NFC-83 Use StateFlow instead of LiveData. Centralize PIN clearing. Remove padding for remember me.

Author: SanderKondratjevNortal

app/src/main/kotlin/ee/ria/DigiDoc/fragment/screen/WebEidScreen.kt

@@ -73,7 +73,6 @@ import androidx.compose.ui.text.style.TextOverflow
 import androidx.compose.ui.tooling.preview.Preview
 import androidx.compose.ui.unit.dp
 import androidx.hilt.lifecycle.viewmodel.compose.hiltViewModel
-import androidx.lifecycle.asFlow
 import androidx.navigation.NavHostController
 import androidx.navigation.compose.rememberNavController
 import ee.ria.DigiDoc.R
@@ -126,7 +125,7 @@ fun WebEidScreen(
     val snackBarHostState = remember { SnackbarHostState() }
     val snackBarScope = rememberCoroutineScope()
     val messages by SnackBarManager.messages.collectAsState(emptyList())
-    val dialogError by viewModel.dialogError.asFlow().collectAsState(0)
+    val dialogError by viewModel.dialogError.collectAsState()
     var rememberMe by rememberSaveable { mutableStateOf(true) }
     val hasStoredCanNumber = sharedSettingsViewModel.dataStore.getCanNumber().isNotEmpty()
 
@@ -303,8 +302,6 @@ fun WebEidScreen(
                 )
 
                 if (!isWebEidAuthenticating) {
-                    Spacer(modifier = Modifier.height(SPadding))
-
                     WebEidRememberMe(
                         rememberMe = rememberMe,
                         onRememberMeChange = { rememberMe = it },
@@ -356,8 +353,6 @@ fun WebEidScreen(
                     )
 
                     if (!isWebEidAuthenticating) {
-                        Spacer(modifier = Modifier.height(SPadding))
-
                         WebEidRememberMe(
                             rememberMe = rememberMe,
                             onRememberMeChange = { rememberMe = it },

app/src/main/kotlin/ee/ria/DigiDoc/viewmodel/NFCViewModel.kt

@@ -54,6 +54,7 @@ import ee.ria.DigiDoc.smartcardreader.SmartCardReaderException
 import ee.ria.DigiDoc.smartcardreader.nfc.NfcSmartCardReaderManager
 import ee.ria.DigiDoc.smartcardreader.nfc.NfcSmartCardReaderManager.NfcStatus
 import ee.ria.DigiDoc.utils.pin.PinCodeUtil.isPINLengthValid
+import ee.ria.DigiDoc.utilsLib.extensions.clearSensitive
 import ee.ria.DigiDoc.utilsLib.logging.LoggingUtil.Companion.debugLog
 import ee.ria.DigiDoc.utilsLib.logging.LoggingUtil.Companion.errorLog
 import ee.ria.libdigidocpp.ExternalSigner
@@ -275,9 +276,7 @@ class NFCViewModel
 
                                 val signatureArray =
                                     card.calculateSignature(pin2Code, dataToSignBytes, true)
-                                if (null != pin2Code && pin2Code.isNotEmpty()) {
-                                    Arrays.fill(pin2Code, 0.toByte())
-                                }
+                                pin2Code.clearSensitive()
                                 debugLog(logTag, "Signature: " + Hex.toHexString(signatureArray))
 
                                 containerWrapper.finalizeSignature(
@@ -374,9 +373,7 @@ class NFCViewModel
 
                                 errorLog(logTag, "Exception: " + ex.message, ex)
                             } finally {
-                                if (null != pin2Code && pin2Code.isNotEmpty()) {
-                                    Arrays.fill(pin2Code, 0.toByte())
-                                }
+                                pin2Code.clearSensitive()
                                 nfcSmartCardReaderManager.disableNfcReaderMode()
                                 activity.requestedOrientation =
                                     ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED
@@ -437,9 +434,7 @@ class NFCViewModel
                                         cdoc2Settings,
                                         configurationRepository,
                                     )
-                                if (pin1Code.isNotEmpty()) {
-                                    Arrays.fill(pin1Code, 0.toByte())
-                                }
+                                pin1Code.clearSensitive()
                                 CoroutineScope(Main).launch {
                                     _shouldResetPIN.postValue(true)
                                     _decryptStatus.postValue(true)
@@ -531,9 +526,7 @@ class NFCViewModel
 
