SSL connection through proxy server - php

Question

I'm trying to connect to the Twitter api server to make an "Application-only Autentication".
I don't care any other way to connect to Twitter. I need this specific method.
I need to go from localhost through my corporation's proxy to api.twitter.com which needs ssl
Following the instruction of this twitter developer's page https://dev.twitter.com/docs/auth/application-only-auth, i tried with:
cUrl:
try {
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
if ($this->proxy != '') {
curl_setopt($ch, CURLOPT_PROXY, $this->proxy);
curl_setopt($ch, CURLOPT_PROXYPORT, $this->port);
curl_setopt($ch, CURLOPT_PROXYUSERPWD, $this->userpwd);
}
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_SSLVERSION, 3);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_HTTPHEADER, array("
POST /oauth2/token HTTP/1.1
Host: api.twitter.com
User-Agent: My Twitter App v1.0.23
Authorization: Basic ".base64_encode(urlencode($consumer_key).":".urlencode($consumer_secret))."
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
Content-Length: 29
Accept-Encoding: gzip
grant_type=client_credentials
"));
$response = curl_exec($ch);
if (FALSE === $response) throw new Exception(curl_error($ch), curl_errno($ch));
curl_close($ch);
var_dump(json_decode($response));
}
catch(Exception $e) {
trigger_error(sprintf('Curl failed with error #%d: %s', $e->getCode(), $e->getMessage()), E_USER_ERROR);
}
Which gives me
Fatal error: Curl failed with error #35: Unknown SSL protocol error in connection to api.twitter.com
file_get_contents:
$context = stream_context_create(array(
"http" => array(
"method"=>"CONNECT",
"proxy" => $this->proxy.":".$this->port,
"request_fulluri" => true,
"header" => "
POST /oauth2/token HTTP/1.1
Host: api.twitter.com
User-Agent: My Twitter App v1.0.23
Proxy-Authorization: Basic ".base64_encode(urlencode($this->userpwd))."
Authorization: Basic ".base64_encode(urlencode($consumer_key).":".urlencode($consumer_secret))."
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
Content-Length: 29
Accept-Encoding: gzip
grant_type=client_credentials
",
),
));
$response = file_get_contents($url, False, $context);
var_dump(json_decode($response));
Which gives me
Warning: file_get_contents(https://api.twitter.com/oauth2/token) [function.file-get-contents]: failed to open stream: Cannot connect to HTTPS server through proxy
fsockopen:
$fp = fsockopen($this->proxy, $this->port);
fputs($fp, "
POST /oauth2/token HTTP/1.1
Host: api.twitter.com
User-Agent: My Twitter App v1.0.23
Authorization: Basic ".base64_encode(urlencode($consumer_key).":".urlencode($consumer_secret))."
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
Content-Length: 29
Accept-Encoding: gzip
grant_type=client_credentials
");
$data="";
while (!feof($fp)) $data .= fgets($fp,1024);
fclose($fp);
var_dump($data);
Which gives me
HTTP/1.1 400 Bad Request
Cache-Control: no-cache
Pragma: no-cache
Content-Type: text/html; charset=utf-8
Proxy-Connection: close
Connection: close
Content-Length: 727
I am sure that the 443 port is open and it's not a problem of the localhost (I got the same error trying on an online server).
I tried even using CONNECT method instead of POST.
I tried tunneling the proxy, but I'm neither sure I made it nor that that's the problem.
I'm running out ideas..

Answer 1

Try to remove this:
curl_setopt($ch, CURLOPT_SSLVERSION, 3);
You only have one value in this array, it's wrong.
curl_setopt($ch, CURLOPT_HTTPHEADER, array("
POST /oauth2/token HTTP/1.1
Host: api.twitter.com
User-Agent: My Twitter App v1.0.23
Authorization: Basic ".base64_encode(urlencode($consumer_key).":".urlencode($consumer_secret))."
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
Content-Length: 29
Accept-Encoding: gzip
grant_type=client_credentials
"));
Change the above for this:
$consumer_key = base64_encode(urlencode($consumer_key);
$consumer_secret = urlencode($consumer_secret);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
"Host: api.twitter.com",
"User-Agent: My Twitter App v1.0.23",
"Authorization: Basic $consumer_key:$consumer_secret",
"Content-Type: application/x-www-form-urlencoded;charset=UTF-8",
"Accept-Encoding: gzip",
"grant_type=client_credentials"
));
if you want to include the Content-Length: xx, you need to use strlen() to get string length of the post, ex;
$length = strlen($post_content);
Then add it to the CURLOPT_HTTPHEADER array:
"Content-Length: $length"

Answer 2

Found the problem. There's no need (maybe only in this case, i'm not sure) to base64 encode the credentials. They'll be encoded by the server.
I don't know the reason of that different error responses, but was in fact a problem of double encoding, because of which the server was not able to verify my credentials.