给APP提供支付宝支付签名PHP代码

//$no 是订单编号  $price 是价格
function ali_pay($no, $price){

    $data['subject'] = '订单'.$no;
    $data['out_trade_no'] = 订单号;
    $data['total_amount'] = 价格;
    $data['product_code'] = 'QUICK_MSECURITY_PAY';
    $data = json_encode($data);

    $params['app_id'] = "app_id";
    $params['method'] = 'alipay.trade.app.pay';
    $params['sign_type'] = 'RSA2';
    $params['timestamp'] = date("Y-m-d H:i:s");
    $params['charset'] = 'UTF-8';
    $params['version'] = '1.0';
    $params['notify_url'] = "支付成功回调地址";
    $params['biz_content'] = $data;

    ksort($params); //对将要签名的数组排序
    $string = toUrlParam($params); //将数组转换成字符串

    $params['sign'] = alipay_sign($string); //将字符串签名
    $params = http_build_query($params);
    return $params;

}

//app支付宝签名
function alipay_sign($data, $signType = "RSA2") {

    $priKey = '支付商户后台应用私钥';

    $res = "-----BEGIN RSA PRIVATE KEY-----\n" .
        wordwrap($priKey, 64, "\n", true) .
        "\n-----END RSA PRIVATE KEY-----";

    ($res) or die('您使用的私钥格式错误，请检查RSA私钥配置');

    if ("RSA2" == $signType) {
        openssl_sign($data, $sign, $res, OPENSSL_ALGO_SHA256);
    } else {
        openssl_sign($data, $sign, $res);
    }

    $sign = base64_encode($sign);

    return $sign;
}

/*
 * 格式化参数格式化成url参数
*/
function toUrlParam($param)
{
    $buff = "";
    foreach($param as $k => $v)
    {
        if($k != "sign" && $v != "" && !is_array($v)){
            $buff .= $k."=".$v."&";
        }
    }

    $buff = trim($buff, "&");
    return $buff;
}