Add basic re-reg support to regV5.

demo/registration/src/main/java/org/signal/registration/sample/dependencies/RealNetworkController.kt

@@ -289,6 +289,9 @@ class RealNetworkController(
     fcmToken: String?,
     skipDeviceTransfer: Boolean
   ): RegistrationNetworkResult<RegisterAccountResponse, RegisterAccountError> = withContext(Dispatchers.IO) {
+    check(sessionId != null || recoveryPassword != null) { "Either sessionId or recoveryPassword must be provided" }
+    check(sessionId == null || recoveryPassword == null) { "Either sessionId or recoveryPassword must be provided, but not both" }
+
     try {
       val serviceAttributes = attributes.toServiceAccountAttributes()
       val serviceAciPreKeys = aciPreKeys.toServicePreKeyCollection()

demo/registration/src/main/java/org/signal/registration/sample/screens/pinsettings/PinSettingsViewModel.kt

@@ -178,7 +178,7 @@ class PinSettingsViewModel(
         ),
         name = null,
         pniRegistrationId = RegistrationPreferences.pniRegistrationId,
-        recoveryPassword = null
+        recoveryPassword = RegistrationPreferences.masterKey?.deriveRegistrationRecoveryPassword()
       )
 
       when (val result = networkController.setAccountAttributes(attributes)) {

feature/registration/src/main/java/org/signal/registration/RegistrationActivity.kt

@@ -28,12 +28,6 @@ class RegistrationActivity : ComponentActivity() {
     )
   }
 
-  private val viewModel: RegistrationViewModel by viewModels(factoryProducer = {
-    RegistrationViewModel.Factory(
-      repository = repository
-    )
-  })
-
   @OptIn(ExperimentalPermissionsApi::class)
   override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)

feature/registration/src/main/java/org/signal/registration/RegistrationFlowState.kt

@@ -5,44 +5,24 @@
 
 package org.signal.registration
 
-import android.os.Parcel
 import android.os.Parcelable
-import kotlinx.parcelize.Parceler
 import kotlinx.parcelize.Parcelize
 import kotlinx.parcelize.TypeParceler
 import org.signal.core.models.AccountEntropyPool
 import org.signal.core.models.MasterKey
+import org.signal.registration.util.AccountEntropyPoolParceler
+import org.signal.registration.util.MasterKeyParceler
 
 @Parcelize
 @TypeParceler<MasterKey?, MasterKeyParceler>
-@TypeParceler<AccountEntropyPool?, AepParceler>
+@TypeParceler<AccountEntropyPool?, AccountEntropyPoolParceler>
 data class RegistrationFlowState(
   val backStack: List<RegistrationRoute> = listOf(RegistrationRoute.Welcome),
   val sessionMetadata: NetworkController.SessionMetadata? = null,
   val sessionE164: String? = null,
   val accountEntropyPool: AccountEntropyPool? = null,
   val temporaryMasterKey: MasterKey? = null,
-  val registrationLockProof: String? = null
+  val registrationLockProof: String? = null,
+  val preExistingRegistrationData: PreExistingRegistrationData? = null
 ) : Parcelable
 
-object MasterKeyParceler : Parceler<MasterKey?> {
-  override fun create(parcel: Parcel): MasterKey? {
-    val bytes = parcel.createByteArray()
-    return bytes?.let { MasterKey(it) }
-  }
-
-  override fun MasterKey?.write(parcel: Parcel, flags: Int) {
-    parcel.writeByteArray(this?.serialize())
-  }
-}
-
-object AepParceler : Parceler<AccountEntropyPool?> {
-  override fun create(parcel: Parcel): AccountEntropyPool? {
-    val aep = parcel.readString()
-    return aep?.let { AccountEntropyPool(it) }
-  }
-
-  override fun AccountEntropyPool?.write(parcel: Parcel, flags: Int) {
-    parcel.writeString(this?.value)
-  }
-}

feature/registration/src/main/java/org/signal/registration/RegistrationRepository.kt

@@ -108,6 +108,30 @@ class RegistrationRepository(val networkController: NetworkController, val stora
     }
   }
 
