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https://github.com/DreamSoule/ollvm17
Obfuscation LLVM 17
https://github.com/DreamSoule/ollvm17
Last synced: 3 months ago
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Obfuscation LLVM 17
- Host: GitHub
- URL: https://github.com/DreamSoule/ollvm17
- Owner: DreamSoule
- Created: 2023-09-20T13:54:42.000Z (9 months ago)
- Default Branch: main
- Last Pushed: 2024-01-05T12:44:33.000Z (6 months ago)
- Last Synced: 2024-01-16T22:52:27.508Z (5 months ago)
- Language: C++
- Size: 201 KB
- Stars: 91
- Watchers: 4
- Forks: 14
- Open Issues: 7
-
Metadata Files:
- Readme: README.md
Lists
- awesome-stars - DreamSoule/ollvm17 - Obfuscation LLVM 17 (C++)
README
# 前言
项目大致内容与我之前发布的[OLLVM16](https://github.com/DreamSoule/ollvm16)区别不大, 仅对LLVM17做了兼容性修复
感兴趣的可以自己下载之前项目对比查看修改部分
# 更新内容
由于Visual Studio无法传入annotation ~~(也可能是我有问题?)~~
增加了个使用函数名匹配混淆功能是否在此函数开关的功能
> 例子:
```cpp
int function_fla_bcf_(int a);
```
# 图例
函数源码
原版IDA反编译
函数名加_fla_
函数名加_fla_bcf_
# 混淆功能列表
> 命令行添加位置: 项目->属性->C/C++->Command Line
```bash
- bcf # 虚假控制流
- bcf_prob # 虚假控制流混淆概率 1~100, 默认70
- bcf_loop # 虚假控制流重复次数, 无限制, 默认2
- fla # 控制流平坦化
- sub # 指令替换(add/and/sub/or/xor)
- sub_loop # 指令替换次数, 无限制, 默认1
- sobf # 字符串混淆(仅窄字符)
- split # 基本块分割
- split_num # 将原基本块分割数量, 无限制, 默认3
- ibr # 间接分支
- icall # 间接调用 (call 寄存器)
- igv # 间接全局变量
- fncmd # 启用函数名控制混淆功能( function_fla_bcf_(); )
```
# 功能全开
> 命令行添加位置: 项目->属性->C/C++->命令行
> fla和bcf会导致编译速度很慢且部分函数无法使用
> 推荐启用fncmd并删除-mllvm -fla -mllvm -bcf
> 然后在需要这俩功能的函数名加上对应的控制符, 例子在: [#更新内容]
```bash
-mllvm -fla -mllvm -bcf -mllvm -bcf_prob=80 -mllvm -bcf_loop=3 -mllvm -sobf -mllvm -icall -mllvm -ibr -mllvm -igv -mllvm -sub -mllvm -sub_loop=3 -mllvm -split -mllvm -split_num=5
```
# 官方LLVM修补教程
1.下载LLVM官方源码 [LLVM 17.0.6](https://github.com/llvm/llvm-project/releases/tag/llvmorg-17.0.6) 并解压
2.下载此项目, 将项目内文件替换至官方源码内
3.使用cmake创建自己需要的编译工具生成文件, 以 VisualStudio 2022 为例
```bash
cd llvm-project
mkdir build_vs2022
cd build_vs2022
cmake -G "Visual Studio 17 2022" -DCMAKE_C_FLAGS=/utf-8 -DCMAKE_CXX_FLAGS=/utf-8 -DCMAKE_BUILD_TYPE=Release -DLLVM_ENABLE_EH=OFF -DLLVM_ENABLE_RTTI=OFF -DLLVM_ENABLE_ASSERTIONS=ON -DLLVM_ENABLE_PROJECTS="clang;lld" -A x64 ../llvm
```
4.等cmake生成出解决方案后打开build_vs2022目录内的LLVM.sln点击生成解决方案即可
>如果编译过程中有提示部分函数是private的无法调用的话把private注释即可 LLVM 17.0.6注释后正常无报错
>要取消private属性的文件及目标行(LLVM17.0.1): ...\llvm-project\llvm\include\llvm\IR\Function.h:722
>此函数的private属性: getBasicBlockList
# 修补细节
> ...\llvm-project\llvm\lib\Passes\PassBuilder.cpp
```cpp
// 引用 Obfuscation 相关文件
#include "Obfuscation/BogusControlFlow.h" // 虚假控制流
#include "Obfuscation/Flattening.h" // 控制流平坦化
#include "Obfuscation/SplitBasicBlock.h" // 基本块分割
#include "Obfuscation/Substitution.h" // 指令替换
#include "Obfuscation/StringEncryption.h" // 字符串加密
#include "Obfuscation/IndirectGlobalVariable.h" // 间接全局变量
