PayPal IPN - 如果详细信息有误怎么办？

Question

在 IPN 文档的末尾，它说了以下内容:

Important: After you have authenticated an IPN message (that is, received a VERIFIED response from PayPal), you must perform these important checks before you can assume that the IPN is both legitimate and has not already been processed:
1.Check that the payment_status is Completed.
2.If the payment_status is Completed, check the txn_id against the previous PayPal transaction that you processed to ensure the IPN message is not a duplicate.
3.Check that the receiver_email is an email address registered in your PayPal account.
4.Check that the price (carried in mc_gross) and the currency (carried in mc_currency) are correct for the item (carried in item_name or item_number).

如果其中一项检查失败，您应该怎么办？我们是否应该以某种方式调用 PayPal API 来“拒绝”交易？

Answer 1

大多数商店会将未通过这些检查的订单/交易标记为“可能欺诈”或类似的东西。订单状态应提高处理订单的员工的意识 - 仔细查看应显示哪个检查失败并可以启动进一步的操作。

这可能包括从交易退款到联系 PayPal 以应对可能的欺诈企图。在任何情况下，都应检查订单，而不是将其视为任何其他“已完成”订单。

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示例场景:

• 您正在使用未加密的 Website Payments Standard、HTML 表单来接收付款。

• 欺诈买家通过编辑提交的表格发现并开始修改商品价格

• 您收到的订单是已付款的，并且没有根据交易核对您店铺内的订单值(value)

• 一名员工没有发现这一点，并以 0.01 美元的价格寄出一件值(value) 200 美元的元素

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