Sending Sorted Attendees List and Validation for CloseRollCall

fe2-android/app/src/main/java/com/github/dedis/popstellar/model/network/method/message/data/election/QuestionResult.kt

@@ -11,7 +11,9 @@ class QuestionResult(ballotOption: String?, count: Int) {
   val count: Int
 
   init {
-    verify().stringNotEmpty(ballotOption, "ballot option").greaterOrEqualThan(count, 0, "count")
+    verify()
+        .stringNotEmpty(ballotOption, "ballot option")
+        .greaterOrEqualThan(count.toLong(), 0, "count")
 
     ballot = ballotOption!!
     this.count = count

fe2-android/app/src/main/java/com/github/dedis/popstellar/model/network/method/message/data/rollcall/CloseRollCall.kt

@@ -4,8 +4,9 @@ import com.github.dedis.popstellar.model.Immutable
 import com.github.dedis.popstellar.model.network.method.message.data.Action
 import com.github.dedis.popstellar.model.network.method.message.data.Data
 import com.github.dedis.popstellar.model.network.method.message.data.Objects
-import com.github.dedis.popstellar.model.objects.RollCall
+import com.github.dedis.popstellar.model.objects.RollCall.Companion.generateCloseRollCallId
 import com.github.dedis.popstellar.model.objects.security.PublicKey
+import com.github.dedis.popstellar.utility.MessageValidator.verify
 import com.google.gson.annotations.SerializedName
 
 /** Data sent to close a Roll-Call */
@@ -25,12 +26,23 @@ class CloseRollCall(
     @field:SerializedName("closed_at") val closedAt: Long,
     attendees: List<PublicKey>
 ) : Data {
-  @SerializedName("update_id")
-  val updateId: String = RollCall.generateCloseRollCallId(laoId, closes, closedAt)
+  @SerializedName("update_id") val updateId: String
 
-  val attendees: List<PublicKey> = ArrayList(attendees)
+  var attendees: List<PublicKey> = ArrayList()
     get() = ArrayList(field)
 
+  init {
+    verify()
+        .stringListIsSorted(attendees, "attendees")
+        .validPastTimes(closedAt)
+        .greaterOrEqualThan(closedAt, 0, "closedAt")
+        .isNotEmptyBase64(laoId, "laoId")
+        .isNotEmptyBase64(closes, "closes")
+
+    this.updateId = generateCloseRollCallId(laoId, closes, closedAt)
+    this.attendees = ArrayList(attendees)
+  }
+
   override val `object`: String
     get() = Objects.ROLL_CALL.`object`
 

fe2-android/app/src/main/java/com/github/dedis/popstellar/model/objects/event/RollCallBuilder.kt

@@ -30,7 +30,7 @@ class RollCallBuilder {
     start = rollCall.startTimestamp
     end = rollCall.end
     state = rollCall.state
-    attendees = HashSet(rollCall.attendees)
+    attendees = LinkedHashSet(rollCall.attendees)
     location = rollCall.location
     description = rollCall.description
   }
@@ -66,12 +66,12 @@ class RollCallBuilder {
   }
 
   fun setAttendees(attendees: Set<PublicKey>): RollCallBuilder {
-    this.attendees = HashSet(attendees)
+    this.attendees = LinkedHashSet(attendees)
     return this
   }
 
   fun setEmptyAttendees(): RollCallBuilder {
-    attendees = HashSet()
+    attendees = LinkedHashSet()
     return this
   }
 
@@ -102,7 +102,7 @@ class RollCallBuilder {
         start,
         end,
         state!!,
-        attendees!!,
+        LinkedHashSet(attendees),
         location!!,
         description!!)
   }

fe2-android/app/src/main/java/com/github/dedis/popstellar/ui/lao/event/rollcall/RollCallArrayAdapter.kt

@@ -14,8 +14,13 @@ class RollCallArrayAdapter(
     private val layout: Int,
     private val attendeesList: List<String>,
     private val myToken: PoPToken?,
+    private val fragment: RollCallFragment
 ) : ArrayAdapter<String>(context, layout, attendeesList) {
 
