Properly fall back to setting the master key during provisioning

Author: pete-signal

SignalServiceKit/Contacts/OWSSyncManager.swift

@@ -197,7 +197,13 @@ extension OWSSyncManager: SyncManagerProtocol, SyncManagerProtocolSwift {
             return owsFailDebug("Missing thread")
         }
 
-        let accountEntropyPool = DependenciesBridge.shared.accountKeyStore.getAccountEntropyPool(tx: tx.asV2Read)
+        let accountEntropyPool: AccountEntropyPool?
+        if FeatureFlags.enableAccountEntropyPool {
+            accountEntropyPool = DependenciesBridge.shared.accountKeyStore.getAccountEntropyPool(tx: tx.asV2Read)
+        } else {
+            accountEntropyPool = nil
+        }
+
         if FeatureFlags.enableAccountEntropyPool,
            accountEntropyPool == nil
         {

SignalServiceKit/SecureValueRecovery/SVR2/SecureValueRecovery2Impl.swift

@@ -428,11 +428,17 @@ public class SecureValueRecovery2Impl: SecureValueRecovery {
             }
         }
 
+        var didSetAEP = false
         do {
             if let aep = try provisioningMessage.accountEntropyPool.map({ try AccountEntropyPool(key: $0) }) {
                 accountKeyStore.setAccountEntropyPool(aep, tx: tx)
+                didSetAEP = true
             }
         } catch {
+            Logger.warn("Failed to parse AEP")
+        }
+
+        if !didSetAEP {
             do {
                 accountKeyStore.setMasterKey(try MasterKey(data: provisioningMessage.masterKey), tx: tx)
             } catch {

SignalServiceKit/StorageService/StorageServiceManager.swift

@@ -724,9 +724,21 @@ class StorageServiceOperation {
         }
 
         guard let masterKey else {
-            // We don't have backup keys, do nothing. We'll try a
-            // fresh restore once the keys are set.
-            Logger.info("Skipping storage service operation due to missing master key.")
+            if
+                !isPrimaryDevice,
+                DependenciesBridge.shared.tsAccountManager.registrationStateWithMaybeSneakyTransaction.isRegistered
+            {
+                // This is a linked device, and keys are missing. There's nothing that can be done
+                // until we receive new keys, so send a key sync message and return early.
+                await SSKEnvironment.shared.databaseStorageRef.awaitableWrite { tx in
+                    SSKEnvironment.shared.syncManagerRef.sendKeysSyncRequestMessage(transaction: tx)
+                }
+            } else {
+                // We're either not registered, or a primary.  Either way,
+                // we don't have backup keys, or a means to get them, so do nothing.
+                // We'll try a fresh restore once the keys are set.
+                Logger.info("Skipping storage service operation due to missing master key.")
+            }
             return
         }
         self.masterKey = masterKey