(CkPython) 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 Python Downloads install with pip pip3 install chilkat or download... Python Module for Windows, MacOS, Linux, Alpine Linux, Solaris

import chilkat

# 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 = chilkat.CkGzip()
gzOrderData = gzip.compressStringENC(strHtml,"utf-8","base64")

xml = chilkat.CkXml()
xml.put_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(True)

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

sbTags = chilkat.CkStringBuilder()
sbValues = chilkat.CkStringBuilder()

sbContent = chilkat.CkStringBuilder()
n = xml.get_NumChildren()
i = 0
while i < n :
    if (i > 0):
        sbTags.Append(":")
        sbValues.Append(":")

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

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

    i = i + 1

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

crypt = chilkat.CkCrypt2()
crypt.put_HashAlgorithm("sha256")
crypt.put_MacAlgorithm("hmac")

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

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

print(merchantSig)