(Android™) Adyen HMAC Signature Calculation for Hosted Payment Pages

Demonstrates how to do the HMAC Signature Calculation for a hosted payment page (HPP) in Adyen.

For a C# ASP.NET Razor Pages example showing the HTML Form with HMAC signature code, see Adyen HMAC Signature Calculation in C#

For more information, see https://docs.adyen.com/classic-integration/hosted-payment-pages/hmac-signature-calculation/

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    boolean success;

    String strHtml = "<table class=\"od\"><tr><th>Description</th><th>Quantity</th><th>Amount</th></tr><tr><td>1 Digital Camera</td><td class=\"r\">1</td><td class=\"r\">100 GBP</td></tr><tr><td class=\"b\">Total</td><td class=\"r\"></td><td class=\"b r\">100.00 GBP</td></tr></table>";

    CkGzip gzip = new CkGzip();
    String gzOrderData = gzip.compressStringENC(strHtml,"utf-8","base64");

    CkXml xml = new CkXml();
    xml.put_Tag("keyValuePairs");

    xml.NewChild2("orderData",gzOrderData);

    // required, The payment deadline; the payment needs to occur within the specified time value.
    String sessionValidity = "2019-08-11T10:30:00Z";
    xml.NewChild2("sessionValidity",sessionValidity);

    // optional.  Normally we'll let Adyen automatically know the country based on the IP address.
    // By default, the payment methods offered to a shopper are filtered based on the country the shopper's IP address is mapped to. 
    // In this way, shoppers are not offered payment methods that are not available in the country they are carrying out the transaction from. 
    // This IP-to-country mapping is not 100% accurate, so if you have already established the country of the shopper, you can set it explicitly 
    // in the countryCode parameter.
    String countryCode = "GB";
    xml.NewChild2("countryCode",countryCode);

    // optional
    String shopperLocale = "en_GB";
    // If not specified, the locale preference is set to en_GB   by default.
    // When it is not necessary to include the country-specific part, use only the language code.
    // For example: it instead of it_IT to set the locale preferences to Italian.
    xml.NewChild2("shopperLocale",shopperLocale);

    // required, A reference to uniquely identify the payment. This reference is used in all communication with you about the payment status. 
    // We recommend using a unique value per payment; however, it is not a requirement. If you need to provide multiple references for a transaction, 
    // you can enter them in this field. Separate each reference value with a hyphen character ("-"). This field has a length restriction: 
    // you can enter max. 80 characters.
    String merchantReference = "paymentTest1234";
    xml.NewChild2("merchantReference",merchantReference);

    // required, The merchant account identifier you want to process the (transaction) request with.
    String merchantAccount = "ChilkatSoftwareIncCOM";
    xml.NewChild2("merchantAccount",merchantAccount);

    // required.  10000 for $100.00
    String paymentAmount = "10000";
    xml.NewChild2("paymentAmount",paymentAmount);

    // required, The three-character ISO currency code
    String currencyCode = "GBP";
    xml.NewChild2("currencyCode",currencyCode);

    // required.
    String skinCode = "S7uWsvfB";
    xml.NewChild2("skinCode",skinCode);

    // optional, A unique identifier for the shopper, for example, a customer ID.
    // We recommend providing this information, as it is used in velocity fraud checks. It is also the key in recurring payments.
    // This field is mandatory in recurring payments.  
    String shopperReference = "somebody@example.com";
    xml.NewChild2("shopperReference",shopperReference);

    // optional
    String shopperEmail = "somebody@example.com";
    xml.NewChild2("shopperEmail",shopperEmail);

    // optional, An integer value that adds up to the normal fraud score.
    // The value can be either a positive or negative integer.
    xml.NewChild2("offset","0");

    // Apparently this is a required field.
    String shipBeforeDate = "2019-06-04";
    xml.NewChild2("shipBeforeDate",shipBeforeDate);

    xml.SortByTag(true);

    // Encode...
    //  "\" (backslash) as "\\"
    //  ":" (colon) as "\:"

    CkStringBuilder sbTags = new CkStringBuilder();
    CkStringBuilder sbValues = new CkStringBuilder();

    CkStringBuilder sbContent = new CkStringBuilder();
    int n = xml.get_NumChildren();
    int i = 0;
    while (i < n) {
        if (i > 0) {
            sbTags.Append(":");
            sbValues.Append(":");
            }

        xml.GetChild2(i);
        sbTags.Append(xml.tag());

        sbContent.SetString(xml.content());
        int numReplaced = sbContent.Replace("\\","\\\\");
        numReplaced = sbContent.Replace(":","\\:");
        sbValues.AppendSb(sbContent);
        xml.GetParent2();

        i = i + 1;
        }

    CkStringBuilder sbSigningStr = new CkStringBuilder();
    sbSigningStr.AppendSb(sbTags);
    sbSigningStr.Append(":");
    sbSigningStr.AppendSb(sbValues);

    CkCrypt2 crypt = new CkCrypt2();
    crypt.put_HashAlgorithm("sha256");
    crypt.put_MacAlgorithm("hmac");

    String hmacKey = "934D1E806DDD99595EB430076FD7F8E4D12D0A3F51243A4C0C3897703118E739";
    crypt.SetMacKeyEncoded(hmacKey,"hex");

    crypt.put_EncodingMode("base64");
    String merchantSig = crypt.hmacStringENC(sbSigningStr.getAsString());

    Log.i(TAG, merchantSig);

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}