PHP实现SHA256withRSA的私钥加签

代码如下：

//定义私钥证书
$pri_key = "-----BEGIN PRIVATE KEY-----
MIIEvwIBADANBgkqhkiG9w0BAQEFAASCBKkwggSlAgEAAoIBAQCtypUdHZJKlQ9L
-----END PRIVATE KEY-----";
//要加密的字符
$char = 'test';
//开始加密
openssl_sign($char,$encryptedData,$pri_key,OPENSSL_ALGO_SHA256);
//base编码加密后内容
$encryptedData = base64_encode($encryptedData);
echo($encryptedData);