Add support for call link epochs.

2025-12-23 20:48:43 +00:00 · 2025-07-03 15:07:34 -04:00
parent 5d0f71e02c
commit b42dcece48
34 changed files with 211 additions and 71 deletions
--- a/app/src/androidTest/java/org/thoughtcrime/securesms/conversation/v2/items/V2ConversationItemShapeTest.kt
+++ b/app/src/androidTest/java/org/thoughtcrime/securesms/conversation/v2/items/V2ConversationItemShapeTest.kt
@@ -18,6 +18,7 @@ import com.bumptech.glide.RequestManager
 import org.junit.Assert.assertEquals
 import org.junit.Rule
 import org.junit.Test
+import org.signal.ringrtc.CallLinkEpoch
 import org.signal.ringrtc.CallLinkRootKey
 import org.thoughtcrime.securesms.components.voice.VoiceNotePlaybackState
 import org.thoughtcrime.securesms.contactshare.Contact
@@ -326,7 +327,7 @@ class V2ConversationItemShapeTest {

    override fun onShowGroupDescriptionClicked(groupName: String, description: String, shouldLinkifyWebLinks: Boolean) = Unit

-    override fun onJoinCallLink(callLinkRootKey: CallLinkRootKey) = Unit
+    override fun onJoinCallLink(callLinkRootKey: CallLinkRootKey, callLinkEpoch: CallLinkEpoch?) = Unit

    override fun onItemClick(item: MultiselectPart?) = Unit

--- a/app/src/androidTest/java/org/thoughtcrime/securesms/database/CallLinkTableTest.kt
+++ b/app/src/androidTest/java/org/thoughtcrime/securesms/database/CallLinkTableTest.kt
@@ -81,7 +81,8 @@ class CallLinkTableTest {
        roomId = CallLinkRoomId.fromBytes(roomId),
        credentials = CallLinkCredentials(
          linkKeyBytes = roomId,
-          adminPassBytes = null
+          adminPassBytes = null,
+          epochBytes = null
        ),
        state = SignalCallLinkState(),
        deletionTimestamp = 0L
--- a/app/src/debug/java/org/thoughtcrime/securesms/components/settings/app/internal/conversation/test/InternalConversationTestFragment.kt
+++ b/app/src/debug/java/org/thoughtcrime/securesms/components/settings/app/internal/conversation/test/InternalConversationTestFragment.kt
@@ -18,6 +18,7 @@ import io.reactivex.rxjava3.android.schedulers.AndroidSchedulers
 import io.reactivex.rxjava3.kotlin.subscribeBy
 import org.signal.core.util.concurrent.LifecycleDisposable
 import org.signal.core.util.logging.Log
+import org.signal.ringrtc.CallLinkEpoch
 import org.signal.ringrtc.CallLinkRootKey
 import org.thoughtcrime.securesms.R
 import org.thoughtcrime.securesms.components.ViewBinderDelegate
@@ -292,7 +293,7 @@ class InternalConversationTestFragment : Fragment(R.layout.conversation_test_fra
      Toast.makeText(requireContext(), "Can't touch this.", Toast.LENGTH_SHORT).show()
    }

-    override fun onJoinCallLink(callLinkRootKey: CallLinkRootKey) {
+    override fun onJoinCallLink(callLinkRootKey: CallLinkRootKey, callLinkEpoch: CallLinkEpoch?) {
      Toast.makeText(requireContext(), "Can't touch this.", Toast.LENGTH_SHORT).show()
    }

--- a/app/src/main/java/org/thoughtcrime/securesms/BindableConversationItem.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/BindableConversationItem.java
@@ -11,6 +11,7 @@ import androidx.lifecycle.Observer;

 import com.bumptech.glide.RequestManager;

+import org.signal.ringrtc.CallLinkEpoch;
 import org.signal.ringrtc.CallLinkRootKey;
 import org.thoughtcrime.securesms.components.voice.VoiceNotePlaybackState;
 import org.thoughtcrime.securesms.contactshare.Contact;
@@ -133,7 +134,7 @@ public interface BindableConversationItem extends Unbindable, GiphyMp4Playable,
    void goToMediaPreview(ConversationItem parent, View sharedElement, MediaIntentFactory.MediaPreviewArgs args);
    void onEditedIndicatorClicked(@NonNull ConversationMessage conversationMessage);
    void onShowGroupDescriptionClicked(@NonNull String groupName, @NonNull String description, boolean shouldLinkifyWebLinks);
-    void onJoinCallLink(@NonNull CallLinkRootKey callLinkRootKey);
+    void onJoinCallLink(@NonNull CallLinkRootKey callLinkRootKey, @Nullable CallLinkEpoch callLinkEpoch);
    void onShowSafetyTips(boolean forGroup);
    void onReportSpamLearnMoreClicked();
    void onMessageRequestAcceptOptionsClicked();
--- a/app/src/main/java/org/thoughtcrime/securesms/backup/v2/exporters/CallLinkArchiveExporter.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/backup/v2/exporters/CallLinkArchiveExporter.kt
@@ -6,6 +6,7 @@
 package org.thoughtcrime.securesms.backup.v2.database

 import android.database.Cursor
+import okio.ByteString
 import okio.ByteString.Companion.toByteString
 import org.signal.core.util.nullIfEmpty
 import org.signal.ringrtc.CallLinkState
@@ -40,6 +41,7 @@ class CallLinkArchiveExporter(private val cursor: Cursor) : Iterator<ArchiveReci
      id = callLink.recipientId.toLong(),
      callLink = CallLink(
        rootKey = callLink.credentials!!.linkKeyBytes.toByteString(),
+        epoch = callLink.credentials.epochBytes?.toByteString() ?: ByteString.EMPTY,
        adminKey = callLink.credentials.adminPassBytes?.toByteString()?.nullIfEmpty(),
        name = callLink.state.name,
        expirationMs = expirationTime.takeIf { it != Long.MAX_VALUE }?.clampToValidBackupRange() ?: 0,
--- a/app/src/main/java/org/thoughtcrime/securesms/backup/v2/importer/CallLinkArchiveImporter.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/backup/v2/importer/CallLinkArchiveImporter.kt
@@ -7,6 +7,7 @@ package org.thoughtcrime.securesms.backup.v2.importer