+  init {
+    fragment.isAttendeeListSorted(attendeesList, context)
+  }
+
   override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
     val view = super.getView(position, convertView, parent)
 

fe2-android/app/src/main/java/com/github/dedis/popstellar/ui/lao/event/rollcall/RollCallFragment.kt

@@ -1,6 +1,7 @@
 package com.github.dedis.popstellar.ui.lao.event.rollcall
 
 import android.annotation.SuppressLint
+import android.content.Context
 import android.content.pm.ActivityInfo
 import android.graphics.Color
 import android.os.Bundle
@@ -9,6 +10,7 @@ import android.view.View
 import android.view.ViewGroup
 import androidx.annotation.VisibleForTesting
 import androidx.appcompat.content.res.AppCompatResources
+import androidx.lifecycle.MutableLiveData
 import com.github.dedis.popstellar.R
 import com.github.dedis.popstellar.databinding.RollCallFragmentBinding
 import com.github.dedis.popstellar.model.objects.RollCall
@@ -51,6 +53,8 @@ class RollCallFragment : AbstractEventFragment {
   private val managementTextMap = buildManagementTextMap()
   private val managementIconMap = buildManagementIconMap()
 
+  private val deAnonymizationWarned = MutableLiveData(false)
+
   constructor()
 
   override fun onCreateView(
@@ -253,15 +257,16 @@ class RollCallFragment : AbstractEventFragment {
               .getAttendees()
               .stream()
               .map(PublicKey::encoded)
+              .sorted(compareBy(String::toString))
               .collect(Collectors.toList())
 
       binding.rollCallAttendeesText.text =
           String.format(
               resources.getString(R.string.roll_call_scanned),
               rollCallViewModel.getAttendees().size)
     } else if (rollCall.isClosed) {
-      attendeesList =
-          rollCall.attendees.stream().map(PublicKey::encoded).collect(Collectors.toList())
+      val orderedAttendees: MutableSet<PublicKey> = LinkedHashSet(rollCall.attendees)
+      attendeesList = orderedAttendees.stream().map(PublicKey::encoded).collect(Collectors.toList())
 
       // Show the list of attendees if the roll call has ended
       binding.rollCallAttendeesText.text =
@@ -271,11 +276,7 @@ class RollCallFragment : AbstractEventFragment {
     if (attendeesList != null) {
       binding.listViewAttendees.adapter =
           RollCallArrayAdapter(
-              requireContext(),
-              android.R.layout.simple_list_item_1,
-              attendeesList,
-              popToken,
-          )
+              requireContext(), android.R.layout.simple_list_item_1, attendeesList, popToken, this)
     }
   }
 
@@ -335,6 +336,17 @@ class RollCallFragment : AbstractEventFragment {
     return map
   }
 
+  fun isAttendeeListSorted(attendeesList: List<String>, context: Context): Boolean {
+    if (attendeesList.isNotEmpty() &&
+        attendeesList != attendeesList.sorted() &&
+        deAnonymizationWarned.value == false) {
+      deAnonymizationWarned.value = true
+      logAndShow(context, TAG, R.string.roll_call_attendees_list_not_sorted)
+      return false
+    }
+    return true
+  }
+
   @VisibleForTesting(otherwise = VisibleForTesting.NONE)
   constructor(rollCall: RollCall) {
     this.rollCall = rollCall
@@ -349,7 +361,6 @@ class RollCallFragment : AbstractEventFragment {
       val bundle = Bundle(1)
       bundle.putString(ROLL_CALL_ID, persistentId)
       fragment.arguments = bundle
-
       return fragment
     }
 

fe2-android/app/src/main/java/com/github/dedis/popstellar/ui/lao/event/rollcall/RollCallViewModel.kt

