Add capability for KT username syncs.

2026-06-03 10:03:01 -04:00 · 2026-06-03 10:03:01 -04:00 · 1371663163
commit 1371663163
parent 1f0c24a5d5
24 changed files with 187 additions and 33 deletions
--- a/app/src/androidTest/java/org/thoughtcrime/securesms/testing/SignalActivityRule.kt
+++ b/app/src/androidTest/java/org/thoughtcrime/securesms/testing/SignalActivityRule.kt
@ -139,7 +139,7 @@ class SignalActivityRule(private val othersCount: Int = 4, private val createGro
      val recipientId = RecipientId.from(SignalServiceAddress(aci, "+15555551%03d".format(i)))
      SignalDatabase.recipients.setProfileName(recipientId, ProfileName.fromParts("Buddy", "#$i"))
      SignalDatabase.recipients.setProfileKeyIfAbsent(recipientId, ProfileKeyUtil.createNew())
-      SignalDatabase.recipients.setCapabilities(recipientId, SignalServiceProfile.Capabilities(true, true))
+      SignalDatabase.recipients.setCapabilities(recipientId, SignalServiceProfile.Capabilities(true, true, true))
      SignalDatabase.recipients.setProfileSharing(recipientId, true)
      SignalDatabase.recipients.markRegistered(recipientId, aci)
      val otherIdentity = IdentityKeyPair.generate()
--- a/app/src/benchmarkShared/java/org/signal/benchmark/setup/TestUsers.kt
+++ b/app/src/benchmarkShared/java/org/signal/benchmark/setup/TestUsers.kt
@ -133,7 +133,7 @@ object TestUsers {
        val recipientId = RecipientId.from(SignalServiceAddress(aci, "+15555551%03d".format(i)))
        SignalDatabase.recipients.setProfileName(recipientId, ProfileName.fromParts("Buddy", "#$i"))
        SignalDatabase.recipients.setProfileKeyIfAbsent(recipientId, ProfileKeyUtil.createNew())
-        SignalDatabase.recipients.setCapabilities(recipientId, SignalServiceProfile.Capabilities(true, true))
+        SignalDatabase.recipients.setCapabilities(recipientId, SignalServiceProfile.Capabilities(true, true, true))
        SignalDatabase.recipients.setProfileSharing(recipientId, true)
        SignalDatabase.recipients.markRegistered(recipientId, aci)
        val otherIdentity = IdentityKeyPair.generate()
@ -157,7 +157,7 @@ object TestUsers {
        val recipientId = RecipientId.from(SignalServiceAddress(otherClient.serviceId, otherClient.e164))
        SignalDatabase.recipients.setProfileName(recipientId, ProfileName.fromParts("Buddy", "#$i"))
        SignalDatabase.recipients.setProfileKeyIfAbsent(recipientId, otherClient.profileKey)
-        SignalDatabase.recipients.setCapabilities(recipientId, SignalServiceProfile.Capabilities(true, true))
+        SignalDatabase.recipients.setCapabilities(recipientId, SignalServiceProfile.Capabilities(true, true, true))
        SignalDatabase.recipients.setProfileSharing(recipientId, true)
        SignalDatabase.recipients.markRegistered(recipientId, otherClient.serviceId)
        AppDependencies.protocolStore.aci().saveIdentity(SignalProtocolAddress(otherClient.serviceId.toString(), 1), otherClient.identityKeyPair.publicKey)
--- a/app/src/main/java/org/thoughtcrime/securesms/AppCapabilities.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/AppCapabilities.kt
@ -13,7 +13,8 @@ object AppCapabilities {
      storage = storageCapable,
      versionedExpirationTimer = true,
      attachmentBackfill = true,
-      spqr = true
+      spqr = true,
+      usernameChangeSyncMessage = false // TODO(michelle): Turn on once all clients support it and add a migration
    )
  }
 }
--- a/app/src/main/java/org/thoughtcrime/securesms/components/settings/conversation/InternalConversationSettingsState.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/components/settings/conversation/InternalConversationSettingsState.kt
@ -7,7 +7,12 @@ package org.thoughtcrime.securesms.components.settings.conversation