 import org.signal.core.util.isEmpty
 import org.signal.core.util.logging.Log
+import org.signal.core.util.nullIfEmpty
 import org.signal.ringrtc.CallLinkRootKey
 import org.signal.ringrtc.CallLinkState
 import org.thoughtcrime.securesms.backup.v2.ArchiveCallLink
@@ -42,7 +43,11 @@ object CallLinkArchiveImporter {
      CallLinkTable.CallLink(
        recipientId = RecipientId.UNKNOWN,
        roomId = CallLinkRoomId.fromCallLinkRootKey(rootKey),
-        credentials = CallLinkCredentials(callLink.rootKey.toByteArray(), callLink.adminKey?.toByteArray()),
+        credentials = CallLinkCredentials(
+          callLink.rootKey.toByteArray(),
+          callLink.epoch.nullIfEmpty()?.toByteArray(),
+          callLink.adminKey?.toByteArray()
+        ),
        state = SignalCallLinkState(
          name = callLink.name,
          restrictions = callLink.restrictions.toLocal(),
--- a/app/src/main/java/org/thoughtcrime/securesms/calls/links/CallLinks.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/calls/links/CallLinks.kt
@@ -8,12 +8,14 @@ package org.thoughtcrime.securesms.calls.links
 import io.reactivex.rxjava3.core.Observable
 import org.signal.core.util.logging.Log
 import org.signal.ringrtc.CallException
+import org.signal.ringrtc.CallLinkEpoch
 import org.signal.ringrtc.CallLinkRootKey
 import org.thoughtcrime.securesms.database.CallLinkTable
 import org.thoughtcrime.securesms.database.DatabaseObserver
 import org.thoughtcrime.securesms.database.SignalDatabase
 import org.thoughtcrime.securesms.dependencies.AppDependencies
 import org.thoughtcrime.securesms.service.webrtc.links.CallLinkRoomId
+import java.io.UnsupportedEncodingException
 import java.net.URLDecoder

 /**
@@ -21,12 +23,19 @@ import java.net.URLDecoder
 */
 object CallLinks {
  private const val ROOT_KEY = "key"
+  private const val EPOCH = "epoch"
  private const val HTTPS_LINK_PREFIX = "https://signal.link/call/#key="
  private const val SNGL_LINK_PREFIX = "sgnl://signal.link/call/#key="

  private val TAG = Log.tag(CallLinks::class.java)

-  fun url(linkKeyBytes: ByteArray) = "$HTTPS_LINK_PREFIX${CallLinkRootKey(linkKeyBytes)}"
+  fun url(rootKeyBytes: ByteArray, epochBytes: ByteArray?): String {
+    return if (epochBytes == null) {
+      "$HTTPS_LINK_PREFIX${CallLinkRootKey(rootKeyBytes)}"
+    } else {
+      "$HTTPS_LINK_PREFIX${CallLinkRootKey(rootKeyBytes)}&epoch=${CallLinkEpoch.fromBytes(epochBytes)}"
+    }
+  }

  fun watchCallLink(roomId: CallLinkRoomId): Observable<CallLinkTable.CallLink> {
    return Observable.create { emitter ->
@@ -60,8 +69,13 @@ object CallLinks {
    return url.split("#").last().startsWith("key=")
  }

+  data class CallLinkParseResult(
+    val rootKey: CallLinkRootKey,
+    val epoch: CallLinkEpoch?
+  )
+
  @JvmStatic
-  fun parseUrl(url: String): CallLinkRootKey? {
+  fun parseUrl(url: String): CallLinkParseResult? {
    if (!url.startsWith(HTTPS_LINK_PREFIX) && !url.startsWith(SNGL_LINK_PREFIX)) {
      Log.w(TAG, "Invalid url prefix.")
      return null
@@ -73,18 +87,33 @@ object CallLinks {
      return null
    }

-    val fragment = parts[1]
-    val fragmentParts = fragment.split("&")
-    val fragmentQuery = fragmentParts.associate {
-      val kv = it.split("=")
-      if (kv.size != 2) {
-        Log.w(TAG, "Invalid fragment keypair. Skipping.")
+    val fragmentQuery = mutableMapOf<String, String?>()
+
+    try {
+      for (part in parts[1].split("&")) {
+        val kv = part.split("=")
+        // Make sure we don't have an empty key (i.e. handle the case
+        // of "a=0&&b=0", for example)
+        if (kv[0].isEmpty()) {
+          Log.w(TAG, "Invalid url: $url (empty key)")
+          return null
+        }
+        val key = URLDecoder.decode(kv[0], "utf8")
+        val value = when (kv.size) {
+          1 -> null
+          2 -> URLDecoder.decode(kv[1], "utf8")
+          else -> {
+            // Cannot have more than one value per key (i.e. handle the case
+            // of "a=0&b=0=1=2", for example.
+            Log.w(TAG, "Invalid url: $url (multiple values)")
+            return null
+          }
+        }
+        fragmentQuery += key to value
      }
-
-      val key = URLDecoder.decode(kv[0], "utf8")
-      val value = URLDecoder.decode(kv[1], "utf8")
-
-      key to value
+    } catch (_: UnsupportedEncodingException) {
+      Log.w(TAG, "Invalid url: $url")
+      return null
    }

    val key = fragmentQuery[ROOT_KEY]
@@ -94,9 +123,13 @@ object CallLinks {
    }

    return try {
-      CallLinkRootKey(key)
+      val epoch = fragmentQuery[EPOCH]?.let { s -> CallLinkEpoch(s) }
+      CallLinkParseResult(
+        rootKey = CallLinkRootKey(key),
+        epoch = epoch
+      )
    } catch (e: CallException) {
-      Log.w(TAG, "Invalid root key found in fragment query string.")
+      Log.w(TAG, "Invalid root key or epoch found in fragment query string.")
      null
    }
  }
--- a/app/src/main/java/org/thoughtcrime/securesms/calls/links/SignalCallRow.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/calls/links/SignalCallRow.kt
@@ -53,7 +53,7 @@ import org.signal.core.ui.R as CoreUiR
@Composable
 private fun SignalCallRowPreview() {
  val callLink = remember {
-    val credentials = CallLinkCredentials(byteArrayOf(1, 2, 3, 4), byteArrayOf(5, 6, 7, 8))
+    val credentials = CallLinkCredentials(byteArrayOf(1, 2, 3, 4), byteArrayOf(0, 1, 2, 3), byteArrayOf(5, 6, 7, 8))
    CallLinkTable.CallLink(
      recipientId = RecipientId.UNKNOWN,
      roomId = CallLinkRoomId.fromBytes(byteArrayOf(1, 3, 5, 7)),
@@ -97,7 +97,7 @@ fun SignalCallRow(
    "https://signal.call.example.com"
  } else {
    remember(callLink.credentials) {
-      callLink.credentials?.let { CallLinks.url(it.linkKeyBytes) } ?: ""
+      callLink.credentials?.let { CallLinks.url(it.linkKeyBytes, it.epochBytes) } ?: ""
    }
  }