@@ -33,6 +33,8 @@ import io.reactivex.Completable
 import io.reactivex.Observable
 import io.reactivex.Single
 import java.time.Instant
+import java.util.ArrayList
+import java.util.TreeSet
 import java.util.stream.Collectors
 import javax.inject.Inject
 import timber.log.Timber
@@ -52,7 +54,7 @@ constructor(
 ) : AndroidViewModel(application), QRCodeScanningViewModel {
   private lateinit var laoId: String
 
-  private val attendees: MutableSet<PublicKey> = HashSet()
+  private val attendees: TreeSet<PublicKey> = TreeSet(compareBy { it.toString() })
   override val nbScanned = MutableLiveData<Int>()
   lateinit var attendedRollCalls: Observable<List<RollCall>>
     private set
@@ -261,6 +263,7 @@ constructor(
     nbScanned.postValue(attendees.size)
   }
 
+  @Inject
   fun getAttendees(): Set<PublicKey> {
     return attendees
   }

fe2-android/app/src/main/java/com/github/dedis/popstellar/utility/MessageValidator.kt

@@ -211,7 +211,7 @@ object MessageValidator {
      * @param value the value to compare to
      * @throws IllegalArgumentException if the value is not greater or equal than the given value
      */
-    fun greaterOrEqualThan(input: Int, value: Int, field: String): MessageValidatorBuilder {
+    fun greaterOrEqualThan(input: Long, value: Long, field: String): MessageValidatorBuilder {
       require(input >= value) { "$field must be greater or equal than $value" }
       return this
     }
@@ -305,6 +305,12 @@ object MessageValidator {
       return this
     }
 
+    /** Helper method to check that a string list is sorted */
+    fun stringListIsSorted(list: List<*>, field: String): MessageValidatorBuilder {
+      require(list == list.sortedBy { it.toString() }) { "$field must be sorted" }
+      return this
+    }
+
     private fun validBallotOptions(ballotOptions: List<String>?): MessageValidatorBuilder {
       requireNotNull(ballotOptions) { "Ballot options cannot be null" }
       listNotEmpty(ballotOptions)

fe2-android/app/src/main/java/com/github/dedis/popstellar/utility/handler/data/RollCallHandler.kt

@@ -125,8 +125,18 @@ constructor(
     val updateId = closeRollCall.updateId
     val closes = closeRollCall.closes
     val existingRollCall = rollCallRepo.getRollCallWithId(laoView.id, closes)
-    val currentAttendees = existingRollCall.attendees
-    currentAttendees.addAll(closeRollCall.attendees)
+
+    val currentAttendees: Set<PublicKey>
+    if (closeRollCall.attendees.containsAll(existingRollCall.attendees)) {
+      // closeRollCall.attendees is sorted, so we prefer to use it if we can
+      currentAttendees = closeRollCall.attendees.toMutableSet()
+    } else {
+      // if both lists have different attendees, we merge them even though we lose the order
+      // We are not ordering it because it is important to keep the order that we received to know
+      // if we face de-anonymization
+      currentAttendees = existingRollCall.attendees
+      currentAttendees.addAll(closeRollCall.attendees)
+    }
 
     val builder = RollCallBuilder()
     builder
@@ -142,7 +152,6 @@ constructor(
         .setEnd(closeRollCall.closedAt)
     val laoId = laoView.id
     val rollCall = builder.build()
-
     witnessingRepo.addWitnessMessage(laoId, closeRollCallWitnessMessage(messageId, rollCall))
     if (witnessingRepo.areWitnessesEmpty(laoId)) {
       addRollCallRoutine(rollCallRepo, digitalCashRepo, laoId, rollCall)

fe2-android/app/src/main/res/values/strings.xml

@@ -176,6 +176,8 @@
   <string name="roll_call_scanned">Scanned tokens : %1$d</string>
   <string name="roll_call_description_title">Description</string>
   <string name="roll_call_location_title">Location</string>
+<string name="roll_call_attendees_list_not_sorted">Attendees list is not sorted, risk of de-anonymization"</string>
+
 
