Added code for encrypting username and password during device registration

app/build.gradle

@@ -19,8 +19,8 @@ android {
         applicationId "in.sminnovations.hpostesting.dev"
         minSdk 21
         targetSdk 34
-        versionCode 113
-        versionName "2.1.113"
+        versionCode 114
+        versionName "2.1.114"
 
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }

app/src/main/java/com/example/hpostesting/data/encryption/AESCrypt.kt

@@ -0,0 +1,36 @@
+package com.example.hpostesting.data.encryption
+
+import android.security.keystore.KeyGenParameterSpec
+import android.security.keystore.KeyProperties
+import android.util.Base64
+import javax.crypto.Cipher
+import javax.crypto.KeyGenerator
+import javax.crypto.spec.SecretKeySpec
+
+
+object AESCrypt {
+    private const val ALGORITHM = "AES"
+    private const val KEY = "your_secret_key"
+
+    @Throws(Exception::class)
+    fun encrypt(value: String): String {
+        val keySpec = SecretKeySpec(KEY.toByteArray(), ALGORITHM)
+        val cipher = Cipher.getInstance(ALGORITHM)
+        cipher.init(Cipher.ENCRYPT_MODE, keySpec)
+        val encryptedBytes = cipher.doFinal(value.toByteArray())
+        return Base64.encodeToString(encryptedBytes, Base64.DEFAULT)
+    }
+
+    @Throws(Exception::class)
+    fun decrypt(encrypted: String?): String {
+        val keySpec = SecretKeySpec(KEY.toByteArray(), ALGORITHM)
+        val cipher = Cipher.getInstance(ALGORITHM)
+        cipher.init(Cipher.DECRYPT_MODE, keySpec)
+        val encryptedBytes = Base64.decode(encrypted, Base64.DEFAULT)
+        val decryptedBytes = cipher.doFinal(encryptedBytes)
+        return String(decryptedBytes)
+    }
+
+    //generates a secret key for the encryption functions to use
+    //TODO: Generating keys requires a higher API level. ask someone if this is okay.
+}

app/src/main/java/com/example/hpostesting/presentation/deviceprovision/DeviceProvisionActivity.kt

@@ -93,7 +93,6 @@ class DeviceProvisionActivity : AppCompatActivity(), DeviceCommunicationHandler
         supportActionBar?.setDisplayHomeAsUpEnabled(true)
         setupListener()
         connectUsb(false)
-
     }
 
     private fun setupListener() {

app/src/main/java/com/example/hpostesting/presentation/deviceprovision/DeviceProvisionFragment.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import android.content.Intent
 import android.content.SharedPreferences
 import android.os.Bundle
+import android.util.Base64
 import android.util.Log
 import android.view.LayoutInflater
 import android.view.View
@@ -15,6 +16,7 @@ import androidx.lifecycle.MutableLiveData
 import com.example.hpostesting.data.Result
 import com.example.hpostesting.data.constant.Constants
 import com.example.hpostesting.data.constant.HemoCubeCommands
+import com.example.hpostesting.data.encryption.AESCrypt
 import com.example.hpostesting.data.model.deviceprovision.DeviceProvisionRequest
 import com.example.hpostesting.data.model.patient.DeviceData
 import com.example.hpostesting.presentation.UsbServiceListener
@@ -22,6 +24,9 @@ import com.example.hpostesting.presentation.dashboard.DashboardActivity
 import com.google.firebase.crashlytics.ktx.crashlytics
 import com.google.firebase.ktx.Firebase
 import `in`.sminnovations.hpostesting.databinding.FragmentDeviceProvisionBinding
+import javax.crypto.Cipher
+import javax.crypto.spec.SecretKeySpec
+
 
 class DeviceProvisionFragment : Fragment() {
     private var resultData: String = ""
@@ -123,6 +128,9 @@ class DeviceProvisionFragment : Fragment() {
                         Log.e("idpass", response.toString())
                         Log.e("idpass", response.data.data?.credentials?.username.toString())
                         Log.e("idpass", deviceProvisionResponse)
+
+                        saveDataToLocalFile(response.data.data?.credentials?.username.toString(),  response.data.data?.credentials?.password.toString())
+
                     } else {
                         Toast.makeText(
                             activity,
@@ -218,4 +226,17 @@ class DeviceProvisionFragment : Fragment() {
             }
         }
     }
+
+
+    //saves username and password to a local file after encrypting it.
+    private fun saveDataToLocalFile(username : String, password : String){
+        val encryptedUsername = AESCrypt.encrypt(username)
+        val encryptedPassword = AESCrypt.encrypt(password)
+        val encryptedData = encryptedUsername + "\n" + encryptedPassword
+
+        val fos = requireContext().openFileOutput("credentials.txt", Context.MODE_PRIVATE)
+        fos.write(encryptedData.toByteArray())
+        fos.close()
+    }
+
 }