+  /**
+   * Registers a new account using a recovery password derived from the user's [MasterKey].
+   *
+   * This method:
+   * 1. Generates and stores all required cryptographic key material
+   * 2. Creates account attributes with registration IDs and capabilities
+   * 3. Calls the network controller to register the account
+   * 4. On success, saves the registration data to persistent storage
+   *
+   * @param e164 The phone number in E.164 format (used for basic auth)
+   * @param recoveryPassword The recovery password, derived from the user's [MasterKey], which allows us to forgo session creation.
+   * @param registrationLock The registration lock token derived from the master key (if unlocking a reglocked account)
+   * @param skipDeviceTransfer Whether to skip device transfer flow
+   * @return The registration result containing account information or an error
+   */
+  suspend fun registerAccountWithRecoveryPassword(
+    e164: String,
+    recoveryPassword: String,
+    registrationLock: String? = null,
+    skipDeviceTransfer: Boolean = true
+  ): RegistrationNetworkResult<Pair<RegisterAccountResponse, KeyMaterial>, RegisterAccountError> = withContext(Dispatchers.IO) {
+    registerAccount(e164, sessionId = null, recoveryPassword, registrationLock, skipDeviceTransfer)
+  }
+
   /**
    * Registers a new account after successful phone number verification.
    *
@@ -123,12 +147,41 @@ class RegistrationRepository(val networkController: NetworkController, val stora
    * @param skipDeviceTransfer Whether to skip device transfer flow
    * @return The registration result containing account information or an error
    */
-  suspend fun registerAccount(
+  suspend fun registerAccountWithSession(
     e164: String,
     sessionId: String,
     registrationLock: String? = null,
     skipDeviceTransfer: Boolean = true
   ): RegistrationNetworkResult<Pair<RegisterAccountResponse, KeyMaterial>, RegisterAccountError> = withContext(Dispatchers.IO) {
+    registerAccount(e164, sessionId, recoveryPassword = null, registrationLock, skipDeviceTransfer)
+  }
+
+  /**
+   * Registers a new account.
+   *
+   * This method:
+   * 1. Generates and stores all required cryptographic key material
+   * 2. Creates account attributes with registration IDs and capabilities
+   * 3. Calls the network controller to register the account
+   * 4. On success, saves the registration data to persistent storage
+   *
+   * @param e164 The phone number in E.164 format (used for basic auth)
+   * @param sessionId The verified session ID from phone number verification. Must provide if you're not using [recoveryPassword].
+   * @param recoveryPassword The recovery password, derived from the user's [MasterKey], which allows us to forgo session creation. Must provide if you're not using [sessionId].
+   * @param registrationLock The registration lock token derived from the master key (if unlocking a reglocked account)
+   * @param skipDeviceTransfer Whether to skip device transfer flow
+   * @return The registration result containing account information or an error
+   */
+  private suspend fun registerAccount(
+    e164: String,
+    sessionId: String?,
+    recoveryPassword: String?,
+    registrationLock: String? = null,
+    skipDeviceTransfer: Boolean = true
+  ): RegistrationNetworkResult<Pair<RegisterAccountResponse, KeyMaterial>, RegisterAccountError> = withContext(Dispatchers.IO) {
+    check(sessionId != null || recoveryPassword != null) { "Either sessionId or recoveryPassword must be provided" }
+    check(sessionId == null || recoveryPassword == null) { "Either sessionId or recoveryPassword must be provided, but not both" }
+
     val keyMaterial = storageController.generateAndStoreKeyMaterial()
     val fcmToken = networkController.getFcmToken()
 
@@ -150,7 +203,7 @@ class RegistrationRepository(val networkController: NetworkController, val stora
       ),
       name = null,
       pniRegistrationId = keyMaterial.pniRegistrationId,
-      recoveryPassword = null
+      recoveryPassword = keyMaterial.accountEntropyPool.deriveMasterKey().deriveRegistrationRecoveryPassword()
     )
 
     val aciPreKeys = PreKeyCollection(
@@ -169,7 +222,7 @@ class RegistrationRepository(val networkController: NetworkController, val stora
       e164 = e164,
       password = keyMaterial.servicePassword,
       sessionId = sessionId,
-      recoveryPassword = null,
+      recoveryPassword = recoveryPassword,
       attributes = accountAttributes,
       aciPreKeys = aciPreKeys,
       pniPreKeys = pniPreKeys,
@@ -205,4 +258,8 @@ class RegistrationRepository(val networkController: NetworkController, val stora
 
     result
   }
+
+  suspend fun getPreExistingRegistrationData(): PreExistingRegistrationData? {
+    return storageController.getPreExistingRegistrationData()
+  }
 }

feature/registration/src/main/java/org/signal/registration/RegistrationViewModel.kt

