Description:
------------
When I manualy sign a certificate from the shell:
./CA.sh -sign
or
openssl ca -policy policy_anything -out newcert.pem -infiles newreq.pem

the value in the file 'serial' increase  ($value++).

When I sign a certificate with php (openssl_csr_sign):
-the serial (file) doesn't change
-the new certificate has a good 'serial' value



Reproduce code:
---------------
	$CAcrt = file_get_contents("/usr/lib/ssl/misc/demoCA/cacert.pem");
	$serial_hexa = file_get_contents("/usr/lib/ssl/misc/demoCA/serial");
	$serial_dec_net=intval($serial_hexa,16); /*04*/

	$CAkey = array(file_get_contents("/usr/lib/ssl/misc/demoCA/private/cakey.pem"), "Gas/ZWmUkz7y2");
	
	echo "--".$serial_hexa."--";
	echo "<br>++".$serian_dec_net."++";
	


	$clientKeys = openssl_pkey_new();
	$dn = array(
		"countryName" => "FR",
		"stateOrProvinceName" => "Ain",
		"localityName" => "Jouan",
		"organizationName" => "Certificat client",
		"organizationalUnitName" => "Info",
		"commonName" => "www.abc.fr",
		"emailAddress" => "lolo@xp.fr"
	);
	$csr = openssl_csr_new($dn, $clientPrivKey);
	
	$config = array(
		"config" => "/etc/ssl/openssl.cnf",
	);

	$cert = openssl_csr_sign($csr, $CAcrt, $CAkey, 1095, $config, '04');
	openssl_x509_export($cert, $certout);
	echo $certout;
	openssl_pkcs12_export_to_file  ( $certout, "tmp/tito.p12"  , $clientPrivKey , "mimine")

Expected result:
----------------
The result is good, as the certificate, but the value inside 'serial' doesn't change....