(Delphi ActiveX) 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 for Delphi Downloads Chilkat ActiveX DLL for Delphi Chilkat non-ActiveX DLL for Delphi * The examples here use the ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
strHtml: WideString;
gzip: TChilkatGzip;
gzOrderData: WideString;
xml: TChilkatXml;
sessionValidity: WideString;
countryCode: WideString;
shopperLocale: WideString;
merchantReference: WideString;
merchantAccount: WideString;
paymentAmount: WideString;
currencyCode: WideString;
skinCode: WideString;
shopperReference: WideString;
shopperEmail: WideString;
shipBeforeDate: WideString;
sbTags: TChilkatStringBuilder;
sbValues: TChilkatStringBuilder;
sbContent: TChilkatStringBuilder;
n: Integer;
i: Integer;
numReplaced: Integer;
sbSigningStr: TChilkatStringBuilder;
crypt: TChilkatCrypt2;
hmacKey: WideString;
merchantSig: WideString;

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

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>';

gzip := TChilkatGzip.Create(Self);
gzOrderData := gzip.CompressStringENC(strHtml,'utf-8','base64');

xml := TChilkatXml.Create(Self);
xml.Tag := 'keyValuePairs';

xml.NewChild2('orderData',gzOrderData);

// required, The payment deadline; the payment needs to occur within the specified time value.
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.
countryCode := 'GB';
xml.NewChild2('countryCode',countryCode);

// optional
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.
merchantReference := 'paymentTest1234';
xml.NewChild2('merchantReference',merchantReference);

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

// required.  10000 for $100.00
paymentAmount := '10000';
xml.NewChild2('paymentAmount',paymentAmount);

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

// required.
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.  
shopperReference := 'somebody@example.com';
xml.NewChild2('shopperReference',shopperReference);

// optional
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.
shipBeforeDate := '2019-06-04';
xml.NewChild2('shipBeforeDate',shipBeforeDate);

xml.SortByTag(1);

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

sbTags := TChilkatStringBuilder.Create(Self);
sbValues := TChilkatStringBuilder.Create(Self);

sbContent := TChilkatStringBuilder.Create(Self);
n := xml.NumChildren;
i := 0;
while i < n do
  begin
    if (i > 0) then
      begin
        sbTags.Append(':');
        sbValues.Append(':');
      end;
    xml.GetChild2(i);
    sbTags.Append(xml.Tag);

    sbContent.SetString(xml.Content);
    numReplaced := sbContent.Replace('\",'\\\");
    numReplaced := sbContent.Replace(':','\\:');
    sbValues.AppendSb(sbContent.ControlInterface);
    xml.GetParent2();

    i := i + 1;
  end;

sbSigningStr := TChilkatStringBuilder.Create(Self);
sbSigningStr.AppendSb(sbTags.ControlInterface);
sbSigningStr.Append(':');
sbSigningStr.AppendSb(sbValues.ControlInterface);

crypt := TChilkatCrypt2.Create(Self);
crypt.HashAlgorithm := 'sha256';
crypt.MacAlgorithm := 'hmac';

hmacKey := '934D1E806DDD99595EB430076FD7F8E4D12D0A3F51243A4C0C3897703118E739';
crypt.SetMacKeyEncoded(hmacKey,'hex');

crypt.EncodingMode := 'base64';
merchantSig := crypt.HmacStringENC(sbSigningStr.GetAsString());

Memo1.Lines.Add(merchantSig);
end;