Description:
------------
The configargs which apply to both openssl_pkey_new and openssl_csr_new have incorrect documentation.  The documentation says that private_key_bits should be a string, but if this argument is not an integer type, the function fails.

Reproduce code:
---------------
$res = openssl_pkey_new (array("private_key_bits"=>"1024"));

if (is_resource($res))
{
openssl_pkey_export ($res, $string);

echo $string;
}
else
{
echo "key generation failed";
}

Expected result:
----------------
I would expect to get a new 1024 bit private key PEM string output.

Actual result:
--------------
key generation failed