 import androidx.annotation.WorkerThread
 import androidx.compose.runtime.Immutable
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.text.AnnotatedString
+import androidx.compose.ui.text.SpanStyle
+import androidx.compose.ui.text.buildAnnotatedString
+import androidx.compose.ui.text.font.FontStyle
+import androidx.compose.ui.text.withStyle
 import org.signal.core.util.Base64
 import org.signal.core.util.Hex
 import org.thoughtcrime.securesms.components.settings.app.subscription.InAppPaymentsRepository
@ -98,18 +103,18 @@ data class InternalConversationSettingsState(
        val capabilities: RecipientRecord.Capabilities? = SignalDatabase.recipients.getCapabilities(recipient.id)
        if (capabilities != null) {
          AnnotatedString("No capabilities right now.")
-          // Left as an example in case we add one in the future
-//          val style: SpanStyle = when (capabilities.storageServiceEncryptionV2) {
-//            Recipient.Capability.SUPPORTED -> SpanStyle(color = Color(0, 150, 0))
-//            Recipient.Capability.NOT_SUPPORTED -> SpanStyle(color = Color.Red)
-//            Recipient.Capability.UNKNOWN -> SpanStyle(fontStyle = FontStyle.Italic)
-//          }
-//
-//          buildAnnotatedString {
-//            withStyle(style = style) {
-//              append("SSREv2")
-//            }
-//          }
+          // Always leave one as an example in case we add one in the future
+          val style: SpanStyle = when (capabilities.usernameSyncMessages) {
+            Recipient.Capability.SUPPORTED -> SpanStyle(color = Color(0, 150, 0))
+            Recipient.Capability.NOT_SUPPORTED -> SpanStyle(color = Color.Red)
+            Recipient.Capability.UNKNOWN -> SpanStyle(fontStyle = FontStyle.Italic)
+          }
+
+          buildAnnotatedString {
+            withStyle(style = style) {
+              append("usernameSyncMessages")
+            }
+          }
        } else {
          AnnotatedString("Recipient not found!")
        }
--- a/app/src/main/java/org/thoughtcrime/securesms/database/RecipientTable.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/RecipientTable.kt
@ -424,6 +424,7 @@ open class RecipientTable(context: Context, databaseHelper: SignalDatabase) : Da
    fun maskCapabilitiesToLong(capabilities: SignalServiceProfile.Capabilities): Long {
      var value: Long = 0
      value = Bitmask.update(value, Capabilities.STORAGE_SERVICE_ENCRYPTION_V2, Capabilities.BIT_LENGTH, Recipient.Capability.fromBoolean(capabilities.isStorageServiceEncryptionV2).serialize().toLong())
+      value = Bitmask.update(value, Capabilities.USERNAME_SYNC_MESSAGES, Capabilities.BIT_LENGTH, Recipient.Capability.fromBoolean(capabilities.isUsernameSyncMessages).serialize().toLong())
      return value
    }
  }
@ -4953,8 +4954,9 @@ open class RecipientTable(context: Context, databaseHelper: SignalDatabase) : Da
 //    const val DELETE_SYNC = 9
 //    const val VERSIONED_EXPIRATION_TIMER = 10
    const val STORAGE_SERVICE_ENCRYPTION_V2 = 11
+    const val USERNAME_SYNC_MESSAGES = 12

-    // IMPORTANT: We cannot sore more than 32 capabilities in the bitmask.
+    // IMPORTANT: We cannot store more than 32 capabilities in the bitmask.
  }

  enum class VibrateState(val id: Int) {
--- a/app/src/main/java/org/thoughtcrime/securesms/database/RecipientTableCursorUtil.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/RecipientTableCursorUtil.kt
@ -10,6 +10,7 @@ import android.database.Cursor
 import com.google.protobuf.InvalidProtocolBufferException
 import org.signal.core.models.ServiceId
 import org.signal.core.util.Base64
+import org.signal.core.util.Bitmask
 import org.signal.core.util.Util
 import org.signal.core.util.logging.Log
 import org.signal.core.util.optionalBlob
@ -174,7 +175,8 @@ object RecipientTableCursorUtil {
  fun readCapabilities(cursor: Cursor): RecipientRecord.Capabilities {
    val capabilities = cursor.requireLong(RecipientTable.CAPABILITIES)
    return RecipientRecord.Capabilities(
-      rawBits = capabilities
+      rawBits = capabilities,
+      usernameSyncMessages = Recipient.Capability.deserialize(Bitmask.read(capabilities, RecipientTable.Capabilities.USERNAME_SYNC_MESSAGES, RecipientTable.Capabilities.BIT_LENGTH).toInt())
    )
  }

