BuildCell.Emv 0.1.2

BuildCell.Emv

This library facilitates the generation and parsing of EMV QR codes, adhering to the specifications for merchant-presented QR codes. It is a C# port of the steplix/emv-qrcps library.

Installation

Install the package from NuGet:

dotnet add package BuildCell.Emv

Merchant Module

The primary module for merchant-presented QR codes.

Usage

To create an EMV QR code payload, instantiate MerchantEmv and populate its fields.

Generating a Payload

using BuildCell.Emv.Merchant;
using BuildCell.Emv.Merchant.Contracts;

// Create a new MerchantEmv instance
var emv = new MerchantEmv();

// Set mandatory fields
emv.SetPayloadFormatIndicator("01");
emv.SetMerchantCategoryCode("5411"); // Grocery Stores, Supermarkets
emv.SetTransactionCurrency("986"); // BRL
emv.SetCountryCode("BR");
emv.SetMerchantName("My Awesome Store");
emv.SetMerchantCity("Brasilia");

// Add merchant account information
var merchantAccountInfo = new MerchantAccountInformation();
merchantAccountInfo.SetGloballyUniqueIdentifier("com.example.myapp");
merchantAccountInfo.AddContextSpecificData("01", "1234567890");
emv.AddMerchantAccountInformation("26", merchantAccountInfo);

// Generate the payload
string payload = emv.GeneratePayload();

Console.WriteLine(payload);

This will output a string that can be encoded into a QR code.

Parsing a Payload

To parse an existing EMV QR code payload, use the MerchantParser.

using BuildCell.Emv.Merchant;

string payload = "00020101021126380009com.mercadolibre011559876543210000520400005303986540510.005802BR5913My Test Store6008Brasilia62070503***6304E4A6";

var emv = MerchantParser.ToEmv(payload);

// You can now access the parsed fields
Console.WriteLine(emv.GetMerchantName()); // My Test Store

Key Classes

• MerchantEmv: The main class representing the entire EMV QR code structure.
• MerchantParser: Provides static methods to parse a string payload into a MerchantEmv object.
• Tlv: Represents a Tag-Length-Value component of the EMV structure.
• MerchantAccountInformation: Represents the merchant's account details.
• AdditionalDataFieldTemplate: For optional additional data.
• MerchantInformationLanguageTemplate: For language-specific merchant information.

MerchantEmv Methods

• GeneratePayload(): Generates the complete EMV QR code string.
• Validate(): Checks if all mandatory fields are set.
• Set...() methods (e.g., SetMerchantName, SetTransactionAmount): Set the values for the corresponding fields.
• Add...() methods (e.g., AddMerchantAccountInformation): Add complex data structures.

MerchantParser Methods

• ToEmv(string payload): Parses a payload string and returns a MerchantEmv object.

Contributing

Contributions are welcome! Please feel free to submit a pull request.

License

This project is licensed under the MIT License.