--- a/app/src/main/java/org/thoughtcrime/securesms/calls/links/create/CreateCallLinkBottomSheetDialogFragment.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/calls/links/create/CreateCallLinkBottomSheetDialogFragment.kt
@@ -163,7 +163,7 @@ class CreateCallLinkBottomSheetDialogFragment : ComposeBottomSheetDialogFragment
          startActivity(
            ShareActivity.sendSimpleText(
              requireContext(),
-              getString(R.string.CreateCallLink__use_this_link_to_join_a_signal_call, CallLinks.url(viewModel.linkKeyBytes))
+              getString(R.string.CreateCallLink__use_this_link_to_join_a_signal_call, CallLinks.url(viewModel.linkKeyBytes, viewModel.epochBytes))
            )
          )
        }
@@ -177,7 +177,7 @@ class CreateCallLinkBottomSheetDialogFragment : ComposeBottomSheetDialogFragment
    lifecycleDisposable += viewModel.commitCallLink().subscribeBy(onSuccess = {
      when (it) {
        is EnsureCallLinkCreatedResult.Success -> {
-          Util.copyToClipboard(requireContext(), CallLinks.url(viewModel.linkKeyBytes))
+          Util.copyToClipboard(requireContext(), CallLinks.url(viewModel.linkKeyBytes, viewModel.epochBytes))
          Toast.makeText(requireContext(), R.string.CreateCallLinkBottomSheetDialogFragment__copied_to_clipboard, Toast.LENGTH_LONG).show()
        }

@@ -192,7 +192,7 @@ class CreateCallLinkBottomSheetDialogFragment : ComposeBottomSheetDialogFragment
        is EnsureCallLinkCreatedResult.Success -> {
          val mimeType = Intent.normalizeMimeType("text/plain")
          val shareIntent = ShareCompat.IntentBuilder(requireContext())
-            .setText(CallLinks.url(viewModel.linkKeyBytes))
+            .setText(CallLinks.url(viewModel.linkKeyBytes, viewModel.epochBytes))
            .setType(mimeType)
            .createChooserIntent()

--- a/app/src/main/java/org/thoughtcrime/securesms/calls/links/create/CreateCallLinkViewModel.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/calls/links/create/CreateCallLinkViewModel.kt
@@ -31,12 +31,12 @@ class CreateCallLinkViewModel(
  private val repository: CreateCallLinkRepository = CreateCallLinkRepository(),
  private val mutationRepository: UpdateCallLinkRepository = UpdateCallLinkRepository()
 ) : ViewModel() {
-  private val credentials = CallLinkCredentials.generate()
+  private val initialCredentials = CallLinkCredentials.generate()
  private val _callLink: MutableState<CallLinkTable.CallLink> = mutableStateOf(
    CallLinkTable.CallLink(
      recipientId = RecipientId.UNKNOWN,
-      roomId = credentials.roomId,
-      credentials = credentials,
+      roomId = initialCredentials.roomId,
+      credentials = initialCredentials,
      state = SignalCallLinkState(
        name = "",
        restrictions = Restrictions.ADMIN_APPROVAL,
@@ -48,7 +48,12 @@ class CreateCallLinkViewModel(
  )

  val callLink: State<CallLinkTable.CallLink> = _callLink
-  val linkKeyBytes: ByteArray = credentials.linkKeyBytes
+
+  val linkKeyBytes: ByteArray
+    get() = callLink.value.credentials!!.linkKeyBytes
+
+  val epochBytes: ByteArray?
+    get() = callLink.value.credentials!!.epochBytes

  private val internalShowAlreadyInACall = MutableStateFlow(false)
  val showAlreadyInACall: StateFlow<Boolean> = internalShowAlreadyInACall
@@ -59,7 +64,7 @@ class CreateCallLinkViewModel(
  private val disposables = CompositeDisposable()

  init {
-    disposables += CallLinks.watchCallLink(credentials.roomId)
+    disposables += CallLinks.watchCallLink(initialCredentials.roomId)
      .subscribeBy {
        _callLink.value = it
      }
@@ -75,7 +80,7 @@ class CreateCallLinkViewModel(
  }

  fun commitCallLink(): Single<EnsureCallLinkCreatedResult> {
-    return repository.ensureCallLinkCreated(credentials)
+    return repository.ensureCallLinkCreated(initialCredentials)
      .observeOn(AndroidSchedulers.mainThread())
  }

@@ -84,7 +89,7 @@ class CreateCallLinkViewModel(
      .flatMap {
        when (it) {
          is EnsureCallLinkCreatedResult.Success -> mutationRepository.setCallRestrictions(
-            credentials,
+            callLink.value.credentials!!,
            if (approveAllMembers) Restrictions.ADMIN_APPROVAL else Restrictions.NONE
          )
          is EnsureCallLinkCreatedResult.Failure -> Single.just(UpdateCallLinkResult.Failure(it.failure.status))
@@ -104,7 +109,7 @@ class CreateCallLinkViewModel(
      .flatMap {
        when (it) {
          is EnsureCallLinkCreatedResult.Success -> mutationRepository.setCallName(
-            credentials,
+            callLink.value.credentials!!,
            callName
          )
          is EnsureCallLinkCreatedResult.Failure -> Single.just(UpdateCallLinkResult.Failure(it.failure.status))
--- a/app/src/main/java/org/thoughtcrime/securesms/calls/links/details/CallLinkDetailsFragment.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/calls/links/details/CallLinkDetailsFragment.kt
@@ -118,7 +118,7 @@ class CallLinkDetailsFragment : ComposeFragment(), CallLinkDetailsCallback {
  override fun onShareClicked() {
    val mimeType = Intent.normalizeMimeType("text/plain")
    val shareIntent = ShareCompat.IntentBuilder(requireContext())
-      .setText(CallLinks.url(viewModel.rootKeySnapshot))
+      .setText(CallLinks.url(viewModel.rootKeySnapshot, viewModel.epochSnapshot))
      .setType(mimeType)
      .createChooserIntent()

@@ -130,7 +130,7 @@ class CallLinkDetailsFragment : ComposeFragment(), CallLinkDetailsCallback {
  }

  override fun onCopyClicked() {
-    Util.copyToClipboard(requireContext(), CallLinks.url(viewModel.rootKeySnapshot))
+    Util.copyToClipboard(requireContext(), CallLinks.url(viewModel.rootKeySnapshot, viewModel.epochSnapshot))
    Toast.makeText(requireContext(), R.string.CreateCallLinkBottomSheetDialogFragment__copied_to_clipboard, Toast.LENGTH_LONG).show()
  }

@@ -138,7 +138,7 @@ class CallLinkDetailsFragment : ComposeFragment(), CallLinkDetailsCallback {
    startActivity(
      ShareActivity.sendSimpleText(
        requireContext(),
-        getString(R.string.CreateCallLink__use_this_link_to_join_a_signal_call, CallLinks.url(viewModel.rootKeySnapshot))
+        getString(R.string.CreateCallLink__use_this_link_to_join_a_signal_call, CallLinks.url(viewModel.rootKeySnapshot, viewModel.epochSnapshot))
      )
    )
  }
@@ -230,6 +230,7 @@ private fun CallLinkDetailsPreview() {
  val callLink = remember {
    val credentials = CallLinkCredentials(
      byteArrayOf(1, 2, 3, 4),
+      byteArrayOf(0, 1, 2, 3),
      byteArrayOf(3, 4, 5, 6)
    )
    CallLinkTable.CallLink(
--- a/app/src/main/java/org/thoughtcrime/securesms/calls/links/details/CallLinkDetailsViewModel.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/calls/links/details/CallLinkDetailsViewModel.kt
@@ -40,6 +40,9 @@ class CallLinkDetailsViewModel(
  val rootKeySnapshot: ByteArray
    get() = state.value.callLink?.credentials?.linkKeyBytes ?: error("Call link not loaded yet.")