--- a/app/src/main/java/org/thoughtcrime/securesms/database/model/RecipientRecord.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/model/RecipientRecord.kt
@ -121,12 +121,14 @@ data class RecipientRecord(
  )

  data class Capabilities(
-    val rawBits: Long
+    val rawBits: Long,
+    val usernameSyncMessages: Recipient.Capability
  ) {
    companion object {
      @JvmField
      val UNKNOWN = Capabilities(
-        rawBits = 0
+        rawBits = 0,
+        usernameSyncMessages = Recipient.Capability.UNKNOWN
      )
    }
  }
--- a/app/src/main/java/org/thoughtcrime/securesms/jobs/CheckKeyTransparencyJob.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/jobs/CheckKeyTransparencyJob.kt
@ -117,11 +117,11 @@ class CheckKeyTransparencyJob private constructor(
      aciIdentityKey = SignalStore.account.aciIdentityKey.publicKey,
      e164 = recipient.e164!!,
      unidentifiedAccessKey = ProfileKeyUtil.profileKeyOrNull(recipient.profileKey).let { UnidentifiedAccess.deriveAccessKeyFrom(it) },
-      usernameHash = SignalStore.account.username?.let { Username(it).hash },
+      usernameHash = SignalStore.account.username?.let { Username(it).hash }.takeIf { Recipient.self().usernameSyncMessagesCapability.isSupported },
      keyTransparencyStore = KeyTransparencyStore
    )

