(PHP 4 >= 4.2.0, PHP 5, PHP 7)
openssl_pkey_get_private — 获取私钥
openssl_get_privatekey() 解析
key 供其他函数使用。
key
key 可以是如下密钥之一：
passphrase
如果指定的密钥已被加密了(受密码保护)，可选参数 passphrase 是必须要的。
成功，返回真实的密钥资源标识符，失败，返回 FALSE .
Since this function can be used to load a PEM encoded string also, those that are using it relying on user input should be sure to check that the passed data is indeed a PEM encoded string and not a malicious file path.
The following should be sufficient.
<?PHP
$private = trim($_POST['private']);
if (strpos($private, '-----') !== 0) return false;
?>
It's actually "file://key.pem" when you want to give a relative path using unix systems. It will be three '/' in case of absolute path (e.g "file:///home/username/..."). But this path consists of two '/' originated from "file://" and one '/' from the fact that home is a subfolder of the unix filesystem's root directory ("/home/username/..."). This two part will be concatenated and you will get three '/' characters following each other.
So you only have to concatenate "file://" with an existing path string in every case.
Please note that "file://path/to/file.pem" in documentation means file protocol + file path. In UNIX like OS, that is something like file:///rsa_private_key.pem. There is THREE slashes in the path string, not TWO.