode(il, il.Create(OpCodes.Ldarg_0));
//define the assembly lock
var objConstructor = assembly.Import(typeof(object).GetConstructor(Type.EmptyTypes));
il.Append(il.Create(OpCodes.Newobj, objConstructor));
il.Append(il.Create(OpCodes.Stfld, assemblyLock));
il.Append(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Call, objConstructor));
il.Append(OpCodes.Nop);
il.Append(OpCodes.Nop);
il.Append(OpCodes.Ldarg_0);
var cacheConstructor = assembly.Import(typeof(Dictionary<string, Assembly>).GetConstructor(Type.EmptyTypes));
il.Append(il.Create(OpCodes.Newobj, cacheConstructor));
il.Append(il.Create(OpCodes.Stfld, loadedAssemblies));
il.Append(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Call, getExecutingAssembly));
il.Append(il.Create(OpCodes.Stfld, executingAssembly));
il.Append(il.Create(OpCodes.Call, currentDomain));
il.Append(OpCodes.Stloc_0);
il.Append(OpCodes.Ldloc_0);
il.Append(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Ldftn, resolveMethod));
il.Append(il.Create(OpCodes.Newobj, eventHandler));
il.Append(il.Create(OpCodes.Callvirt, assemblyResolve));
il.Append(OpCodes.Nop);
il.Append(OpCodes.Nop);
il.Append(OpCodes.Ret);
}
/// <summary>
/// Builds the main entry point to the bootstrapper.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="assembly">The assembly.</param>
/// <param name="passwordKey">The password key.</param>
/// <param name="salt">The salt.</param>
private static void BuildBootstrapper(ICloakContext context, AssemblyDefinition assembly, string passwordKey, Guid salt)
{
//See http://blog.paul-mason.co.nz/2010/02/tamper-proofing-implementation-part-2.html
//First create the actual program runner
#if USE_FRIENDLY_NAMING
TypeDefinition programType = new TypeDefinition("ProgramRunner",
"NCloak.Bootstrapper.Internal",
TypeAttributes.NotPublic | TypeAttributes.Class |
TypeAttributes.AutoClass | TypeAttributes.AnsiClass |
TypeAttributes.Serializable | TypeAttributes.BeforeFieldInit,
assembly.Import(typeof(object)));
#else
TypeDefinition programType = new TypeDefinition(context.NameManager.GenerateName(NamingTable.Type),
context.NameManager.GenerateName(NamingTable.Type),
TypeAttributes.NotPublic | TypeAttributes.Class |
TypeAttributes.AutoClass | TypeAttributes.AnsiClass |
TypeAttributes.Serializable | TypeAttributes.BeforeFieldInit,
assembly.Import(typeof(object)));
#endif
assembly.MainModule.Types.Add(programType);
//Add the class level fields
#if USE_FRIENDLY_NAMING
string assembliesLoadedVariableName = "assembliesLoaded";
string assemblyLockVariableName = "assemblyLock";
string executingAssemblyVariableName = "executingAssembly";
string loadedAssembliesVariableName = "loadedAssemblies";
#else
string assembliesLoadedVariableName = context.NameManager.GenerateName(NamingTable.Field);
string assemblyLockVariableName = context.NameManager.GenerateName(NamingTable.Field);
string executingAssemblyVariableName = context.NameManager.GenerateName(NamingTable.Field);
string loadedAssembliesVariableName = context.NameManager.GenerateName(NamingTable.Field);
#endif
var assembliesLoaded = new FieldDefinition(assembliesLoadedVariableName, FieldAttributes.Private, assembly.Import(typeof(bool)));
var assemblyLock = new FieldDefinition(assemblyLockVariableName, FieldAttributes.Private | FieldAttributes.InitOnly, assembly.Import(typeof(object)));
var executingAssembly = new FieldDefinition(executingAssemblyVariableName, FieldAttributes.Private | FieldAttributes.InitOnly, assembly.Import(typeof(Assembly)));
