Lua

Payeezy HMAC Computation

See more HTTP Misc Examples

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

local chilkat = require("chilkat")

local success = false

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

local crypt = chilkat.Crypt2.new()
local prng = chilkat.Prng.new()

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

-- The nonce is a random number (bytes), something like "6057786719490086000"
local nonce = prng:gen_random(8, "decimal")
print("nonce = " .. nonce)

local dtNow = chilkat.DateTime.new()
dtNow:set_from_current_system_time()
local sbTimestamp = chilkat.StringBuilder.new()
-- Get the epoch timestamp in seconds
sbTimestamp:append(dtNow:get_as_unix_time_str(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).
local timestamp = sbTimestamp:get_as_string()
print("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"
--         }
--       }
--     }

local json = chilkat.JsonObject.new()
json:update_string("merchant_ref", "Astonishing-Sale")
json:update_string("transaction_type", "authorize")
json:update_string("method", "token")
json:update_string("amount", "200")
json:update_string("currency_code", "USD")
json:update_string("token.token_type", "FDToken")
json:update_string("token.token_data.type", "visa")
json:update_string("token.token_data.value", "2537446225198291")
json:update_string("token.token_data.cardholder_name", "JohnSmith")
json:update_string("token.token_data.exp_date", "1030")
json:update_string("token.token_data.special_payment", "B")

-- string hashData = apiKey + nonce + timestamp + token + jsonString;
local sbHmacData = chilkat.StringBuilder.new()
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.encoding_mode = "hexlower"
crypt.mac_algorithm = "hmac"
crypt:set_mac_key_string(apiSecret)
crypt.hash_algorithm = "sha256"
crypt.charset = "utf-8"
local hexHash = crypt:mac_string_enc(sbHmacData:get_as_string())

-- Now base64 encode the hex string:
local sbBase64Hash = chilkat.StringBuilder.new()
sbBase64Hash:append(hexHash)
sbBase64Hash:encode("base64", "utf-8")

print("This is the Authorization header to be sent with the payeezy request:")
print("Authorization: " .. sbBase64Hash:get_as_string())