AepsDataModel

 
data class AepsDataModel(
var apiUserName: String = "",
var userName: String = "",
var clientRefID: String = "",
var transactionType: String = "",
var transactionAmount: String = "",
var shopName: String = "",
var brandName: String = "",
var paramB: String = "",
var paramC: String = "",
var agent: String = "",
var location: String = "",
var headerSecrets: String = "",
var skipReceipt: Boolean = false,
var passKey: String = ""
)

 

Step 1: Steps to generate header secret and encrypted data 

Generate header_secret:

{
"client_id":"42Zuw71Ok7e2TGAgHPKttM7PFGMspJLLy3ewq15dhgjtGM9l",
"client_secret":"MDB9krmA8OqYdgjTKflkXXU7BTNAJgVDEWBmhWjQ8YBvAPNKNPLbxnJGSKcKiEV9",
"epoch": "1724136430"
}
Key :- (This key is unique for each client) (Will Provided by iServeU)

Sample Code:

 
val dataToEncrypt = JSONObject().apply {
put(client_id, client_id_value)
put(client_secret,client_secret_value)
put(epoch,epoch_value)
}

Step 2: Get epoch using code

Convert this JSON to String then pass the string and key into encrypt method.

 
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O)
 {
  val epochTime = Instant.now().epochSecond
 }

 

Step 3: How to generate encrypted Header secret

Sample Code:

 
val encryptedData = generateEncryptedData(dataToEncrypt.toString().toByteArray(),
ENCRYPTION_KEY)
NOTE:- ENCRYPTION_KEY will be provided by iServeU.
 

Encrypt method:

 
private fun generateEncryptedData(dataToEncrypt : ByteArray, key: String?): String?
{
val AES_KEY_SIZE: Int = 256
val AES_BLOCK_SIZE: Int = 16
try {
    val iv = ByteArray(AES_BLOCK_SIZE)
    val random = SecureRandom()
    random.nextBytes(iv)
val decodedKey: ByteArray = Base64.decodeBase64(key)
    val secretKeySpec = SecretKeySpec(decodedKey, "AES")
val cipher = Cipher.getInstance("AES/CBC/PKCS5Padding")
     cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, IvParameterSpec(iv))
     val paddedData: ByteArray = pkcs7Padding(dataToEncrypt, AES_BLOCK_SIZE)
     val encrypted = cipher.doFinal(paddedData)
     val result = ByteArray(iv.size + encrypted.size)
     System.arraycopy(iv, 0, result, 0, iv.size)
     System.arraycopy(encrypted, 0, result, iv.size, encrypted.size)
     return Base64.encodeBase64String(result)
} catch (e: Exception) {
     return null
}
}
private fun pkcs7Padding(data: ByteArray, blockSize: Int): ByteArray {
val padding = blockSize - (data.size % blockSize)
val padText = ByteArray(padding)
Arrays.fill(padText, padding.toByte())
val paddedData = ByteArray(data.size + padding)
System.arraycopy(data, 0, paddedData, 0, data.size)
System.arraycopy(padText, 0, paddedData, data.size, padding)
return paddedData
}

 

 

! Notes 

The encrypted method will return one header_secret which will be sent in place of client id and client secret.

! Notes 

In place of client_id and client_secret send headerSecrets.

 

Step 4:Base64 Encryption of Transaction data

 

 
fun getBase64DataModel(aepsDataModel:AepsDataModel):String
{
val gson = Gson()
val getData = gson.toJson(aepsDataModel)
val bytes = getData.toString().toByteArray()
val responseToBase64 = String(android.util.Base64.encode(bytes, android.util.Base64.NO_WRAP)) return responseToBase64 
}

 

Send Data To Service

 
private fun sendDataToService(
context: Context,
activityResultLauncher: ManagedActivityResultLauncher<Intent, ActivityResult>
) {
try {
     val encryptedHeader =generateEncryptedData(dataToEncrypt.toString().toByteArray(), 
ENCRYPTION_KEY)  // Follow the step 1 to generate dataToEncrypt.
     val aepsDataModel = AepsDataModel(
apiUserName =apiUserName , // Mandatory
         userName = userName,  // Mandatory
         transactionType = transactionType, //mandatory, Set the transaction type 0-Balance Enquiry, 1-
Cash Withdrawal, 2-Mini Statement, 3-Aadhaar Pay, 4-Cash Deposit
         transactionAmount = amount, // mandatory, Set the transaction amount for cash withdrawal, cash 
deposit, aadhaar pay and for others it to 0
         clientRefID = referenceID,
         shopName = shopName,
         brandName = brandName,
         paramB = "",
         paramC = "",
         agent = "",
         location = "",
         passKey = "",// Mandatory provided by iServeU
         headerSecrets = encryptedHeader  // Mandatory
     )
     // Convert AepsDataModel to Base64 
     val encodedData = getBase64DataModel(aepsDataModel)
     val manager: PackageManager = context.packageManager
     val intent = manager.getLaunchIntentForPackage("com.isu.aepssdk")
     intent!!.addCategory(Intent.CATEGORY_LAUNCHER)
     intent.flags = 0
     intent.putExtra("dataToAepsSdk", encodedData)
     activityResultLauncher.launch(intent)
} catch (e: Exception) {
     Toast.makeText(context, e.localizedMessage, Toast.LENGTH_SHORT).show()
}
}

 

Call back data handle(Kotlin)

 
val activityResultLauncher = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) 
{ result ->
if (result.resultCode == RESULT_OK && result.data != null) {
val encodedData = result.data!!.getStringExtra("encodedSkipReceiptData")
     if (!encodedData.isNullOrEmpty()) {
         // Decode the Base64 encoded data
val decodedBytes = Base64.decode(encodedData, Base64.DEFAULT)
         val decodedData = String(decodedBytes)
     // Parse the JSON back into SkipReceiptData
     val gson = Gson()
     val skipReceiptData = gson.fromJson(decodedData, SkipReceiptData::class.java)
     // Use the decoded SkipReceiptData for example
     Toast.makeText(this@MainActivity, "Status: ${skipReceiptData.status}, Transaction Amount: $
{skipReceiptData.transactionAmount}", Toast.LENGTH_LONG).show()
}
}
}