-    Log.i(TAG, "Key transparency complete, result: $result")
+    Log.i(TAG, "Key transparency complete, result: $result. Included username in check: ${Recipient.self().usernameSyncMessagesCapability.isSupported}")
    return when (result) {
      is RequestResult.Success -> {
        SignalStore.misc.hasKeyTransparencyFailure = false
--- a/app/src/main/java/org/thoughtcrime/securesms/jobs/JobManagerFactories.java
+++ b/app/src/main/java/org/thoughtcrime/securesms/jobs/JobManagerFactories.java
@ -224,6 +224,7 @@ public final class JobManagerFactories {
      put(MultiDeviceStickerPackSyncJob.KEY,           new MultiDeviceStickerPackSyncJob.Factory());
      put(MultiDeviceStorageSyncRequestJob.KEY,        new MultiDeviceStorageSyncRequestJob.Factory());
      put(MultiDeviceSubscriptionSyncRequestJob.KEY,   new MultiDeviceSubscriptionSyncRequestJob.Factory());
+      put(MultiDeviceUsernameChangeSyncJob.KEY,        new MultiDeviceUsernameChangeSyncJob.Factory());
      put(MultiDeviceVerifiedUpdateJob.KEY,            new MultiDeviceVerifiedUpdateJob.Factory());
      put(MultiDeviceViewOnceOpenJob.KEY,              new MultiDeviceViewOnceOpenJob.Factory());
      put(MultiDeviceViewedUpdateJob.KEY,              new MultiDeviceViewedUpdateJob.Factory());
--- a/app/src/main/java/org/thoughtcrime/securesms/jobs/MultiDeviceUsernameChangeSyncJob.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/jobs/MultiDeviceUsernameChangeSyncJob.kt
@ -0,0 +1,95 @@
+package org.thoughtcrime.securesms.jobs
+
+import androidx.annotation.WorkerThread
+import org.signal.core.util.logging.Log
+import org.thoughtcrime.securesms.dependencies.AppDependencies
+import org.thoughtcrime.securesms.jobmanager.Job
+import org.thoughtcrime.securesms.jobmanager.impl.NetworkConstraint
+import org.thoughtcrime.securesms.keyvalue.SignalStore
+import org.thoughtcrime.securesms.messages.SignalServiceProtoUtil.pad
+import org.thoughtcrime.securesms.recipients.Recipient
+import org.whispersystems.signalservice.api.crypto.UntrustedIdentityException
+import org.whispersystems.signalservice.internal.push.Content
+import org.whispersystems.signalservice.internal.push.SyncMessage
+import java.io.IOException
+import java.util.Optional
+import kotlin.time.Duration.Companion.days
+
+/**
+ * Sends a sync message to alert linked devices of a username change so they can reset KT.
+ */
+class MultiDeviceUsernameChangeSyncJob private constructor(
+  parameters: Parameters
+) : Job(parameters) {
+
+  companion object {
+    const val KEY = "MultiDeviceUsernameChangeSyncJob"
+    private val TAG = Log.tag(MultiDeviceUsernameChangeSyncJob::class.java)
+
+    @WorkerThread
+    @JvmStatic
+    fun enqueueUsernameChangeSync() {
+      if (!SignalStore.account.isMultiDevice) {
+        return
+      }
+
+      AppDependencies.jobManager.add(
+        MultiDeviceUsernameChangeSyncJob(
+          parameters = Parameters.Builder()
+            .addConstraint(NetworkConstraint.KEY)
+            .setMaxAttempts(Parameters.UNLIMITED)
+            .setLifespan(1.days.inWholeMilliseconds)
+            .build()
+        )
+      )
+    }
+  }
+
+  override fun serialize(): ByteArray? = null
+
+  override fun getFactoryKey(): String = KEY
+
+  override fun run(): Result {
+    if (!Recipient.self().isRegistered) {
+      Log.w(TAG, "Not registered")
+      return Result.failure()
+    }
+
+    if (!SignalStore.account.isMultiDevice) {
+      Log.w(TAG, "Not multi-device")
+      return Result.failure()
+    }
+
+    val syncMessageContent = Content(
+      syncMessage = SyncMessage.Builder()
+        .pad()
+        .usernameChange(SyncMessage.UsernameChange())
+        .build()
+    )
+
+    return try {
+      Log.d(TAG, "Sending username change sync")
+      val success = AppDependencies.signalServiceMessageSender.sendSyncMessage(syncMessageContent, true, Optional.empty()).isSuccess
+      if (success) {
+        Result.success()
+      } else {
+        Log.w(TAG, "Unsuccessful username change send. Retrying.")
+        Result.retry(defaultBackoff())
+      }
+    } catch (e: IOException) {
+      Log.w(TAG, "Unable to send username change sync due to io exception", e)
+      Result.retry(defaultBackoff())
+    } catch (e: UntrustedIdentityException) {
+      Log.w(TAG, "Unable to send username change sync due to untrusted exception", e)
+      Result.failure()
+    }
+  }
+
+  override fun onFailure() = Unit
+
+  class Factory : Job.Factory<MultiDeviceUsernameChangeSyncJob> {
+    override fun create(parameters: Parameters, serializedData: ByteArray?): MultiDeviceUsernameChangeSyncJob {
+      return MultiDeviceUsernameChangeSyncJob(parameters)
+    }
+  }
+}
--- a/app/src/main/java/org/thoughtcrime/securesms/messages/SyncMessageProcessor.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/messages/SyncMessageProcessor.kt
@ -14,6 +14,7 @@ import org.signal.core.util.Util
 import org.signal.core.util.UuidUtil
 import org.signal.core.util.isNotEmpty
 import org.signal.core.util.orNull
+import org.signal.libsignal.net.KeyTransparency
 import org.signal.libsignal.protocol.IdentityKey
 import org.signal.libsignal.protocol.IdentityKeyPair
 import org.signal.libsignal.protocol.InvalidKeyException
@ -42,6 +43,7 @@ import org.thoughtcrime.securesms.database.PaymentMetaDataUtil
 import org.thoughtcrime.securesms.database.SentStorySyncManifest
 import org.thoughtcrime.securesms.database.SignalDatabase
 import org.thoughtcrime.securesms.database.model.DistributionListId
+import org.thoughtcrime.securesms.database.model.KeyTransparencyStore
 import org.thoughtcrime.securesms.database.model.Mention
 import org.thoughtcrime.securesms.database.model.MessageRecord
 import org.thoughtcrime.securesms.database.model.MmsMessageRecord
@ -58,6 +60,7 @@ import org.thoughtcrime.securesms.database.model.databaseprotos.PollTerminate
 import org.thoughtcrime.securesms.database.model.toBodyRangeList
 import org.thoughtcrime.securesms.database.withAttachments
 import org.thoughtcrime.securesms.dependencies.AppDependencies
+import org.thoughtcrime.securesms.dependencies.KeyTransparencyApi
 import org.thoughtcrime.securesms.groups.BadGroupIdException
 import org.thoughtcrime.securesms.groups.GroupChangeBusyException
 import org.thoughtcrime.securesms.groups.GroupId
@ -188,6 +191,7 @@ object SyncMessageProcessor {
      syncMessage.deleteForMe != null -> handleSynchronizeDeleteForMe(context, syncMessage.deleteForMe!!, envelope.clientTimestamp!!, earlyMessageCacheEntry)
      syncMessage.attachmentBackfillRequest != null -> handleSynchronizeAttachmentBackfillRequest(syncMessage.attachmentBackfillRequest!!, envelope.clientTimestamp!!)
      syncMessage.attachmentBackfillResponse != null -> warn(envelope.clientTimestamp!!, "Contains a backfill response, but we don't handle these!")
+      syncMessage.usernameChange != null -> handleSynchronizeUsernameChange(envelope.clientTimestamp!!)
      else -> warn(envelope.clientTimestamp!!, "Contains no known sync types...")
    }
  }
@ -2026,6 +2030,12 @@ object SyncMessageProcessor {
    return threadId
  }