+  val epochSnapshot: ByteArray?
+    get() = state.value.callLink?.credentials?.epochBytes
+
  private val recipientSubject = BehaviorSubject.create<Recipient>()
  val recipientSnapshot: Recipient?
    get() = recipientSubject.value
--- a/app/src/main/java/org/thoughtcrime/securesms/components/LinkPreviewView.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/components/LinkPreviewView.java
@@ -172,11 +172,11 @@ public class LinkPreviewView extends FrameLayout {
    spinner.setVisibility(GONE);
    noPreview.setVisibility(GONE);

-    CallLinkRootKey callLinkRootKey = CallLinks.parseUrl(linkPreview.getUrl());
+    CallLinks.CallLinkParseResult linkParseResult = CallLinks.parseUrl(linkPreview.getUrl());
    if (!Util.isEmpty(linkPreview.getTitle())) {
      title.setText(linkPreview.getTitle());
      title.setVisibility(VISIBLE);
-    } else if (callLinkRootKey != null) {
+    } else if (linkParseResult != null) {
      title.setText(R.string.Recipient_signal_call);
      title.setVisibility(VISIBLE);
    } else {
@@ -186,7 +186,7 @@ public class LinkPreviewView extends FrameLayout {
    if (showDescription && !Util.isEmpty(linkPreview.getDescription())) {
      description.setText(linkPreview.getDescription());
      description.setVisibility(VISIBLE);
-    } else if (callLinkRootKey != null) {
+    } else if (linkParseResult != null) {
      description.setText(R.string.LinkPreviewView__use_this_link_to_join_a_signal_call);
      description.setVisibility(VISIBLE);
    } else {
@@ -221,14 +221,14 @@ public class LinkPreviewView extends FrameLayout {
      thumbnail.get().setImageResource(requestManager, new ImageSlide(linkPreview.getThumbnail().get()), type == TYPE_CONVERSATION && !scheduleMessageMode, false);
      thumbnail.get().showSecondaryText(false);
      thumbnail.get().setOutlineEnabled(true);
-    } else if (callLinkRootKey != null) {
+    } else if (linkParseResult != null) {
      thumbnail.setVisibility(VISIBLE);
      thumbnailState.applyState(thumbnail);
      thumbnail.get().setImageDrawable(
          requestManager,
          new FallbackAvatarDrawable(
              getContext(),
-              new FallbackAvatar.Resource.CallLink(AvatarColorHash.forCallLink(callLinkRootKey.getKeyBytes()))
+              new FallbackAvatar.Resource.CallLink(AvatarColorHash.forCallLink(linkParseResult.getRootKey().getKeyBytes()))
          ).circleCrop()
      );
      thumbnail.get().showSecondaryText(false);
--- a/app/src/main/java/org/thoughtcrime/securesms/components/webrtc/controls/ControlsAndInfoViewModel.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/components/webrtc/controls/ControlsAndInfoViewModel.kt
@@ -34,6 +34,8 @@ class ControlsAndInfoViewModel(

  val rootKeySnapshot: ByteArray
    get() = state.value.callLink?.credentials?.linkKeyBytes ?: error("Call link not loaded yet.")
+  val epochSnapshot: ByteArray?
+    get() = state.value.callLink?.credentials?.epochBytes

  fun setRecipient(recipient: Recipient) {
    if (recipient.isCallLink && callRecipientId != recipient.id) {
--- a/app/src/main/java/org/thoughtcrime/securesms/components/webrtc/v2/CallInfoCallbacks.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/components/webrtc/v2/CallInfoCallbacks.kt
@@ -31,7 +31,7 @@ class CallInfoCallbacks(
  override fun onShareLinkClicked() {
    val mimeType = Intent.normalizeMimeType("text/plain")
    val shareIntent = ShareCompat.IntentBuilder(activity)
-      .setText(CallLinks.url(controlsAndInfoViewModel.rootKeySnapshot))
+      .setText(CallLinks.url(controlsAndInfoViewModel.rootKeySnapshot, controlsAndInfoViewModel.epochSnapshot))
      .setType(mimeType)
      .createChooserIntent()

--- a/app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationItem.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/conversation/ConversationItem.java
@@ -1172,14 +1172,14 @@ public final class ConversationItem extends RelativeLayout implements BindableCo
      //noinspection ConstantConditions
      LinkPreview linkPreview = ((MmsMessageRecord) messageRecord).getLinkPreviews().get(0);

-      CallLinkRootKey callLinkRootKey = CallLinks.parseUrl(linkPreview.getUrl());
-      if (callLinkRootKey != null) {
+      CallLinks.CallLinkParseResult linkParseResult = CallLinks.parseUrl(linkPreview.getUrl());
+      if (linkParseResult != null) {
        joinCallLinkStub.setVisibility(View.VISIBLE);
        joinCallLinkStub.get().setTextColor(ContextCompat.getColor(context, messageRecord.isOutgoing() ? R.color.signal_light_colorOnPrimary : R.color.signal_colorOnPrimaryContainer));
        joinCallLinkStub.get().setBackgroundColor(ContextCompat.getColor(context, messageRecord.isOutgoing() ? R.color.signal_light_colorTransparent2 : R.color.signal_colorOnPrimary));
        joinCallLinkStub.get().setOnClickListener(v -> {
          if (eventListener != null) {
-            eventListener.onJoinCallLink(callLinkRootKey);
+            eventListener.onJoinCallLink(linkParseResult.getRootKey(), linkParseResult.getEpoch());
          }
        });
      }
--- a/app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationFragment.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/conversation/v2/ConversationFragment.kt
@@ -103,6 +103,7 @@ import org.signal.core.util.logging.Log
 import org.signal.core.util.orNull
 import org.signal.core.util.setActionItemTint
 import org.signal.donations.InAppPaymentType
+import org.signal.ringrtc.CallLinkEpoch
 import org.signal.ringrtc.CallLinkRootKey
 import org.thoughtcrime.securesms.BlockUnblockDialog
 import org.thoughtcrime.securesms.GroupMembersDialog
@@ -3365,8 +3366,8 @@ class ConversationFragment :
      GroupDescriptionDialog.show(childFragmentManager, groupName, description, shouldLinkifyWebLinks)
    }

