与 POS 交互 - 终端设备和银行交换系统

Question

我有一个项目，需要与 POS - 终端设备和磁卡/芯片卡进行交互。 比方说，每当顾客从我的百货商店购买商品时，这家商店的工作人员就会刷卡顾客的金融卡并进行付款交易。

对于那些类似的系统，大多数论坛都说应该考虑使用第三方API，例如：

• PayPal
• Braintree
• Authorize.NET。
• Google 结帐 API。

但我认为这些 API 应该用于那些将进行国际支付处理的系统。就我而言，我认为我的系统不像国际支付处理那么大，并将开始作为国内小型系统运行。

那么我想知道哪个是最好的解决方案以及系统架构如何？

当我阅读Authorize.Net页面时，我发现了信用卡的套路处理。

• 无论我的项目是大还是小，国际运行还是国内运行，我都需要遵循整个程序吗？

• 我真的需要按照此程序使用 POS 终端设备进行支付流程吗？

我知道的一件事是 ISO 8583 是重要的金融消息传递协议，因为大多数对于我所在的地区，银行交换软件系统仅使用这些消息格式。这意味着我无法使用其他消息格式，例如 NDC 或 D912。

Answer 1

Authorize.net 非常容易使用。处理卡片所需要做的就是发送 XML 格式的 https 帖子。 Authorize.net 开发者网站上有几个示例。
就刷卡而言，大多数读卡器都会模拟键盘按键。刷卡看起来与此类似：

'%B5500692805076849^SMITH/STEPHEN A^12041010000000      00969000000?;5500692805076849=12041010000000969?`

然后解析卡号“5500692805076849”、名称“SMITH/STEPHEN A”和到期日期“1204”
并在 Authorize.net 上传递这些内容

Private Sub cmdCharge_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdCharge.Click
    ' By default, this sample code is designed to post to our test server for
    ' developer accounts: https://test.authorize.net/gateway/transact.dll
    ' for real accounts (even in test mode), please make sure that you are
    ' posting to: https://secure.authorize.net/gateway/transact.dll
    cmdCharge.Enabled = False
    lblResponse.Text = "Processing....."
    Application.DoEvents()
    Dim post_url
    post_url = "https://test.authorize.net/gateway/transact.dll"

    Dim post_values As New Dictionary(Of String, String)

    'the API Login ID and Transaction Key must be replaced with valid values
    post_values.Add("x_login", "XXXXXXX")
    post_values.Add("x_tran_key", "XXXXXXXXX")
    'post_values.Add("x_test_request", "TRUE")
    post_values.Add("x_delim_data", "TRUE")
    post_values.Add("x_delim_char", "|")
    post_values.Add("x_relay_response", "FALSE")

    post_values.Add("x_type", "AUTH_CAPTURE")
    post_values.Add("x_method", "CC")
    post_values.Add("x_card_num", txtCard.Text)
    post_values.Add("x_exp_date", txtExp.Text)

    post_values.Add("x_amount", txtAmount.Text)
    'post_values.Add("x_description", "Sample Transaction")

    post_values.Add("x_first_name", txtFirst.Text)
    post_values.Add("x_last_name", txtLast.Text)
    'post_values.Add("x_address", "1234 Street")
    'post_values.Add("x_state", "WA")
    post_values.Add("x_zip", txtZip.Text)
    post_values.Add("x_card_code", txt3CV.Text)

    ' Additional fields can be added here as outlined in the AIM integration
    ' guide at: http://developer.authorize.net

    ' This section takes the input fields and converts them to the proper format
    ' for an http post.  For example: "x_login=username&x_tran_key=a1B2c3D4"
    Dim post_string As String = ""
    For Each field As KeyValuePair(Of String, String) In post_values
        post_string &= field.Key & "=" & field.Value & "&"
    Next
    ' post_string = Left(post_string, Len(post_string) - 1)
    post_string = post_string.Substring(0, Len(post_string) - 1)

    ' create an HttpWebRequest object to communicate with Authorize.net
    Dim objRequest As HttpWebRequest = CType(WebRequest.Create(post_url), HttpWebRequest)
    objRequest.Method = "POST"
    objRequest.ContentLength = post_string.Length
    objRequest.ContentType = "application/x-www-form-urlencoded"

    ' post data is sent as a stream
    Dim myWriter As StreamWriter = Nothing
    myWriter = New StreamWriter(objRequest.GetRequestStream())
    myWriter.Write(post_string)
    myWriter.Close()

    ' returned values are returned as a stream, then read into a string
    Dim objResponse As HttpWebResponse = CType(objRequest.GetResponse(), HttpWebResponse)
    Dim responseStream As New StreamReader(objResponse.GetResponseStream())
    Dim post_response As String = responseStream.ReadToEnd()
    responseStream.Close()

    ' the response string is broken into an array
    Dim response_array As Array = Split(post_response, post_values("x_delim_char"), -1)

    ' the results are output to the screen in the form of an html numbered list.
    Select Case response_array(0)

        Case "1" 'Approved
            lblResponse.Text = "Transaction Approved. " & vbCrLf & response_array(4)

        Case "2" 'Declined
            lblResponse.Text = "Transaction Declined. " & vbCrLf & response_array(3)

        Case "3" 'Error
            lblResponse.Text = "Transaction Error. " & vbCrLf & response_array(3)

        Case "4" 'Held for Review
            lblResponse.Text = "Transaction Held. " & vbCrLf & response_array(3)

    End Select

    ' individual elements of the array could be accessed to read certain response
    ' fields.  For example, response_array(0) would return the Response Code,
    ' response_array(2) would return the Response Reason Code.
    ' for a list of response fields, please review the AIM Implementation Guide

    cmdCharge.Enabled = True
End Sub