How to use ctypes.windll.Wininet.InternetQueryOptionW in python

Question

several month ago,I wrote https://github.com/325862401/goagent/blob/master/local/ieproxysetting.cpp. that program can set internet proxy automatically.

Now I want to use ctypes.windll.Wininet to do the same thing.

But I donot know how to pass the argument to InternetQueryOptionW. and I also don't find the class refer to the INTERNET_PER_CONN_OPTION_LIST structure.

is there any demo for the usage of InternetQueryOptionW or InternetSetOptionW in python.

this https://bitbucket.org/canassa/switch-proxy/src/685ac447783a7cb3ead6ce8369b66483790c26be/proxy.py?at=default maybe be helpful. but I donot want to modify Registry. just use the api.

Thanks a lot. sorry for poor English.

Answer 1

Here is Python equivalent to your cpp code, pretty much straight forward conversation (I didn't test it that much):

#-*- coding: utf-8 -*-
#!python

from ctypes import *
from ctypes.wintypes import *

# stick to unicode version
LPWSTR = POINTER(WCHAR)
HINTERNET = LPVOID

INTERNET_PER_CONN_FLAGS = 1
INTERNET_PER_CONN_AUTOCONFIG_URL = 4
INTERNET_PER_CONN_AUTODISCOVERY_FLAGS = 5
INTERNET_OPTION_REFRESH = 37
INTERNET_OPTION_SETTINGS_CHANGED = 39
INTERNET_OPTION_PER_CONNECTION_OPTION = 75

PROXY_TYPE_AUTO_PROXY_URL = 4

class INTERNET_PER_CONN_OPTION(Structure):
    class Value(Union):
        _fields_ = [
            ('dwValue', DWORD),
            ('pszValue', LPWSTR),
            ('ftValue', FILETIME),
        ]

    _fields_ = [
        ('dwOption', DWORD),
        ('Value', Value),
    ]

class INTERNET_PER_CONN_OPTION_LIST(Structure):
    _fields_ = [
        ('dwSize', DWORD),
        ('pszConnection', LPWSTR),
        ('dwOptionCount', DWORD),
        ('dwOptionError', DWORD),
        ('pOptions', POINTER(INTERNET_PER_CONN_OPTION)),
    ]

InternetSetOption = windll.wininet.InternetSetOptionW
InternetSetOption.argtypes = [HINTERNET, DWORD, LPVOID, DWORD]
InternetSetOption.restype  = BOOL

if __name__ == '__main__':
    proxy = create_unicode_buffer('http://127.0.0.1:8086/proxy.pac')
    List = INTERNET_PER_CONN_OPTION_LIST()
    Option = (INTERNET_PER_CONN_OPTION * 2)()
    nSize = c_ulong(sizeof(INTERNET_PER_CONN_OPTION_LIST))

    Option[0].dwOption = INTERNET_PER_CONN_AUTOCONFIG_URL
    Option[0].Value.pszValue = proxy
    Option[1].dwOption = INTERNET_PER_CONN_FLAGS
    Option[1].Value.dwValue = PROXY_TYPE_AUTO_PROXY_URL

    List.dwSize = sizeof(INTERNET_PER_CONN_OPTION_LIST)
    List.pszConnection = None
    List.dwOptionCount = 2
    List.dwOptionError = 0
    List.pOptions = Option

    assert InternetSetOption(None, INTERNET_OPTION_PER_CONNECTION_OPTION, byref(List), nSize) == True
    assert InternetSetOption(None, INTERNET_OPTION_SETTINGS_CHANGED, None, 0) == True
    assert InternetSetOption(None, INTERNET_OPTION_REFRESH, None, 0) == True

You don't need MultiByteToWideChar, create_unicode_buffer and the unicode version of InternetSetOption should do the job.