@@ -11,10 +11,12 @@ import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.createSavedStateHandle
+import androidx.lifecycle.viewModelScope
 import androidx.lifecycle.viewmodel.CreationExtras
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.launch
 import org.signal.core.ui.navigation.ResultEventBus
 import org.signal.core.util.logging.Log
 import kotlin.reflect.KClass
@@ -34,6 +36,14 @@ class RegistrationViewModel(private val repository: RegistrationRepository, save
 
   val resultBus = ResultEventBus()
 
+  init {
+    viewModelScope.launch {
+      repository.getPreExistingRegistrationData()?.let {
+        _state.value = _state.value.copy(preExistingRegistrationData = it)
+      }
+    }
+  }
+
   fun onEvent(event: RegistrationFlowEvent) {
     _state.value = applyEvent(_state.value, event)
   }

feature/registration/src/main/java/org/signal/registration/StorageController.kt

@@ -5,6 +5,9 @@
 
 package org.signal.registration
 
+import android.os.Parcelable
+import kotlinx.parcelize.Parcelize
+import kotlinx.parcelize.TypeParceler
 import org.signal.core.models.AccountEntropyPool
 import org.signal.core.models.MasterKey
 import org.signal.core.models.ServiceId.ACI
@@ -12,6 +15,12 @@ import org.signal.core.models.ServiceId.PNI
 import org.signal.libsignal.protocol.IdentityKeyPair
 import org.signal.libsignal.protocol.state.KyberPreKeyRecord
 import org.signal.libsignal.protocol.state.SignedPreKeyRecord
+import org.signal.registration.util.ACIParceler
+import org.signal.registration.util.AccountEntropyPoolParceler
+import org.signal.registration.util.IdentityKeyPairParceler
+import org.signal.registration.util.KyberPreKeyRecordParceler
+import org.signal.registration.util.PNIParceler
+import org.signal.registration.util.SignedPreKeyRecordParceler
 
 interface StorageController {
 
@@ -63,6 +72,11 @@ interface StorageController {
 /**
  * Container for all cryptographic key material generated during registration.
  */
+@Parcelize
+@TypeParceler<IdentityKeyPair, IdentityKeyPairParceler>
+@TypeParceler<SignedPreKeyRecord, SignedPreKeyRecordParceler>
+@TypeParceler<KyberPreKeyRecord, KyberPreKeyRecordParceler>
+@TypeParceler<AccountEntropyPool, AccountEntropyPoolParceler>
 data class KeyMaterial(
   /** Identity key pair for the Account Identity (ACI). */
   val aciIdentityKeyPair: IdentityKeyPair,
@@ -86,7 +100,7 @@ data class KeyMaterial(
   val servicePassword: String,
   /** Account entropy pool for key derivation. */
   val accountEntropyPool: AccountEntropyPool
-)
+) : Parcelable
 
 data class NewRegistrationData(
   val e164: String,
@@ -96,10 +110,14 @@ data class NewRegistrationData(
   val aep: AccountEntropyPool
 )
 
+@Parcelize
+@TypeParceler<AccountEntropyPool, AccountEntropyPoolParceler>
+@TypeParceler<ACI, ACIParceler>
+@TypeParceler<PNI, PNIParceler>
 data class PreExistingRegistrationData(
   val e164: String,
   val aci: ACI,
   val pni: PNI,
   val servicePassword: String,
   val aep: AccountEntropyPool
-)
+) : Parcelable

feature/registration/src/main/java/org/signal/registration/screens/phonenumber/PhoneNumberEntryState.kt

@@ -6,6 +6,7 @@
 package org.signal.registration.screens.phonenumber
 
 import org.signal.registration.NetworkController.SessionMetadata
+import org.signal.registration.PreExistingRegistrationData
 import kotlin.time.Duration
 
 data class PhoneNumberEntryState(
@@ -13,9 +14,11 @@ data class PhoneNumberEntryState(
   val countryCode: String = "1",
   val nationalNumber: String = "",
   val formattedNumber: String = "",
+  val sessionE164: String? = null,
   val sessionMetadata: SessionMetadata? = null,
   val showFullScreenSpinner: Boolean = false,
-  val oneTimeEvent: OneTimeEvent? = null
+  val oneTimeEvent: OneTimeEvent? = null,
+  val preExistingRegistrationData: PreExistingRegistrationData? = null
 ) {
   sealed interface OneTimeEvent {
     data object NetworkError : OneTimeEvent

feature/registration/src/main/java/org/signal/registration/screens/phonenumber/PhoneNumberEntryViewModel.kt

