php加密方式：SHA256方法

**私钥加密：**ksort( $params );//数组排序$signData 		= implode( '', $params );$pi_key 			= openssl_pkey_get_private($rsaPriKey);//私钥$signature		='';openssl_sign( $signData, $signature, $pi_key, OPENSSL_ALGO_SHA256 );openssl_free_key($pi_key);$params['sign'] 	= base64_encode($signature);**验证：**$sign = base64_decode($sign);//验证公钥是否可用$pu = openssl_get_publickey($this->merchant_public_key);//公钥验证$isSuccess = (bool)openssl_verify ($returnArray,$sign,$pu,OPENSSL_ALGO_SHA256);