update testing dependencies

// FREEBIE

.travis.yml

@@ -1,3 +1,5 @@
 language: objective-c
 
+osx_image: xcode8
+
 script: bin/ci

AxolotlKit Tests/SessionCipherTest.m

@@ -46,6 +46,28 @@
     [self runInteractionWithAliceRecord:aliceSessionRecord bobRecord:bobSessionRecord];
 }
 
+- (void)testBasicSessionCipherDispatchQueue {
+    SessionRecord *aliceSessionRecord = [SessionRecord new];
+    SessionRecord *bobSessionRecord   = [SessionRecord new];
+
+    XCTestExpectation *expectation = [self expectationWithDescription:@"session cipher completed"];
+
+    dispatch_queue_t sessionCipherDispatchQueue = dispatch_queue_create("session cipher queue", DISPATCH_QUEUE_SERIAL);
+
+    [SessionCipher setSessionCipherDispatchQueue:sessionCipherDispatchQueue];
+    dispatch_async(sessionCipherDispatchQueue, ^{
+        [self sessionInitialization:aliceSessionRecord.sessionState bobSessionState:bobSessionRecord.sessionState];
+        [self runInteractionWithAliceRecord:aliceSessionRecord bobRecord:bobSessionRecord];
+        [expectation fulfill];
+    });
+
+    [self waitForExpectationsWithTimeout:5.0 handler:^(NSError * _Nullable error) {
+        if (error) {
+            XCTFail(@"Expectation failed with error: %@", error);
+        }
+    }];
+}
+
 -(void)sessionInitialization:(SessionState*)aliceSessionState bobSessionState:(SessionState*)bobSessionState{
     
     ECKeyPair *aliceIdentityKeyPair = [Curve25519 generateKeyPair];

AxolotlKit/Classes/SessionCipher.h

@@ -19,6 +19,16 @@
 
 @interface SessionCipher : NSObject
 
+/**
+ * To keep Session state synchronized, encryption and decryption must happen on the same (serial) dispatch queue. If no
+ * queue is specified, the main queue will be used by default. We only assert that this invariant is held. Dispatching 
+ * to this thread is the responsibility of the caller.
+ *
+ * @param dispatchQueue    serial dispatch queue on which all encryption/decryption must be dispatched.
+ */
++ (void)setSessionCipherDispatchQueue:(dispatch_queue_t)dispatchQueue;
++ (dispatch_queue_t)getSessionCipherDispatchQueue;
+
 - (instancetype)initWithAxolotlStore:(id<AxolotlStore>)sessionStore recipientId:(NSString*)recipientId deviceId:(int)deviceId;
 
 - (instancetype)initWithSessionStore:(id<SessionStore>)sessionStore preKeyStore:(id<PreKeyStore>)preKeyStore signedPreKeyStore:(id<SignedPreKeyStore>)signedPreKeyStore identityKeyStore:(id<IdentityKeyStore>)identityKeyStore recipientId:(NSString*)recipientId deviceId:(int)deviceId;
@@ -30,4 +40,4 @@
 - (int)remoteRegistrationId;
 - (int)sessionVersion;
 
-@end
+@end

AxolotlKit/Classes/SessionCipher.m

@@ -29,6 +29,11 @@
 
 #import <HKDFKit/HKDFKit.h>
 
+#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(major, minor) \
+    ([[NSProcessInfo processInfo] isOperatingSystemAtLeastVersion:(NSOperatingSystemVersion){.majorVersion = major, .minorVersion = minor, .patchVersion = 0}])
+
+static dispatch_queue_t _sessionCipherDispatchQueue;
+
 @interface SessionCipher ()
 
 @property NSString* recipientId;
@@ -77,8 +82,31 @@
     return self;
 }
 
+#pragma mark - dispatch queue 
+
++ (dispatch_queue_t)getSessionCipherDispatchQueue;
+{
+    if (_sessionCipherDispatchQueue) {
+        return _sessionCipherDispatchQueue;
+    } else {
+        return dispatch_get_main_queue();
+    }
+}
+
++ (void)setSessionCipherDispatchQueue:(dispatch_queue_t)dispatchQueue
+{
+    _sessionCipherDispatchQueue = dispatchQueue;
+}
+
+- (void)assertOnSessionCipherDispatchQueue
+{
+    if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(10, 0)) {
+        dispatch_assert_queue([[self class] getSessionCipherDispatchQueue]);
+    } // else, skip assert as it's a development convenience.
+}
+
 - (id<CipherMessage>)encryptMessage:(NSData*)paddedMessage{
-    
+    [self assertOnSessionCipherDispatchQueue];
     SessionRecord *sessionRecord = [self.sessionStore loadSession:self.recipientId deviceId:self.deviceId];
     SessionState  *session       = sessionRecord.sessionState;
     ChainKey *chainKey           = session.senderChainKey;
@@ -118,6 +146,7 @@
 }
 