@@ -26,7 +26,10 @@ import org.signal.registration.RegistrationFlowState
 import org.signal.registration.RegistrationRepository
 import org.signal.registration.RegistrationRoute
 import org.signal.registration.screens.phonenumber.PhoneNumberEntryState.OneTimeEvent
+import org.signal.registration.screens.phonenumber.PhoneNumberEntryState.OneTimeEvent.*
 import org.signal.registration.screens.util.navigateTo
+import org.signal.registration.screens.verificationcode.VerificationCodeState
+import org.signal.registration.screens.verificationcode.VerificationCodeViewModel
 
 class PhoneNumberEntryViewModel(
   val repository: RegistrationRepository,
@@ -53,7 +56,7 @@ class PhoneNumberEntryViewModel(
       val stateEmitter: (PhoneNumberEntryState) -> Unit = { state ->
         _state.value = state
       }
-      applyEvent(_state.value, event, stateEmitter, parentEventEmitter)
+      applyEvent(state.value, event, stateEmitter, parentEventEmitter)
     }
   }
 
@@ -86,7 +89,11 @@ class PhoneNumberEntryViewModel(
 
   @VisibleForTesting
   fun applyParentState(state: PhoneNumberEntryState, parentState: RegistrationFlowState): PhoneNumberEntryState {
-    return state.copy(sessionMetadata = parentState.sessionMetadata)
+    return state.copy(
+      sessionE164 =  parentState.sessionE164,
+      sessionMetadata = parentState.sessionMetadata,
+      preExistingRegistrationData = parentState.preExistingRegistrationData
+    )
   }
 
   private fun applyCountryCodeChanged(state: PhoneNumberEntryState, countryCode: String): PhoneNumberEntryState {
@@ -122,15 +129,6 @@ class PhoneNumberEntryViewModel(
     )
   }
 
-  private fun formatNumber(nationalNumber: String): String {
-    formatter.clear()
-    var result = ""
-    for (digit in nationalNumber) {
-      result = formatter.inputDigit(digit)
-    }
-    return result
-  }
-
   private suspend fun applyPhoneNumberSubmitted(
     inputState: PhoneNumberEntryState,
     parentEventEmitter: (RegistrationFlowEvent) -> Unit
@@ -138,7 +136,77 @@ class PhoneNumberEntryViewModel(
     val e164 = "+${inputState.countryCode}${inputState.nationalNumber}"
     var state = inputState.copy()
 