-    override fun onJoinCallLink(callLinkRootKey: CallLinkRootKey) {
-      CommunicationActions.startVideoCall(this@ConversationFragment, callLinkRootKey) {
+    override fun onJoinCallLink(callLinkRootKey: CallLinkRootKey, callLinkEpoch: CallLinkEpoch?) {
+      CommunicationActions.startVideoCall(this@ConversationFragment, callLinkRootKey, callLinkEpoch) {
        YouAreAlreadyInACallSnackbar.show(requireView())
      }
    }
--- a/app/src/main/java/org/thoughtcrime/securesms/database/CallLinkTable.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/CallLinkTable.kt
@@ -21,6 +21,7 @@ import org.signal.core.util.requireNonNullString
 import org.signal.core.util.select
 import org.signal.core.util.update
 import org.signal.core.util.withinTransaction
+import org.signal.ringrtc.CallLinkEpoch
 import org.signal.ringrtc.CallLinkRootKey
 import org.signal.ringrtc.CallLinkState.Restrictions
 import org.thoughtcrime.securesms.calls.log.CallLogRow
@@ -47,6 +48,7 @@ class CallLinkTable(context: Context, databaseHelper: SignalDatabase) : Database
    const val TABLE_NAME = "call_link"
    const val ID = "_id"
    const val ROOT_KEY = "root_key"
+    const val EPOCH = "epoch"
    const val ROOM_ID = "room_id"
    const val ADMIN_KEY = "admin_key"
    const val NAME = "name"
@@ -61,6 +63,7 @@ class CallLinkTable(context: Context, databaseHelper: SignalDatabase) : Database
      CREATE TABLE $TABLE_NAME (
        $ID INTEGER PRIMARY KEY,
        $ROOT_KEY BLOB,
+        $EPOCH BLOB,
        $ROOM_ID TEXT NOT NULL UNIQUE,
        $ADMIN_KEY BLOB,
        $NAME TEXT NOT NULL,
@@ -128,6 +131,7 @@ class CallLinkTable(context: Context, databaseHelper: SignalDatabase) : Database
      .values(
        contentValuesOf(
          ROOT_KEY to credentials.linkKeyBytes,
+          EPOCH to credentials.epochBytes,
          ADMIN_KEY to credentials.adminPassBytes
        )
      )
@@ -188,7 +192,8 @@ class CallLinkTable(context: Context, databaseHelper: SignalDatabase) : Database
  }

  fun getOrCreateCallLinkByRootKey(
-    callLinkRootKey: CallLinkRootKey
+    callLinkRootKey: CallLinkRootKey,
+    callLinkEpoch: CallLinkEpoch?
  ): CallLink {
    val roomId = CallLinkRoomId.fromBytes(callLinkRootKey.deriveRoomId())
    val callLink = getCallLinkByRoomId(roomId)
@@ -198,6 +203,7 @@ class CallLinkTable(context: Context, databaseHelper: SignalDatabase) : Database
        roomId = roomId,
        credentials = CallLinkCredentials(
          linkKeyBytes = callLinkRootKey.keyBytes,
+          epochBytes = callLinkEpoch?.bytes,
          adminPassBytes = null
        ),
        state = SignalCallLinkState(),
@@ -207,12 +213,26 @@ class CallLinkTable(context: Context, databaseHelper: SignalDatabase) : Database
      insertCallLink(link)
      return getCallLinkByRoomId(roomId)!!
    } else {
-      callLink
+      if (callLink.credentials?.epoch != callLinkEpoch) {
+        overwriteEpoch(callLink, callLinkEpoch)
+      } else {
+        callLink
+      }
    }
  }

+  private fun overwriteEpoch(callLink: CallLink, callLinkEpoch: CallLinkEpoch?): CallLink {
+    val modifiedCallLink = callLink.copy(
+      deletionTimestamp = 0,
+      credentials = callLink.credentials!!.copy(epochBytes = callLinkEpoch?.bytes)
+    )
+    updateCallLinkCredentials(modifiedCallLink.roomId, modifiedCallLink.credentials!!)
+    return modifiedCallLink
+  }
+
  fun insertOrUpdateCallLinkByRootKey(
    callLinkRootKey: CallLinkRootKey,
+    callLinkEpoch: CallLinkEpoch?,
    adminPassKey: ByteArray?,
    deletionTimestamp: Long = 0L,
    storageId: StorageId? = null
@@ -227,6 +247,7 @@ class CallLinkTable(context: Context, databaseHelper: SignalDatabase) : Database
          roomId = roomId,
          credentials = CallLinkCredentials(
            linkKeyBytes = callLinkRootKey.keyBytes,
+            epochBytes = callLinkEpoch?.bytes,
            adminPassBytes = adminPassKey
          ),
          state = SignalCallLinkState(),
@@ -253,7 +274,8 @@ class CallLinkTable(context: Context, databaseHelper: SignalDatabase) : Database
          writableDatabase.update(TABLE_NAME)
            .values(
              ADMIN_KEY to adminPassKey,
-              ROOT_KEY to callLinkRootKey.keyBytes
+              ROOT_KEY to callLinkRootKey.keyBytes,
+              EPOCH to callLinkEpoch?.bytes
            )
            .where("$ROOM_ID = ?", callLink.roomId.serialize())
            .run()
@@ -464,6 +486,7 @@ class CallLinkTable(context: Context, databaseHelper: SignalDatabase) : Database
        RECIPIENT_ID to data.recipientId.takeIf { it != RecipientId.UNKNOWN }?.toLong(),
        ROOM_ID to data.roomId.serialize(),
        ROOT_KEY to data.credentials?.linkKeyBytes,
+        EPOCH to data.credentials?.epochBytes,
        ADMIN_KEY to data.credentials?.adminPassBytes
      ).apply {
        putAll(data.state.serialize())
@@ -487,6 +510,7 @@ class CallLinkTable(context: Context, databaseHelper: SignalDatabase) : Database
        credentials = data.requireBlob(ROOT_KEY)?.let { linkKey ->
          CallLinkCredentials(
            linkKeyBytes = linkKey,
+            epochBytes = data.requireBlob(EPOCH),
            adminPassBytes = data.requireBlob(ADMIN_KEY)
          )
        },
--- a/app/src/main/java/org/thoughtcrime/securesms/database/helpers/SignalDatabaseMigrations.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/helpers/SignalDatabaseMigrations.kt
@@ -139,6 +139,7 @@ import org.thoughtcrime.securesms.database.helpers.migration.V281_RemoveArchiveT
 import org.thoughtcrime.securesms.database.helpers.migration.V282_AddSnippetMessageIdColumnToThreadTable
 import org.thoughtcrime.securesms.database.helpers.migration.V283_ViewOnceRemoteDataCleanup
 import org.thoughtcrime.securesms.database.helpers.migration.V284_SetPlaceholderGroupFlag
+import org.thoughtcrime.securesms.database.helpers.migration.V285_AddEpochToCallLinksTable
 import org.thoughtcrime.securesms.database.SQLiteDatabase as SignalSqliteDatabase

