Alipay payment error returns ILLEGAL_SIGN, signature verification error

The ECSHOP mall framework is used, and when tested locally (windows system), transactions are normal. But after reaching the production environment (Centos system), Alipay will report an ILLEGAL_SIGN (signature verification error) error. I've seen some solutions online, but none of them work. The following is the code to generate Alipay payment code:

<code>    function get_code($order, $payment)
    {
        if (!defined('EC_CHARSET'))
        {
            $charset = 'utf-8';
        }
        else
        {
            $charset = EC_CHARSET;
        }

        $real_method = $payment['alipay_pay_method'];

        switch ($real_method){
            case '0':
                $service = 'trade_create_by_buyer';
                break;
            case '1':
                $service = 'create_partner_trade_by_buyer';
                break;
            case '2':
                $service = 'create_direct_pay_by_user';
                break;
        }


        $parameter = array(
            'agent'             => $payment['alipay_agent'],
            'service'           => $service,
            'partner'           => $payment['alipay_partner'],
            //'partner'           => ALIPAY_ID,
            '_input_charset'    => $charset,
            'notify_url'        => return_url(basename(__FILE__, '.php')),
            'return_url'        => return_url(basename(__FILE__, '.php')),
            /* 业务参数 */
            'subject'           => $order['order_sn'],
            'out_trade_no'      => $order['order_sn'] . $order['log_id'],
            'extra_common_param'=> !empty($order['all_pay'])?$order['all_pay']:0, //判断是不是合并付款 add by ouzhiming
            'price'             => $order['order_amount'],
            'quantity'          => 1,
            'payment_type'      => 1,
            /* 物流参数 */
            'logistics_type'    => 'EXPRESS',
            'logistics_fee'     => 0,
            'logistics_payment' => 'BUYER_PAY_AFTER_RECEIVE',
            /* 买卖双方信息 */
            'seller_email'      => $payment['alipay_account']
        );

        ksort($parameter);
        reset($parameter);

        $param = '';
        $sign  = '';

        foreach ($parameter AS $key => $val)
        {
            $param .= "$key=" .urlencode($val). "&";
            $sign  .= "$key=$val&";
        }

        $param = substr($param, 0, -1);
        $sign  = substr($sign, 0, -1).$payment['alipay_key'];
        //$sign  = substr($sign, 0, -1). ALIPAY_AUTH;

        $button = '<div style="text-align:center"><input type="button" class="pay_button" onclick="window.open(\'https://www.alipay.com/cooperate/gateway.do?'.$param. '&sign='.md5($sign).'&sign_type=MD5\')" value="' .$GLOBALS['_LANG']['pay_button']. '" /></div>';

        return $button;
    }
</code>

Reply content:

The ECSHOP mall framework is used, and when tested locally (windows system), transactions are normal. But after reaching the production environment (Centos system), Alipay will report an ILLEGAL_SIGN (signature verification error) error. I've seen some solutions online, but none of them work. The following is the code to generate Alipay payment code:

<code>    function get_code($order, $payment)
    {
        if (!defined('EC_CHARSET'))
        {
            $charset = 'utf-8';
        }
        else
        {
            $charset = EC_CHARSET;
        }

        $real_method = $payment['alipay_pay_method'];

        switch ($real_method){
            case '0':
                $service = 'trade_create_by_buyer';
                break;
            case '1':
                $service = 'create_partner_trade_by_buyer';
                break;
            case '2':
                $service = 'create_direct_pay_by_user';
                break;
        }


        $parameter = array(
            'agent'             => $payment['alipay_agent'],
            'service'           => $service,
            'partner'           => $payment['alipay_partner'],
            //'partner'           => ALIPAY_ID,
            '_input_charset'    => $charset,
            'notify_url'        => return_url(basename(__FILE__, '.php')),
            'return_url'        => return_url(basename(__FILE__, '.php')),
            /* 业务参数 */
            'subject'           => $order['order_sn'],
            'out_trade_no'      => $order['order_sn'] . $order['log_id'],
            'extra_common_param'=> !empty($order['all_pay'])?$order['all_pay']:0, //判断是不是合并付款 add by ouzhiming
            'price'             => $order['order_amount'],
            'quantity'          => 1,
            'payment_type'      => 1,
            /* 物流参数 */
            'logistics_type'    => 'EXPRESS',
            'logistics_fee'     => 0,
            'logistics_payment' => 'BUYER_PAY_AFTER_RECEIVE',
            /* 买卖双方信息 */
            'seller_email'      => $payment['alipay_account']
        );

        ksort($parameter);
        reset($parameter);

        $param = '';
        $sign  = '';

        foreach ($parameter AS $key => $val)
        {
            $param .= "$key=" .urlencode($val). "&";
            $sign  .= "$key=$val&";
        }

        $param = substr($param, 0, -1);
        $sign  = substr($sign, 0, -1).$payment['alipay_key'];
        //$sign  = substr($sign, 0, -1). ALIPAY_AUTH;

        $button = '<div style="text-align:center"><input type="button" class="pay_button" onclick="window.open(\'https://www.alipay.com/cooperate/gateway.do?'.$param. '&sign='.md5($sign).'&sign_type=MD5\')" value="' .$GLOBALS['_LANG']['pay_button']. '" /></div>';

        return $button;
    }
</code>

I suggest you check if there is a case issue. The case of the method. The case of the class. The case of the parameters.