added vm::ctx_t which can be passed around >:)

merge-requests/9/head
_xeroxz 4 years ago
parent c49210e150
commit 1a0ba7ef56

@ -5,25 +5,6 @@
namespace vm namespace vm
{ {
namespace calc_jmp
{
bool get( const zydis_routine_t &vm_entry, zydis_routine_t &calc_jmp );
std::optional< vmp2::exec_type_t > get_advancement( const zydis_routine_t &calc_jmp );
} // namespace calc_jmp
namespace instrs
{
// decrypt transformations for encrypted virtual instruction rva...
bool get_rva_decrypt( const zydis_routine_t &vm_entry, std::vector< zydis_decoded_instr_t > &transform_instrs );
std::pair< std::uint64_t, std::uint64_t > decrypt_operand( transform::map_t &transforms, std::uint64_t operand,
std::uint64_t rolling_key );
std::pair< std::uint64_t, std::uint64_t > encrypt_operand( transform::map_t &transforms, std::uint64_t operand,
std::uint64_t rolling_key );
} // namespace instrs
namespace handler namespace handler
{ {
using instr_callback_t = bool ( * )( const zydis_decoded_instr_t &instr ); using instr_callback_t = bool ( * )( const zydis_decoded_instr_t &instr );
@ -187,4 +168,89 @@ namespace vm
&lrflags, &vmexit, &call }; &lrflags, &vmexit, &call };
} // namespace profile } // namespace profile
} // namespace handler } // namespace handler
class ctx_t
{
public:
explicit ctx_t( std::uintptr_t module_base, std::uintptr_t image_base, std::uint32_t vm_entry_rva );
ctx_t( std::vector< vm::handler::handler_t > &vm_handlers, zydis_routine_t &vm_entry, zydis_routine_t &calc_jmp,
vmp2::exec_type_t exec_type );
vmp2::exec_type_t exec_type;
zydis_routine_t vm_entry, calc_jmp;
std::vector< vm::handler::handler_t > vm_handlers;
};
namespace instrs
{
struct virt_instr_t
{
vm::handler::mnemonic_t mnemonic_t;
std::uint8_t opcode; // aka vm handler idx...
// can be used to look at values on the stack...
vmp2::v2::entry_t trace_data;
struct
{
bool has_imm;
struct
{
std::uint8_t imm_size; // size in bits...
union
{
std::int64_t s;
std::uint64_t u;
};
} imm;
} operand;
};
enum class jcc_type
{
none,
branching,
absolute
};
struct code_block_t
{
struct
{
bool has_jcc;
jcc_type type;
std::uint32_t block_rva[ 2 ];
} jcc;
std::uint32_t code_block_rva;
std::vector< virt_instr_t > vinstrs;
};
// decrypt transformations for encrypted virtual instruction rva...
bool get_rva_decrypt( const zydis_routine_t &vm_entry, std::vector< zydis_decoded_instr_t > &transform_instrs );
std::pair< std::uint64_t, std::uint64_t > decrypt_operand( transform::map_t &transforms, std::uint64_t operand,
std::uint64_t rolling_key );
std::pair< std::uint64_t, std::uint64_t > encrypt_operand( transform::map_t &transforms, std::uint64_t operand,
std::uint64_t rolling_key );
std::optional< virt_instr_t > get( vm::ctx_t &ctx, vmp2::v2::entry_t &entry );
/// <summary>
/// gets the second operand (imm) given vip and vm::ctx_t...
/// </summary>
/// <param name="ctx">vm context</param>
/// <param name="imm_size">immediate value size in bits...</param>
/// <param name="vip">virtual instruction pointer, linear virtual address...</param>
/// <returns>returns immediate value if imm_size is not 0...</returns>
std::optional< std::uint64_t > get_imm( vm::ctx_t &ctx, std::uint8_t imm_size, std::uintptr_t vip );
} // namespace instrs
namespace calc_jmp
{
bool get( const zydis_routine_t &vm_entry, zydis_routine_t &calc_jmp );
std::optional< vmp2::exec_type_t > get_advancement( const zydis_routine_t &calc_jmp );
} // namespace calc_jmp
} // namespace vm } // namespace vm