var loadedAssemblies = new FieldDefinition(loadedAssembliesVariableName,FieldAttributes.Private | FieldAttributes.InitOnly, assembly.Import(typeof(Dictionary<string, Assembly>)));
programType.Fields.Add(assembliesLoaded);
programType.Fields.Add(assemblyLock);
programType.Fields.Add(executingAssembly);
programType.Fields.Add(loadedAssemblies);
//Get some method references we share
MethodReference currentDomain = assembly.Import(typeof(AppDomain).GetProperty("CurrentDomain").GetGetMethod());
MethodReference eventHandler = assembly.Import(typeof(ResolveEventHandler).GetConstructor(new[] { typeof(object), typeof(IntPtr) }));
MethodReference assemblyResolve = assembly.Import(typeof(AppDomain).GetEvent("AssemblyResolve").GetAddMethod());
MethodReference getExecutingAssembly = assembly.Import(typeof(Assembly).GetMethod("GetExecutingAssembly"));
//Define decrypt data method
var decryptMethod = BuildDecryptMethod(context, assembly);
programType.Methods.Add(decryptMethod);
//Define hash data method
var hashMethod = BuildHashMethod(context, assembly);
programType.Methods.Add(hashMethod);
//Define load assembly
var loadAssemblyMethod = BuildLoadAssemblyMethod(context, assembly, loadedAssemblies, executingAssembly, decryptMethod, hashMethod, passwordKey, salt);
programType.Methods.Add(loadAssemblyMethod);
//Define load type method
var loadTypeMethod = BuildLoadTypeMethod(context, assembly, loadAssemblyMethod);
programType.Methods.Add(loadTypeMethod);
//Define load assemblies method
var loadAssembliesMethod = BuildLoadAssembliesMethod(context, assembly, executingAssembly, loadAssemblyMethod);
programType.Methods.Add(loadAssembliesMethod);
//Define resolve method
var resolveMethod = BuildResolveMethod(context, assembly, assemblyLock, assembliesLoaded, loadAssembliesMethod);
programType.Methods.Add(resolveMethod);
//Define start method
var startMethod = BuildStartMethod(context, assembly, executingAssembly, assembliesLoaded, loadTypeMethod, loadAssembliesMethod);
programType.Methods.Add(startMethod);
//Now define a constructor
BuildProgramConstructor(assembly, programType, assemblyLock, executingAssembly, loadedAssemblies, currentDomain, eventHandler, assemblyResolve, getExecutingAssembly, resolveMethod);
//Now create a type to hold the entry point
#if USE_FRIENDLY_NAMING
TypeDefinition entryType = new TypeDefinition("Program",
"NCloak.Bootstrapper",
TypeAttributes.NotPublic | TypeAttributes.Class |
TypeAttributes.AutoClass | TypeAttributes.AnsiClass |
TypeAttributes.BeforeFieldInit,
assembly.Import(typeof(object)));
#else
TypeDefinition entryType = new TypeDefinition(context.NameManager.GenerateName(NamingTable.Type),
context.NameManager.GenerateName(NamingTable.Type),
TypeAttributes.NotPublic | TypeAttributes.Class |
TypeAttributes.AutoClass | TypeAttributes.AnsiClass |
TypeAttributes.BeforeFieldInit,
assembly.Import(typeof(object)));
#endif
assembly.MainModule.Types.Add(entryType);
//Create a default constructor
var ctor = assembly.CreateDefaultConstructor(entryType);
ctor.MaxStackSize = 8;
var il = ctor.GetILProcessor();
InjectAntiReflectorCode(il, il.Create(OpCodes.Ldarg_0));
var objectCtor = assembly.Import(typeof (object).GetConstructor(Type.EmptyTypes));
il.Append(il.Create(OpCodes.Call, objectCtor));
il.Append(OpCodes.Ret);
//Create an entry point
var mainMethod = BuildMainMethod(assembly, context, programType, getExecutingAssembly, currentDomain, eventHandler, assemblyResolve, resolveMethod, startMethod);
entryType.Methods.Add(mainMethod);
}
private static void DebugLine(AssemblyDefinition assembly, CilWorker il, string text, params Instruction[] appendInstructions)
