Visual FoxPro

Payeezy HMAC Computation

See more HTTP Misc Examples

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

LOCAL lnSuccess
LOCAL loCrypt
LOCAL loPrng
LOCAL lcApiKey
LOCAL lcApiSecret
LOCAL lcToken
LOCAL lcNonce
LOCAL loDtNow
LOCAL loSbTimestamp
LOCAL lcTimestamp
LOCAL loJson
LOCAL loSbHmacData
LOCAL lcHexHash
LOCAL loSbBase64Hash

lnSuccess = 0

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

loCrypt = CreateObject('Chilkat.Crypt2')
loPrng = CreateObject('Chilkat.Prng')

* 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('Chilkat.CkDateTime')
loDtNow.SetFromCurrentSystemTime()
loSbTimestamp = CreateObject('Chilkat.StringBuilder')
* Get the epoch timestamp in seconds
loSbTimestamp.Append(loDtNow.GetAsUnixTimeStr(0))
* 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('Chilkat.JsonObject')
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('Chilkat.StringBuilder')
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('Chilkat.StringBuilder')
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