(Lianja) Payeezy HMAC Computation

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

Chilkat Lianja Extension Download Chilkat Lianja Extension

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

loCrypt = createobject("CkCrypt2")
loPrng = createobject("CkPrng")

// An API key such as y6pWAJNyJyjGv66IsVuWnklkKUPFbb0a
lcApiKey = "my_api_key"
// An API secret such as 86fbae7030253af3cd15faef2a1f4b67353e41fb6799f576b5093ae52901e6f7
lcApiSecret = "my_api_secret"
// A token such as fdoa-a480ce8951daa73262734cf102641994c1e55e7cdf4c02b6
lcToken = "my_merchant_token"

// The nonce is a random number (bytes), something like "6057786719490086000"
lcNonce = loPrng.GenRandom(8,"decimal")
? "nonce = " + lcNonce

loDtNow = createobject("CkDateTime")
loDtNow.SetFromCurrentSystemTime()
loSbTimestamp = createobject("CkStringBuilder")
// Get the epoch timestamp in seconds
loSbTimestamp.Append(loDtNow.GetAsUnixTimeStr(.F.))
// Change it to milliseconds
loSbTimestamp.Append("000")
// The timestamp is a number similar to this: 1546011905000 (which is a timestamp taken on 28-Dec-2018).
lcTimestamp = loSbTimestamp.GetAsString()
? "timestamp = " + lcTimestamp

// 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"
// 	    }
// 	  }
// 	}

loJson = createobject("CkJsonObject")
loJson.UpdateString("merchant_ref","Astonishing-Sale")
loJson.UpdateString("transaction_type","authorize")
loJson.UpdateString("method","token")
loJson.UpdateString("amount","200")
loJson.UpdateString("currency_code","USD")
loJson.UpdateString("token.token_type","FDToken")
loJson.UpdateString("token.token_data.type","visa")
loJson.UpdateString("token.token_data.value","2537446225198291")
loJson.UpdateString("token.token_data.cardholder_name","JohnSmith")
loJson.UpdateString("token.token_data.exp_date","1030")
loJson.UpdateString("token.token_data.special_payment","B")

// string hashData = apiKey + nonce + timestamp + token + jsonString;
loSbHmacData = createobject("CkStringBuilder")
loSbHmacData.Append(lcApiKey)
loSbHmacData.Append(lcNonce)
loSbHmacData.Append(lcTimestamp)
loSbHmacData.Append(lcToken)
loSbHmacData.Append(loJson.Emit())

// HMAC the data to produce a hex string.
loCrypt.EncodingMode = "hexlower"
loCrypt.MacAlgorithm = "hmac"
loCrypt.SetMacKeyString(lcApiSecret)
loCrypt.HashAlgorithm = "sha256"
loCrypt.Charset = "utf-8"
lcHexHash = loCrypt.MacStringENC(loSbHmacData.GetAsString())

// Now base64 encode the hex string:
loSbBase64Hash = createobject("CkStringBuilder")
loSbBase64Hash.Append(lcHexHash)
loSbBase64Hash.Encode("base64","utf-8")

? "This is the Authorization header to be sent with the payeezy request:"
? "Authorization: " + loSbBase64Hash.GetAsString()


release loCrypt
release loPrng
release loDtNow
release loSbTimestamp
release loJson
release loSbHmacData
release loSbBase64Hash