PHP Curl error code 60: SSL Certificate error unable to get local issuer certificate

Question

Now I'm running PHP 5.6.29 (cli), curl 7.19.7 (x86_64-redhat-linux-gnu) and Apache/2.2.15 (Unix) on Ubuntu Server 14.04.

When I'm trying use App Facebook validate to domain https://[domain].vn:3443. I got a valid SSL certificate from https://www.ssl.com for that domain and apache setup correctly -all goods.

But when I go to FB and try to subscribe to that URL - it keeps failing with this error:

The URL couldn't be validated.  
Callback verification failed with the following errors: curl_errno = 60; Curl_error = SSL certificate problem: unable to get local issuer certificate; HTTP Status Code = 200;  
HTTP Message = Connection established

Can anyone advise on what else can I try? Thanks a lot

Solution

I'm understand problems of you. Please, you downloads and use this certificate root certificate bundle: https://curl.haxx.se/ca/cacert.pem

After you can copy and add file to use in /etc/php.ini:

curl.cainfo = "[path_cacert]\cacert.pem"

You should restart php after added line:

 service php5-fpm restart

For more details you can reading on Stack Overflow: https://stackoverflow.com/questions/21114371/php-curl-error-code-60.