How to resolve HTTPS status code 404 using WinHTTP?

Question

I am getting status code 404 for the below code snippet.
Note: please add `<HOSTNAME>` when you are trying to figure out the issue.
HINTERNET m_hConnect;
HINTERNET m_hSession;
HINTERNET m_hRequest;
m_hSession = WinHttpOpen(userAgent,
WINHTTP_ACCESS_TYPE_NO_PROXY,
WINHTTP_NO_PROXY_NAME,
WINHTTP_NO_PROXY_BYPASS, 0);
if (!m_hSession) {
printf("WinHttpOpen:Error %d has occurred.",GetLastError());
return 0;
// connect to the IPP server on the given port
m_hConnect = WinHttpConnect( m_hSession, <HOSTNAME>, 443, 0);
if (!m_hConnect) {
printf("WinHttpConnect: Error %d has occurred.",GetLastError());
return 0;
// Create an HTTP Request handle.
m_hRequest = WinHttpOpenRequest(m_hConnect, L"POST" ,L"/ipp",
L"HTTP/1.1", WINHTTP_NO_REFERER,
WINHTTP_DEFAULT_ACCEPT_TYPES,WINHTTP_FLAG_SECURE);
if (!m_hRequest) {
printf("WinHttpOpenRequest:Error %d has occurred.",GetLastError());
return 0;
DWORD secureflags = SECURITY_FLAG_IGNORE_UNKNOWN_CA | SECURITY_FLAG_IGNORE_CERT_CN_INVALID |SECURITY_FLAG_IGNORE_CERT_WRONG_USAGE | SECURITY_FLAG_IGNORE_CERT_DATE_INVALID;
BOOL bResult= WinHttpSetOption(m_hRequest, WINHTTP_OPTION_SECURITY_FLAGS, (LPVOID)&secureflags, sizeof(secureflags));
if (!bResult) {
printf("WinHttpSetOption:Error %d has occurred.",GetLastError());
return 0;
bResult = WinHttpSendRequest(m_hRequest, WINHTTP_NO_ADDITIONAL_HEADERS,0,WINHTTP_NO_REQUEST_DATA,0,0,0);
if (!bResult) {
printf("WinHttpSendRequest:Error %d has occurred.",GetLastError());
return 0;
if( !WinHttpReceiveResponse( m_hRequest, NULL ) )
if( GetLastError( ) == ERROR_WINHTTP_CLIENT_AUTH_CERT_NEEDED )
HCERTSTORE hMyStore = 0;
PCCERT_CONTEXT pCertContext = 0;
WCHAR szCertName[256]={0};
//MY is the store the certificate is in.
hMyStore = CertOpenSystemStore( 0, TEXT("MY") );
if( hMyStore )
pCertContext = CertFindCertificateInStore( hMyStore,
X509_ASN_ENCODING | PKCS_7_ASN_ENCODING,
0,
CERT_FIND_SUBJECT_STR,
(LPVOID) szCertName, //Subject string in the certificate.
NULL );
if( pCertContext )
WinHttpSetOption( m_hRequest,
WINHTTP_OPTION_CLIENT_CERT_CONTEXT,
(LPVOID) pCertContext,
sizeof(CERT_CONTEXT) );
CertFreeCertificateContext( pCertContext );
CertCloseStore( hMyStore, 0 );
// NOTE: Application should now resend the request.
bResult = WinHttpSendRequest(m_hRequest, WINHTTP_NO_ADDITIONAL_HEADERS,0,WINHTTP_NO_REQUEST_DATA,0,0,0);
if (!bResult) {
printf("WinHttpSendRequest:Error %d has occurred.",GetLastError());
return 0;
DWORD dwStatusCode = 0;
DWORD dwSize = sizeof(DWORD);
BOOL bResults = true;
bResults = WinHttpQueryHeaders( m_hRequest, WINHTTP_QUERY_STATUS_CODE | WINHTTP_QUERY_FLAG_NUMBER, NULL, &dwStatusCode, &dwSize, NULL );
Result: I am getting status code of 404. I am not able to figure out why it is happening.
FYI, Using `WinINet`,  I have followed the same procedure, I am getting status code of 200, which is success. But my requirement is to use only `WinHttp`.
Could any one please help me out to solve this issue. This is very urgent for me.
SivaV

Answer 1

Dear Henri,
Thanks for your reply, it was really very helpful.
I debugged
HTTP session with Fiddler,
I am getting certificate error.
When I say 'Yes' in Fiddler, I am getting 200 success.
Could you please help me out how to
"Ignore certificate errors" using WinHTTP
API's.
Thanks in Advance.
Best Regards,
Siva
SivaV