{
il.Append(il.Create(OpCodes.Ldstr, text));
//Append any instructions we need to
if (appendInstructions.Length > 0)
{
var concat =
assembly.Import(typeof (String).GetMethod("Concat", new[] {typeof (string), typeof (string)}));
foreach (Instruction i in appendInstructions)
{
il.Append(il.Create(OpCodes.Ldstr, ","));
il.Append(il.Create(OpCodes.Call, concat));
il.Append(i);
il.Append(il.Create(OpCodes.Call, concat));
}
}
var writeLine = assembly.Import(typeof (Console).GetMethod("WriteLine", new[] {typeof (string)}));
il.Append(il.Create(OpCodes.Call, writeLine));
}
/// <summary>
/// Builds the start method.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="assembly">The assembly.</param>
/// <param name="executingAssembly">The executing assembly.</param>
/// <param name="assembliesLoaded">The assemblies loaded.</param>
/// <param name="loadType">Type of the load.</param>
/// <param name="loadAssemblies">The load assemblies.</param>
/// <returns></returns>
private static MethodDefinition BuildStartMethod(ICloakContext context, AssemblyDefinition assembly, FieldReference executingAssembly, FieldReference assembliesLoaded, MethodReference loadType, MethodReference loadAssemblies)
{
#if USE_FRIENDLY_NAMING
MethodDefinition method = new MethodDefinition("Start",
MethodAttributes.Public | MethodAttributes.HideBySig, assembly.Import(typeof(void)));
#else
MethodDefinition method = new MethodDefinition(context.NameManager.GenerateName(NamingTable.Method),
MethodAttributes.Public | MethodAttributes.HideBySig, assembly.Import(typeof(void)));
#endif
method.Body.InitLocals = true;
method.Body.MaxStackSize = 3;
method.AddLocal(assembly, typeof(string)); //entryAssemblyResource
method.AddLocal(assembly, typeof(string)); //entryType
method.AddLocal(assembly, typeof(string)); //entryMethod
method.AddLocal(assembly, typeof(string)); //resourceName
var s = method.AddLocal(assembly, typeof(Stream)); //s
var sr = method.AddLocal(assembly, typeof(StreamReader)); //sr
var type = method.AddLocal(assembly, typeof(Type)); //type
var methodInfo = method.AddLocal(assembly, typeof(MethodInfo)); //method
var tempStringArray = method.AddLocal(assembly, typeof (string[]));
var tempInt = method.AddLocal(assembly, typeof(int));
var tempBool = method.AddLocal(assembly, typeof(bool));
//Get the il builder
var il = method.Body.GetILProcessor();
//Inject the anti reflector code
InjectAntiReflectorCode(il, il.Create(OpCodes.Nop));
//Start it off - declare some variables
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Stloc_0);
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Stloc_1);
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Stloc_2);
il.Append(OpCodes.Nop);
il.Append(OpCodes.Ldarg_0);
//We need to find the entry point so start a loop to find
il.Append(il.Create(OpCodes.Ldfld, executingAssembly));
var getManifestResourceNames = assembly.Import(typeof (Assembly).GetMethod("GetManifestResourceNames"));
il.Append(il.Create(OpCodes.Callvirt, getManifestResourceNames));
il.Append(il.Create(OpCodes.Stloc_S, tempStringArray));
//Init the loop counter
il.Append(OpCodes.Ldc_I4_0);
il.Append(il.Create(OpCodes.Stloc_S, tempInt));
//Jump to the loop comparison
var startLoopComparison = il.Create(OpCodes.Ldloc_S, tempInt);
il.Append(il.Create(OpCodes.Br, startLoopComparison));
//Load the current item in a temp variable
var getTempVar = il.Create(OpCodes.Ldloc_S, tempStringArray);
il.Append(getTempVar);
il.Append(il.Create(OpCodes.Ldloc_S, tempInt));
il.Append(OpCodes.Ldelem_Ref);
