Bail on startup if DB password is inaccessible

Most likely this would be  because the user hasn't unlocked their device
since last restart.

This behavior existed once before, but the startup ordering is pretty
delicate. So, we're now redundantly checking in SSK in case this
delicate startup logic gets mis-ordered again.

Also fixed the AppDelegate method to check for the proper
applicationState, since it will never be "active" in didFinishLaunching.

fixes https://github.com/WhisperSystems/Signal-iOS/issues/1627

// FREEBIE

Podfile

@@ -4,7 +4,7 @@ source 'https://github.com/CocoaPods/Specs.git'
 target 'Signal' do
     pod 'SocketRocket',               :git => 'https://github.com/facebook/SocketRocket.git'
     pod 'AxolotlKit', git: 'https://github.com/WhisperSystems/SignalProtocolKit.git'
-    pod 'SignalServiceKit',           git: 'https://github.com/WhisperSystems/SignalServiceKit.git', branch: 'master'
+    pod 'SignalServiceKit',           git: 'https://github.com/WhisperSystems/SignalServiceKit.git', branch: 'mkirk/dont-reset-storage-before-first-unlock'
     #pod 'SignalServiceKit',           path: '../SignalServiceKit'
     pod 'OpenSSL'
     pod 'PastelogKit',                '~> 1.3'

Podfile.lock

@@ -121,7 +121,7 @@ DEPENDENCIES:
   - OpenSSL
   - PastelogKit (~> 1.3)
   - SCWaveformView (~> 1.0)
-  - SignalServiceKit (from `https://github.com/WhisperSystems/SignalServiceKit.git`, branch `master`)
+  - SignalServiceKit (from `https://github.com/WhisperSystems/SignalServiceKit.git`, branch `mkirk/dont-reset-storage-before-first-unlock`)
   - SocketRocket (from `https://github.com/facebook/SocketRocket.git`)
   - ZXingObjC
 
@@ -129,7 +129,7 @@ EXTERNAL SOURCES:
   AxolotlKit:
     :git: https://github.com/WhisperSystems/SignalProtocolKit.git
   SignalServiceKit:
-    :branch: master
+    :branch: mkirk/dont-reset-storage-before-first-unlock
     :git: https://github.com/WhisperSystems/SignalServiceKit.git
   SocketRocket:
     :git: https://github.com/facebook/SocketRocket.git
@@ -139,7 +139,7 @@ CHECKOUT OPTIONS:
     :commit: 714f5ebe199ecc999b33c6f97a4bb57e2db90e75
     :git: https://github.com/WhisperSystems/SignalProtocolKit.git
   SignalServiceKit:
-    :commit: 8f81015730111d235ce90edc2f920170134a9e62
+    :commit: 4846aabd13d30bb39bcc3bea395abe40beaced57
     :git: https://github.com/WhisperSystems/SignalServiceKit.git
   SocketRocket:
     :commit: 41b57bb2fc292a814f758441a05243eb38457027
@@ -170,6 +170,6 @@ SPEC CHECKSUMS:
   YapDatabase: b1e43555a34a5298e23a045be96817a5ef0da58f
   ZXingObjC: bf15b3814f7a105b6d99f47da2333c93a063650a
 
-PODFILE CHECKSUM: cb24c78080551874a45d1a20de4a1bef7427b41f
+PODFILE CHECKSUM: 92037a2e2a31e58603ec77779d6e87f5f54b0d2a
 
 COCOAPODS: 1.0.1

Signal/src/AppDelegate.m

@@ -63,6 +63,9 @@ static NSString *const kURLHostVerifyPrefix             = @"verify";
     [logger addLoggingCallback:^(NSString *category, id details, NSUInteger index){
     }];
 
+    // XXX - careful when moving this. It must happen before we initialize TSStorageManager.
+    [self verifyDBKeysAvailableBeforeBackgroundLaunch];
+
     // Setting up environment
     [Environment setCurrent:[Release releaseEnvironmentWithLogging:logger]];
 
@@ -88,7 +91,6 @@ static NSString *const kURLHostVerifyPrefix             = @"verify";
 #elif RELEASE
     loggingIsEnabled = Environment.preferences.loggingIsEnabled;
 #endif
-    [self verifyBackgroundBeforeKeysAvailableLaunch];
 
     if (loggingIsEnabled) {
         [DebugLogger.sharedLogger enableFileLogging];
@@ -378,31 +380,23 @@ static NSString *const kURLHostVerifyPrefix             = @"verify";
 }
 
 /**
- *  Signal requires an iPhone to be unlocked after reboot to be able to access keying material.
+ *  The user must unlock the device once after reboot before the database encryption key can be accessed.
  */
-- (void)verifyBackgroundBeforeKeysAvailableLaunch {
-    if ([self applicationIsActive]) {
+- (void)verifyDBKeysAvailableBeforeBackgroundLaunch
+{
+    if (UIApplication.sharedApplication.applicationState != UIApplicationStateBackground) {
         return;
     }
 
-    if (![[TSStorageManager sharedManager] databasePasswordAccessible]) {
+    if ([TSStorageManager isDatabasePasswordAccessible]) {
         UILocalNotification *notification = [[UILocalNotification alloc] init];
         notification.alertBody            = NSLocalizedString(@"PHONE_NEEDS_UNLOCK", nil);
         [[UIApplication sharedApplication] presentLocalNotificationNow:notification];
+        DDLogInfo(@"%@ exiting because we are in the background and the database password is not accessible.", self.tag);
         exit(0);
     }
 }
 
-- (BOOL)applicationIsActive {
-    UIApplication *app = [UIApplication sharedApplication];
-
-    if (app.applicationState == UIApplicationStateActive) {
-        return YES;
-    }
-
-    return NO;
-}
-
 #pragma mark - Logging
 
 + (NSString *)tag