#include "Obfuscation/IndirectBranch.h" // 间接跳转
#include "Obfuscation/IndirectCall.h" // 间接调用
#include "Obfuscation/Utils.h" // 为了控制函数名混淆开关 (bool obf_function_name_cmd;)
// 添加命令行支持
static cl::opt s_obf_split("split", cl::init(false), cl::desc("SplitBasicBlock: split_num=3(init)"));
static cl::opt s_obf_sobf("sobf", cl::init(false), cl::desc("String Obfuscation"));
static cl::opt s_obf_fla("fla", cl::init(false), cl::desc("Flattening"));
static cl::opt s_obf_sub("sub", cl::init(false), cl::desc("Substitution: sub_loop"));
static cl::opt s_obf_bcf("bcf", cl::init(false), cl::desc("BogusControlFlow: application number -bcf_loop=x must be x > 0"));
static cl::opt s_obf_ibr("ibr", cl::init(false), cl::desc("Indirect Branch"));
static cl::opt s_obf_igv("igv", cl::init(false), cl::desc("Indirect Global Variable"));
static cl::opt s_obf_icall("icall", cl::init(false), cl::desc("Indirect Call"));
static cl::opt s_obf_fn_name_cmd("fncmd", cl::init(false), cl::desc("use function name control obfuscation(_ + command + _ | example: function_fla_bcf_)"));
// 在此函数内直接注册Pipeline回调
PassBuilder::PassBuilder(...) {
...
this->registerPipelineStartEPCallback(
[](llvm::ModulePassManager &MPM,
llvm::OptimizationLevel Level) {
outs() << "[Soule] run.PipelineStartEPCallback\n";
obf_function_name_cmd = s_obf_fn_name_cmd;
if (obf_function_name_cmd) {
outs() << "[Soule] enable function name control obfuscation(_ + command + _ | example: function_fla_)\n";
}
MPM.addPass(StringEncryptionPass(s_obf_sobf)); // 先进行字符串加密 出现字符串加密基本块以后再进行基本块分割和其他混淆 加大解密难度
llvm::FunctionPassManager FPM;
FPM.addPass(IndirectCallPass(s_obf_icall)); // 间接调用
FPM.addPass(SplitBasicBlockPass(s_obf_split)); // 优先进行基本块分割
FPM.addPass(FlatteningPass(s_obf_fla)); // 对于控制流平坦化
FPM.addPass(SubstitutionPass(s_obf_sub)); // 指令替换
FPM.addPass(BogusControlFlowPass(s_obf_bcf)); // 虚假控制流
MPM.addPass(createModuleToFunctionPassAdaptor(std::move(FPM)));
MPM.addPass(IndirectBranchPass(s_obf_ibr)); // 间接指令 理论上间接指令应该放在最后
MPM.addPass(IndirectGlobalVariablePass(s_obf_igv)); // 间接全局变量
MPM.addPass(RewriteSymbolPass()); // 根据yaml信息 重命名特定symbols
}
);
}
```
> ...\llvm-project\llvm\lib\Passes\CMakeLists.txt
``` bash
# 添加 Obfuscation 相关源码
add_llvm_component_library(LLVMPasses
...
Obfuscation/Utils.cpp
Obfuscation/CryptoUtils.cpp
Obfuscation/ObfuscationOptions.cpp
Obfuscation/BogusControlFlow.cpp
Obfuscation/IPObfuscationContext.cpp
Obfuscation/Flattening.cpp
Obfuscation/StringEncryption.cpp
Obfuscation/SplitBasicBlock.cpp
Obfuscation/Substitution.cpp
Obfuscation/IndirectBranch.cpp
Obfuscation/IndirectCall.cpp
Obfuscation/IndirectGlobalVariable.cpp
...
)
```
# Credits
[LLVM](https://github.com/llvm/llvm-project)
[SsagePass](https://github.com/SsageParuders/SsagePass)
[wwh1004-ollvm16](https://github.com/wwh1004/ollvm-16)