Can WinHttpGetIEProxyConfigForCurrentUser obtain proxy from WPAD - c++

Question

I was able to obtain proxy data that was manually entered into proxy settings on my Windows machine (Use a proxy server for your LAN option was checked) but I'm wondering if WinHttpGetIEProxyConfigForCurrentUser will also set field LPWSTR lpszProxy in case when Use automatic configuration script or Automatically detect settings checkboxes are checked in this dialog:
If not, how to obtain address of the currently used proxy?

Answer 1

You will get that in lpszAutoConfigUrl.
lpszAutoConfigUrl is variable of the structure WINHTTP_CURRENT_USER_IE_PROXY_CONFIG that is parameter of WinHttpGetIEProxyConfigForCurrentUser
Documentation link.
https://learn.microsoft.com/en-us/windows/desktop/api/winhttp/ns-winhttp-winhttp_current_user_ie_proxy_config
Code used for a quick test:
WINHTTP_CURRENT_USER_IE_PROXY_CONFIG pProxyConfig;
pProxyConfig.fAutoDetect = TRUE;
WinHttpGetIEProxyConfigForCurrentUser(&pProxyConfig);

Answer 2

WinHttpGetIEProxyConfigForCurrentUser() can be used to determine if both:
"Automatically detect settings" is enabled (member 'fAutoDetect' of WINHTTP_CURRENT_USER_IE_PROXY_CONFIG structure) and
"Automatic configuration script" is set (member 'lpszAutoConfigUrl' of WINHTTP_CURRENT_USER_IE_PROXY_CONFIG structure)
However, to obtain the proxy address itself for particular endpoint, WinHttpGetProxyForUrl() should be used.
If you already have 'Automatic configuration script' read from IE Internet options, you may use it like this:
WINHTTP_AUTOPROXY_OPTIONS autoProxyOptions= {0};
WINHTTP_PROXY_INFO proxyInfo= {0};
PCWSTR endpointUrl = <URL, that you need proxy for>;
autoProxyOptions.lpszAutoConfigUrl = <auto config address obtain from WINHTTP_CURRENT_USER_IE_PROXY_CONFIG>;
.
. //set suitable autoProxyOptions flags
.
if (!WinHttpGetProxyForUrl(hSession, endpointUrl, &autoProxyOptions, &proxyInfo))
{
GetLastError();
}