-    // TODO Consider that someone may back into this screen and change the number, requiring us to create a new session.
+    // If we're re-registering for the same number we used to be registered for, we should try to skip right to registration
+    if (state.preExistingRegistrationData?.e164 == e164) {
+      val masterKey = state.preExistingRegistrationData.aep.deriveMasterKey()
+      val recoveryPassword = masterKey.deriveRegistrationRecoveryPassword()
+      val registrationLock = masterKey.deriveRegistrationLock()
+
+      when (val registerResult = repository.registerAccountWithRecoveryPassword(e164, recoveryPassword, registrationLock, skipDeviceTransfer = true)) {
+        is NetworkController.RegistrationNetworkResult.Success -> {
+          val (response, keyMaterial) = registerResult.data
+
+          parentEventEmitter(RegistrationFlowEvent.Registered(keyMaterial.accountEntropyPool))
+
+          if (response.storageCapable) {
+            parentEventEmitter.navigateTo(RegistrationRoute.PinEntryForSvrRestore)
+          } else {
+            parentEventEmitter.navigateTo(RegistrationRoute.PinCreate)
+          }
+        }
+        is NetworkController.RegistrationNetworkResult.Failure -> {
+          when (registerResult.error) {
+            is NetworkController.RegisterAccountError.SessionNotFoundOrNotVerified -> {
+              Log.w(TAG, "[Register] Got told that our session could not be found when registering with RRP. We should never get into this state. Resetting.")
+              parentEventEmitter(RegistrationFlowEvent.ResetState)
+              return state
+            }
+            is NetworkController.RegisterAccountError.DeviceTransferPossible -> {
+              Log.w(TAG, "[Register] Got told a device transfer is possible. We should never get into this state. Resetting.")
+              parentEventEmitter(RegistrationFlowEvent.ResetState)
+              return state
+            }
+            is NetworkController.RegisterAccountError.RegistrationLock -> {
+              Log.w(TAG, "[Register] Reglocked.")
+              parentEventEmitter.navigateTo(
+                RegistrationRoute.PinEntryForRegistrationLock(
+                  timeRemaining = registerResult.error.data.timeRemaining,
+                  svrCredentials = registerResult.error.data.svr2Credentials
+                )
+              )
+              return state
+            }
+            is NetworkController.RegisterAccountError.RateLimited -> {
+              Log.w(TAG, "[Register] Rate limited.")
+              return state.copy(oneTimeEvent = OneTimeEvent.RateLimited(registerResult.error.retryAfter))
+            }
+            is NetworkController.RegisterAccountError.InvalidRequest -> {
+              Log.w(TAG, "[Register] Invalid request when registering account with RRP. Ditching pre-existing data and continuing with session creation. Message: ${registerResult.error.message}")
+              // TODO should we clear it in the parent state as well?
+              state = state.copy(preExistingRegistrationData = null)
+            }
+            is NetworkController.RegisterAccountError.RegistrationRecoveryPasswordIncorrect -> {
+              Log.w(TAG, "[Register] Registration recovery password incorrect. Ditching pre-existing data and continuing with session creation. Message: ${registerResult.error.message}")
+              // TODO should we clear it in the parent state as well?
+              state = state.copy(preExistingRegistrationData = null)
+            }
+          }
+        }
+        is NetworkController.RegistrationNetworkResult.NetworkError -> {
+          Log.w(TAG, "[Register] Network error.", registerResult.exception)
+          return state.copy(oneTimeEvent = OneTimeEvent.NetworkError)
+        }
+        is NetworkController.RegistrationNetworkResult.ApplicationError -> {
+          Log.w(TAG, "[Register] Unknown error when registering account.", registerResult.exception)
+          return state.copy(oneTimeEvent = OneTimeEvent.UnknownError)
+        }
+      }
+    }
+
+    // Detect if someone backed into this screen and entered a different number
+    if (state.sessionE164 != null && state.sessionE164 != e164) {
+      state = state.copy(sessionMetadata = null)
+    }
 
     var sessionMetadata: NetworkController.SessionMetadata = state.sessionMetadata ?: when (val response = this@PhoneNumberEntryViewModel.repository.createSession(e164)) {
       is NetworkController.RegistrationNetworkResult.Success<NetworkController.SessionMetadata> -> {
@@ -346,6 +414,15 @@ class PhoneNumberEntryViewModel(
     return state
   }
 
+  private fun formatNumber(nationalNumber: String): String {
+    formatter.clear()
+    var result = ""
+    for (digit in nationalNumber) {
+      result = formatter.inputDigit(digit)
+    }
+    return result
+  }
+
   class Factory(
     val repository: RegistrationRepository,
     val parentState: StateFlow<RegistrationFlowState>,

feature/registration/src/main/java/org/signal/registration/screens/pinentry/PinEntryForRegistrationLockViewModel.kt

@@ -127,7 +127,7 @@ class PinEntryForRegistrationLockViewModel(
     }
 
     Log.d(TAG, "[PinEntered] Attempting to register with registration lock token...")
-    val registerResult = repository.registerAccount(
+    val registerResult = repository.registerAccountWithSession(
       e164 = e164,
       sessionId = sessionId,
       registrationLock = registrationLockToken,

feature/registration/src/main/java/org/signal/registration/screens/verificationcode/VerificationCodeViewModel.kt

