(PowerShell) Payeezy HMAC Computation

Demonstrates how to calculate the HMAC for a Payeezy REST request.

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

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

$crypt = New-Object Chilkat.Crypt2
$prng = New-Object Chilkat.Prng

# An API key such as y6pWAJNyJyjGv66IsVuWnklkKUPFbb0a
$apiKey = "my_api_key"
# An API secret such as 86fbae7030253af3cd15faef2a1f4b67353e41fb6799f576b5093ae52901e6f7
$apiSecret = "my_api_secret"
# A token such as fdoa-a480ce8951daa73262734cf102641994c1e55e7cdf4c02b6
$token = "my_merchant_token"

# The nonce is a random number (bytes), something like "6057786719490086000"
$nonce = $prng.GenRandom(8,"decimal")
$("nonce = " + $nonce)

$dtNow = New-Object Chilkat.CkDateTime
$dtNow.SetFromCurrentSystemTime()
$sbTimestamp = New-Object Chilkat.StringBuilder
# Get the epoch timestamp in seconds
$sbTimestamp.Append($dtNow.GetAsUnixTimeStr($false))
# Change it to milliseconds
$sbTimestamp.Append("000")
# The timestamp is a number similar to this: 1546011905000 (which is a timestamp taken on 28-Dec-2018).
$timestamp = $sbTimestamp.GetAsString()
$("timestamp = " + $timestamp)

# Generate the following JSON request body:
# 	{
# 	  "merchant_ref": "Astonishing-Sale",
# 	  "transaction_type": "authorize",
# 	  "method": "token",
# 	  "amount": "200",
# 	  "currency_code": "USD",
# 	  "token": {
# 	    "token_type": "FDToken",
# 	    "token_data": {
# 	      "type": "visa",
# 	      "value": "2537446225198291",
# 	      "cardholder_name": "JohnSmith",
# 	      "exp_date": "1030",
# 	      "special_payment": "B"
# 	    }
# 	  }
# 	}

$json = New-Object Chilkat.JsonObject
$json.UpdateString("merchant_ref","Astonishing-Sale")
$json.UpdateString("transaction_type","authorize")
$json.UpdateString("method","token")
$json.UpdateString("amount","200")
$json.UpdateString("currency_code","USD")
$json.UpdateString("token.token_type","FDToken")
$json.UpdateString("token.token_data.type","visa")
$json.UpdateString("token.token_data.value","2537446225198291")
$json.UpdateString("token.token_data.cardholder_name","JohnSmith")
$json.UpdateString("token.token_data.exp_date","1030")
$json.UpdateString("token.token_data.special_payment","B")

# string hashData = apiKey + nonce + timestamp + token + jsonString;
$sbHmacData = New-Object Chilkat.StringBuilder
$sbHmacData.Append($apiKey)
$sbHmacData.Append($nonce)
$sbHmacData.Append($timestamp)
$sbHmacData.Append($token)
$sbHmacData.Append($json.Emit())

# HMAC the data to produce a hex string.
$crypt.EncodingMode = "hexlower"
$crypt.MacAlgorithm = "hmac"
$crypt.SetMacKeyString($apiSecret)
$crypt.HashAlgorithm = "sha256"
$crypt.Charset = "utf-8"
$hexHash = $crypt.MacStringENC($sbHmacData.GetAsString())

# Now base64 encode the hex string:
$sbBase64Hash = New-Object Chilkat.StringBuilder
$sbBase64Hash.Append($hexHash)
$sbBase64Hash.Encode("base64","utf-8")

$("This is the Authorization header to be sent with the payeezy request:")
$("Authorization: " + $sbBase64Hash.GetAsString())