php5.38openssl_get_privatekey（）这个方法不能用求大神帮助

$priv_key = file_get_contents("pcarduser-sandbox-fzh.pem");  	
$pkeyid = openssl_get_privatekey($priv_key);//运行到这里就报错
Fatal error: Call to undefined function openssl_get_privatekey()	
openssl_sign($kq_all_para, $signMsg, $pkeyid,OPENSSL_ALGO_SHA1);// compute signature	
openssl_free_key($pkeyid);	
// free the key from memory	
$kq_sign_msg = base64_encode($signMsg);

求大神 ！ 帮帮忙啊！

回复讨论(解决方案)

openssl_pkey_get_private().具php.com上是说这个方法是一个别名,尝试下这个方法.