il.Append(OpCodes.Stloc_3);
//Now start the actual body
il.Append(OpCodes.Nop);
il.Append(OpCodes.Ldloc_3);
il.Append(il.Create(OpCodes.Ldstr, ".e"));
var endsWith = assembly.Import(typeof (String).GetMethod("EndsWith", new[] {typeof (string)}));
il.Append(il.Create(OpCodes.Callvirt, endsWith));
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
//Branch to increment statement if not true (i.e. equal to 0/false)
var startIncrement = il.Create(OpCodes.Nop);
il.Append(il.Create(OpCodes.Brtrue, startIncrement));
//Get the stream
il.Append(OpCodes.Nop);
il.Append(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Ldfld, executingAssembly));
il.Append(OpCodes.Ldloc_3);
var getManifestResourceStream =
assembly.Import(typeof (Assembly).GetMethod("GetManifestResourceStream", new[] {typeof (string)}));
il.Append(il.Create(OpCodes.Callvirt, getManifestResourceStream));
il.Append(il.Create(OpCodes.Stloc_S, s));
//Make sure it's not null
il.Append(il.Create(OpCodes.Ldloc_S, s));
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
//Branch to read it if necessary
var startUnpack = il.Create(OpCodes.Ldloc_S, s);
il.Append(il.Create(OpCodes.Brtrue_S, startUnpack));
var startIncrement2 = il.Create(OpCodes.Ldloc_S, tempInt);
il.Append(il.Create(OpCodes.Br_S, startIncrement2));
il.Append(startUnpack);
//It's all in unicode
var unicode = assembly.Import(typeof (Encoding).GetProperty("Unicode").GetGetMethod());
il.Append(il.Create(OpCodes.Call, unicode));
//Create a new stream reader to read it
var streamReaderCtor =
assembly.Import(typeof (StreamReader).GetConstructor(new[] {typeof (Stream), typeof (Encoding)}));
il.Append(il.Create(OpCodes.Newobj, streamReaderCtor));
il.Append(il.Create(OpCodes.Stloc_S, sr));
//Try start
var tryStart = il.Create(OpCodes.Nop);
il.Append(tryStart);
//Load the current bootstrapper namespace
//il.Append(il.Create(OpCodes.Ldstr, resourceNamespace + "."));
il.Append(il.Create(OpCodes.Ldloc_S, sr));
//Read in a line or two
var readLine = assembly.Import(typeof (TextReader).GetMethod("ReadLine"));
il.Append(il.Create(OpCodes.Callvirt, readLine));
//Joing the strings
//var stringConcat =
// assembly.Import(typeof (String).GetMethod("Concat", new[] {typeof (string), typeof (string)}));
//il.Append(il.Create(OpCodes.Call, stringConcat));
il.Append(OpCodes.Stloc_0);
il.Append(il.Create(OpCodes.Ldloc_S, sr));
il.Append(il.Create(OpCodes.Callvirt, readLine));
il.Append(OpCodes.Stloc_1);
il.Append(il.Create(OpCodes.Ldloc_S, sr));
il.Append(il.Create(OpCodes.Callvirt, readLine));
il.Append(OpCodes.Stloc_2);
//HACK - load all assemblies here
il.Append(OpCodes.Ldarg_0);
il.Append(OpCodes.Ldc_I4_1);
il.Append(il.Create(OpCodes.Stfld, assembliesLoaded));
il.Append(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Call, loadAssemblies));
//END HACK
il.Append(OpCodes.Nop);
var afterFinally = il.Create(OpCodes.Nop);
il.Append(il.Create(OpCodes.Leave_S, afterFinally));
var tryEnd = il.Create(OpCodes.Ldloc_S, sr);
il.Append(tryEnd);
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
var endFinally = il.Create(OpCodes.Endfinally);
il.Append(il.Create(OpCodes.Brtrue_S, endFinally));
il.Append(il.Create(OpCodes.Ldloc_S, sr));
//dispose it
var dispose = assembly.Import(typeof (IDisposable).GetMethod("Dispose"));
il.Append(il.Create(OpCodes.Callvirt, dispose));
il.Append(OpCodes.Nop);
il.Append(endFinally);
il.Append(afterFinally);
//Make sure nothing is null
il.Append(OpCodes.Ldloc_0);
var isNullOrEmpty = assembly.Import(typeof (string).GetMethod("IsNullOrEmpty", new[] {typeof (string)}));
