can't get image using php CURL with SSL

问题:

so I'm trying to make a CURL connection using PHP....when I use command line here's what gets returned

curl -iv https://example.com/image.gif
* Hostname was NOT found in DNS cache
*   Trying ip.ad.dr.es.ss...
* Connected to site.com (ip.ad.dr.es.ss) port 443 (#0)
* TLS 1.2 connection using TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384
* Server certificate: example.com
* Server certificate: Symantec Class 3 Secure Server CA - G4
* Server certificate: VeriSign Class 3 Public Primary Certification Authority - G5
> GET /image.gif HTTP/1.1
> User-Agent: curl/7.37.1
> Host: example.com
> Accept: */*
> 
< HTTP/1.1 200 OK
HTTP/1.1 200 OK
< Content-Type: image/gif
Content-Type: image/gif
< Last-Modified: Thu, 14 Jul 2011 22:16:46 GMT
Last-Modified: Thu, 14 Jul 2011 22:16:46 GMT
< Accept-Ranges: bytes
Accept-Ranges: bytes
< ETag: "09bd8b77342cc1:0"
ETag: "09bd8b77342cc1:0"
* Server Microsoft-IIS/7.5 is not blacklisted
< Server: Microsoft-IIS/7.5
Server: Microsoft-IIS/7.5
< X-Powered-By: ASP.NET
X-Powered-By: ASP.NET
< X-UA-Compatible: IE=EmulateIE10, requiresActiveX=true
X-UA-Compatible: IE=EmulateIE10, requiresActiveX=true
< Date: Thu, 05 Nov 2015 20:57:22 GMT
Date: Thu, 05 Nov 2015 20:57:22 GMT
< Content-Length: 43
Content-Length: 43
< Set-Cookie: BIGipServerSpace=596747530.20480.0000; path=/
Set-Cookie: BIGipServerSpace=596747530.20480.0000; path=/

< 
* Connection #0 to host example.com left intact

And here's how I try to access it via PHP

 $ch = curl_init();
  $url_to_check = 'https://example.com/image.gif';
  curl_setopt( $ch, CURLOPT_URL, $url_to_check );
  curl_setopt($ch, CURLOPT_SSLVERSION, CURL_SSLVERSION_TLSv1_2);
  curl_setopt($ch, CURLOPT_PORT, 443);
  curl_exec( $ch );
  $httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
  echo curl_error($ch);
  echo '||';
  echo $httpcode;
  curl_close( $ch );

But then it ends up returning

Empty reply from server||0

What did I do wrong? How can I fetch the image using SSL via php CURL accordingly?

回答1:

What cURL version is your PHP using? Perhaps it doesn't support TLS 1.2 which was added in cURL 7.34.0.

Or your CA bundle might not recognize the CA of the site you are connecting to.

Try adding:

curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);

To see the debug output from cURL in PHP like you get on the command line, you can add:

curl_setopt($ch, CURLOPT_VERBOSE, true);
curl_setopt($ch, CURLOPT_STDERR, fopen('php://output', 'w'));

That might shed some light on the issue, as well as calling var_dump(curl_getinfo($ch)); after the request is executed.