+  private fun handleSynchronizeUsernameChange(timestamp: Long) {
+    log(timestamp, "[handleSynchronizeUsernameChange] Synchronize username change. Resetting KT.")
+
+    KeyTransparencyApi.reset(aci = SignalStore.account.requireAci().libSignalAci, field = KeyTransparency.AccountDataField.USERNAME_HASH, keyTransparencyStore = KeyTransparencyStore)
+  }
+
  private fun ConversationIdentifier.toRecipientId(): RecipientId? {
    val threadServiceId = ServiceId.parseOrNull(this.threadServiceId, this.threadServiceIdBinary)
    return when {
--- a/app/src/main/java/org/thoughtcrime/securesms/profiles/manage/UsernameRepository.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/profiles/manage/UsernameRepository.kt
@ -20,9 +20,13 @@ import org.signal.network.NetworkResult
 import org.thoughtcrime.securesms.components.settings.app.usernamelinks.main.UsernameLinkResetResult
 import org.thoughtcrime.securesms.database.SignalDatabase
 import org.thoughtcrime.securesms.dependencies.AppDependencies
+import org.thoughtcrime.securesms.jobs.MultiDeviceUsernameChangeSyncJob
 import org.thoughtcrime.securesms.keyvalue.AccountValues
 import org.thoughtcrime.securesms.keyvalue.SignalStore
 import org.thoughtcrime.securesms.net.SignalNetwork
+import org.thoughtcrime.securesms.profiles.manage.UsernameRepository.confirmUsernameAndCreateNewLink
+import org.thoughtcrime.securesms.profiles.manage.UsernameRepository.reserveUsername
+import org.thoughtcrime.securesms.profiles.manage.UsernameRepository.updateUsernameDisplayForCurrentLink
 import org.thoughtcrime.securesms.recipients.Recipient
 import org.thoughtcrime.securesms.storage.StorageSyncHelper
 import org.thoughtcrime.securesms.util.NetworkUtil
@ -444,6 +448,9 @@ object UsernameRepository {
        SignalStore.account.usernameSyncErrorCount = 0
        SignalStore.misc.needsUsernameRestore = false

+        if (Recipient.self().usernameSyncMessagesCapability.isSupported) {
+          MultiDeviceUsernameChangeSyncJob.enqueueUsernameChangeSync()
+        }
        SignalDatabase.recipients.markNeedsSync(Recipient.self().id)
        StorageSyncHelper.scheduleSyncForDataChange()
        Log.i(TAG, "[updateUsernameDisplayForCurrentLink] Successfully updated username.")
@ -477,6 +484,9 @@ object UsernameRepository {
        SignalStore.account.usernameSyncErrorCount = 0
        SignalStore.misc.needsUsernameRestore = false

+        if (Recipient.self().usernameSyncMessagesCapability.isSupported) {
+          MultiDeviceUsernameChangeSyncJob.enqueueUsernameChangeSync()
+        }
        SignalDatabase.recipients.markNeedsSync(Recipient.self().id)
        StorageSyncHelper.scheduleSyncForDataChange()
        Log.i(TAG, "[confirmUsernameAndCreateNewLink] Successfully confirmed username.")
@ -534,6 +544,10 @@ object UsernameRepository {
        SignalStore.account.usernameSyncState = AccountValues.UsernameSyncState.IN_SYNC
        SignalStore.account.usernameSyncErrorCount = 0
        SignalStore.misc.needsUsernameRestore = false
+
+        if (Recipient.self().usernameSyncMessagesCapability.isSupported) {
+          MultiDeviceUsernameChangeSyncJob.enqueueUsernameChangeSync()
+        }
        SignalDatabase.recipients.markNeedsSync(Recipient.self().id)
        StorageSyncHelper.scheduleSyncForDataChange()
        Log.i(TAG, "[deleteUsername] Successfully deleted the username.")
--- a/app/src/main/java/org/thoughtcrime/securesms/recipients/Recipient.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/recipients/Recipient.kt
@ -352,6 +352,9 @@ class Recipient(
    sealedSenderAccessModeValue
  }

