(Visual FoxPro) 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 ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

LOCAL lnSuccess
LOCAL lcStrHtml
LOCAL loGzip
LOCAL lcGzOrderData
LOCAL loXml
LOCAL lcSessionValidity
LOCAL lcCountryCode
LOCAL lcShopperLocale
LOCAL lcMerchantReference
LOCAL lcMerchantAccount
LOCAL lcPaymentAmount
LOCAL lcCurrencyCode
LOCAL lcSkinCode
LOCAL lcShopperReference
LOCAL lcShopperEmail
LOCAL lcShipBeforeDate
LOCAL loSbTags
LOCAL loSbValues
LOCAL loSbContent
LOCAL n
LOCAL i
LOCAL lnNumReplaced
LOCAL loSbSigningStr
LOCAL loCrypt
LOCAL lcHmacKey
LOCAL lcMerchantSig

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

lcStrHtml = '<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>'

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Gzip')
loGzip = CreateObject('Chilkat.Gzip')
lcGzOrderData = loGzip.CompressStringENC(lcStrHtml,"utf-8","base64")

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Xml')
loXml = CreateObject('Chilkat.Xml')
loXml.Tag = "keyValuePairs"

loXml.NewChild2("orderData",lcGzOrderData)

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

* 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.
lcCountryCode = "GB"
loXml.NewChild2("countryCode",lcCountryCode)

* optional
lcShopperLocale = "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.
loXml.NewChild2("shopperLocale",lcShopperLocale)

* 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.
lcMerchantReference = "paymentTest1234"
loXml.NewChild2("merchantReference",lcMerchantReference)

* required, The merchant account identifier you want to process the (transaction) request with.
lcMerchantAccount = "ChilkatSoftwareIncCOM"
loXml.NewChild2("merchantAccount",lcMerchantAccount)

* required.  10000 for $100.00
lcPaymentAmount = "10000"
loXml.NewChild2("paymentAmount",lcPaymentAmount)

* required, The three-character ISO currency code
lcCurrencyCode = "GBP"
loXml.NewChild2("currencyCode",lcCurrencyCode)

* required.
lcSkinCode = "S7uWsvfB"
loXml.NewChild2("skinCode",lcSkinCode)

* 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.  
lcShopperReference = "somebody@example.com"
loXml.NewChild2("shopperReference",lcShopperReference)

* optional
lcShopperEmail = "somebody@example.com"
loXml.NewChild2("shopperEmail",lcShopperEmail)

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

* Apparently this is a required field.
lcShipBeforeDate = "2019-06-04"
loXml.NewChild2("shipBeforeDate",lcShipBeforeDate)

loXml.SortByTag(1)

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

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbTags = CreateObject('Chilkat.StringBuilder')
* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbValues = CreateObject('Chilkat.StringBuilder')

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbContent = CreateObject('Chilkat.StringBuilder')
n = loXml.NumChildren
i = 0
DO WHILE i < n
    IF (i > 0) THEN
        loSbTags.Append(":")
        loSbValues.Append(":")
    ENDIF

    loXml.GetChild2(i)
    loSbTags.Append(loXml.Tag)

    loSbContent.SetString(loXml.Content)
    lnNumReplaced = loSbContent.Replace("\","\\")
    lnNumReplaced = loSbContent.Replace(":","\:")
    loSbValues.AppendSb(loSbContent)
    loXml.GetParent2()

    i = i + 1
ENDDO

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.StringBuilder')
loSbSigningStr = CreateObject('Chilkat.StringBuilder')
loSbSigningStr.AppendSb(loSbTags)
loSbSigningStr.Append(":")
loSbSigningStr.AppendSb(loSbValues)

* For versions of Chilkat < 10.0.0, use CreateObject('Chilkat_9_5_0.Crypt2')
loCrypt = CreateObject('Chilkat.Crypt2')
loCrypt.HashAlgorithm = "sha256"
loCrypt.MacAlgorithm = "hmac"

lcHmacKey = "934D1E806DDD99595EB430076FD7F8E4D12D0A3F51243A4C0C3897703118E739"
loCrypt.SetMacKeyEncoded(lcHmacKey,"hex")

loCrypt.EncodingMode = "base64"
lcMerchantSig = loCrypt.HmacStringENC(loSbSigningStr.GetAsString())

? lcMerchantSig

RELEASE loGzip
RELEASE loXml
RELEASE loSbTags
RELEASE loSbValues
RELEASE loSbContent
RELEASE loSbSigningStr
RELEASE loCrypt