@@ -130,7 +130,7 @@ class VerificationCodeViewModel(
     }
 
     // Attempt to register
-    val registerResult = repository.registerAccount(e164 = state.e164, sessionId = sessionMetadata.id, skipDeviceTransfer = true)
+    val registerResult = repository.registerAccountWithSession(e164 = state.e164, sessionId = sessionMetadata.id, skipDeviceTransfer = true)
 
     return when (registerResult) {
       is NetworkController.RegistrationNetworkResult.Success -> {
@@ -174,8 +174,9 @@ class VerificationCodeViewModel(
             state.copy(oneTimeEvent = OneTimeEvent.RegistrationError)
           }
           is NetworkController.RegisterAccountError.RegistrationRecoveryPasswordIncorrect -> {
-            Log.w(TAG, "[Register] Registration recovery password incorrect: ${registerResult.error.message}")
+            Log.w(TAG, "[Register] Got told the registration recovery password incorrect. We don't use the RRP in this flow, and should never get this error. Resetting. Message: ${registerResult.error.message}")
-            state.copy(oneTimeEvent = OneTimeEvent.RegistrationError)
+            parentEventEmitter(RegistrationFlowEvent.ResetState)
+            state
           }
         }
       }

feature/registration/src/main/java/org/signal/registration/util/ACIParceler.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.signal.registration.util
+
+import android.os.Parcel
+import kotlinx.parcelize.Parceler
+import org.signal.core.models.ServiceId
+
+class ACIParceler : Parceler<ServiceId.ACI> {
+  override fun ServiceId.ACI.write(parcel: Parcel, flags: Int) {
+    parcel.writeByteArray(this.toByteArray())
+  }
+
+  override fun create(parcel: Parcel): ServiceId.ACI {
+    return ServiceId.ACI.parseOrThrow(parcel.createByteArray())
+  }
+}

feature/registration/src/main/java/org/signal/registration/util/AccountEntropyPoolParceler.kt

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.signal.registration.util
+
+import android.os.Parcel
+import kotlinx.parcelize.Parceler
+import org.signal.core.models.AccountEntropyPool
+
+object AccountEntropyPoolParceler : Parceler<AccountEntropyPool?> {
+  override fun create(parcel: Parcel): AccountEntropyPool? {
+    val aep = parcel.readString()
+    return aep?.let { AccountEntropyPool(it) }
+  }
+
+  override fun AccountEntropyPool?.write(parcel: Parcel, flags: Int) {
+    parcel.writeString(this?.value)
+  }
+}

feature/registration/src/main/java/org/signal/registration/util/IdentityKeyPairParceler.kt

@@ -0,0 +1,26 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.signal.registration.util
+
+import android.os.Parcel
+import kotlinx.parcelize.Parceler
+import org.signal.libsignal.protocol.IdentityKey
+import org.signal.libsignal.protocol.IdentityKeyPair
+import org.signal.libsignal.protocol.ecc.ECPrivateKey
+
+class IdentityKeyPairParceler : Parceler<IdentityKeyPair> {
+  override fun IdentityKeyPair.write(parcel: Parcel, flags: Int) {
+    parcel.writeByteArray(publicKey.serialize())
+    parcel.writeByteArray(privateKey.serialize())
+  }
+
+  override fun create(parcel: Parcel): IdentityKeyPair {
+    return IdentityKeyPair(
+      IdentityKey(parcel.createByteArray()!!),
+      ECPrivateKey(parcel.createByteArray()!!)
+    )
+  }
+}

feature/registration/src/main/java/org/signal/registration/util/KyberPreKeyRecordParceler.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.signal.registration.util
+
+import android.os.Parcel
+import kotlinx.parcelize.Parceler
+import org.signal.libsignal.protocol.state.KyberPreKeyRecord
+
+class KyberPreKeyRecordParceler : Parceler<KyberPreKeyRecord> {
+  override fun KyberPreKeyRecord.write(parcel: Parcel, flags: Int) {
+    parcel.writeByteArray(this.serialize())
+  }
+
+  override fun create(parcel: Parcel): KyberPreKeyRecord {
+    return KyberPreKeyRecord(parcel.createByteArray())
+  }
+}

feature/registration/src/main/java/org/signal/registration/util/MasterKeyParceler.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.signal.registration.util
+
+import android.os.Parcel
+import kotlinx.parcelize.Parceler
+import org.signal.core.models.MasterKey
+
+object MasterKeyParceler : Parceler<MasterKey?> {
+  override fun create(parcel: Parcel): MasterKey? {
+    val bytes = parcel.createByteArray()
+    return bytes?.let { MasterKey(it) }
+  }
+
+  override fun MasterKey?.write(parcel: Parcel, flags: Int) {
+    parcel.writeByteArray(this?.serialize())
+  }
+}
+

