Native OTP on Android Custom Checkout

Advantages

Using the Native OTP feature, you can:

• Increase success rates by up to 4%.
• Reduce payment failures due to low internet speeds.
• Avoid failures due to redirects to bank pages.
• Offer a consistent experience on mobile and web checkout.

Prerequisites

Before implementing the Native OTP feature, check the following prerequisites:

1. Create a

   Curlec account

   .
2. Generate the

   API Keys

   on the Curlec Dashboard.
3. Integrate with the

   Curlec Android Custom SDK

   .

Integration Steps

1.1

1.2

1.3

1.4

1.5

1.6

1.1 Update Curlec Android Custom SDK version

Update the

1.2 Implement CardsFlowCallback Interface in getCardsFlow Function

Implement the CardsFlowCallback interface in the getCardsFlow function in the payment activity. The SDK fires the isNativeOtpEnabled function and determines whether the native OTP flow is enabled for the BIN.

Sample Code

razorpay.getCardsFlow(payload, new CardsFlowCallback() {
        @Override
        public void isNativeOtpEnabled(boolean isNativeOtpEnabled) {
            if (isNativeOtpEnabled) {
                //this generates the OTP for the card holder
                razorpay.getCardOtpData(this);
            }else{
                //use your normal payment flow here
                sendRequest();
            }
        }

1.3 Call razorpay.getCardOtpData(CardsFlowCallback) Function

If Native OTP is enabled for BIN, you should call the razorpay.getCardOtpData(CardsFlowCallback) function. The SDK then fires the otpGenerateResponse(boolean otpGenerated) function and confirms if the OTP was successfully sent to the customer. Based on this information, you can display the generated OTP UI to the customer.

After entering the OTP, the customer can either:

• Submit OTP
  The customer needs to submit the OTP for authenticating the payment. The customer receives the OTP through your application frontend. For card payments, the customer receives the OTP via their preferred notification medium, SMS or email.

  Handy Tips

  Do not perform any validation on the length of the OTP since this can vary across banks. However, the OTP should not be blank.

• Request for OTP to be resent
  There could be situations when customers have to re-enter the OTP sent to them. The bank determines the number of retries that the user is allowed.

• Cancel OTP
  Cancel the payment by cancelling the OTP.

Sample Code

@Override
        public void otpGenerateResponse(boolean otpGenerated) {
            //check if otp was generated successfully and show UI
            if (otpGenerated) {
                //show UI to the user here
                //will have submit_otp btn resend_otp btn & redirect_to_bank_page button
                razorpay.otpSubmit(otpEnteredByUser,this);//for submitting OTP entered by USER, if payment was successful, the onPaymentSuccess function will be called.
                razorpay.otpResend(this);//for resending the OTP to the user
                razorpay.redirectToBankPage();//to open webview and redirect the user to bank page no callback for this
            }else {
                //otp wasn't generated call getCardOtpData again
                razorpay.getCardOtpData(this);
            }
        }
        @Override
        public void otpResendResponse(boolean otpResent) {
            //status response for otp_resend function, change UI accordingly
        }
        @Override
        public void onOtpSubmitError(boolean otpSubmitError) {
            //status response for error during otp submit. Wrong OTP, network issue, or timeout, this function will be called with the boolean
            //change UI accordingly
        }

1.4 Handle Success and Error Events

You must handle the payment success and error events as shown in the code sample below:

try {
    razorpay.submit(data, new PaymentResultListener() {
        @Override
        public void onPaymentSuccess(String razorpayPaymentId) {
            // Razorpay payment ID is passed here after a successful payment
        }

        @Override
        public void onPaymentError(int code, String description) {
            // Error code and description is passed here
        }
    });

} catch (Exception e) {
    Log.e(TAG, "Error in submitting payment details", e);
}

Use PaymentResultWithDataListener

You have the option to implement PaymentResultListener or PaymentResultWithDataListener to receive callbacks for the payment result.

• PaymentResultListener provides only payment_id as the payment result.
• PaymentResultWithDataListener provides additional payment data such as email and contact of the customer, along with the order_id, payment_id, signature and more.

razorpay.submit(data, new PaymentResultWithDataListener() {
        @Override
        public void onPaymentSuccess(String razorpayPaymentId, PaymentData paymentData) {
            // Razorpay payment ID and PaymentData passed here after a successful payment
        }

        @Override
        public void onPaymentError(int code, String description) {
            // Error code and description is passed here
        }
    });

} catch (Exception e) {
    Log.e(TAG, "Error in submitting payment details", e);
}

Step 5: Store the Fields in Server

A successful payment returns the following fields to the Checkout form.

• You need to store these fields in your server.
• You can confirm the authenticity of these details by verifying the signature in the next step.

Step 6: Verify Payment Signature

This is a mandatory step to confirm the authenticity of the details returned to the Checkout form for successful payments.

To verify the razorpay_signature returned to you by the Checkout form:

1. Create a signature in your server using the following attributes:

   • order_id: Retrieve the order_id from your server. Do not use the razorpay_order_id returned by Checkout.
   • razorpay_payment_id: Returned by Checkout.
   • key_secret: Available in your server. The key_secret that was generated from the
     Curlec Dashboard
     .

2. Use the SHA256 algorithm, the razorpay_payment_id and the order_id to construct a HMAC hex digest as shown below:

   HMAC Hex Digest

   copy

   generated_signature = hmac_sha256(order_id + "|" + razorpay_payment_id, secret);
   
     if (generated_signature == razorpay_signature) {
       payment is successful
     }

3. If the signature you generate on your server matches the razorpay_signature returned to you by the Checkout form, the payment received is from an authentic source.

Generate Signature on Your Server

Given below is the sample code for payment signature verification:

RazorpayClient razorpay = new RazorpayClient("[YOUR_KEY_ID]", "[YOUR_KEY_SECRET]");


String secret = "EnLs21M47BllR3X8PSFtjtbd";


JSONObject options = new JSONObject();
options.put("razorpay_order_id", "order_IEIaMR65cu6nz3");
options.put("razorpay_payment_id", "pay_IH4NVgf4Dreq1l");
options.put("razorpay_signature", "0d4e745a1838664ad6c9c9902212a32d627d68e917290b0ad5f08ff4561bc50f");


boolean status =  Utils.verifyPaymentSignature(options, secret);

Post Signature Verification

After you have completed the integration, you can

Test the Integration

After the integration is complete, a Pay button appears on your webpage/app.

Click the button and make a test transaction to ensure the integration is working as expected. You can start accepting actual payments from your customers once the test transaction is successful.

You can make test payments using one of the payment methods configured at the Checkout.