如何使用ctypes在python中创建int缓冲区

Question

我正在尝试用python写内存。我需要写一个整数，但是对于WriteProcessMemory函数，我需要一个缓冲区。你知道吗

writeProcessMemory = kernel.WriteProcessMemory
writeProcessMemory.argtypes = [ctypes.wintypes.HANDLE, 
ctypes.wintypes.LPVOID, ctypes.wintypes.LPCVOID, ctypes.c_size_t, 
                         ctypes.POINTER(ctypes.c_size_t)]
writeProcessMemory.restype = ctypes.wintypes.BOOL


openProcess = kernel.OpenProcess
openProcess.argtypes = [ctypes.wintypes.DWORD, ctypes.wintypes.BOOL, 
ctypes.wintypes.DWORD]
openProcess.restype = ctypes.wintypes.HANDLE

handle = openProcess(PROCESS_ALL_ACCESS, False, pid)
addr = 0x024EA498
data = ctypes.c_int(1000)
buffer = #i need to create a buffer here

Answer 1

你可以使用^{}

buffer = ctypes.create_string_buffer(b"",1000 * 4)

创建1000个4大小整数的0填充缓冲区。这个缓冲区是ctypes.c_char_Array_4000类型，可以作为指针传递给导入的函数。你知道吗

This function creates a mutable character buffer. The returned object is a ctypes array of c_char.

init_or_size must be an integer which specifies the size of the array, or a bytes object which will be used to initialize the array items.

If a bytes object is specified as first argument, the buffer is made one item larger than its length so that the last element in the array is a NUL termination character. An integer can be passed as second argument which allows specifying the size of the array if the length of the bytes should not be used.

现在调用导入的函数，获取刚才使用以下命令编写的pythonbytes对象：

python_bytes_array = ctypes.string_at(buffer)

并使用struct获取整数值。不需要指定端点。I是4个字节。如果调用的函数使用4字节整数，则它将起作用：

import struct
integer_tuple = struct.unpack("1000I",python_bytes_array)