+  /** The user's capability to receive username sync messages */
+  val usernameSyncMessagesCapability: Capability = capabilities.usernameSyncMessages
+
  /** The wallpaper to render as the chat background, if present. */
  val wallpaper: ChatWallpaper?
    get() {
--- a/app/src/main/java/org/thoughtcrime/securesms/registration/v2/AppRegistrationNetworkController.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/registration/v2/AppRegistrationNetworkController.kt
@ -731,7 +731,8 @@ class AppRegistrationNetworkController(
      storage,
      versionedExpirationTimer,
      attachmentBackfill,
-      spqr
+      spqr,
+      usernameChangeSyncMessage
    )
  }

--- a/app/src/spinner/java/org/thoughtcrime/securesms/ApiPlugin.kt
+++ b/app/src/spinner/java/org/thoughtcrime/securesms/ApiPlugin.kt
@ -368,7 +368,7 @@ class ApiPlugin : Plugin {
      }

      SignalDatabase.recipients.setProfileKeyIfAbsent(recipientId, ProfileKeyUtil.createNew())
-      SignalDatabase.recipients.setCapabilities(recipientId, SignalServiceProfile.Capabilities(true, true))
+      SignalDatabase.recipients.setCapabilities(recipientId, SignalServiceProfile.Capabilities(true, true, true))
      SignalDatabase.recipients.setProfileSharing(recipientId, profileSharing)

      if (registered) {
--- a/app/src/test/java/org/thoughtcrime/securesms/database/RecipientDatabaseTestUtils.kt
+++ b/app/src/test/java/org/thoughtcrime/securesms/database/RecipientDatabaseTestUtils.kt
@ -122,7 +122,8 @@ object RecipientDatabaseTestUtils {
      notificationChannel = notificationChannel,
      sealedSenderAccessMode = sealedSenderAccessMode,
      capabilities = RecipientRecord.Capabilities(
-        rawBits = capabilities
+        rawBits = capabilities,
+        usernameSyncMessages = Recipient.Capability.SUPPORTED
      ),
      storageId = storageId,
      mentionSetting = mentionSetting,
--- a/app/src/test/java/org/thoughtcrime/securesms/testutil/RecipientTestRule.kt
+++ b/app/src/test/java/org/thoughtcrime/securesms/testutil/RecipientTestRule.kt
@ -184,7 +184,7 @@ class RecipientTestRule : TestRule {
    val id = SignalDatabase.recipients.getOrInsertFromServiceId(aci)
    SignalDatabase.recipients.setProfileName(id, profileName)
    SignalDatabase.recipients.setProfileKeyIfAbsent(id, ProfileKey(Random.nextBytes(32)))
-    SignalDatabase.recipients.setCapabilities(id, SignalServiceProfile.Capabilities(true, true))
+    SignalDatabase.recipients.setCapabilities(id, SignalServiceProfile.Capabilities(true, true, true))
    SignalDatabase.recipients.setProfileSharing(id, profileSharing)
    SignalDatabase.recipients.markRegistered(id, aci)
    return id
--- a/demo/registration/src/main/java/org/signal/registration/sample/dependencies/DemoNetworkController.kt
+++ b/demo/registration/src/main/java/org/signal/registration/sample/dependencies/DemoNetworkController.kt
@ -885,7 +885,8 @@ class DemoNetworkController(
        storage = !RegistrationPreferences.pinsOptedOut,
        versionedExpirationTimer = true,
        attachmentBackfill = true,
-        spqr = true
+        spqr = true,
+        usernameChangeSyncMessage = true
      ),
      name = null,
      pniRegistrationId = RegistrationPreferences.pniRegistrationId,
@ -1127,7 +1128,8 @@ class DemoNetworkController(
      storage,
      versionedExpirationTimer,
      attachmentBackfill,
-      spqr
+      spqr,
+      usernameChangeSyncMessage
    )
  }

