I recently stumbled on a cURL error 60 SSL certificate problem with WordPress. when using a new plugin that makes HTTP requests and API calls.
I verified that my site’s SSL was configured correctly (phew), but I still received the cURL error 60 which denoted an SSL certificate problem. Weird.
I did some Googling and thought that it might be an issue with the WordPress certificates in the wp-includes/certificates folder, since WordPress uses these by default for secure connections . So I downloaded the latest certificate from here, renamed it to ca-bundle.crt and placed it inside wp-includes/certificates within my WordPress installation. However it still didn’t work.
So I reverted the change, and instead placed the downloaded certificate (that I now renamed to cacert.pem) into my PHP installation folder:
. I then opened the PHP.ini file and set the following line:
Beware of any preceeding semi-colon (;) which essentially comments out the line. So remove it if present. After saving the PHP.ini and doing an IIS reset on the site in question (wasn’t sure if this was required so try without in the first instance), everything worked as it should!