POST Request in WinHttp c++
15,899
In order for PHP (or any other post-processing language) to recognise POST data, add this:
LPCWSTR additionalHeaders = L"Content-Type: application/x-www-form-urlencoded\r\n";
DWORD headersLength = -1;
bResults = WinHttpSendRequest( hRequest,
additionalHeaders,
headersLength ,
(LPVOID)data,
data_len,
data_len,
0);
The rest of a code is functional, should work:
Author by
Jose
Updated on June 04, 2022Comments
-
Jose almost 2 years
I'm trying to make a POST request in c++ with the WinHTTP api Click to the Microsoft Guide, the problem is that the example that is available in the microsoft webpage is a "GET" request so I came up with this code searching on the internet:
First we call the code:
HttpsWebRequestPost("example.com", "/api.php?action=UserLogin", "loginUsername=" + USERNAME + "&loginPassword=" + PASSWORD + "&url=/index.php?page=Portal");
Then:
#include <Windows.h> #include <WinHttp.h> #include <stdio.h> #include <iostream> //getchar #include <fstream> #pragma comment(lib, "winhttp.lib") using namespace std; std::wstring get_utf16(const std::string &str, int codepage) { if (str.empty()) return std::wstring(); int sz = MultiByteToWideChar(codepage, 0, &str[0], (int)str.size(), 0, 0); std::wstring res(sz, 0); MultiByteToWideChar(codepage, 0, &str[0], (int)str.size(), &res[0], sz); return res; } string HttpsWebRequestPost(string domain, string url, string dat) { //Extra LPSTR data = const_cast<char *>(dat.c_str());; DWORD data_len = strlen(data); wstring sdomain = get_utf16(domain, CP_UTF8); wstring surl = get_utf16(url, CP_UTF8); string response; DWORD dwSize = 0; DWORD dwDownloaded = 0; LPSTR pszOutBuffer; BOOL bResults = FALSE; HINTERNET hSession = NULL, hConnect = NULL, hRequest = NULL; // Use WinHttpOpen to obtain a session handle. hSession = WinHttpOpen(L"WinHTTP Example/1.0", WINHTTP_ACCESS_TYPE_DEFAULT_PROXY, WINHTTP_NO_PROXY_NAME, WINHTTP_NO_PROXY_BYPASS, 0); // Specify an HTTP server. if (hSession) hConnect = WinHttpConnect(hSession, sdomain.c_str(), INTERNET_DEFAULT_HTTP_PORT, 0); // Create an HTTP request handle. if (hConnect) hRequest = WinHttpOpenRequest(hConnect, L"POST", surl.c_str(), NULL, WINHTTP_NO_REFERER, WINHTTP_DEFAULT_ACCEPT_TYPES, 0); // Send a request. if (hRequest) bResults = WinHttpSendRequest(hRequest, WINHTTP_NO_ADDITIONAL_HEADERS, 0, (LPVOID)data, data_len, data_len, 0); // End the request. if (bResults) bResults = WinHttpReceiveResponse(hRequest, NULL); // Keep checking for data until there is nothing left. if (bResults) { do { // Check for available data. dwSize = 0; if (!WinHttpQueryDataAvailable(hRequest, &dwSize)) printf("Error %u in WinHttpQueryDataAvailable.\n", GetLastError()); // Allocate space for the buffer. pszOutBuffer = new char[dwSize + 1]; if (!pszOutBuffer) { printf("Out of memory\n"); dwSize = 0; } else { // Read the data. ZeroMemory(pszOutBuffer, dwSize + 1); if (!WinHttpReadData(hRequest, (LPVOID)pszOutBuffer, dwSize, &dwDownloaded)) printf("Error %u in WinHttpReadData.\n", GetLastError()); else //printf("%s", pszOutBuffer); response = response + string(pszOutBuffer); // Free the memory allocated to the buffer. delete[] pszOutBuffer; } } while (dwSize > 0); } // Report any errors. if (!bResults) printf("Error %d has occurred.\n", GetLastError()); // Close any open handles. if (hRequest) WinHttpCloseHandle(hRequest); if (hConnect) WinHttpCloseHandle(hConnect); if (hSession) WinHttpCloseHandle(hSession); return response; }
But using WireShark I only get:
Hypertext Transfer Protocol POST ***************** HTTP/1.1\r\n Connection: Keep-Alive\r\n User-Agent: WinHTTP Example/1.0\r\n Content-Length: **\r\n Host: ******\r\n \r\n
Anyone can help meto fix this or know an easier method? Thanks