504 Gateway Time-out when calling curl_exec() in PHP with SSL peer verification (CURLOPT_SSL_VERIFYPEER) off

[Ben Johnson]

On 8/23/2013 2:05 PM, Maxim Dounin wrote:
> Hello!
> 
> On Fri, Aug 23, 2013 at 12:46:44PM -0400, Ben Johnson wrote:
> 
>> Hello,
>>
>> I'm seeing a strange problem with nginx (1.5.2 on Windows) and PHP
>> (5.4.8 on Windows).
>>
>> Whenever I make a cURL request with PHP's curl_exec() function to a
>> secure URL (https protocol), and I disable peer verification, like this
>>
>> curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, FALSE);
>>
>> nginx responds with a "504 Gateway Time-out".
>>
>> If I set CURLOPT_SSL_VERIFYPEER to TRUE, nginx responds with a "200 OK",
>> although curl_exec() returns false, which is expected due to the
>> verification failure (I'm using a self-signed certificate in nginx).
>>
>> I have tried executing the same script under Apache and it functions as
>> expected with peer verification disabled.
> 
> What URL is requested by your script?  Symptoms described suggest 
> you are requesting some php script from the same server, and 504 
> is likely due to only one php backend process.
> 

Thank you for the quick reply, Maxim! I appreciate it.

You are exactly right; my script requests another URL on the same server
(which happens to be localhost in this case).

Just so I understand the problem, are you saying that the script that
contains the cURL call (via PHP's curl_exec() function) essentially
ties-up the only available PHP backend process, which causes curl_exec()
to time-out when it requests another URL on the same server?

Is there a solution to this problem?

My setup is essentially the same as what is described at
http://wiki.nginx.org/PHPFastCGIOnWindows .

Thanks again,

-Ben