 /**
@@ -283,10 +284,11 @@ object SignalDatabaseMigrations {
    281 to V281_RemoveArchiveTransferFile,
    282 to V282_AddSnippetMessageIdColumnToThreadTable,
    283 to V283_ViewOnceRemoteDataCleanup,
-    284 to V284_SetPlaceholderGroupFlag
+    284 to V284_SetPlaceholderGroupFlag,
+    285 to V285_AddEpochToCallLinksTable
  )

-  const val DATABASE_VERSION = 284
+  const val DATABASE_VERSION = 285

  @JvmStatic
  fun migrate(context: Application, db: SignalSqliteDatabase, oldVersion: Int, newVersion: Int) {
--- a/app/src/main/java/org/thoughtcrime/securesms/database/helpers/migration/V285_AddEpochToCallLinksTable.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/helpers/migration/V285_AddEpochToCallLinksTable.kt
@@ -0,0 +1,16 @@
+/*
+ * Copyright 2025 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.thoughtcrime.securesms.database.helpers.migration
+
+import android.app.Application
+import org.thoughtcrime.securesms.database.SQLiteDatabase
+
+@Suppress("ClassName")
+object V285_AddEpochToCallLinksTable : SignalDatabaseMigration {
+  override fun migrate(context: Application, db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
+    db.execSQL("ALTER TABLE call_link ADD COLUMN epoch BLOB DEFAULT NULL")
+  }
+}
--- a/app/src/main/java/org/thoughtcrime/securesms/jobs/RefreshCallLinkDetailsJob.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/jobs/RefreshCallLinkDetailsJob.kt
@@ -48,6 +48,7 @@ class RefreshCallLinkDetailsJob private constructor(
    val manager: SignalCallLinkManager = AppDependencies.signalCallManager.callLinkManager
    val credentials = CallLinkCredentials(
      linkKeyBytes = callLinkUpdate.rootKey!!.toByteArray(),
+      epochBytes = callLinkUpdate.epoch?.toByteArray(),
      adminPassBytes = callLinkUpdate.adminPasskey?.toByteArray()
    )

--- a/app/src/main/java/org/thoughtcrime/securesms/linkpreview/LinkPreviewRepository.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/linkpreview/LinkPreviewRepository.java
@@ -20,6 +20,7 @@ import org.signal.libsignal.protocol.InvalidMessageException;
 import org.signal.libsignal.protocol.util.Pair;
 import org.signal.libsignal.zkgroup.VerificationFailedException;
 import org.signal.libsignal.zkgroup.groups.GroupMasterKey;
+import org.signal.ringrtc.CallLinkEpoch;
 import org.signal.ringrtc.CallLinkRootKey;
 import org.signal.storageservice.protos.groups.local.DecryptedGroupJoinInfo;
 import org.thoughtcrime.securesms.R;
@@ -326,15 +327,20 @@ public class LinkPreviewRepository {
                                                        @NonNull String callLinkUrl,
                                                        @NonNull Callback callback) {

-    CallLinkRootKey callLinkRootKey = CallLinks.parseUrl(callLinkUrl);
-    if (callLinkRootKey == null) {
+    CallLinks.CallLinkParseResult linkParseResult = CallLinks.parseUrl(callLinkUrl);
+    if (linkParseResult == null) {
      callback.onError(Error.PREVIEW_NOT_AVAILABLE);
      return () -> { };
    }

+    CallLinkEpoch epoch = linkParseResult.getEpoch();
+    byte[] epochBytes = epoch != null ? epoch.getBytes() : null;
+
    Disposable disposable = AppDependencies.getSignalCallManager()
                                           .getCallLinkManager()
-                                           .readCallLink(new CallLinkCredentials(callLinkRootKey.getKeyBytes(), null))
+                                           .readCallLink(new CallLinkCredentials(linkParseResult.getRootKey().getKeyBytes(),
+                                                                                 epochBytes,
+                                                                                 null))
                                           .observeOn(Schedulers.io())
                                           .subscribe(
                                                        result -> {
--- a/app/src/main/java/org/thoughtcrime/securesms/messagedetails/MessageDetailsFragment.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/messagedetails/MessageDetailsFragment.kt
@@ -12,6 +12,7 @@ import androidx.recyclerview.widget.RecyclerView
 import com.bumptech.glide.Glide
 import com.bumptech.glide.RequestManager
 import org.signal.core.util.logging.Log
+import org.signal.ringrtc.CallLinkEpoch
 import org.signal.ringrtc.CallLinkRootKey
 import org.thoughtcrime.securesms.R
 import org.thoughtcrime.securesms.components.FullScreenDialogFragment
@@ -358,7 +359,7 @@ class MessageDetailsFragment : FullScreenDialogFragment(), MessageDetailsAdapter
    Log.w(TAG, "Not yet implemented!", Exception())
  }

-  override fun onJoinCallLink(callLinkRootKey: CallLinkRootKey) {
+  override fun onJoinCallLink(callLinkRootKey: CallLinkRootKey, callLinkEpoch: CallLinkEpoch?) {
    Log.w(TAG, "Not yet implemented!", Exception())
  }

--- a/app/src/main/java/org/thoughtcrime/securesms/messages/SyncMessageProcessor.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/messages/SyncMessageProcessor.kt
@@ -1370,6 +1370,7 @@ object SyncMessageProcessor {
        roomId,
        CallLinkCredentials(
          callLinkUpdate.rootKey!!.toByteArray(),
+          callLinkUpdate.epoch?.toByteArray(),
          callLinkUpdate.adminPasskey?.toByteArray()
        )
      )
@@ -1381,6 +1382,7 @@ object SyncMessageProcessor {
          roomId = roomId,
          credentials = CallLinkCredentials(
            linkKeyBytes = callLinkRootKey.keyBytes,
+            epochBytes = callLinkUpdate.epoch?.toByteArray(),
            adminPassBytes = callLinkUpdate.adminPasskey?.toByteArray()
          ),
          state = SignalCallLinkState(),
--- a/app/src/main/java/org/thoughtcrime/securesms/service/webrtc/CallLinkPreJoinActionProcessor.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/service/webrtc/CallLinkPreJoinActionProcessor.kt
@@ -70,7 +70,7 @@ class CallLinkPreJoinActionProcessor(
        serverPublicParams.endorsementPublicKey,
        callLinkAuthCredentialPresentation.serialize(),
        callLinkRootKey,
-        null,
+        callLink.credentials.epoch,
        callLink.credentials.adminPassBytes,
        ByteArray(0),
        AUDIO_LEVELS_INTERVAL,
--- a/app/src/main/java/org/thoughtcrime/securesms/service/webrtc/SignalCallManager.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/service/webrtc/SignalCallManager.java
@@ -25,6 +25,7 @@ import org.signal.libsignal.zkgroup.calllinks.CallLinkSecretParams;
 import org.signal.libsignal.zkgroup.groups.GroupIdentifier;
 import org.signal.ringrtc.CallException;
 import org.signal.ringrtc.CallId;
+import org.signal.ringrtc.CallLinkEpoch;
 import org.signal.ringrtc.CallLinkRootKey;
 import org.signal.ringrtc.CallManager;
 import org.signal.ringrtc.GroupCall;
@@ -406,6 +407,7 @@ public final class SignalCallManager implements CallManager.Observer, GroupCall.
        }

