Zyan Disassembler Engine (Zydis)

Fast and lightweight x86/x86-64 disassembler library.

Features

• Supports all x86 and x86-64 (AMD64) general-purpose and system instructions.
• Supports pretty much all ISA extensions:
  • FPU (x87), MMX
  • SSE, SSE2, SSE3, SSSE3, SSE4.1, SSE4.2, SSE4A, AESNI
  • AVX, AVX2, AVX512BW, AVX512CD, AVX512DQ, AVX512ER, AVX512F, AVX512PF, AVX512VL
  • ADX, BMI1, BMI2, FMA, FMA4
  • ..
• Optimized for high performance
• No dynamic memory allocation
  • Perfect for kernel-mode drivers and embedded devices
• Very small file-size overhead compared to other common disassembler libraries
• Complete doxygen documentation

Roadmap

• Language bindings [v2.0 final]
• Tests [v2.0 final]
• Graphical editor for the instruction-database [v2.0 final]
• Implement CMake feature gates. Currently, everything is always included. [v2.0 final]
• Encoding support [v2.1]

Quick Example

The following example program uses Zydis to disassemble a given memory buffer and prints the output to the console.

#include <stdio.h>
#include <Zydis/Zydis.h>

int main()
{
    uint8_t data[] =
    {
        0x51, 0x8D, 0x45, 0xFF, 0x50, 0xFF, 0x75, 0x0C, 0xFF, 0x75, 
        0x08, 0xFF, 0x15, 0xA0, 0xA5, 0x48, 0x76, 0x85, 0xC0, 0x0F, 
        0x88, 0xFC, 0xDA, 0x02, 0x00
    };

    ZydisDecoder decoder;
    ZydisDecoderInit(&decoder, ZYDIS_MACHINE_MODE_LONG_64, ZYDIS_ADDRESS_WIDTH_64);

    ZydisFormatter formatter;
    ZydisFormatterInitEx(&formatter, ZYDIS_FORMATTER_STYLE_INTEL,
        ZYDIS_FMTFLAG_FORCE_SEGMENTS | ZYDIS_FMTFLAG_FORCE_OPERANDSIZE,
        ZYDIS_FORMATTER_ADDR_ABSOLUTE, ZYDIS_FORMATTER_DISP_DEFAULT, ZYDIS_FORMATTER_IMM_DEFAULT);
  
    uint64_t instructionPointer = 0x007FFFFFFF400000;

    ZydisDecodedInstruction instruction;
    char buffer[256];
    while (ZYDIS_SUCCESS(
        ZydisDecoderDecodeBuffer(decoder, data, length, instructionPointer, &instruction)))
    {
        data += instruction.length;
        length -= instruction.length;
        instructionPointer += instruction.length;
        printf("%016" PRIX64 "  ", instruction.instrAddress);
        ZydisFormatterFormatInstruction(&formatter, &instruction, &buffer[0], sizeof(buffer));  
        printf(" %s\n", &buffer[0]);
    }
}

Sample Output

The above example program generates the following output:

007FFFFFFF400000   push rcx
007FFFFFFF400001   lea eax, dword ptr ss:[rbp-0x01]
007FFFFFFF400004   push rax
007FFFFFFF400005   push qword ptr ss:[rbp+0x0C]
007FFFFFFF400008   push qword ptr ss:[rbp+0x08]
007FFFFFFF40000B   call qword ptr ds:[0x008000007588A5B1]
007FFFFFFF400011   test eax, eax
007FFFFFFF400013   js 0x007FFFFFFF42DB15

Compilation

Zydis builds cleanly on most platforms without any external dependencies. You can use CMake to generate project files for your favorite C99 compiler.

# Linux and OS X
git clone 'https://github.com/zyantific/zydis.git'
cd zydis
mkdir build && cd build
cmake ..
make

ZydisInfo tool

License

Zydis is licensed under the MIT license.