PayU BharatKosh Encryption Wrapper - Flutter Plugin

A Flutter plugin that wraps the native PayU BharatKosh encryption wrapper SDKs for Android and iOS, providing a unified Dart API for Flutter apps.

Overview

This plugin is a thin wrapper that uses the existing native SDKs:

  • Android: payu-cp-encryption-wrapper (via Maven)
  • iOS: PayUIndia-CP-Encryption-SDK (via CocoaPods)

The plugin only contains the Flutter platform channel bridge code - all encryption/decryption logic remains in the native SDKs.

Features

  • Request Decryption: Decrypts encrypted payloads from BharatKosh
  • Response Encryption: Encrypts CheckoutPro responses before sending back to BharatKosh
  • Hash Generation: Handles hash generation for CheckoutPro SDK
  • Cancel & Error Handling: Proper handling of user cancellation and error scenarios
  • Dual API Support: Both callback-based and async/await approaches

Installation

Step 1: Add Flutter Plugin Dependency

Add this to your pubspec.yaml:

dependencies:
  payu_bharatkosh_encryption_wrapper:
    path: path/to/payu_bharatkosh_encryption_wrapper

Step 2: Android Setup

Add the Maven repositories to your android/settings.gradle:

dependencyResolutionManagement {
    repositories {
        google()
        mavenCentral()
        maven { url "https://maven.payu.in" }
        maven { url "https://central.sonatype.com/repository/maven-snapshots/" }
    }
}

Ensure minimum SDK is 24 in android/app/build.gradle:

android {
    defaultConfig {
        minSdk 24
    }
}

Step 3: iOS Setup

Ensure your ios/Podfile has the correct platform:

platform :ios, '13.0'

target 'Runner' do
  use_frameworks!
  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
end

Run pod install:

cd ios
pod install

Usage

Import the package

import 'package:payu_bharatkosh_encryption_wrapper/payu_bharatkosh_encryption_wrapper.dart';

Method 1: Using Callback (Traditional)

final wrapper = BharatkoshWrapper();

wrapper.startPayment(
  encRequestParameter: 'encrypted_payload_from_bharatkosh',
  reqDigitalSignature: 'digital_signature_from_bharatkosh',
  merchIdVal: 'merchant_id',
  isProduction: false, // true for production
  callback: MyPaymentCallback(),
);

class MyPaymentCallback implements BharatkoshWrapperCallback {
  @override
  void onSuccess(String encryptedResponse) {
    // Payment successful - send encryptedResponse to BharatKosh
    print('Payment Success: $encryptedResponse');
  }

  @override
  void onFailure(String encryptedResponse) {
    // Payment failed - send encryptedResponse to BharatKosh
    print('Payment Failed: $encryptedResponse');
  }

  @override
  void onCancel(String encryptedResponse) {
    // User cancelled - send encryptedResponse to BharatKosh
    print('Payment Cancelled: $encryptedResponse');
  }

  @override
  void onError(String encryptedResponse) {
    // Error occurred - send encryptedResponse to BharatKosh
    print('Payment Error: $encryptedResponse');
  }
}

Method 2: Using async/await (Modern)

final wrapper = BharatkoshWrapper();

try {
  final result = await wrapper.startPaymentAsync(
    encRequestParameter: 'encrypted_payload_from_bharatkosh',
    reqDigitalSignature: 'digital_signature_from_bharatkosh',
    merchIdVal: 'merchant_id',
    isProduction: false, // true for production
  );

  switch (result.type) {
    case BharatkoshResultType.success:
      print('Payment successful: ${result.encryptedResponse}');
      break;
    case BharatkoshResultType.failure:
      print('Payment failed: ${result.encryptedResponse}');
      break;
    case BharatkoshResultType.cancel:
      print('Payment cancelled: ${result.encryptedResponse}');
      break;
    case BharatkoshResultType.error:
      print('Payment error: ${result.encryptedResponse}');
      break;
  }

  // Send result.encryptedResponse back to BharatKosh
} catch (e) {
  print('Exception: $e');
}

API Reference

BharatkoshWrapper

The main class for interacting with the BharatKosh encryption wrapper.

startPayment()

Starts the payment flow using a callback.

Future<void> startPayment({
  required String encRequestParameter,
  required String reqDigitalSignature,
  required String merchIdVal,
  required bool isProduction,
  required BharatkoshWrapperCallback callback,
})

startPaymentAsync()

Starts the payment flow and returns a Future with the result.

Future<BharatkoshPaymentResult> startPaymentAsync({
  required String encRequestParameter,
  required String reqDigitalSignature,
  required String merchIdVal,
  required bool isProduction,
})

Parameters

Parameter Type Description
encRequestParameter String Encrypted request from BharatKosh
reqDigitalSignature String Digital signature from BharatKosh
merchIdVal String Merchant ID value
isProduction bool true for production, false for UAT

BharatkoshWrapperCallback

Abstract class for receiving payment callbacks.

Method Description
onSuccess(String) Called when payment succeeds
onFailure(String) Called when payment fails
onCancel(String) Called when user cancels
onError(String) Called when an error occurs

BharatkoshPaymentResult

Result object returned by startPaymentAsync().

Property Type Description
type BharatkoshResultType Type of result
encryptedResponse String Encrypted response to send to BharatKosh

BharatkoshResultType

Enum representing the result type.

Value Description
success Payment completed successfully
failure Payment failed
cancel User cancelled the payment
error An error occurred

Environment Configuration

The plugin supports two environments:

  • UAT (Test): isProduction: false

    • Base URL: https://compulsiveuat.payu.in/

  • Production: isProduction: true

    • Base URL: https://compulsive.payu.in/

Project Structure

CPWrapperFlutter/payu_bharatkosh_encryption_wrapper/
├── lib/                           # Dart API
│   ├── payu_bharatkosh_encryption_wrapper.dart
│   └── src/
│       ├── bharatkosh_wrapper.dart
│       ├── bharatkosh_wrapper_callback.dart
│       └── bharatkosh_payment_result.dart
│
├── android/                       # Android Plugin (thin bridge)
│   └── src/main/kotlin/.../PayuBharatkoshEncryptionWrapperPlugin.kt
│
├── ios/                           # iOS Plugin (thin bridge)
│   └── Classes/PayuBharatkoshEncryptionWrapperPlugin.swift
│
└── example/                       # Example Flutter App

Requirements

  • Flutter: 3.0.0 or later
  • Dart: 3.0.0 or later
  • Android: API 24 (Android 7.0) or later
  • iOS: 13.0 or later

Native SDK Dependencies

Platform SDK Source
Android payu-cp-encryption-wrapper Maven
iOS PayUIndia-CP-Encryption-SDK CocoaPods

Documentation

For comprehensive integration guide, see:

Support

For issues and questions:

  • Create an issue in the repository
  • Contact PayU support team

License

MIT License

Libraries

payu_bharatkosh_encryption_wrapper
Flutter wrapper for BharatKosh encryption SDK.