B4X

Adyen HMAC Signature Calculation for Hosted Payment Pages

See more Adyen Examples

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#

B4X

Dim success As Boolean = False

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

Dim strHtml As String = "<table class=" & Chr(34) & "od" & Chr(34) & "><tr><th>Description</th><th>Quantity</th><th>Amount</th></tr><tr><td>1 Digital Camera</td><td class=" & Chr(34) & "r" & Chr(34) & ">1</td><td class=" & Chr(34) & "r" & Chr(34) & ">100 GBP</td></tr><tr><td class=" & Chr(34) & "b" & Chr(34) & ">Total</td><td class=" & Chr(34) & "r" & Chr(34) & "></td><td class=" & Chr(34) & "b r" & Chr(34) & ">100.00 GBP</td></tr></table>"

Dim gzip As ChilkatGzip
gzip.Initialize("gzip")
Dim gzOrderData As String = gzip.CompressStringENC(strHtml, "utf-8", "base64")

Dim xml As ChilkatXml
xml.Initialize
xml.Tag = "keyValuePairs"

xml.NewChild2("orderData", gzOrderData)

'  required, The payment deadline; the payment needs to occur within the specified time value.
Dim sessionValidity As String = "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.
Dim countryCode As String = "GB"
xml.NewChild2("countryCode", countryCode)

'  optional
Dim shopperLocale As String = "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.
Dim merchantReference As String = "paymentTest1234"
xml.NewChild2("merchantReference", merchantReference)

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

'  required.  10000 for $100.00
Dim paymentAmount As String = "10000"
xml.NewChild2("paymentAmount", paymentAmount)

'  required, The three-character ISO currency code
Dim currencyCode As String = "GBP"
xml.NewChild2("currencyCode", currencyCode)

'  required.
Dim skinCode As String = "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.  
Dim shopperReference As String = "somebody@example.com"
xml.NewChild2("shopperReference", shopperReference)

'  optional
Dim shopperEmail As String = "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.
Dim shipBeforeDate As String = "2019-06-04"
xml.NewChild2("shipBeforeDate", shipBeforeDate)

xml.SortByTag(True)

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

Dim sbTags As ChilkatStringBuilder
sbTags.Initialize
Dim sbValues As ChilkatStringBuilder
sbValues.Initialize

Dim sbContent As ChilkatStringBuilder
sbContent.Initialize
Dim n As Int = xml.NumChildren
Dim i As Int = 0
Do While i < n
    If i > 0 Then
        sbTags.Append(":")
        sbValues.Append(":")
    End If

    xml.GetChild2(i)
    sbTags.Append(xml.Tag)

    sbContent.SetString(xml.Content)
    Dim numReplaced As Int = sbContent.Replace("\", "\\")
    numReplaced = sbContent.Replace(":", "\:")
    sbValues.AppendSb(sbContent)
    xml.GetParent2

    i = i + 1
Loop

Dim sbSigningStr As ChilkatStringBuilder
sbSigningStr.Initialize
sbSigningStr.AppendSb(sbTags)
sbSigningStr.Append(":")
sbSigningStr.AppendSb(sbValues)

Dim crypt As ChilkatCrypt2
crypt.Initialize("crypt")
crypt.HashAlgorithm = "sha256"
crypt.MacAlgorithm = "hmac"

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

crypt.EncodingMode = "base64"
Dim merchantSig As String = crypt.MacStringENC(sbSigningStr.GetAsString)

Log(merchantSig)