# td-ollvm td-olvm is a reinforcement confusion project, which is used to protect the security of TrustDevice. After a period of internal use, we decided to open source to everyone. In the future, every update and adaptation of llvm and clang will be handled in a timely manner. We hope you can pay attention to this project. Your attention is our motivation for updating. ## Installation ### Requirement Please ensure that the following environments have been installed. + [Xcode 14.1](https://download.developer.apple.com/Developer_Tools/Xcode_14.2/Xcode_14.2.xip) + [cmake](https://cmake.org/download/) + [ninja](https://ninja-build.org/) ### Build + Download the respoitory and create a new build directory ```cmake $ git clone https://github.com/trustdecision/td-ollvm.git && cd td-ollvm $ mkdir build && cd build ``` + Use cmake to build llvm ```cmake $ cmake -G "Ninja" -DCMAKE_BUILD_TYPE=Release -DLLVM_CREATE_XCODE_TOOLCHAIN=ON -DLLVM_INCLUDE_TESTS=Off -DLLVM_INCLUDE_EXAMPLES=Off -DLLVM_ENABLE_BACKTRACES=Off -DLLVM_INCLUDE_BENCHMARKS=OFF -DLLVM_BUILD_DOCS=OFF -DCMAKE_OSX_ARCHITECTURES="x86_64" -DLLVM_TARGETS_TO_BUILD="host;AArch64" -DCMAKE_INSTALL_PREFIX="/Applications/Xcode.app/Contents/Developer/" -DLLVM_ENABLE_PROJECTS="clang;clang-tools-extra;compiler-rt" -DLLVM_ENABLE_NEW_PASS_MANAGER=OFF ../llvm ``` + Use ninja to build xcode-toolchain ```cmake $ ninja -j 6 ``` + Install toolchains to Xcode ```cmake $ ninja install-xcode-toolchain ``` ### Usage #### Xcode IDE ##### Config Toolchains Make the following configuration in Xcode : > Xcode -> Toolchains -> org.llvm.14.0.6 Make the following configuration to No in project settings : > Targets -> Build Settings -> Build Options -> Enable Index-While-Building Functionality ##### Obfuscation + Open project and find the following path : > TARGETS -> Build Settings -> Apple Clang - Custom Compiler Flags -> Other C Flags + Add confusion parameters to Other C Flags + The simplest way to use td-ollvm, is to pass a flag to the LLVM backend from Clang. The current available flags are : 1. `-fla` for the control flow flattening pass, - `-mllvm -fla`: activates control flow flattening - `-mllvm -split`: activates basic block splitting. Improve the flattening when applied together. - `-mllvm -split_num=3`: if the pass is activated, applies it 3 times on each basic block. Default: 1 2. `-sub` for the instruction substitution pass, - `-mllvm -sub`: activate instructions substitution - `-mllvm -sub_loop=3`: if the pass is activated, applies it 3 times on a function. Default : 1. 3. `-bcf` for the bogus control flow pass, - `-mllvm -bcf`: activates the bogus control flow pass - `-mllvm -bcf_loop=3`: if the pass is activated, applies it 3 times on a function. Default: 1 - `-mllvm -bcf_prob=40`: if the pass is activated, a basic bloc will be obfuscated with a probability of 40%. Default: 30 ## Issues Please use [Issues](https://github.com/trustdecision/td-ollvm/issues) to submit bugs to ask questions. ## License This library is MIT licensed. Copyright trustdecision, Inc. 2022