feature/registration/src/main/java/org/signal/registration/util/PNIParceler.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.signal.registration.util
+
+import android.os.Parcel
+import kotlinx.parcelize.Parceler
+import org.signal.core.models.ServiceId
+
+class PNIParceler : Parceler<ServiceId.PNI> {
+  override fun ServiceId.PNI.write(parcel: Parcel, flags: Int) {
+    parcel.writeByteArray(this.toByteArray())
+  }
+
+  override fun create(parcel: Parcel): ServiceId.PNI {
+    return ServiceId.PNI.parseOrThrow(parcel.createByteArray())
+  }
+}

feature/registration/src/main/java/org/signal/registration/util/SignedPreKeyRecordParceler.kt

@@ -0,0 +1,20 @@
+/*
+ * Copyright 2026 Signal Messenger, LLC
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+package org.signal.registration.util
+
+import android.os.Parcel
+import kotlinx.parcelize.Parceler
+import org.signal.libsignal.protocol.state.SignedPreKeyRecord
+
+class SignedPreKeyRecordParceler : Parceler<SignedPreKeyRecord> {
+  override fun SignedPreKeyRecord.write(parcel: Parcel, flags: Int) {
+    parcel.writeByteArray(this.serialize())
+  }
+
+  override fun create(parcel: Parcel): SignedPreKeyRecord {
+    return SignedPreKeyRecord(parcel.createByteArray())
+  }
+}

feature/registration/src/test/java/org/signal/registration/screens/pinentry/PinEntryForRegistrationLockViewModelTest.kt

@@ -74,7 +74,7 @@ class PinEntryForRegistrationLockViewModelTest {
 
     coEvery { mockRepository.restoreMasterKeyFromSvr(any(), any(), any(), forRegistrationLock = true) } returns
       NetworkController.RegistrationNetworkResult.Success(NetworkController.MasterKeyResponse(masterKey))
-    coEvery { mockRepository.registerAccount(any(), any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Success(registerResponse to keyMaterial)
 
     viewModel.applyEvent(initialState, PinEntryScreenEvents.PinEntered("123456"), stateEmitter, parentEventEmitter)
@@ -200,7 +200,7 @@ class PinEntryForRegistrationLockViewModelTest {
 
     coEvery { mockRepository.restoreMasterKeyFromSvr(any(), any(), any(), forRegistrationLock = true) } returns
       NetworkController.RegistrationNetworkResult.Success(NetworkController.MasterKeyResponse(masterKey))
-    coEvery { mockRepository.registerAccount(any(), any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Failure(
         NetworkController.RegisterAccountError.RegistrationLock(registrationLockData)
       )
@@ -220,7 +220,7 @@ class PinEntryForRegistrationLockViewModelTest {
 
     coEvery { mockRepository.restoreMasterKeyFromSvr(any(), any(), any(), forRegistrationLock = true) } returns
       NetworkController.RegistrationNetworkResult.Success(NetworkController.MasterKeyResponse(masterKey))
-    coEvery { mockRepository.registerAccount(any(), any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Failure(
         NetworkController.RegisterAccountError.RateLimited(retryAfter)
       )
@@ -242,7 +242,7 @@ class PinEntryForRegistrationLockViewModelTest {
 
     coEvery { mockRepository.restoreMasterKeyFromSvr(any(), any(), any(), forRegistrationLock = true) } returns
       NetworkController.RegistrationNetworkResult.Success(NetworkController.MasterKeyResponse(masterKey))
-    coEvery { mockRepository.registerAccount(any(), any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Failure(
         NetworkController.RegisterAccountError.InvalidRequest("Bad request")
       )
@@ -261,7 +261,7 @@ class PinEntryForRegistrationLockViewModelTest {
 
     coEvery { mockRepository.restoreMasterKeyFromSvr(any(), any(), any(), forRegistrationLock = true) } returns
       NetworkController.RegistrationNetworkResult.Success(NetworkController.MasterKeyResponse(masterKey))
-    coEvery { mockRepository.registerAccount(any(), any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Failure(
         NetworkController.RegisterAccountError.DeviceTransferPossible
       )
@@ -280,7 +280,7 @@ class PinEntryForRegistrationLockViewModelTest {
 
