QR Code Integrity Validation Checklist
Source Validation:
Ensure the QR code is uploaded by a trusted partner (partner verification).
Check that the uploaded QR code is from a recognized payment provider (e.g., Paytm, Google Pay, etc.).
QR Code Decoding:
Use a QR code scanning library to decode the QR content (e.g., URL or string).
Ensure the QR code is readable (i.e., no errors during decoding).
URL Structure Validation:
If the QR code contains a URL, check for the following:
URL must begin with "https" (secure connection).
Ensure the domain matches the expected payment provider (e.g., "paymentgateway.com").
Ensure there are no unusual or suspicious characters or misspellings in the URL.
Merchant Identification:
Extract and verify merchant details from the QR code:
Look for merchant-related parameters (e.g., merchant_id, business_name).
Cross-check the extracted merchant details against the registered merchant database.
Amount Validation:
Verify if the QR code contains an expected amount field (amount or similar) and ensure it is correct.
Match the amount with what was agreed upon with the partner or renter.
Transaction Scope:
Ensure the QR code is valid for a specific transaction (e.g., check if the code is limited to the expected transaction amount or merchant).
Flag if the amount exceeds expected ranges or is inconsistent with rental agreements.
Multiple QR Code Checks:
Check that no duplicate QR codes have been uploaded.
If multiple QR codes for the same payment are found, validate their integrity and authenticity.
Real-time Monitoring:
Implement real-time logging and monitoring of QR code uploads and associated transactions.
Alert the system for suspicious patterns or unusual merchant activity.
Flag Suspicious Codes:
Flag QR codes with unexpected or suspicious URLs/merchant information.
Block QR codes that do not pass integrity checks.
Confirmation to Renters:
Display the merchant’s name/business and transaction details (amount, merchant) to renters before payment.
Allow renters to confirm the payment details before proceeding with the payment.
Merchant Reporting:
Provide an option for renters to report suspicious QR codes.
Enable easy access for renters to contact support if they suspect fraudulent activity.
Educational Alerts:
Display a clear warning message to renters about verifying merchant information before making payments.
This checklist will guide your developers to build a secure, validated process for handling QR codes and ensuring integrity during payment transactions.
Add QR Decoding and Validation in _uploadQrCode
Add the QR Code Decoding Library
Add to your pubspec.yaml:
dependencies:
qr_code_tools: ^2.1.0
Run flutter pub get.
Update Your Code: QR Decoding and Validation
Import the package:
import 'package:qr_code_tools/qr_code_tools.dart';
Future<void> _uploadQrCode() async {
if (_selectedFile == null) {
ScaffoldMessenger.of(context).showSnackBar(
const SnackBar(content: Text("Please select a file first.")),
);
return;
}
setState(() {
isLoading = true;
});
try {
// 1. Decode the QR code from the image file
String? qrContent;
try {
qrContent = await QrCodeToolsPlugin.decodeFrom(_selectedFile!.path!);
} catch (e) {
qrContent = null;
}
// 2. Check if QR code is readable
if (qrContent == null || qrContent.isEmpty) {
ScaffoldMessenger.of(context).showSnackBar(
const SnackBar(content: Text("The selected image does not contain a valid QR code.")),
);
setState(() {
isLoading = false;
});
return;
}
// 3. Validate QR content for transaction scope (customize as per your business logic)
// Example: Let's say the QR should contain a JSON string with amount and merchant
bool isValidTransaction = false;
String? errorMessage;
try {
final decoded = qrContent; // If your QR contains JSON, parse it: jsonDecode(qrContent)
// Example: Suppose QR contains "TXN:MERCHANT123:AMOUNT:500"
final parts = decoded.split(':');
if (parts.length == 4 && parts[0] == "TXN" && parts[2] == "AMOUNT") {
final merchant = parts[1];
final amount = double.tryParse(parts[3]) ?? 0.0;
// Example validation
if (merchant == "MERCHANT123" && amount <= 10000) {
isValidTransaction = true;
} else if (amount > 10000) {
errorMessage = "Transaction amount exceeds allowed limit.";
} else {
errorMessage = "Merchant mismatch or invalid QR code.";
}
} else {
errorMessage = "QR code format is invalid or not supported.";
}
} catch (e) {
errorMessage = "Unable to parse QR code content.";
}
if (!isValidTransaction) {
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(content: Text(errorMessage ?? "Invalid QR code for this transaction.")),
);
setState(() {
isLoading = false;
});
return;
}
// 4. Proceed with upload if all checks pass
final partnerViewModel = Provider.of<PartnerViewModel>(context, listen: false);
Map<String, dynamic> response;
if (widget.qrId == null) {
response = await partnerViewModel.uploadQrCode(widget.email, _selectedFile!.path.toString());
} else {
response = await partnerViewModel.updateQrCode(widget.qrId.toString(), widget.email, _selectedFile!.path.toString());
}
if (response['success'] == true && widget.vehicle == null) {
Navigator.pushReplacement(
context,
MaterialPageRoute(
builder: (context) => QrScreen(email: widget.email.toString()),
),
);
} else {
Navigator.pushReplacement(
context,
MaterialPageRoute(
builder: (context) => Vechicle(email: widget.email.toString()),
),
);
}
} catch (e) {
ScaffoldMessenger.of(context).showSnackBar(
SnackBar(content: Text("Error uploading file: $e")),
);
} finally {
setState(() {
isLoading = false;
});
}
}
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