        CallLinkRootKey           callLinkRootKey           = new CallLinkRootKey(callLink.getCredentials().getLinkKeyBytes());
+        CallLinkEpoch             callLinkEpoch             = callLink.getCredentials().getEpoch();
        GenericServerPublicParams genericServerPublicParams = new GenericServerPublicParams(AppDependencies.getSignalServiceNetworkAccess()
                                                                                                           .getConfiguration()
                                                                                                           .getGenericServerPublicParams());
@@ -417,7 +419,7 @@ public final class SignalCallManager implements CallManager.Observer, GroupCall.
                                                                                                   CallLinkSecretParams.deriveFromRootKey(callLinkRootKey.getKeyBytes())
                                                                                               );

-        callManager.peekCallLinkCall(SignalStore.internal().getGroupCallingServer(), callLinkAuthCredentialPresentation.serialize(), callLinkRootKey, null, peekInfo -> {
+        callManager.peekCallLinkCall(SignalStore.internal().getGroupCallingServer(), callLinkAuthCredentialPresentation.serialize(), callLinkRootKey, callLinkEpoch, peekInfo -> {
          PeekInfo info = peekInfo.getValue();
          if (info == null) {
            Log.w(TAG, "Failed to get peek info: " + peekInfo.getStatus());
--- a/app/src/main/java/org/thoughtcrime/securesms/service/webrtc/links/CallLinkCredentials.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/service/webrtc/links/CallLinkCredentials.kt
@@ -7,6 +7,7 @@ package org.thoughtcrime.securesms.service.webrtc.links

 import android.os.Parcelable
 import kotlinx.parcelize.Parcelize
+import org.signal.ringrtc.CallLinkEpoch
 import org.signal.ringrtc.CallLinkRootKey

 /**
@@ -15,6 +16,7 @@ import org.signal.ringrtc.CallLinkRootKey
@Parcelize
 data class CallLinkCredentials(
  val linkKeyBytes: ByteArray,
+  val epochBytes: ByteArray?,
  val adminPassBytes: ByteArray?
 ) : Parcelable {

@@ -22,6 +24,10 @@ data class CallLinkCredentials(
    CallLinkRoomId.fromCallLinkRootKey(CallLinkRootKey(linkKeyBytes))
  }

+  val epoch: CallLinkEpoch? by lazy {
+    epochBytes?.let { CallLinkEpoch.fromBytes(it) }
+  }
+
  override fun equals(other: Any?): Boolean {
    if (this === other) return true
    if (javaClass != other?.javaClass) return false
@@ -35,6 +41,12 @@ data class CallLinkCredentials(
    } else if (other.adminPassBytes != null) {
      return false
    }
+    if (epochBytes != null) {
+      if (other.epochBytes == null) return false
+      if (!epochBytes.contentEquals(other.epochBytes)) return false
+    } else if (other.epochBytes != null) {
+      return false
+    }

    return true
  }
@@ -52,6 +64,7 @@ data class CallLinkCredentials(
    fun generate(): CallLinkCredentials {
      return CallLinkCredentials(
        CallLinkRootKey.generate().keyBytes,
+        null,
        CallLinkRootKey.generateAdminPasskey()
      )
    }
--- a/app/src/main/java/org/thoughtcrime/securesms/service/webrtc/links/SignalCallLinkManager.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/service/webrtc/links/SignalCallLinkManager.kt
@@ -120,9 +120,10 @@ class SignalCallLinkManager(
      ) { result ->
        if (result.isSuccess) {
          Log.d(TAG, "Successfully created call link.")
+          val epoch = result.value!!.epoch
          emitter.onSuccess(
            CreateCallLinkResult.Success(
-              credentials = CallLinkCredentials(rootKey.keyBytes, adminPassKey),
+              credentials = CallLinkCredentials(rootKey.keyBytes, epoch?.bytes, adminPassKey),
              state = result.value!!.toAppState()
            )
          )
@@ -142,7 +143,7 @@ class SignalCallLinkManager(
        SignalStore.internal.groupCallingServer,
        requestCallLinkAuthCredentialPresentation(credentials.linkKeyBytes).serialize(),
        CallLinkRootKey(credentials.linkKeyBytes),
-        null
+        credentials.epoch
      ) {
        if (it.isSuccess) {
          emitter.onSuccess(ReadCallLinkResult.Success(it.value!!.toAppState()))
@@ -169,7 +170,7 @@ class SignalCallLinkManager(
        SignalStore.internal.groupCallingServer,
        credentialPresentation.serialize(),
        CallLinkRootKey(credentials.linkKeyBytes),
-        null,
+        credentials.epoch,
        credentials.adminPassBytes,
        name
      ) { result ->
@@ -197,7 +198,7 @@ class SignalCallLinkManager(
        SignalStore.internal.groupCallingServer,
        credentialPresentation.serialize(),
        CallLinkRootKey(credentials.linkKeyBytes),
-        null,
+        credentials.epoch,
        credentials.adminPassBytes,
        restrictions
      ) { result ->
@@ -224,7 +225,7 @@ class SignalCallLinkManager(
        SignalStore.internal.groupCallingServer,
        credentialPresentation.serialize(),
        CallLinkRootKey(credentials.linkKeyBytes),
-        null,
+        credentials.epoch,
        credentials.adminPassBytes
      ) { result ->
        if (result.isSuccess && result.value == true) {
--- a/app/src/main/java/org/thoughtcrime/securesms/storage/CallLinkRecordProcessor.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/storage/CallLinkRecordProcessor.kt
@@ -5,10 +5,12 @@

 package org.thoughtcrime.securesms.storage

+import okio.ByteString
 import okio.ByteString.Companion.toByteString
 import org.signal.core.util.isNotEmpty
 import org.signal.core.util.logging.Log
 import org.signal.core.util.toOptional
+import org.signal.ringrtc.CallLinkEpoch
 import org.signal.ringrtc.CallLinkRootKey
 import org.thoughtcrime.securesms.database.SignalDatabase
 import org.thoughtcrime.securesms.service.webrtc.links.CallLinkRoomId
@@ -46,8 +48,10 @@ class CallLinkRecordProcessor : DefaultStorageRecordProcessor<SignalCallLinkReco
    val callLink = SignalDatabase.callLinks.getCallLinkByRoomId(roomId)

