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Dec 1, 2021
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源码部分

网上的教程还是很多的 ,这里记录一下自己的编译之路 llvm源码 用到的ollvm源码目前感觉还不错的主要是以下三个
这里我用到的是第一个 heroims-ollvm NDK版本:21.1.6352462 CMake版本:3.10.2.4988404 heroims-ollvm:https://github.com/heroims/obfuscator/tree/llvm-9.0.1
首先还是下载源码 git clone -b llvm-9.0.1 https://github.com/heroims/obfuscator.git 再或者直接 download 都行

编译源码

windows下的编译就以下两条路 使用CMake生成 Visual Studio工程 或是 MinGW Makefiles 使用mingw进行编译 需要使用版本8.1,若使用6.x 必报错
建议 Visual Studio 进行编译 https://github.com/heroims 12+以上的ollvm 12+ 以上的源码 独立拆开了 clang
参见:https://llvm.org/docs/GettingStarted.html 在12 以前 clang 作为 tools 放在 llvm 中 在12 以后是独立作为 plugin
// 生成 Visual Studio 工程 cmake -G "Visual Studio 16 2019" -DLLVM_ENABLE_PROJECTS="clang" -DCMAKE_BUILD_TYPE=Release ../llvm cmake -DLLVM_ENABLE_PROJECTS="clang;libcxx" -G "Visual Studio 16 2019" -A x64 -Thost=x64 -DCMAKE_BUILD_TYPE=Release ..\\llvm // 生成 Ninja 工程 (速度是真的比其他两个快很多) cmake -G "Ninja" -DLLVM_ENABLE_PROJECTS="clang" -DCMAKE_BUILD_TYPE=Release -DLLVM_TARGETS_TO_BUILD="X86" -DBUILD_SHARED_LIBS=OFF ../llvm // 生成 MinGW Makefiles cmake -G "MinGW Makefiles" -DLLVM_ENABLE_PROJECTS="clang" -DCMAKE_BUILD_TYPE=Release -DLLVM_INCLUDE_TESTS=OFF ../llvm // mingw编译 cmake --build .
编译完成后,从 obfuscator-llvm-9.0.1\build\lib\clang\9.0.1\include 复制 stdarg.h stddef.h __stddef_max_align_t.h float.h 到 21.1.6352462\toolchains\llvm\prebuilt\windows-x86_64\sysroot\usr\include 即可
对应替换bin目录下的对应的 三个 exe clang.exe clang++.exe clang-format.exe

注意事项

  1. 编译不成功 : versionhelpers.h : not such file or directory cmake加个参数:-DLLVM_INCLUDE_BENCHMARKS=OFF 或者修改cmakelists.txt中的LLVM_INCLUDE_BENCHMARKS ON 改成OFF
  1. 编译90%退出 ... z3/bin/libz3.lib: error adding symbols: File format not recognized collect2.exe: error: ld returned 1 exit status 安装一个z3 ,和你平台对应,32位还是64位

OLLVM 的使用

  1. Instructions Substitution (指令替换)
      • mllvm -sub: 启用instructions substitution
      • mllvm -sub_loop=3: 对每个函数混淆3次,默认1词
  1. Control Flow Flattening (控制流平坦化)
      • mllvm -fla: 启用control flow flattening
      • mllvm -split: 启用block切分,提升平展程度
      • mllvm -split_num=3: 对每个block混淆3次,默认1词
  1. Bogus Control Flow (虚假控制流)
      • mllvm -bcf: 启用 bogus control flow
      • mllvm -bcf_loop=3: 对一个函数混淆3次,默认1次
      • mllvm -bcf_prob=40: 代码块被混淆的概率是40%,默认30%
  1. mllvm -sobf: 字符串加密
  1. 函数注解的使用 //Functions annotations int foo() __attribute((annotate(("sub")))); int foo() { return 2; }
CMakeLists.txt #debug and release all enable set(CMAKE_CXX_FLAGS "-mllvm -fla -mllvm -sub -mllvm -sobf ") #so体积优化 #SET(CMAKE_CXX_FLAGS_DEBUG "$ENV{CXXFLAGS} -O0 -Wall -g2 -ggdb") #SET(CMAKE_CXX_FLAGS_RELEASE "$ENV{CXXFLAGS} -Os -Wall -s") #设置llvm debug模式混淆编译 SET(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -mllvm -fla") SET(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -mllvm -fla") #设置llvm release模式混淆编译 SET(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -mllvm -fla -mllvm -sub -mllvm -bcf") SET(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -mllvm -fla -mllvm -sub -mllvm -bcf") #set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -s -O3 -Wall -fvisibility=hidden -mllvm -fla")

