Files
hakril-PythonForWindows/windows/native_exec/native_function.py
T

118 lines
3.4 KiB
Python

import ctypes
import mmap
import platform
import sys
import windows
import windows.winproxy
from . import simple_x86 as x86
from . import simple_x64 as x64
class PyObj(ctypes.Structure):
_fields_ = [("ob_refcnt", ctypes.c_size_t),
("ob_type", ctypes.c_void_p)] # must be cast
class PyMmap(PyObj):
_fields_ = [("ob_addr", ctypes.c_size_t), ("ob_size", ctypes.c_size_t)]
# Specific mmap class for code injection
class MyMap(mmap.mmap):
""" A mmap that is never unmapped and that contains the page address """
def __init__(self, *args, **kwarg):
# Get the page address by 'introspection' of the C struct
m = PyMmap.from_address(id(self))
self.addr = m.ob_addr
# Prevent garbage collection (so unmaping) of the page
m.ob_refcnt += 1
@classmethod
def get_map(cls, size):
""" Dispatch to the good mmap implem depending on the current system """
systems = {'windows': Win32MyMap,
'linux': UnixMyMap}
x = platform.system().lower()
if x not in systems:
raise ValueError("Unknow system {0}".format(x))
return systems[x].get_map(size)
class Win32MyMap(MyMap):
@classmethod
def get_map(cls, size):
addr = windows.winproxy.VirtualAlloc(0, size, 0x1000, 0x40)
new_map = (ctypes.c_char * size).from_address(addr)
new_map.addr = addr
if new_map.addr == 0:
raise ctypes.WinError()
return new_map
class UnixMyMap(MyMap):
@classmethod
def get_map(cls, size):
prot = mmap.PROT_EXEC | mmap.PROT_WRITE | mmap.PROT_READ
return cls(-1, size, prot=prot)
class CustomAllocator(object):
int_size = {'32bit': 4, '64bit': 8}
def __init__(self):
self.maps = []
self.cur_offset = 0
self.cur_page_size = 0 # Force get_new_page on first request
self.names = []
@classmethod
def get_int_size(cls):
bits = platform.architecture()[0]
if bits not in cls.int_size:
raise ValueError("Unknow platform bits <{0}>".format(bits))
return cls.int_size[bits]
def get_new_page(self, size):
self.maps.append(MyMap.get_map(size))
self.cur_offset = 0
self.cur_page_size = size
def reserve_size(self, size):
if size + self.cur_offset > self.cur_page_size:
self.get_new_page((size + 0x1000) & ~0xfff)
addr = self.maps[-1].addr + self.cur_offset
self.cur_offset += size
return addr
def reserve_int(self, nb_int=1):
int_size = self.get_int_size()
return self.reserve_size(int_size * nb_int)
def write_code(self, code):
size = len(code)
if size + self.cur_offset > self.cur_page_size:
self.get_new_page((size + 0x1000) & ~0xfff)
self.maps[-1][self.cur_offset: self.cur_offset + size] = code
addr = self.maps[-1].addr + self.cur_offset
self.cur_offset += size
return addr
allocator = CustomAllocator()
def create_function(code, types):
"""Create a python function that call raw machine code
:param str code: Raw machine code that will be called
:param list types: Return type and parameters type (see :mod:`ctypes`)
:return: the created function
:rtype: function
"""
func_type = ctypes.CFUNCTYPE(*types)
addr = allocator.write_code(code)
res = func_type(addr)
res.code_addr = addr
return res