    if (callLink != null && callLink.credentials?.adminPassBytes != null) {
+      val epochBytes = callLink.credentials.epochBytes
      return SignalCallLinkRecord.newBuilder(null).apply {
        rootKey = callRootKey.keyBytes.toByteString()
+        epoch = epochBytes?.toByteString() ?: ByteString.EMPTY
        adminPasskey = callLink.credentials.adminPassBytes.toByteString()
        deletedAtTimestampMs = callLink.deletionTimestamp
      }.build().toSignalCallLinkRecord(StorageId.forCallLink(keyGenerator.generate())).toOptional()
@@ -88,8 +92,15 @@ class CallLinkRecordProcessor : DefaultStorageRecordProcessor<SignalCallLinkReco
  private fun insertOrUpdateRecord(record: SignalCallLinkRecord) {
    val rootKey = CallLinkRootKey(record.proto.rootKey.toByteArray())

+    val epoch = if (record.proto.epoch.isNotEmpty()) {
+      CallLinkEpoch.fromBytes(record.proto.epoch.toByteArray())
+    } else {
+      null
+    }
+
    SignalDatabase.callLinks.insertOrUpdateCallLinkByRootKey(
      callLinkRootKey = rootKey,
+      callLinkEpoch = epoch,
      adminPassKey = record.proto.adminPasskey.toByteArray(),
      deletionTimestamp = record.proto.deletedAtTimestampMs,
      storageId = record.id
--- a/app/src/main/java/org/thoughtcrime/securesms/util/CommunicationActions.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/util/CommunicationActions.java
@@ -27,6 +27,7 @@ import org.signal.core.util.concurrent.JvmRxExtensions;
 import org.signal.core.util.concurrent.SignalExecutors;
 import org.signal.core.util.concurrent.SimpleTask;
 import org.signal.core.util.logging.Log;
+import org.signal.ringrtc.CallLinkEpoch;
 import org.signal.ringrtc.CallLinkRootKey;
 import org.thoughtcrime.securesms.R;
 import org.thoughtcrime.securesms.calls.links.CallLinks;
@@ -325,8 +326,8 @@ public class CommunicationActions {
      return;
    }

-    CallLinkRootKey rootKey = CallLinks.parseUrl(potentialUrl);
-    if (rootKey == null) {
+    CallLinks.CallLinkParseResult linkParseResult = CallLinks.parseUrl(potentialUrl);
+    if (linkParseResult == null) {
      Log.w(TAG, "Failed to parse root key from call link");
      new MaterialAlertDialogBuilder(activity)
          .setTitle(R.string.CommunicationActions_invalid_link)
@@ -336,7 +337,7 @@ public class CommunicationActions {
      return;
    }

-    startVideoCall(new ActivityCallContext(activity), rootKey, onUserAlreadyInAnotherCall);
+    startVideoCall(new ActivityCallContext(activity), linkParseResult.getRootKey(), linkParseResult.getEpoch(), onUserAlreadyInAnotherCall);
  }

  /**
@@ -345,14 +346,14 @@ public class CommunicationActions {
   *
   * @param fragment The fragment, which will be used for context and permissions routing.
   */
-  public static void startVideoCall(@NonNull Fragment fragment, @NonNull CallLinkRootKey rootKey, @NonNull OnUserAlreadyInAnotherCall onUserAlreadyInAnotherCall) {
-    startVideoCall(new FragmentCallContext(fragment), rootKey, onUserAlreadyInAnotherCall);
+  public static void startVideoCall(@NonNull Fragment fragment, @NonNull CallLinkRootKey rootKey, @Nullable CallLinkEpoch epoch, @NonNull OnUserAlreadyInAnotherCall onUserAlreadyInAnotherCall) {
+    startVideoCall(new FragmentCallContext(fragment), rootKey, epoch, onUserAlreadyInAnotherCall);
  }

-  private static void startVideoCall(@NonNull CallContext callContext, @NonNull CallLinkRootKey rootKey, @NonNull OnUserAlreadyInAnotherCall onUserAlreadyInAnotherCall) {
+  private static void startVideoCall(@NonNull CallContext callContext, @NonNull CallLinkRootKey rootKey, @Nullable CallLinkEpoch epoch, @NonNull OnUserAlreadyInAnotherCall onUserAlreadyInAnotherCall) {
    SimpleTask.run(() -> {
      CallLinkRoomId         roomId   = CallLinkRoomId.fromBytes(rootKey.deriveRoomId());
-      CallLinkTable.CallLink callLink = SignalDatabase.callLinks().getOrCreateCallLinkByRootKey(rootKey);
+      CallLinkTable.CallLink callLink = SignalDatabase.callLinks().getOrCreateCallLinkByRootKey(rootKey, epoch);

      if (callLink.getState().hasBeenRevoked()) {
        return Optional.<Recipient>empty();
--- a/app/src/main/protowire/Backup.proto
+++ b/app/src/main/protowire/Backup.proto
@@ -344,6 +344,7 @@ message CallLink {
  string name = 3;
  Restrictions restrictions = 4;
  uint64 expirationMs = 5;
+  bytes epoch = 6; // May be absent/empty for older links
 }

 message AdHocCall {
--- a/app/src/test/java/org/thoughtcrime/securesms/storage/CallLinkRecordProcessorTest.kt
+++ b/app/src/test/java/org/thoughtcrime/securesms/storage/CallLinkRecordProcessorTest.kt
@@ -34,6 +34,7 @@ class CallLinkRecordProcessorTest {
  private val testSubject = CallLinkRecordProcessor()
  private val mockCredentials = CallLinkCredentials(
    "root key".toByteArray(),
+    "abcd".toByteArray(),
    "admin pass".toByteArray()
  )

--- a/libsignal-service/src/main/protowire/SignalService.proto
+++ b/libsignal-service/src/main/protowire/SignalService.proto
@@ -628,6 +628,7 @@ message SyncMessage {
    optional bytes rootKey = 1;
    optional bytes adminPasskey = 2;
    optional Type type = 3; // defaults to UPDATE
+    optional bytes epoch = 4;
  }

  message CallLogEvent {
--- a/libsignal-service/src/main/protowire/StorageService.proto
+++ b/libsignal-service/src/main/protowire/StorageService.proto
@@ -306,6 +306,7 @@ message CallLinkRecord {
  bytes rootKey               = 1;
  bytes adminPasskey          = 2;
  uint64 deletedAtTimestampMs = 3;
+  bytes epoch                 = 4;
 }

 message Recipient {