参考

  1. heroims 大佬的 文章
  1. 官方文档 https://llvm.org/docs/GettingStarted.html
https://sourceforge.net/projects/mingw-w64/files/mingw-w64/ ps:若在编译的成品 clang 运行出现了一下情况,请使用 vs studio 重新编译(不要使用mingw32-make)
notion image

NDK版本对应的clang版本

版本:21.1.6352462 Android (6317467 based on r365631c1) clang version 9.0.8 (<https://android.googlesource.com/toolchain/llvm-project> e0caee08e5f09b374a27a676d04978c81fcb1928) (based on LLVM 9.0.8svn) Target: x86_64-w64-windows-gnu Thread model: posix ------------------------------------------------------------------------------------ 版本:21.2.6472646 Android (6454773 based on r365631c2) clang version 9.0.8 (<https://android.googlesource.com/toolchain/llvm-project> 98c855489587874b2a325e7a516b99d838599c6f) (based on LLVM 9.0.8svn) Target: x86_64-w64-windows-gnu Thread model: posix ------------------------------------------------------------------------------------ 版本:21.3.6528147 Android (6454773 based on r365631c2) clang version 9.0.8 (<https://android.googlesource.com/toolchain/llvm-project> 98c855489587874b2a325e7a516b99d838599c6f) (based on LLVM 9.0.8svn) Target: x86_64-w64-windows-gnu Thread model: posix ------------------------------------------------------------------------------------ 版本:21.4.7075529 Android (7019983 based on r365631c3) clang version 9.0.9 (<https://android.googlesource.com/toolchain/llvm-project> a2a1e703c0edb03ba29944e529ccbf457742737b) (based on LLVM 9.0.9svn) Target: x86_64-w64-windows-gnu Thread model: posix ------------------------------------------------------------------------------------ 版本:22.0.7026061 Android (6875598, based on r399163b) clang version 11.0.5 (<https://android.googlesource.com/toolchain/llvm-project> 87f1315dfbea7c137aa2e6d362dbb457e388158d) Target: x86_64-w64-windows-gnu Thread model: posix ------------------------------------------------------------------------------------ 版本:22.1.7171670 Android (7155654, based on r399163b1) clang version 11.0.5 (<https://android.googlesource.com/toolchain/llvm-project> 87f1315dfbea7c137aa2e6d362dbb457e388158d) Target: x86_64-w64-windows-gnu Thread model: posix ------------------------------------------------------------------------------------ 版本:23.0.7599858 Android (7284624, based on r416183b) clang version 12.0.5 (<https://android.googlesource.com/toolchain/llvm-project> c935d99d7cf2016289302412d708641d52d2f7ee) Target: x86_64-w64-windows-gnu Thread model: posix ------------------------------------------------------------------------------------ 版本:23.1.7779620 Android (7714059, based on r416183c1) clang version 12.0.8 (<https://android.googlesource.com/toolchain/llvm-project> c935d99d7cf2016289302412d708641d52d2f7ee) Target: x86_64-w64-windows-gnu Thread model: posix ------------------------------------------------------------------------------------ 版本:24.0.8215888 Android (8075178, based on r437112b) clang version 14.0.1 (<https://android.googlesource.com/toolchain/llvm-project> 8671348b81b95fc603505dfc881b45103bee1731) Target: x86_64-w64-windows-gnu Thread model: posix
 
__builtin_return_address()引发的思考静态InlineHook的简单实现