     coEvery { mockRepository.restoreMasterKeyFromSvr(any(), any(), any(), forRegistrationLock = true) } returns
       NetworkController.RegistrationNetworkResult.Success(NetworkController.MasterKeyResponse(masterKey))
-    coEvery { mockRepository.registerAccount(any(), any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.NetworkError(java.io.IOException("Network error"))
 
     viewModel.applyEvent(initialState, PinEntryScreenEvents.PinEntered("123456"), stateEmitter, parentEventEmitter)
@@ -297,7 +297,7 @@ class PinEntryForRegistrationLockViewModelTest {
 
     coEvery { mockRepository.restoreMasterKeyFromSvr(any(), any(), any(), forRegistrationLock = true) } returns
       NetworkController.RegistrationNetworkResult.Success(NetworkController.MasterKeyResponse(masterKey))
-    coEvery { mockRepository.registerAccount(any(), any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.ApplicationError(RuntimeException("Unexpected"))
 
     viewModel.applyEvent(initialState, PinEntryScreenEvents.PinEntered("123456"), stateEmitter, parentEventEmitter)

feature/registration/src/test/java/org/signal/registration/screens/verificationcode/VerificationCodeViewModelTest.kt

@@ -198,7 +198,7 @@ class VerificationCodeViewModelTest {
 
     coEvery { mockRepository.submitVerificationCode(any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Success(sessionMetadata)
-    coEvery { mockRepository.registerAccount(any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Success(registerResponse to keyMaterial)
 
     viewModel.applyEvent(initialState, VerificationCodeScreenEvents.CodeEntered("123456"))
@@ -266,7 +266,7 @@ class VerificationCodeViewModelTest {
       NetworkController.RegistrationNetworkResult.Failure(
         NetworkController.SubmitVerificationCodeError.SessionAlreadyVerifiedOrNoCodeRequested(verifiedSession)
       )
-    coEvery { mockRepository.registerAccount(any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Success(registerResponse to keyMaterial)
 
     viewModel.applyEvent(initialState, VerificationCodeScreenEvents.CodeEntered("123456"))
@@ -373,7 +373,7 @@ class VerificationCodeViewModelTest {
 
     coEvery { mockRepository.submitVerificationCode(any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Success(sessionMetadata)
-    coEvery { mockRepository.registerAccount(any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Failure(
         NetworkController.RegisterAccountError.DeviceTransferPossible
       )
@@ -395,7 +395,7 @@ class VerificationCodeViewModelTest {
 
     coEvery { mockRepository.submitVerificationCode(any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Success(sessionMetadata)
-    coEvery { mockRepository.registerAccount(any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Failure(
         NetworkController.RegisterAccountError.RateLimited(30.seconds)
       )
@@ -422,7 +422,7 @@ class VerificationCodeViewModelTest {
 
     coEvery { mockRepository.submitVerificationCode(any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Success(sessionMetadata)
-    coEvery { mockRepository.registerAccount(any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Failure(
         NetworkController.RegisterAccountError.InvalidRequest("Bad request")
       )
@@ -446,7 +446,7 @@ class VerificationCodeViewModelTest {
 
     coEvery { mockRepository.submitVerificationCode(any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Success(sessionMetadata)
-    coEvery { mockRepository.registerAccount(any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Failure(
         NetworkController.RegisterAccountError.RegistrationRecoveryPasswordIncorrect("Wrong password")
       )
@@ -470,7 +470,7 @@ class VerificationCodeViewModelTest {
 
     coEvery { mockRepository.submitVerificationCode(any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Success(sessionMetadata)
-    coEvery { mockRepository.registerAccount(any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.NetworkError(java.io.IOException("Network error"))
 
     val result = viewModel.applyEvent(
@@ -492,7 +492,7 @@ class VerificationCodeViewModelTest {
 
     coEvery { mockRepository.submitVerificationCode(any(), any()) } returns
       NetworkController.RegistrationNetworkResult.Success(sessionMetadata)
-    coEvery { mockRepository.registerAccount(any(), any(), any()) } returns
+    coEvery { mockRepository.registerAccountWithSession(any(), any(), any()) } returns
       NetworkController.RegistrationNetworkResult.ApplicationError(RuntimeException("Unexpected"))
 
     val result = viewModel.applyEvent(