main.kt

import javax.crypto.Mac
import javax.crypto.spec.SecretKeySpec
import kotlin.experimental.and


fun main(args: Array<String>) {

  val hmacFromKomoju = "06cb40bd7c630613e41f874296eddd0153d023857a76a9de52daad5da6c2bbe4"

  val algorithm = "HmacSHA256"
  val key = "secret Key"
  val text = "/api/v1/payment/komoju/success?timestamp=1585286159&transaction%5Badditional_information%5D%5Bconfirmation_code%5D=&transaction%5Badditional_information%5D%5Bend_date%5D=1585493999&transaction%5Badditional_information%5D%5Bkonbini%5D=seven-eleven&transaction%5Badditional_information%5D%5Breceipt%5D=ecvtsmawjn&transaction%5Bamount%5D=1514&transaction%5Bcurrency%5D=JPY&transaction%5Bexternal_order_num%5D=924147676981943169&transaction%5Bgrand_total%5D=1704&transaction%5Bpayment_method%5D=konbini&transaction%5Bpayment_method_fee%5D=190&transaction%5Bstatus%5D=authorized&transaction%5Btax%5D=0&transaction%5Buuid%5D=0q9qy8kznsaj1w1jqnyiutonx"

  // Encryption
  val keySpec = SecretKeySpec(key.toByteArray(), algorithm)
  val mac = Mac.getInstance(algorithm)
  mac.init(keySpec)

  val sign = mac.doFinal(text.toByteArray())
  .joinToString("") { String.format("%02x", it and 255.toByte()) }

}