debug item to locally simulate a SN change

...because constantly reinstalling a secondary device takes too long

You can toggle twice to switch it back, but most of the time you'll
simply pull the latest (real) key when the message view regains focus.

// FREEBIE

Signal/src/ViewControllers/DebugUI/DebugUITableViewController.m

@@ -61,6 +61,9 @@ NS_ASSUME_NONNULL_BEGIN
                                                      }],
                                   ]]];
 
+    if ([thread isKindOfClass:[TSContactThread class]]) {
+        TSContactThread *contactThread = (TSContactThread *)thread;
+
         [contents
             addSection:[OWSTableSection
                            sectionWithTitle:@"Session State"
@@ -75,29 +78,42 @@ NS_ASSUME_NONNULL_BEGIN
                                                                   [[TSStorageManager sharedManager] printAllSessions];
                                                               });
                                                           }],
+                                          [OWSTableItem itemWithTitle:@"Toggle Key Change (Contact Thread Only)"
+                                                          actionBlock:^{
+                                                              DDLogError(
+                                                                  @"Flipping identity Key. Flip again to return.");
+
+                                                              OWSIdentityManager *identityManager =
+                                                                  [OWSIdentityManager sharedManager];
+                                                              NSString *recipientId = [contactThread contactIdentifier];
+
+                                                              NSData *currentKey = [identityManager
+                                                                  identityKeyForRecipientId:recipientId];
+                                                              NSMutableData *flippedKey = [NSMutableData new];
+                                                              const char *currentKeyBytes = currentKey.bytes;
+                                                              for (NSUInteger i = 0; i < currentKey.length; i++) {
+                                                                  const char xorByte = currentKeyBytes[i] ^ 0xff;
+                                                                  [flippedKey appendBytes:&xorByte length:1];
+                                                              }
+
+                                                              OWSAssert(flippedKey.length == 32);
+
+
+                                                              [identityManager saveRemoteIdentity:flippedKey
+                                                                                      recipientId:recipientId];
+                                                          }],
                                           [OWSTableItem
                                               itemWithTitle:@"Delete session (Contact Thread Only)"
                                                 actionBlock:^{
-                                                if (![thread isKindOfClass:[TSContactThread class]]) {
-                                                    DDLogError(@"Refusing to delete session for group thread.");
-                                                    OWSAssert(NO);
-                                                    return;
-                                                }
-                                                TSContactThread *contactThread = (TSContactThread *)thread;
                                                     dispatch_async([OWSDispatch sessionStoreQueue], ^{
                                                         [[TSStorageManager sharedManager]
-                                                        deleteAllSessionsForContact:contactThread.contactIdentifier];
+                                                            deleteAllSessionsForContact:contactThread
+                                                                                            .contactIdentifier];
                                                     });
                                                 }],
                                           [OWSTableItem
                                               itemWithTitle:@"Send session reset (Contact Thread Only)"
                                                 actionBlock:^{
-                                                if (![thread isKindOfClass:[TSContactThread class]]) {
-                                                    DDLogError(@"Refusing to reset session for group thread.");
-                                                    OWSAssert(NO);
-                                                    return;
-                                                }
-                                                TSContactThread *contactThread = (TSContactThread *)thread;
                                                     [OWSSessionResetJob
                                                         runWithContactThread:contactThread
                                                                messageSender:[Environment getCurrent].messageSender
@@ -105,10 +121,8 @@ NS_ASSUME_NONNULL_BEGIN
                                                 }]
                                       ]]];
 
-    [contents addSection:[DebugUIContacts section]];
-
-    // After enqueing the notification you may want to background the app or lock the screen before it triggers, so we
-    // give a little delay.
+        // After enqueing the notification you may want to background the app or lock the screen before it triggers, so
+        // we give a little delay.
         uint64_t notificationDelay = 5;
         [contents
             addSection:
@@ -116,7 +130,8 @@ NS_ASSUME_NONNULL_BEGIN
                     sectionWithTitle:[NSString
                                          stringWithFormat:@"Call Notifications (%llu second delay)", notificationDelay]
                                items:@[
-                               [OWSTableItem itemWithTitle:@"Missed Call"
+                                   [OWSTableItem
+                                       itemWithTitle:@"Missed Call"
                                          actionBlock:^{
                                              SignalCall *call =
                                                  [SignalCall incomingCallWithLocalId:[NSUUID new]
@@ -135,7 +150,8 @@ NS_ASSUME_NONNULL_BEGIN
                                    [OWSTableItem
                                        itemWithTitle:@"Rejected Call with New Safety Number"
                                          actionBlock:^{
-                                         SignalCall *call = [SignalCall incomingCallWithLocalId:[NSUUID new]
+                                             SignalCall *call =
+                                                 [SignalCall incomingCallWithLocalId:[NSUUID new]
                                                                    remotePhoneNumber:thread.contactIdentifier
                                                                          signalingId:0];
 
@@ -151,7 +167,8 @@ NS_ASSUME_NONNULL_BEGIN
                                    [OWSTableItem
                                        itemWithTitle:@"Rejected Call with No Longer Verified Safety Number"
                                          actionBlock:^{
-                                         SignalCall *call = [SignalCall incomingCallWithLocalId:[NSUUID new]
+                                             SignalCall *call =
+                                                 [SignalCall incomingCallWithLocalId:[NSUUID new]
                                                                    remotePhoneNumber:thread.contactIdentifier
                                                                          signalingId:0];
 
@@ -162,10 +179,14 @@ NS_ASSUME_NONNULL_BEGIN
                                                      [[Environment getCurrent].callService.notificationsAdapter
                                                          presentMissedCallBecauseOfNoLongerVerifiedIdentityWithCall:call
                                                                                                          callerName:
-                                                                                                         thread.name];
+                                                                                                             thread
+                                                                                                                 .name];
                                                  });
                                          }],
                                ]]];
+    } // end contact thread section
+
+    [contents addSection:[DebugUIContacts section]];
 
     viewController.contents = contents;
     [viewController presentFromViewController:fromViewController];