il.Append(il.Create(OpCodes.Call, isNullOrEmpty));
var exitCheck = il.Create(OpCodes.Ldc_I4_1);
il.Append(il.Create(OpCodes.Brtrue_S, exitCheck));
il.Append(OpCodes.Ldloc_1);
il.Append(il.Create(OpCodes.Call, isNullOrEmpty));
il.Append(il.Create(OpCodes.Brtrue_S, exitCheck));
il.Append(OpCodes.Ldloc_2);
il.Append(il.Create(OpCodes.Call, isNullOrEmpty));
var doCheck = il.Create(OpCodes.Stloc_S, tempBool);
il.Append(il.Create(OpCodes.Br_S, doCheck));
il.Append(exitCheck);
il.Append(doCheck);
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
var startIncrement3 = il.Create(OpCodes.Nop);
il.Append(il.Create(OpCodes.Brtrue_S, startIncrement3));
//Jump to check if the entry exists
var checkEntryExists = il.Create(OpCodes.Ldloc_0);
il.Append(il.Create(OpCodes.Br_S, checkEntryExists));
il.Append(startIncrement3);
il.Append(startIncrement);
il.Append(startIncrement2);
il.Append(OpCodes.Ldc_I4_1);
il.Append(OpCodes.Add);
il.Append(il.Create(OpCodes.Stloc_S, tempInt));
//Comparison
il.Append(startLoopComparison);
il.Append(il.Create(OpCodes.Ldloc_S, tempStringArray));
il.Append(OpCodes.Ldlen);
il.Append(OpCodes.Conv_I4);
il.Append(OpCodes.Clt);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
il.Append(il.Create(OpCodes.Brtrue, getTempVar));
//Check the entry exists to start the program
il.Append(checkEntryExists);
il.Append(il.Create(OpCodes.Call, isNullOrEmpty));
var failedProgram = il.Create(OpCodes.Ldc_I4_0);
il.Append(il.Create(OpCodes.Brtrue_S, failedProgram));
il.Append(OpCodes.Ldloc_1);
il.Append(il.Create(OpCodes.Call, isNullOrEmpty));
il.Append(il.Create(OpCodes.Brtrue_S, failedProgram));
il.Append(OpCodes.Ldloc_2);
il.Append(il.Create(OpCodes.Call, isNullOrEmpty));
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
var checkIfShouldStart = il.Create(OpCodes.Stloc_S, tempBool);
il.Append(il.Create(OpCodes.Br_S, checkIfShouldStart));
il.Append(failedProgram);
il.Append(checkIfShouldStart);
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
var startLoad = il.Create(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Brtrue_S, startLoad));
var ret = il.Create(OpCodes.Ret);
il.Append(il.Create(OpCodes.Br_S, ret));
//Start the load type
il.Append(startLoad);
il.Append(OpCodes.Ldloc_0);
il.Append(OpCodes.Ldloc_1);
il.Append(il.Create(OpCodes.Call, loadType));
il.Append(il.Create(OpCodes.Stloc_S, type));
#if VERBOSE_OUTPUT
DebugLine(assembly, il, "Loading type: ", il.Create(OpCodes.Ldloc_0), il.Create(OpCodes.Ldloc_1));
#endif
//Check it was found
il.Append(il.Create(OpCodes.Ldloc_S, type));
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
var startFindMethod = il.Create(OpCodes.Ldloc_S, type);
il.Append(il.Create(OpCodes.Brtrue_S, startFindMethod));
il.Append(il.Create(OpCodes.Br_S, ret));
il.Append(startFindMethod);
il.Append(OpCodes.Ldloc_2);
il.Append(il.Create(OpCodes.Ldc_I4_S, (sbyte)0x38));
var getMethod =
assembly.Import(typeof (Type).GetMethod("GetMethod", new[] {typeof (string), typeof (BindingFlags)}));
il.Append(il.Create(OpCodes.Callvirt, getMethod));
il.Append(il.Create(OpCodes.Stloc_S, methodInfo));
#if VERBOSE_OUTPUT
DebugLine(assembly, il, "Get Method has been called");
#endif
//Check it isn't null
il.Append(il.Create(OpCodes.Ldloc_S, methodInfo));
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ceq);
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
var invokeMethodBlock = il.Create(OpCodes.Ldloc_S, methodInfo);
il.Append(il.Create(OpCodes.Brtrue_S, invokeMethodBlock));
il.Append(il.Create(OpCodes.Br_S, ret));
//Invoke the method
il.Append(invokeMethodBlock);