   <!-- Meeting -->
   <string name="meeting_title">Meeting</string>

fe2-android/app/src/test/framework/common/java/com/github/dedis/popstellar/testutils/pages/lao/event/rollcall/RollCallFragmentPageObject.java

@@ -17,7 +17,6 @@ private RollCallFragmentPageObject() {
   public static ViewInteraction rollCallTitle() {
     return onView(withId(R.id.roll_call_fragment_title));
   }
-
   public static ViewInteraction rollCallStatusText() {
     return onView(withId(R.id.roll_call_status));
   }

fe2-android/app/src/test/framework/robolectric/java/com/github/dedis/popstellar/testutils/UITestUtils.kt

@@ -43,6 +43,24 @@ object UITestUtils {
     Assert.assertEquals(expected, ShadowToast.getTextOfLatestToast())
   }
 
+  /**
+   * Assert that the latest toast was shown with the expected text
+   *
+   * @param resId expected
+   * @param args arguments to the resource
+   */
+  @JvmStatic
+  fun assertToastDisplayedHasNotText(@StringRes resId: Int, vararg args: Any?) {
+    MatcherAssert.assertThat(
+      "No toast was displayed",
+      ShadowToast.getLatestToast(),
+      Matchers.notNullValue()
+    )
+
+    val expected = ApplicationProvider.getApplicationContext<Context>().getString(resId, *args)
+    Assert.assertNotEquals(expected, ShadowToast.getTextOfLatestToast())
+  }
+
   @JvmStatic
   fun assertToastIsDisplayedContainsText(@StringRes resId: Int, vararg args: Any?) {
     MatcherAssert.assertThat(

fe2-android/app/src/test/ui/robolectric/com/github/dedis/popstellar/ui/lao/InviteFragmentTest.kt

@@ -2,10 +2,7 @@ package com.github.dedis.popstellar.ui.lao
 
 import android.content.ClipboardManager
 import android.content.Context
-import android.widget.Button
 import androidx.arch.core.executor.testing.InstantTaskExecutorRule
-import androidx.test.espresso.Espresso
-import androidx.test.espresso.EspressoException
 import androidx.test.espresso.action.ViewActions
 import androidx.test.espresso.action.ViewActions.scrollTo
 import androidx.test.espresso.assertion.ViewAssertions
@@ -20,13 +17,11 @@ import com.github.dedis.popstellar.testutils.BundleBuilder
 import com.github.dedis.popstellar.testutils.fragment.ActivityFragmentScenarioRule
 import com.github.dedis.popstellar.testutils.pages.lao.InviteFragmentPageObject
 import com.github.dedis.popstellar.testutils.pages.lao.LaoActivityPageObject
-import com.github.dedis.popstellar.ui.lao.event.election.CastVoteOpenBallotFragmentTest
 import com.github.dedis.popstellar.utility.security.KeyManager
 import dagger.hilt.android.testing.BindValue
 import dagger.hilt.android.testing.HiltAndroidRule
 import dagger.hilt.android.testing.HiltAndroidTest
 import junit.framework.TestCase
-import javax.inject.Inject
 import org.junit.Rule
 import org.junit.Test
 import org.junit.rules.ExternalResource
@@ -35,6 +30,7 @@ import org.mockito.Mock
 import org.mockito.Mockito
 import org.mockito.junit.MockitoJUnit
 import org.mockito.junit.MockitoTestRule
+import javax.inject.Inject
 
 @SmallTest
 @HiltAndroidTest

fe2-android/app/src/test/ui/robolectric/com/github/dedis/popstellar/ui/lao/event/election/CastVoteOpenBallotFragmentTest.kt

@@ -202,7 +202,7 @@ class CastVoteOpenBallotFragmentTest {
     private const val PLURALITY = "Plurality"
     private val laoSubject = BehaviorSubject.createDefault(LaoView(LAO))
     private val ROLL_CALL =
-      RollCall("id", "id", "rc", 0L, 1L, 2L, EventState.CLOSED, HashSet(), "nowhere", "none")
+      RollCall("id", "id", "rc", 0L, 1L, 2L, EventState.CLOSED, LinkedHashSet(), "nowhere", "none")
     private val ELECTION_ID = generateElectionSetupId(LAO_ID, CREATION, TITLE)
     private val ELECTION_QUESTION_1 =
       ElectionQuestion(

fe2-android/app/src/test/ui/robolectric/com/github/dedis/popstellar/ui/lao/event/election/CastVoteSecretBallotFragmentTest.kt

