Error http 407 using libcurl and ntml - c++

Question

i'm developing a small application.
For testing purpouse i'm tryng to "ping" google using libcurl while behind an ntlm proxy.
This is my c++ code:
CURLcode testConnection(void)
{
CURL *curl;
CURLcode res = CURLE_OK;
res = curl_global_init(CURL_GLOBAL_ALL);
curl = curl_easy_init();
if (curl)
{
cout << "Url: " << curl_easy_strerror(curl_easy_setopt(curl, CURLOPT_URL, "http://www.google.com")) << "\n";
cout << "T-out: " << curl_easy_strerror(curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 3)) << "\n";
cout << "No_body: " << curl_easy_strerror(curl_easy_setopt(curl, CURLOPT_NOBODY, true)) << "\n";
cout << "Proxy Url: " << curl_easy_strerror(curl_easy_setopt(curl, CURLOPT_PROXY, "proxyrm.wind.root.it")) << "\n";
cout << "Proxy Port: " << curl_easy_strerror(curl_easy_setopt(curl, CURLOPT_PROXYPORT, 8080)) << "\n";
cout << "Ntml: " << curl_easy_strerror(curl_easy_setopt(curl, CURLOPT_HTTPAUTH, CURLAUTH_NTLM)) << "\n";
cout << "Verbose: " << curl_easy_strerror(curl_easy_setopt(curl, CURLOPT_VERBOSE, true)) << "\n";
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
else
res = CURLE_FAILED_INIT;
curl_global_cleanup();
return res;
}
All thi went good, since the verbose output is the following.
Url: No error
T-out: No error
No_body: No error
Proxy Url: No error
Proxy Port: No error
Ntml: No error
Verbose: No error
* About to connect() to proxy myroxy port 8080 (#0)
* Trying IP...
* Connected to myroxy (IP) port 8080 (#0)
> HEAD http://www.google.com HTTP/1.1
Host: www.google.com
Accept: */*
Proxy-Connection: Keep-Alive
< HTTP/1.1 407 Proxy Authentication Required
< Proxy-Authenticate: NTLM
< Proxy-Authenticate: BASIC realm="windroot"
< Cache-Control: no-cache
< Pragma: no-cache
< Content-Type: text/html; charset=utf-8
* HTTP/1.1 proxy connection set close!
< Proxy-Connection: close
< Set-Cookie: BCSI-CS-602d36a7505d346e=2; Path=/
< Connection: close
< Content-Length: 989
<
* Closing connection 0
Curl Final: No error
But, if i try to ping https://google.com the result become this
Url: No error
T-out: No error
No_body: No error
Proxy Url: No error
Proxy Port: No error
Ntml: No error
Ntml: No error
Ntml: No error
Verbose: No error
* About to connect() to proxy myroxy port 8080 (#0
* Trying IP...
* Connected to myroxy (IP) port 8080 (#0)
* Establish HTTP proxy tunnel to www.google.com:443
> CONNECT www.google.com:443 HTTP/1.1
Host: www.google.com:443
Proxy-Connection: Keep-Alive
< HTTP/1.1 407 Proxy Authentication Required
< Proxy-Authenticate: NTLM
< Proxy-Authenticate: BASIC realm="windroot"
< Cache-Control: no-cache
< Pragma: no-cache
< Content-Type: text/html; charset=utf-8
< Proxy-Connection: close
< Set-Cookie: BCSI-CS-602d36a7505d346e=2; Path=/
< Connection: close
< Content-Length: 1135
<
* Ignore 1135 bytes of response-body
* Received HTTP code 407 from proxy after CONNECT
* Connection #0 to host myroxy left intact
Curl Final: Failure when receiving data from the peer
Using curl in command line allow me to ping https (i have to specify the -k argument) but i don't know if this is really relevant. Someone can help me to figure out what's happening? And how to avoid that?

Answer 1

Solved: i was missing this instruction
curl_easy_setopt(ctx, CURLOPT_PROXYUSERPWD, ":");
This (i think) tell curl to use Username an Password retrieved from SO passing througt ntlm auth