Why does PHP cURL throw an error Problem with the SSL CA cert?

Question

PHP

Please tell me, cURL in PHP, when trying to connect to a host via https, persistently gives an error "Problem with the SSL CA cert (path? access rights?)". The certificate at the address I am accessing is unverified, but I disable the need to verify the certificate in the options.
Here is the code:

if($cu=curl_init('https://example.com')) {
    curl_setopt($cu, CURLOPT_RETURNTRANSFER, TRUE);
    curl_setopt($cu, CURLOPT_SSL_VERIFYHOST, 0);
    curl_setopt($cu, CURLOPT_SSL_VERIFYPEER, 0);
    curl_setopt($cu, CURLOPT_SSLVERSION, 3);
    curl_setopt($cu, CURLOPT_TIMEOUT, 30);
    $res = curl_exec($cu);
    curl_close($cu);
}

Instead of https://example.com I specify my host. On http everything works, but on https it gives this error.
Tell me, please, in which direction to drip.

Answer 1

For those who use nginx+php-fpm scheme in chroot, copy
/usr/lib64/libnsspem.so
/usr/lib64/libsoftokn3.so
to chroot/lib64 directory.

Answer 2

try:
yum reinstall openssl ca-certificates -y

Answer 3

There is also an option like this:

wget http://curl.haxx.se/ca/cacert.pem
cp cacert.pem /usr/local/etc/cacert.pem
echo "curl.cainfo = \"/usr/local/etc/cacert.pem\"" >> /etc/php.ini