PHP RSA2 署名アルゴリズム

//生成原始 RSA私钥文件
openssl genrsa -out rsa_private_key.pem 1024
//将原始 RSA私钥转换为 pkcs8格式
openssl pkcs8 -topk8 -inform PEM -in rsa_private_key.pem -outform PEM -nocrypt -out private_key.pem
//生成RSA公钥
openssl rsa -in rsa_private_key.pem -pubout -out rsa_public_key.pem
//我们将私钥rsa_private_key.pem用在服务器端，公钥发放给android跟ios等前端。

class Rsa2
{
    private static $PRIVATE_KEY = 'rsa_private_key.pem 内容';
    private static $PUBLIC_KEY  = 'rsa_public_key.pem 内容';
    /**
     * 获取私钥
     * @return bool|resource
     */
    private static function getPrivateKey()
    {
        $privKey = self::$PRIVATE_KEY;
        return openssl_pkey_get_private($privKey);
    }
    /**
     * 获取公钥
     * @return bool|resource
     */
    private static function getPublicKey()
    {
        $publicKey = self::$PUBLIC_KEY;
        return openssl_pkey_get_public($publicKey);
    }
    /**
     * 创建签名
     * @param string $data 数据
     * @return null|string
     */
    public function createSign($data = '')
    {
        if (!is_string($data)) {
            return null;
        }
        return openssl_sign(
                    $data,
                    $sign,
                    self::getPrivateKey(),
                    OPENSSL_ALGO_SHA256
                  ) ? base64_encode($sign) : null;
    }
    /**
     * 验证签名
     * @param string $data 数据
     * @param string $sign 签名
     * @return bool
     */
    public function verifySign($data = '', $sign = '')
    {
        if (!is_string($sign) || !is_string($sign)) {
            return false;
        }
        return (bool)openssl_verify(
                      $data,
                      base64_decode($sign),
                      self::getPublicKey(),
                      OPENSSL_ALGO_SHA256
                    );
    }
}

require_once "Rsa2.php";
$rsa2 = new Rsa2();
$data = 'my data'; //待签名字符串
$strSign = $rsa2->createSign($data);      //生成签名
var_dump($strSign);
$is_ok = $rsa2->verifySign($data, $sign); //验证签名
var_dump($is_ok);