 - (NSData*)decrypt:(id<CipherMessage>)whisperMessage{
+    [self assertOnSessionCipherDispatchQueue];
     if ([whisperMessage isKindOfClass:[PreKeyWhisperMessage class]]) {
         return [self decryptPreKeyWhisperMessage:(PreKeyWhisperMessage*)whisperMessage];
     } else{
@@ -126,6 +155,7 @@
 }
 
 - (NSData*)decryptPreKeyWhisperMessage:(PreKeyWhisperMessage*)preKeyWhisperMessage{
+    [self assertOnSessionCipherDispatchQueue];
     SessionRecord *sessionRecord = [self.sessionStore loadSession:self.recipientId deviceId:self.deviceId];
     int unsignedPreKeyId         = [self.sessionBuilder processPrekeyWhisperMessage:preKeyWhisperMessage withSession:sessionRecord];
     NSData *plaintext            = [self decryptWithSessionRecord:sessionRecord whisperMessage:preKeyWhisperMessage.message];
@@ -140,6 +170,7 @@
 }
 
 - (NSData*)decryptWhisperMessage:(WhisperMessage*)message{
+    [self assertOnSessionCipherDispatchQueue];
     if (![self.sessionStore containsSession:self.recipientId deviceId:self.deviceId]) {
         @throw [NSException exceptionWithName:NoSessionException reason:[NSString stringWithFormat:@"No session for: %@, %d", self.recipientId, self.deviceId] userInfo:nil];
     }
@@ -154,6 +185,7 @@
 
 
 -(NSData*)decryptWithSessionRecord:(SessionRecord*)sessionRecord whisperMessage:(WhisperMessage*)message{
+    [self assertOnSessionCipherDispatchQueue];
     SessionState   *sessionState   = [sessionRecord sessionState];
     NSArray        *previousStates = [sessionRecord previousSessionStates];
     NSMutableArray *exceptions     = [NSMutableArray array];
@@ -182,6 +214,7 @@
 }
 
 -(NSData*)decryptWithSessionState:(SessionState*)sessionState whisperMessage:(WhisperMessage*)message{
+    [self assertOnSessionCipherDispatchQueue];
     if (![sessionState hasSenderChain]) {
         @throw [NSException exceptionWithName:InvalidMessageException reason:@"Uninitialized session!" userInfo:nil];
     }
@@ -206,6 +239,7 @@
 }
 
 - (ChainKey*)getOrCreateChainKeys:(SessionState*)sessionState theirEphemeral:(NSData*)theirEphemeral{
+    [self assertOnSessionCipherDispatchQueue];
     @try {
         if ([sessionState hasReceiverChain:theirEphemeral]) {
             return [sessionState receiverChainKey:theirEphemeral];
@@ -230,7 +264,7 @@
 }
 
 - (MessageKeys*)getOrCreateMessageKeysForSession:(SessionState*)sessionState theirEphemeral:(NSData*)theirEphemeral chainKey:(ChainKey*)chainKey counter:(int)counter{
-    
+    [self assertOnSessionCipherDispatchQueue];
     if (chainKey.index > counter) {
         if ([sessionState hasMessageKeys:theirEphemeral counter:counter]) {
             return [sessionState removeMessageKeys:theirEphemeral counter:counter];
@@ -268,6 +302,7 @@
 
 
 - (int)remoteRegistrationId{
+    [self assertOnSessionCipherDispatchQueue];
     SessionRecord *record = [self.sessionStore loadSession:self.recipientId deviceId:_deviceId];
     
     if (!record) {
@@ -278,6 +313,7 @@
 }
 
 - (int)sessionVersion{
+    [self assertOnSessionCipherDispatchQueue];
     SessionRecord *record = [self.sessionStore loadSession:self.recipientId deviceId:_deviceId];
     
