使用Python Ctypes违反访问 [英] Access Violation using Python Ctypes

问题描述

我正在尝试使用Pythons ctypes模块从DLL导入和使用函数，但是我一直收到此错误：

I am trying to import and use a function from a DLL using Pythons ctypes module, but I keep getting this error:

Windows Error: exception: access violation writing 0x0000002C

我在这里已经看过与类似主题有关的其他问题，但是似乎没有人能够提供有效的答案。
我当前的代码如下：

I've had a look at the other questions on similar topics on here, but none seem to be able to provide an answer that works. My current code is as follows:

from ctypes import *

dll = "./WinlicenseSDK/WinlicenseSDK.dll"

mydll = cdll.LoadLibrary(dll)

name = c_char_p("A.N. Body")
org = c_char_p("ACME")
pcID = c_char_p("APC44567")
zero = c_int(0)
licenseKey = create_string_buffer("")    

mydll.WLGenLicenseFileKey(HASH, name, org, pcID, zero, zero, zero, zero, zero, licenseKey)

上下文：I正在研究一种软件的许可技术。上面的函数通过散列参数来生成许可证密钥。

Context: I'm investigating licensing techniques for a piece of software. The above function generates a license key from hashing the parameters.

WLGenLicenseFileKey的最后一个参数是将生成的密钥写入的字符串缓冲区。

The last parameter for the WLGenLicenseFileKey is a string buffer that the generated key is written to.

我尝试使用 mydll.WLGenLicenseFileKey.argtypes = ... 设置该函数的argtypes，但是由于存在

I tried setting the argtypes for the function with mydll.WLGenLicenseFileKey.argtypes = ... but this won't work as there is not a string buffer ctypes raw type as there is for strings, ints, floats etc.

有人可以告诉我我要去哪里了吗？

Can anybody tell me where I am going wrong?

编辑：

C / C ++函数定义：

The C/C++ function definition:

int WLGenLicenseFileKeyW(    
wchar_t* pLicenseHash,     
wchar_t* pUserName,     
wchar_t* pOrganization,    
wchar_t* pCustomData,     
wchar_t* pMachineID,   
int NumDays,    
int NumExec,    
SYSTEMTIME* pExpirationDate,     
int CountryId,     
int Runtime,     
int GlobalTime,    
char* pBufferOut    
);

这是文档提供的有关函数的所有信息。

That is all the information that the documentation gives on the function.

推荐答案

您的licenseKey缓冲区的长度为1个字节，并且您没有传递Unicode字符串。我不在电脑前，但是如果您的参数正确，那应该就近了。确保调用该函数的W版本。只要它们是整数和指针，就不需要创建确切的类型。

The length of your licenseKey buffer is one byte, and you are not passing Unicode strings. I'm not in front of my PC, but I this should be close assuming your parameters are otherwise correct. Make sure to call the W version of the function. You also don't need to create the exact types as long as they are ints and pointers.

buffer = create_string_buffer(REQUIRED_BUFSIZE)
mydll.WLGenLicenseKeyW(u"A.N. Body", u"ACME", u"APC44567", None, None, 0, 0, None, 0, 0, 0, buffer)

如果您确实想使用 argtypes ，那么这就是您想要的：

If you do want to use argtypes, then this is what you want:

mydll.WLGenLicenseKeyW.argtypes = [c_wchar_t,c_wchar_t,c_wchar_t,c_wchar_t,c_wchar_t,c_int,c_int,c_void_p,c_int,c_int,c_int,c_char_p]

SYSTEMTIME

编辑

我找到了一些文档。该函数使用stdcall调用约定，因此请使用：

I found some documentation. The function uses the stdcall calling convention, so use:

mydll = WinDLL(dll)

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