                                 errorLog(logTag, "Exception: " + ex.message, ex)
                             } finally {
-                                if (pin1Code.isNotEmpty()) {
-                                    Arrays.fill(pin1Code, 0.toByte())
-                                }
+                                pin1Code.clearSensitive()
                                 nfcSmartCardReaderManager.disableNfcReaderMode()
                                 activity.requestedOrientation =
                                     ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED
@@ -649,9 +642,7 @@ class NFCViewModel
                                     challenge = challenge,
                                 )
 
-                            if (pin1Code.isNotEmpty()) {
-                                Arrays.fill(pin1Code, 0.toByte())
-                            }
+                            pin1Code.clearSensitive()
                             debugLog(logTag, "Auth certificate: " + Base64.getEncoder().encodeToString(authCert))
                             debugLog(logTag, "Auth signature: " + Hex.toHexString(signatureArray))
 
@@ -946,9 +937,7 @@ class NFCViewModel
 
                             errorLog(logTag, "Exception: " + ex.message, ex)
                         } finally {
-                            if (null != pin2Code && pin2Code.isNotEmpty()) {
-                                Arrays.fill(pin2Code, 0.toByte())
-                            }
+                            pin2Code.clearSensitive()
                             nfcSmartCardReaderManager.disableNfcReaderMode()
                             activity.requestedOrientation =
                                 ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED

app/src/main/kotlin/ee/ria/DigiDoc/viewmodel/WebEidViewModel.kt

@@ -22,8 +22,6 @@
 package ee.ria.DigiDoc.viewmodel
 
 import android.net.Uri
-import androidx.lifecycle.LiveData
-import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
 import dagger.hilt.android.lifecycle.HiltViewModel
 import ee.ria.DigiDoc.R
@@ -59,8 +57,8 @@ class WebEidViewModel
         val signRequest: StateFlow<WebEidSignRequest?> = _signRequest.asStateFlow()
         private val _relyingPartyResponseEvents = MutableSharedFlow<Uri>()
         val relyingPartyResponseEvents: SharedFlow<Uri> = _relyingPartyResponseEvents.asSharedFlow()
-        private val _dialogError = MutableLiveData<Int>(null)
-        val dialogError: LiveData<Int> = _dialogError
+        private val _dialogError = MutableStateFlow(0)
+        val dialogError: StateFlow<Int> = _dialogError
 
         suspend fun handleAuth(uri: Uri) {
             try {
@@ -72,7 +70,7 @@ class WebEidViewModel
                 _relyingPartyResponseEvents.emit(responseUri)
             } catch (e: Exception) {
                 errorLog(logTag, "Unable parse Web eID authentication request: $uri", e)
-                _dialogError.postValue(R.string.web_eid_invalid_auth_request_error)
+                _dialogError.value = R.string.web_eid_invalid_auth_request_error
             }
         }
 
@@ -81,7 +79,7 @@ class WebEidViewModel
                 _signRequest.value = WebEidRequestParser.parseCertificateUri(uri)
             } catch (e: Exception) {
                 errorLog(logTag, "Unable parse Web eID certificate request: $uri", e)
-                _dialogError.postValue(R.string.web_eid_invalid_sign_request_error)
+                _dialogError.value = R.string.web_eid_invalid_sign_request_error
             }
         }
 
@@ -95,13 +93,13 @@ class WebEidViewModel
                 _relyingPartyResponseEvents.emit(responseUri)
             } catch (e: Exception) {
                 errorLog(logTag, "Unable parse Web eID signing request: $uri", e)
-                _dialogError.postValue(R.string.web_eid_invalid_sign_request_error)
+                _dialogError.value = R.string.web_eid_invalid_sign_request_error
             }
         }
 
         fun handleUnknown(uri: Uri) {
             errorLog(logTag, "Unable parse Web eID request: $uri")
-            _dialogError.postValue(R.string.web_eid_invalid_sign_request_error)
+            _dialogError.value = R.string.web_eid_invalid_sign_request_error
         }
 
         suspend fun handleWebEidAuthResult(

utils-lib/src/main/kotlin/ee/ria/DigiDoc/utilsLib/extensions/ByteArrayExtensions.kt

@@ -27,6 +27,7 @@ import java.io.ByteArrayInputStream
 import java.security.cert.CertificateException
 import java.security.cert.CertificateFactory
 import java.security.cert.X509Certificate
+import java.util.Arrays
 
 fun ByteArray.hexString(): String {
     val hexString = Hex.toHexString(this)
@@ -43,3 +44,9 @@ fun ByteArray.x509Certificate(): X509Certificate? =
     } catch (ce: CertificateException) {
         null
     }
+
+fun ByteArray?.clearSensitive() {
+    if (this != null && this.isNotEmpty()) {
+        Arrays.fill(this, 0.toByte())
+    }
+}