Store the authCredentialSalt when registering.

app/src/main/java/org/thoughtcrime/securesms/keyvalue/AccountValues.kt

@@ -49,6 +49,7 @@ class AccountValues internal constructor(store: KeyValueStore, context: Context)
     private const val KEY_DEVICE_NAME = "account.device_name"
     private const val KEY_DEVICE_ID = "account.device_id"
     private const val KEY_PNI_REGISTRATION_ID = "account.pni_registration_id"
+    private const val KEY_AUTH_CREDENTIAL_SALT = "account.auth_credential_salt"
 
     private const val KEY_ACI_IDENTITY_PUBLIC_KEY = "account.aci_identity_public_key"
     private const val KEY_ACI_IDENTITY_PRIVATE_KEY = "account.aci_identity_private_key"
@@ -276,6 +277,9 @@ class AccountValues internal constructor(store: KeyValueStore, context: Context)
     putString(KEY_SERVICE_PASSWORD, servicePassword)
   }
 
+  /** Salt used by the service to generate PNI auth credentials. Only present for an account registered without a phone number. */
+  var authCredentialSalt: ByteArray? by nullableBlobValue(KEY_AUTH_CREDENTIAL_SALT, null)
+
   /** A randomly-generated value that represents this registration instance. Helps the server know if you reinstalled. */
   var registrationId: Int by integerValue(KEY_REGISTRATION_ID, 0)
 

app/src/main/java/org/thoughtcrime/securesms/registration/v2/AppRegistrationStorageController.kt

@@ -820,6 +820,10 @@ class AppRegistrationStorageController(private val context: Context) : StorageCo
       SignalStore.misc.needsUsernameRestore = true
     }
 
+    accountData.authCredentialSalt?.let {
+      SignalStore.account.authCredentialSalt = it.toByteArray()
+    }
+
     SignalStore.account.setServicePassword(accountData.servicePassword)
     SignalStore.account.setRegistered(registered = true, isAciChanged = isAciChanged)
     TextSecurePreferences.setPromptedPushRegistration(context, true)

app/src/test/java/org/thoughtcrime/securesms/registration/v2/AppRegistrationStorageControllerTest.kt

@@ -94,6 +94,7 @@ class AppRegistrationStorageControllerTest {
   private val pniSignedPreKey = PreKeyUtil.generateSignedPreKey(12, pniIdentity.privateKey)
   private val aciLastResortKyberPreKey = PreKeyUtil.generateLastResortKyberPreKey(21, aciIdentity.privateKey)
   private val pniLastResortKyberPreKey = PreKeyUtil.generateLastResortKyberPreKey(22, pniIdentity.privateKey)
+  private val authCredentialSalt = byteArrayOf(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
 
   private val blobData = mutableMapOf<Uri, ByteArray>()
   private var blobCounter = 0
@@ -147,6 +148,7 @@ class AppRegistrationStorageControllerTest {
     assertThat(SignalStore.account.pniIdentityKey.serialize()).isEqualTo(pniIdentity.serialize())
     assertThat(SignalStore.account.accountEntropyPool.value).isEqualTo(aep.value)
     assertThat(SignalStore.account.restoredAccountEntropyPool).isTrue()
+    assertThat(SignalStore.account.authCredentialSalt).isNotNull().isEqualTo(authCredentialSalt)
 
     assertThat(SignalStore.account.aciPreKeys.isSignedPreKeyRegistered).isTrue()
     assertThat(SignalStore.account.aciPreKeys.activeSignedPreKeyId).isEqualTo(11)
@@ -539,7 +541,8 @@ class AppRegistrationStorageControllerTest {
       e164 = E164,
       servicePassword = servicePassword,
       linkedDeviceData = linkedDeviceData,
-      reRegistration = reRegistration
+      reRegistration = reRegistration,
+      authCredentialSalt = authCredentialSalt.toByteString()
     )
   }
 }

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

@@ -715,6 +715,7 @@ class RegistrationRepository(
         this.pni = result.result.pni
         this.servicePassword = keyMaterial.servicePassword
         this.reRegistration = result.result.reregistration
+        this.authCredentialSalt = result.result.authCredentialSalt?.let { Base64.decode(it).toByteString() }
       }
       storageController.commitRegistrationData()
     }

feature/registration/src/main/protowire/Registration.proto

@@ -50,6 +50,9 @@ message AccountData {
 
   // Whether the service reported this registration as a re-registration of an existing account.
   bool reRegistration = 16;
+
+  // Salt used by the service to generate PNI auth credentials. Only present for an account registered without a phone number.
+  optional bytes authCredentialSalt = 17;
 }
 
 message SvrCredential {