@ -0,0 +1,20 @@
#include <vmprofiler.hpp>
namespace vm
{
ctx_t::ctx_t( std::uintptr_t module_base, std::uintptr_t image_base, std::uint32_t vm_entry_rva )
{
vm::util::flatten( vm_entry, vm_entry_rva + module_base );
vm::util::deobfuscate( vm_entry );
vm::calc_jmp::get( vm_entry, calc_jmp );
auto vm_handler_table = vm::handler::table::get( vm_entry );
vm::handler::get_all( module_base, image_base, vm_entry, vm_handler_table, vm_handlers );
}
ctx_t::ctx_t( std::vector< vm::handler::handler_t > &vm_handlers, zydis_routine_t &vm_entry,
zydis_routine_t &calc_jmp, vmp2::exec_type_t exec_type )
: vm_handlers( vm_handlers ), vm_entry( vm_entry ), calc_jmp( calc_jmp ), exec_type( exec_type )
{
}
} // namespace vm

@ -44,8 +44,7 @@ namespace vm
} }
// update rolling key... // update rolling key...
auto result = auto result = transform::apply( update_key.operands[ 0 ].size, update_key.mnemonic, rolling_key, operand );
transform::apply( update_key.operands[ 0 ].size, update_key.mnemonic, rolling_key, operand );
// update decryption key correctly... // update decryption key correctly...
switch ( update_key.operands[ 0 ].size ) switch ( update_key.operands[ 0 ].size )
@ -77,8 +76,7 @@ namespace vm
const auto &generic_decrypt_3 = inverse[ transform::type::generic3 ]; const auto &generic_decrypt_3 = inverse[ transform::type::generic3 ];
const auto &update_key = inverse[ transform::type::update_key ]; const auto &update_key = inverse[ transform::type::update_key ];
auto result = auto result = transform::apply( update_key.operands[ 0 ].size, update_key.mnemonic, rolling_key, operand );
transform::apply( update_key.operands[ 0 ].size, update_key.mnemonic, rolling_key, operand );
// make sure we update the rolling decryption key correctly... // make sure we update the rolling decryption key correctly...
switch ( update_key.operands[ 0 ].size ) switch ( update_key.operands[ 0 ].size )
@ -162,5 +160,41 @@ namespace vm
return true; return true;
} }
std::optional< std::uint64_t > get_imm( vm::ctx_t &ctx, std::uint8_t imm_size, std::uintptr_t vip )
{
if ( !imm_size )
return {};
return ctx.exec_type == vmp2::exec_type_t::forward
? *reinterpret_cast< std::uintptr_t * >( vip + ( imm_size / 8 ) )
: *reinterpret_cast< std::uintptr_t * >( vip - ( imm_size / 8 ) );
}
std::optional< virt_instr_t > get( vm::ctx_t &ctx, vmp2::v2::entry_t &entry )
{
virt_instr_t result;
const auto &vm_handler = ctx.vm_handlers[ entry.handler_idx ];
const auto profile = vm_handler.profile;
result.mnemonic_t = profile ? profile->mnemonic : vm::handler::mnemonic_t::INVALID;
result.opcode = entry.handler_idx;
result.trace_data = entry;
if ( vm_handler.imm_size )
{
result.operand.has_imm = true;
const auto imm_val = get_imm( ctx, vm_handler.imm_size, entry.vip );
if ( !imm_val.has_value() )
return {};
result.operand.imm.u = imm_val.value();
}
else
result.operand.has_imm = false;
return result;
}
} // namespace instrs } // namespace instrs
} // namespace vm } // namespace vm

@ -156,6 +156,7 @@
</ItemGroup> </ItemGroup>
<ItemGroup> <ItemGroup>
<ClCompile Include="src\calc_jmp.cpp" /> <ClCompile Include="src\calc_jmp.cpp" />
<ClCompile Include="src\vmctx.cpp" />
<ClCompile Include="src\vmhandler.cpp" /> <ClCompile Include="src\vmhandler.cpp" />
<ClCompile Include="src\vminstrs.cpp" /> <ClCompile Include="src\vminstrs.cpp" />
<ClCompile Include="src\vmprofiles\add.cpp" /> <ClCompile Include="src\vmprofiles\add.cpp" />

@ -234,5 +234,8 @@
<ClCompile Include="src\vmutils.cpp"> <ClCompile Include="src\vmutils.cpp">
<Filter>Source Files</Filter> <Filter>Source Files</Filter>
</ClCompile> </ClCompile>
<ClCompile Include="src\vmctx.cpp">
<Filter>Source Files</Filter>
</ClCompile>
</ItemGroup> </ItemGroup>
</Project> </Project>
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