fix: validate direct payment callback amounts

Check direct payment callback currency, provider, and paid amount before settling Alipay or WxPay top-ups.

controller/payment_alipay.go

@@ -179,6 +179,11 @@ func AlipayNotify(c *gin.Context) {
 
 	LockOrder(status.ProviderOrderID)
 	defer UnlockOrder(status.ProviderOrderID)
+	if err := model.ValidateTopUpPaymentAmount(status.ProviderOrderID, model.PaymentProviderAlipay, status.Amount, status.Currency); err != nil {
+		logger.LogWarn(c.Request.Context(), fmt.Sprintf("支付宝 异步通知金额校验失败 trade_no=%s amount=%d currency=%s client_ip=%s error=%q", status.ProviderOrderID, status.Amount, status.Currency, c.ClientIP(), err.Error()))
+		c.String(http.StatusOK, "fail")
+		return
+	}
 	if err := model.RechargeAlipay(status.ProviderOrderID, c.ClientIP()); err != nil {
 		logger.LogError(c.Request.Context(), fmt.Sprintf("支付宝 充值处理失败 trade_no=%s client_ip=%s error=%q", status.ProviderOrderID, c.ClientIP(), err.Error()))
 		c.String(http.StatusOK, "fail")

controller/payment_wxpay.go

@@ -164,6 +164,11 @@ func WxpayNotify(c *gin.Context) {
 
 	LockOrder(status.ProviderOrderID)
 	defer UnlockOrder(status.ProviderOrderID)
+	if err := model.ValidateTopUpPaymentAmount(status.ProviderOrderID, model.PaymentProviderWxpay, status.Amount, status.Currency); err != nil {
+		logger.LogWarn(c.Request.Context(), fmt.Sprintf("微信支付 异步通知金额校验失败 trade_no=%s amount=%d currency=%s client_ip=%s error=%q", status.ProviderOrderID, status.Amount, status.Currency, c.ClientIP(), err.Error()))
+		wxpayNotifyFail(c, "金额校验失败")
+		return
+	}
 	if err := model.RechargeWxpay(status.ProviderOrderID, c.ClientIP()); err != nil {
 		logger.LogError(c.Request.Context(), fmt.Sprintf("微信支付 充值处理失败 trade_no=%s client_ip=%s error=%q", status.ProviderOrderID, c.ClientIP(), err.Error()))
 		wxpayNotifyFail(c, "处理失败")

model/payment_method_guard_test.go

@@ -322,6 +322,28 @@ func TestRechargeWaffo_ProcessesAffiliateRebateIdempotently(t *testing.T) {
 	assert.Equal(t, int64(1), count)
 }
 
+func TestValidateTopUpPaymentAmount(t *testing.T) {
+	truncateTables(t)
+
+	insertUserForPaymentGuardTest(t, 186, 0)
+	topUp := &TopUp{
+		UserId:          186,
+		Amount:          2,
+		Money:           12.34,
+		TradeNo:         "direct-pay-amount-guard",
+		PaymentMethod:   PaymentMethodAlipay,
+		PaymentProvider: PaymentProviderAlipay,
+		Status:          common.TopUpStatusPending,
+		CreateTime:      time.Now().Unix(),
+	}
+	require.NoError(t, topUp.Insert())
+
+	require.NoError(t, ValidateTopUpPaymentAmount("direct-pay-amount-guard", PaymentProviderAlipay, 1234, "CNY"))
+	require.ErrorIs(t, ValidateTopUpPaymentAmount("direct-pay-amount-guard", PaymentProviderAlipay, 1233, "CNY"), ErrTopUpAmountMismatch)
+	require.ErrorIs(t, ValidateTopUpPaymentAmount("direct-pay-amount-guard", PaymentProviderAlipay, 1234, "USD"), ErrTopUpCurrencyMismatch)
+	require.ErrorIs(t, ValidateTopUpPaymentAmount("direct-pay-amount-guard", PaymentProviderWxpay, 1234, "CNY"), ErrPaymentMethodMismatch)
+}
+
 func TestCompleteSubscriptionOrder_RejectsMismatchedPaymentProvider(t *testing.T) {
 	truncateTables(t)
 

model/topup.go

@@ -52,6 +52,8 @@ var (
 	ErrPaymentMethodMismatch = errors.New("payment method mismatch")
 	ErrTopUpNotFound         = errors.New("topup not found")
 	ErrTopUpStatusInvalid    = errors.New("topup status invalid")
+	ErrTopUpAmountMismatch   = errors.New("topup amount mismatch")
+	ErrTopUpCurrencyMismatch = errors.New("topup currency mismatch")
 )
 
 type promoCodeBonusInfo struct {
@@ -235,6 +237,28 @@ func UpdatePendingTopUpStatus(tradeNo string, expectedPaymentProvider string, ta
 	})
 }
 
+func ValidateTopUpPaymentAmount(tradeNo string, expectedPaymentProvider string, paidAmountCents int, currency string) error {
+	if tradeNo == "" {
+		return ErrTopUpNotFound
+	}
+	if strings.ToUpper(strings.TrimSpace(currency)) != "CNY" {
+		return ErrTopUpCurrencyMismatch
+	}
+
+	topUp := GetTopUpByTradeNo(tradeNo)
+	if topUp == nil {
+		return ErrTopUpNotFound
+	}
+	if expectedPaymentProvider != "" && topUp.PaymentProvider != expectedPaymentProvider {
+		return ErrPaymentMethodMismatch
+	}
+	expectedAmountCents := int(decimal.NewFromFloat(topUp.Money).Mul(decimal.NewFromInt(100)).Round(0).IntPart())
+	if paidAmountCents != expectedAmountCents {
+		return ErrTopUpAmountMismatch
+	}
+	return nil
+}
+
 func RechargeEpay(tradeNo string, actualPaymentMethod string, callerIp string) (err error) {
 	if tradeNo == "" {
 		return errors.New("未提供支付单号")