This small function gathers expiry information from an SSL certificate and calculates days remaining until expire. You may query multiple domains by calling get_cert_exp function in a loop.
Enjoy!
<?php
function get_cert_exp($url){
$orignal_parse = parse_url($url, PHP_URL_HOST);
$get = stream_context_create(array(“ssl” => array(“capture_peer_cert” => TRUE)));
$read = stream_socket_client(“ssl://”.$orignal_parse.”:443″, $errno, $errstr, 30, STREAM_CLIENT_CONNECT, $get);
$cert = stream_context_get_params($read);
$certinfo = openssl_x509_parse($cert[‘options’][‘ssl’][‘peer_certificate’]);//$expired= getdate($certinfo[validTo]);
$end=($certinfo[validTo]);
$end=substr($end, 0, -1); //remove last char from string
$chunks = str_split($end, 2);
//Convert array to string. Each element separated by the given separator.
$expire_date = implode(‘:’, $chunks);
$expire_date=’20’.$expire_date;// Days left to expire date //
$gd_a = getdate( $certinfo[‘validTo_time_t’] );
$gd_b = getdate( time() );$a_new = mktime( 12, 0, 0, $gd_a[‘mon’], $gd_a[‘mday’], $gd_a[‘year’] );
$b_new = mktime( 12, 0, 0, $gd_b[‘mon’], $gd_b[‘mday’], $gd_b[‘year’] );$days_left=round( abs( $a_new – $b_new ) / 86400 );
// end of calculation //
if ($days_left <= 50 ) {
$days_left=”<b><font color=red>”.$days_left.”</font></b>”;
}else{
$days_left=”<b><font color=green>”.$days_left.”</font></b>”;
}echo “SSL Certificate of <b> $url </b>is valid until “.$expire_date.'</br>’;
echo “Days remaining until expiration : “. $days_left.'</br>’;
}
get_cert_exp(“https://your.nice.expiring.domain/”);
?>