Junk characters in htttps get response - c++

Question

I am facing a weird situation with a Windows application (OCX control) written in C++, which was working fine until 2 days ago. No updates were added to the application. Then suddenly, it started to have errors in the communication with a remote test server. Basically, the error is that in the response of a GET request, I am seeing junk characters like this: ÑòWo †¶âBA etc
The function that I am using for the HTTP requests is:
TCHAR* openUrlFunction(TCHAR *strServer, TCHAR *strPath, TCHAR *userAgent){
HINTERNET httpSession = NULL;
HINTERNET httpConnect = NULL;
HINTERNET httpRequest = NULL;
HINTERNET hFile = NULL;
BOOL resDownload = FALSE;
TCHAR bufferIdent[60] = { 0 };
TCHAR bufferMirror[500] = { 0 };
TCHAR szURL[200] = { 0 };
TCHAR sError[7] = { 0 };
DWORD dwFlags;
// DWORD dwTimeOut = 25000;
DWORD dwBuffLen = sizeof(dwFlags);
int i = 0;
DWORD dwRead, error;
int len;
TCHAR *res1;
TCHAR delimeter[6] = _T("\f\n\r\t\v");
HRESULT resCat;
bufferIdent[0] = '\0';
bufferMirror[0] = '\0';
szURL[0] = '\0';
std::string ss;
httpSession = InternetOpen(strAgent, INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0); // header
if (httpSession)
{
httpConnect = InternetConnect(httpSession, strServer, INTERNET_DEFAULT_HTTPS_PORT, NULL, NULL, INTERNET_SERVICE_HTTP, 0, 0);
if (httpConnect)
{
httpRequest = HttpOpenRequest(httpConnect, "GET", strPath, NULL, NULL, NULL, INTERNET_FLAG_SECURE, 0); parametros.
if (HttpSendRequest(httpRequest, NULL, 0, NULL, 0)) {
if (httpRequest)
{
while (InternetReadFile(httpRequest, bufferMirror, 499, &dwRead)) // Se lee el retorno
{
if (dwRead == 0)
break;
StrTrim(bufferMirror, delimeter);
while (bufferMirror[i] != NULL){
if (bufferMirror[i] != char(10))
ss = ss + bufferMirror[i];
i++;
if (bufferMirror[i] == char(10))
break;
}
i = 0;
}
}
}
else{
error = GetLastError();
_stprintf_s(sError, 7, _T("%d"), error);
InternetCloseHandle(httpRequest);
InternetCloseHandle(httpConnect);
InternetCloseHandle(httpSession);
return sError;
}
InternetCloseHandle(httpRequest);
}
InternetCloseHandle(httpConnect);
}
InternetCloseHandle(httpSession);
len = ss.length();
if (len == 0){
return NULL;
}
res1 = new TCHAR[len + 1];
resCat = StringCchCopyN(res1, len + 1, ss.c_str(), len);
if (!SUCCEEDED(resCat))
return NULL;
return res1;
}
The interesting thing here was that I decided to monitor the traffic so I have installed Fiddler on the same machine (Windows 10) where the problem is happening. After started Fiddler, I made a test with the Application and voila, the response was clear and well-formed and no junk characters were present.
I suspect that the Fiddler Everywhere Certificate that is installed has something to do with the result. So, if I turn off Fiddler, and make a new test, I again receive the junk characters.
I have checked the TLS configuration in the computer and nothing is wrong there. I am not sure if a Windows update could have caused this situation.
We have 3 machines, and the problem is occurring on 2 of the 3. All of them are Windows 10, but maybe different updates.
One other important thing here is that the server is for testing, and the client did not install any SSL certificate.

Answer 1

Well after looking into this problem, I just found that the root of the issue was more related to the fact the one of the variables was not correctly initialized and before the http request, this variable could contain junk characters so the next steps of the process were affected for the garbage that the variable contained. Another thing was that the connection problem with WININET was solved after installing a right SSL certificate. Even after setting some flags to bypass the SSL validation, did not work. The connection only was possible when the server was configured with the SSL certificate.