--- a/demo/registration/src/main/java/org/signal/registration/sample/screens/pinsettings/PinSettingsViewModel.kt
+++ b/demo/registration/src/main/java/org/signal/registration/sample/screens/pinsettings/PinSettingsViewModel.kt
@ -182,7 +182,8 @@ class PinSettingsViewModel(
          storage = !newOptedOut,
          versionedExpirationTimer = true,
          attachmentBackfill = true,
-          spqr = true
+          spqr = true,
+          usernameChangeSyncMessage = true
        ),
        name = null,
        pniRegistrationId = RegistrationPreferences.pniRegistrationId,
--- a/feature/registration/src/main/java/org/signal/registration/NetworkController.kt
+++ b/feature/registration/src/main/java/org/signal/registration/NetworkController.kt
@ -369,7 +369,8 @@ interface NetworkController {
      val storage: Boolean,
      val versionedExpirationTimer: Boolean,
      val attachmentBackfill: Boolean,
-      val spqr: Boolean
+      val spqr: Boolean,
+      val usernameChangeSyncMessage: Boolean
    )
  }

--- a/feature/registration/src/main/java/org/signal/registration/RegistrationRepository.kt
+++ b/feature/registration/src/main/java/org/signal/registration/RegistrationRepository.kt
@ -369,7 +369,8 @@ class RegistrationRepository(val context: Context, val networkController: Networ
        storage = true, // True initially -- can turn off later if users opt-out
        versionedExpirationTimer = true,
        attachmentBackfill = true,
-        spqr = true
+        spqr = true,
+        usernameChangeSyncMessage = false // TODO(michelle): Turn on once all clients support it
      ),
      name = null,
      pniRegistrationId = keyMaterial.pniRegistrationId,
--- a/lib/libsignal-service/src/main/java/org/whispersystems/signalservice/api/account/AccountAttributes.kt
+++ b/lib/libsignal-service/src/main/java/org/whispersystems/signalservice/api/account/AccountAttributes.kt
@ -57,6 +57,7 @@ class AccountAttributes @JsonCreator constructor(
    @JsonProperty val storage: Boolean,
    @JsonProperty val versionedExpirationTimer: Boolean,
    @JsonProperty val attachmentBackfill: Boolean,
-    @JsonProperty val spqr: Boolean
+    @JsonProperty val spqr: Boolean,
+    @JsonProperty val usernameChangeSyncMessage: Boolean
  )
 }
--- a/lib/libsignal-service/src/main/java/org/whispersystems/signalservice/api/profiles/SignalServiceProfile.java
+++ b/lib/libsignal-service/src/main/java/org/whispersystems/signalservice/api/profiles/SignalServiceProfile.java
@ -195,12 +195,16 @@ public class SignalServiceProfile {
    @JsonProperty("ssre2")
    private boolean storageServiceEncryptionV2;

+    @JsonProperty("usernameChangeSyncMessage")
+    private boolean usernameSyncMessages;
+
    @JsonCreator
    public Capabilities() {}

-    public Capabilities(boolean storage, boolean storageServiceEncryptionV2) {
+    public Capabilities(boolean storage, boolean storageServiceEncryptionV2, boolean usernameSyncMessages) {
      this.storage                    = storage;
      this.storageServiceEncryptionV2 = storageServiceEncryptionV2;
+      this.usernameSyncMessages       = usernameSyncMessages;
    }

    public boolean isStorage() {
@ -210,6 +214,10 @@ public class SignalServiceProfile {
    public boolean isStorageServiceEncryptionV2() {
      return storageServiceEncryptionV2;
    }
+
+    public boolean isUsernameSyncMessages() {
+      return usernameSyncMessages;
+    }
  }

  public ExpiringProfileKeyCredentialResponse getExpiringProfileKeyCredentialResponse() {
--- a/lib/libsignal-service/src/main/protowire/SignalService.proto
+++ b/lib/libsignal-service/src/main/protowire/SignalService.proto
@ -850,6 +850,8 @@ message SyncMessage {
    }
  }

+  message UsernameChange {}
+
  oneof content {
    Sent sent = 1;
    Contacts contacts = 2;
@ -870,6 +872,7 @@ message SyncMessage {
    DeviceNameChange deviceNameChange = 23;
    AttachmentBackfillRequest attachmentBackfillRequest = 24;
    AttachmentBackfillResponse attachmentBackfillResponse = 25;
+    UsernameChange usernameChange = 26;
  }

  reserved /*groups*/ 3;