Identify CA

Find the local CA peer verification file to allow drupal to access HTTPS sites.

1. Check if openssl.cafile is set in your php.ini file.
2. Check if curl.cainfo is set in your php.ini file.
3. Check if /etc/pki/tls/certs/ca-bundle.crt exists (Red Hat, CentOS, Fedora; provided by the ca-certificates package)
4. Check if /etc/ssl/certs/ca-certificates.crt exists (Ubuntu, Debian; provided by the ca-certificates package)
5. Check if /usr/local/share/certs/ca-root-nss.crt exists (FreeBSD; provided by the ca_root_nss package)
6. Check if /usr/local/etc/openssl/cert.pem (OS X; provided by homebrew)
7. Check if C:windowssystem32curl-ca-bundle.crt exists (Windows)
8. Check if C:windowscurl-ca-bundle.crt exists (Windows)

@updated: it does not work :-( ini_set can't change the openssl.cafile variable