@@ -136,7 +136,7 @@ class CastVoteSecretBallotFragmentTest {
     private const val PLURALITY = "Plurality"
     private val laoSubject = BehaviorSubject.createDefault(LaoView(LAO))
     private val ROLL_CALL =
-      RollCall("id", "id", "rc", 0L, 1L, 2L, EventState.CLOSED, HashSet(), "nowhere", "none")
+      RollCall("id", "id", "rc", 0L, 1L, 2L, EventState.CLOSED, LinkedHashSet(), "nowhere", "none")
     private val ELECTION_ID = generateElectionSetupId(LAO_ID, CREATION, TITLE)
     private val ELECTION_QUESTION_1 =
       ElectionQuestion(

fe2-android/app/src/test/ui/robolectric/com/github/dedis/popstellar/ui/lao/event/election/ElectionFragmentTest.kt

@@ -66,7 +66,7 @@ class ElectionFragmentTest {
       START,
       END,
       EventState.CLOSED,
-      HashSet(),
+      LinkedHashSet(),
       LOCATION,
       ROLL_CALL_DESC
     )

fe2-android/app/src/test/ui/robolectric/com/github/dedis/popstellar/ui/lao/event/eventlist/EventListAdapterTest.kt

@@ -44,12 +44,12 @@ class EventListAdapterTest {
       1L,
       2L,
       EventState.CREATED,
-      HashSet(),
+      LinkedHashSet(),
       "not lausanne",
       "no"
     )
   private val ROLL_CALL2 =
-    RollCall("12345", "12345", "Name", 2L, 3L, 4L, EventState.CREATED, HashSet(), "nowhere", "foo")
+    RollCall("12345", "12345", "Name", 2L, 3L, 4L, EventState.CREATED, LinkedHashSet(), "nowhere", "foo")
 
   private lateinit var events: Subject<Set<Event>>
 

fe2-android/app/src/test/ui/robolectric/com/github/dedis/popstellar/ui/lao/event/rollcall/RollCallArrayAdapterTest.kt

@@ -44,21 +44,21 @@ class RollCallArrayAdapterTest {
         val myToken = PoPToken(MY_PRIVATE_KEY, MY_PUBLIC_KEY)
         val otherToken = PoPToken(OTHER_PRIVATE_KEY, OTHER_PUBLIC_KEY)
         attendeesList = listOf(myToken.publicKey.encoded, otherToken.publicKey.encoded)
-        adapter = RollCallArrayAdapter(context, R.id.valid_token_layout_text, attendeesList, myToken)
+        adapter = RollCallArrayAdapter(context, R.id.valid_token_layout_text, attendeesList, myToken, mock(RollCallFragment::class.java))
         mockView = TextView(context)
         val colorAccent = ContextCompat.getColor(context, R.color.textOnBackground)
         (mockView as TextView).setTextColor(colorAccent)
     }
 
     @Test
-    fun verify_our_token_is_highlighted() {
+    fun verifyOurTokenIsHighlighted() {
         val view = adapter.getView(0, mockView, mock(ViewGroup::class.java)) as TextView
         val color = ContextCompat.getColor(context, R.color.colorAccent)
         Assert.assertEquals(color, view.currentTextColor)
     }
 
     @Test
-    fun verify_other_token_is_not_highlighted() {
+    fun verifyOtherTokenIsNotHighlighted() {
         val view = adapter.getView(1, mockView, mock(ViewGroup::class.java)) as TextView
         val color = ContextCompat.getColor(context, R.color.textOnBackground)
         Assert.assertEquals(color, view.currentTextColor)