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Ldnull);
var invoke =
assembly.Import(typeof (MethodBase).GetMethod("Invoke", new[] {typeof (object), typeof (object[])}));
il.Append(il.Create(OpCodes.Callvirt, invoke));
il.Append(OpCodes.Pop);
#if VERBOSE_OUTPUT
DebugLine(assembly, il, "Invoke called");
#endif
il.Append(ret);
//Try/Finally
ExceptionHandler finallyBlock = new ExceptionHandler(ExceptionHandlerType.Finally);
finallyBlock.TryStart = tryStart;
finallyBlock.TryEnd = tryEnd;
finallyBlock.HandlerStart = tryEnd;
finallyBlock.HandlerEnd = afterFinally;
method.Body.ExceptionHandlers.Add(finallyBlock);
return method;
}
/// <summary>
/// Builds the resolve method.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="assembly">The definition.</param>
/// <param name="assemblyLock">The assembly lock.</param>
/// <param name="assembliesLoaded">The assemblies loaded.</param>
/// <param name="loadAssemblies">The load assemblies.</param>
/// <returns></returns>
private static MethodDefinition BuildResolveMethod(ICloakContext context, AssemblyDefinition assembly, FieldReference assemblyLock, FieldReference assembliesLoaded, MethodReference loadAssemblies)
{
#if USE_FRIENDLY_NAMING
MethodDefinition method = new MethodDefinition("ResolveAssembly",
MethodAttributes.Public | MethodAttributes.HideBySig, assembly.Import(typeof(Assembly)));
#else
MethodDefinition method = new MethodDefinition(context.NameManager.GenerateName(NamingTable.Method),
MethodAttributes.Public | MethodAttributes.HideBySig, assembly.Import(typeof(Assembly)));
#endif
//Declare the resource parameter
method.Parameters.Add(new ParameterDefinition("sender", Mono.Cecil.ParameterAttributes.None, assembly.Import(typeof(object))));
method.Parameters.Add(new ParameterDefinition(assembly.Import(typeof(ResolveEventArgs))));
method.Body.InitLocals = true;
method.Body.MaxStackSize = 2;
method.AddLocal(assembly, typeof(Assembly[])); //currentAssemblies
method.AddLocal(assembly, typeof(Assembly)); //a
method.AddLocal(assembly, typeof(Assembly)); //temp assembly
method.AddLocal(assembly, typeof (object)); //temp object
var tempBool = method.AddLocal(assembly, typeof (bool)); //temp bool
var tempAssemblyArray = method.AddLocal(assembly, typeof(Assembly[])); //temp assembly array
var tempInt = method.AddLocal(assembly, typeof (int)); //temp int
//Get the il builder
var il = method.Body.GetILProcessor();
//Inject the anti reflector code
InjectAntiReflectorCode(il, il.Create(OpCodes.Nop));
#if VERBOSE_OUTPUT
DebugLine(assembly, il, "Resolving");
#endif
//Start a lock
il.Append(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Ldfld, assemblyLock));
il.Append(OpCodes.Dup);
il.Append(OpCodes.Stloc_3);
var monitorEnter = assembly.Import(typeof (Monitor).GetMethod("Enter", new[] {typeof (object)}));
il.Append(il.Create(OpCodes.Call, monitorEnter));
il.Append(OpCodes.Nop);
var tryStart = il.Create(OpCodes.Nop);
il.Append(tryStart);
//Check if the assemblies are loaded
il.Append(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Ldfld, assembliesLoaded));
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
//If it is set, skip to searching the current appdomain
var startSearchingCurrentAppDomain = il.Create(OpCodes.Nop);
il.Append(il.Create(OpCodes.Brtrue_S, startSearchingCurrentAppDomain));
il.Append(OpCodes.Nop);
il.Append(OpCodes.Ldarg_0);
il.Append(OpCodes.Ldc_I4_1);
il.Append(il.Create(OpCodes.Stfld, assembliesLoaded));
il.Append(OpCodes.Ldarg_0);
il.Append(il.Create(OpCodes.Call, loadAssemblies));
il.Append(OpCodes.Nop);
