After some tests I've been able to get some results this way ...
<?php
$fp = fopen("/etc/httpd/conf/ssl/moncertif.crt", "r");
$cert = fread($fp, 8192);
fclose($fp);
echo "Read<br>";
echo openssl_x509_read($cert);
echo "<br>";
echo "*********************";
echo "<br>";
echo "Parse<br>";
print_r(openssl_x509_parse($cert));
/*
// or
print_r(openssl_x509_parse( openssl_x509_read($cert) ) );
*/
?>
enjoy
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