     if (!record) {
@@ -287,4 +323,4 @@
     return record.sessionState.version;
 }
 
-@end
+@end

Gemfile.lock

@@ -35,38 +35,33 @@ GEM
       fuzzy_match (~> 2.0.4)
       nap (~> 1.0)
     cocoapods-deintegrate (1.0.1)
-    cocoapods-downloader (1.1.2)
+    cocoapods-downloader (1.1.3)
     cocoapods-plugins (1.0.0)
       nap
     cocoapods-search (1.0.0)
     cocoapods-stats (1.0.0)
-    cocoapods-trunk (1.1.1)
+    cocoapods-trunk (1.1.2)
       nap (>= 0.8, < 2.0)
       netrc (= 0.7.8)
     cocoapods-try (1.1.0)
     colored (1.2)
-    commander (4.4.1)
+    commander (4.4.3)
       highline (~> 1.7.2)
-    credentials_manager (0.16.2)
-      colored
-      commander (>= 4.3.5)
-      highline (>= 1.7.1)
-      security
     domain_name (0.5.20161129)
       unf (>= 0.0.5, < 1.0.0)
-    dotenv (2.1.1)
+    dotenv (2.1.2)
     escape (0.0.4)
     excon (0.54.0)
-    faraday (0.10.0)
+    faraday (0.11.0)
       multipart-post (>= 1.2, < 3)
     faraday-cookie_jar (0.0.6)
       faraday (>= 0.7.4)
       http-cookie (~> 1.0.0)
-    faraday_middleware (0.10.1)
+    faraday_middleware (0.11.0.1)
       faraday (>= 0.7.4, < 1.0)
     fastimage (2.0.1)
       addressable (~> 2)
-    fastlane (2.0.1)
+    fastlane (2.9.0)
       activesupport (< 5)
       addressable (>= 2.3, < 3.0.0)
       babosa (>= 1.0.2, < 2.0.0)
@@ -80,7 +75,7 @@ GEM
       faraday_middleware (~> 0.9)
       fastimage (>= 1.6)
       gh_inspector (>= 1.0.1, < 2.0.0)
-      google-api-client (~> 0.9.1)
+      google-api-client (~> 0.9.2)
       highline (>= 1.7.2, < 2.0.0)
       json (< 3.0.0)
       mini_magick (~> 4.5.1)
@@ -88,20 +83,19 @@ GEM
       multi_xml (~> 0.5)
       multipart-post (~> 2.0.0)
       plist (>= 3.1.0, < 4.0.0)
-      rubyzip (>= 1.2.0, < 2.0.0)
+      rubyzip (>= 1.1.0, < 2.0.0)
       security (= 0.1.3)
       slack-notifier (>= 1.3, < 2.0.0)
       terminal-notifier (>= 1.6.2, < 2.0.0)
       terminal-table (>= 1.4.5, < 2.0.0)
       word_wrap (~> 1.0.0)
-      xcode-install (~> 2.0.0)
       xcodeproj (>= 0.20, < 2.0.0)
       xcpretty (>= 0.2.4, < 1.0.0)
       xcpretty-travis-formatter (>= 0.0.3)
     fourflusher (2.0.1)
     fuzzy_match (2.0.4)
-    gh_inspector (1.0.2)
-    google-api-client (0.9.20)
+    gh_inspector (1.0.3)
+    google-api-client (0.9.23)
       addressable (~> 2.3)
       googleauth (~> 0.5)
       httpclient (~> 2.7)
@@ -124,7 +118,7 @@ GEM
     httpclient (2.8.3)
     hurley (0.2)
     i18n (0.7.0)
-    json (1.8.3)
+    json (1.8.6)
     jwt (1.5.6)
     little-plugger (1.1.4)
     logging (2.1.0)
@@ -136,7 +130,7 @@ GEM
     mime-types-data (3.2016.0521)
     mini_magick (4.5.1)
     minitest (5.10.1)
-    molinillo (0.5.4)
+    molinillo (0.5.5)
     multi_json (1.12.1)
     multi_xml (0.6.0)
     multipart-post (2.0.0)
@@ -145,7 +139,7 @@ GEM
     netrc (0.7.8)
     os (0.9.6)
     plist (3.2.0)
-    public_suffix (2.0.4)
+    public_suffix (2.0.5)
     representable (2.3.0)
       uber (~> 0.0.7)
     retriable (2.1.0)
@@ -158,16 +152,6 @@ GEM
       jwt (~> 1.5)
       multi_json (~> 1.10)
     slack-notifier (1.5.1)
-    spaceship (0.39.0)
-      babosa (= 1.0.2)
-      colored
-      credentials_manager (>= 0.16.0)
-      faraday (~> 0.9)
-      faraday-cookie_jar (~> 0.0.6)
-      faraday_middleware (~> 0.9)
-      fastimage (>= 1.6)
-      multi_xml (~> 0.5)
-      plist (>= 3.1.0, < 4.0.0)
     terminal-notifier (1.7.1)
     terminal-table (1.7.3)
       unicode-display_width (~> 1.1.1)
@@ -178,17 +162,14 @@ GEM
     unf (0.1.4)
       unf_ext
     unf_ext (0.0.7.2)
-    unicode-display_width (1.1.2)
+    unicode-display_width (1.1.3)
     word_wrap (1.0.0)
-    xcode-install (2.0.9)
-      claide (>= 0.9.1, < 1.1.0)
-      spaceship (>= 0.25.1, < 1.0.0)
-    xcodeproj (1.4.1)
+    xcodeproj (1.4.2)
       CFPropertyList (~> 2.3.3)
       activesupport (>= 3)
       claide (>= 1.0.1, < 2.0)
       colored (~> 1.2)
-      nanaimo (~> 0.2.0)
+      nanaimo (~> 0.2.3)
     xcpretty (0.2.4)
       rouge (~> 1.8)
     xcpretty-travis-formatter (0.0.4)