il.Append(OpCodes.Nop);
il.Append(startSearchingCurrentAppDomain);
//After the finally
var afterFinally = il.Create(OpCodes.Nop);
//Exit the finally
il.Append(il.Create(OpCodes.Leave_S, afterFinally));
//We're in the finally now
var finallyStart = il.Create(OpCodes.Ldloc_3);
il.Append(finallyStart);
var monitorExit = assembly.Import(typeof (Monitor).GetMethod("Exit", new[] {typeof (object)}));
il.Append(il.Create(OpCodes.Call, monitorExit));
il.Append(OpCodes.Nop);
il.Append(OpCodes.Endfinally);
il.Append(afterFinally);
//Get the current domains assemblies
var currentDomain = assembly.Import(typeof (AppDomain).GetProperty("CurrentDomain").GetGetMethod());
il.Append(il.Create(OpCodes.Call, currentDomain));
var getAssemblies = assembly.Import(typeof (AppDomain).GetMethod("GetAssemblies"));
il.Append(il.Create(OpCodes.Callvirt, getAssemblies));
il.Append(OpCodes.Stloc_0);
il.Append(OpCodes.Nop);
//Lets start a loop in lieu of foreach
il.Append(OpCodes.Ldloc_0);
il.Append(il.Create(OpCodes.Stloc_S, tempAssemblyArray));
il.Append(OpCodes.Ldc_I4_0);
il.Append(il.Create(OpCodes.Stloc_S, tempInt));
//Loop Condition
var loopCondition = il.Create(OpCodes.Ldloc_S, tempInt);
il.Append(il.Create(OpCodes.Br_S, loopCondition));
var startLoopBody = il.Create(OpCodes.Ldloc_S, tempAssemblyArray);
il.Append(startLoopBody);
il.Append(il.Create(OpCodes.Ldloc_S, tempInt));
il.Append(OpCodes.Ldelem_Ref);
il.Append(OpCodes.Stloc_1);
il.Append(OpCodes.Nop);
il.Append(OpCodes.Ldloc_1);
//Check the name
var getFullName = assembly.Import(typeof (Assembly).GetProperty("FullName").GetGetMethod());
il.Append(il.Create(OpCodes.Callvirt, getFullName));
il.Append(OpCodes.Ldarg_2);
var getName = assembly.Import(typeof (ResolveEventArgs).GetProperty("Name").GetGetMethod());
il.Append(il.Create(OpCodes.Callvirt, getName));
//Check if equal
var stringEquality =
assembly.Import(typeof (String).GetMethod("op_Equality", new[] {typeof (string), typeof (string)}));
il.Append(il.Create(OpCodes.Call, stringEquality));
il.Append(OpCodes.Ldc_I4_0);
il.Append(OpCodes.Ceq);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
//Branch to increment block if necessary
var incrementBlock = il.Create(OpCodes.Nop);
il.Append(il.Create(OpCodes.Brtrue_S, incrementBlock));
il.Append(OpCodes.Ldloc_1);
il.Append(OpCodes.Stloc_2);
var returnBlock = il.Create(OpCodes.Nop);
il.Append(il.Create(OpCodes.Leave_S, returnBlock));
//i++
il.Append(incrementBlock);
il.Append(il.Create(OpCodes.Ldloc_S, tempInt));
il.Append(OpCodes.Ldc_I4_1);
il.Append(OpCodes.Add);
il.Append(il.Create(OpCodes.Stloc_S, tempInt));
//The comparison block
il.Append(loopCondition);
il.Append(il.Create(OpCodes.Ldloc_S, tempAssemblyArray));
il.Append(OpCodes.Ldlen);
il.Append(OpCodes.Conv_I4);
il.Append(OpCodes.Clt);
il.Append(il.Create(OpCodes.Stloc_S, tempBool));
il.Append(il.Create(OpCodes.Ldloc_S, tempBool));
il.Append(il.Create(OpCodes.Brtrue_S, startLoopBody));
//Not found block
il.Append(OpCodes.Ldnull);
il.Append(OpCodes.Stloc_2);
il.Append(il.Create(OpCodes.Br_S, returnBlock));
il.Append(returnBlock);
il.Append(OpCodes.Ldloc_2);
il.Append(OpCodes.Ret);
//Finally do the try/finally
ExceptionHandler finallyBlock = new ExceptionHandler(ExceptionHandlerType.Finally); //the lock
finallyBlock.TryStart = tryStart;
finallyBlock.TryEnd = finallyStart;
finallyBlock.HandlerStart = finallyStart;
finallyBlock.HandlerEnd = afterFinally;
method.Body.ExceptionHandlers.Add(finallyBlock);
//Return the method
return method;
}
/// <summary>
/// Generates the xor decryption method.
/// </summary>
/// <param name="assembly">The assembly.</param>
/// <param name="body">The body.</param>
private static void GenerateXorDecryptionMethod(AssemblyDefinition assembly, MethodBody body)
{
var worker = body.GetILProcessor();
//Generate the decryption method
//Since this is XOR it is the same as the encryption method
//In reality its a bit of a joke calling this encryption as its really
//just obfusaction
/*
char[] characters = value.ToCharArray();
for (int i = 0; i < characters.Length; i++)
{
characters[i] = (char)(characters[i] ^ salt);
}
return new String(characters);
*/
//Declare a local to store the char array
body.InitLocals = true;
body.Method.AddLocal(typeof(char[]));
body.Method.AddLocal(typeof(int));
body.Method.AddLocal(typeof(string));
body.Method.AddLocal(typeof(bool));
//Start with a nop
worker.Append(worker.Create(OpCodes.Nop));
//Load the first argument into the register
Instruction ldArg0 = worker.Create(OpCodes.Ldarg_0);
worker.Append(ldArg0);
//Call ToCharArray on this -- need to find it first
var toCharArrayMethodRef = assembly.Import(typeof(string).GetMethod("ToCharArray", Type.EmptyTypes));
//Import the method first
toCharArrayMethodRef = body.ImportMethod(toCharArrayMethodRef);
Instruction toCharArray = worker.Create(OpCodes.Callvirt, toCharArrayMethodRef);
worker.Append(toCharArray);
//Store it in the first local
Instruction stLoc0 = worker.Create(OpCodes.Stloc_0);
worker.Append(stLoc0);
//Set up the loop
worker.Append(worker.Create(OpCodes.Ldc_I4_0));
Instruction stLoc1 = worker.Create(OpCodes.Stloc_1);
worker.Append(stLoc1);
//We'll insert a br.s here later....
//Insert another nop and do the rest of our loop
Instruction loopNop = worker.Create(OpCodes.Nop);
worker.Append(loopNop);
worker.Append(worker.Create(OpCodes.Ldloc_0));
worker.Append(worker.Create(OpCodes.Ldloc_1));
worker.Append(worker.Create(OpCodes.Ldloc_0));
worker.Append(worker.Create(OpCodes.Ldloc_1));
worker.Append(worker.Create(OpCodes.Ldelem_U2)); //Load the array
worker.Append(worker.Create(OpCodes.Ldarg_1));
worker.Append(worker.Create(OpCodes.Xor)); //Do the xor
worker.Append(worker.Create(OpCodes.Conv_U2));
worker.Append(worker.Create(OpCodes.Stelem_I2)); //Store back in the array
worker.Append(worker.Create(OpCodes.Nop));
worker.Append(worker.Create(OpCodes.Ldloc_1));
worker.Append(worker.Create(OpCodes.Ldc_I4_1));
worker.Append(worker.Create(OpCodes.Add));
worker.Append(worker.Create(OpCodes.Stloc_1));
Instruction ldLoc = worker.Create(OpCodes.Ldloc_1);
worker.Append(ldLoc);
//Link to this line from an earlier statement
worker.InsertAfter(stLoc1, worker.Create(OpCodes.Br_S, ldLoc));
worker.Append(worker.Create(OpCodes.Ldloc_0));
worker.Append(worker.Create(OpCodes.Ldlen));
worker.Append(worker.Create(OpCodes.Conv_I4));
worker.Append(worker.Create(OpCodes.Clt)); //i < array.Length
worker.Append(worker.Create(OpCodes.Stloc_3));
worker.Append(worker.Create(OpCodes.Ldloc_3));
worker.Append(worker.Create(OpCodes.Brtrue_S, loopNop)); //Do the loop
//Return a new string
worker.Append(worker.Create(OpCodes.Ldloc_0));
//Find the constructor we want to use
MethodReference constructor = assembly.Import(typeof(string).GetConstructor(new [] { typeof(char[])}));
constructor = body.ImportMethod(constructor);
worker.Append(worker.Create(OpCodes.Newobj, constructor));
Instruction stloc2 = worker.Create(OpCodes.Stloc_2);
worker.Append(stloc2);
Instruction ldloc2 = worker.Create(OpCodes.Ldloc_2);
worker.Append(ldloc2);
worker.InsertAfter(stloc2, worker.Create(OpCodes.Br_S, ldloc2));
worker.Append(worker.Create(OpCodes.Ret));
}
