Privacy preferences for blocking identity change

// FREEBIE

Example/TSKitiOSTestApp/Podfile.lock

@@ -35,7 +35,7 @@ PODS:
   - ProtocolBuffers (1.9.10)
   - Reachability (3.2)
   - SAMKeychain (1.5.0)
-  - SignalServiceKit (0.4.0):
+  - SignalServiceKit (0.6.0):
     - '25519'
     - AFNetworking
     - AxolotlKit
@@ -130,7 +130,7 @@ SPEC CHECKSUMS:
   ProtocolBuffers: d088180c10072b3d24a9939a6314b7b9bcc2340b
   Reachability: 33e18b67625424e47b6cde6d202dce689ad7af96
   SAMKeychain: 1fc9ae02f576365395758b12888c84704eebc423
-  SignalServiceKit: 5c3877241082a778c8c130e1fed17d0904085205
+  SignalServiceKit: c580eb2197f87212fcba9f7faf56163f410225e9
   SocketRocket: 3f77ec2104cc113add553f817ad90a77114f5d43
   SQLCipher: 4c768761421736a247ed6cf412d9045615d53dff
   TwistedOakCollapsingFutures: f359b90f203e9ab13dfb92c9ff41842a7fe1cd0c

SignalServiceKit.podspec

@@ -8,7 +8,7 @@
 
 Pod::Spec.new do |s|
   s.name             = "SignalServiceKit"
-  s.version          = "0.5.3"
+  s.version          = "0.6.0"
   s.summary          = "An Objective-C library for communicating with the Signal messaging service."
 
   s.description      = <<-DESC

src/Account/TSPrivacyPreferences.h

@@ -0,0 +1,16 @@
+//  Created by Michael Kirk on 11/7/16.
+//  Copyright © 2016 Open Whisper Systems. All rights reserved.
+
+#import "TSYapDatabaseObject.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface TSPrivacyPreferences : TSYapDatabaseObject
+
++ (instancetype)sharedInstance;
+
+@property BOOL shouldBlockOnIdentityChange;
+
+@end
+
+NS_ASSUME_NONNULL_END

src/Account/TSPrivacyPreferences.m

@@ -0,0 +1,45 @@
+//  Created by Michael Kirk on 11/7/16.
+//  Copyright © 2016 Open Whisper Systems. All rights reserved.
+
+#import "TSPrivacyPreferences.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+NSString *const TSPrivacyPreferencesSingletonKey = @"TSPrivacyPreferences";
+
+@implementation TSPrivacyPreferences
+
++ (instancetype)sharedInstance
+{
+    static TSPrivacyPreferences *sharedInstance;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        sharedInstance = [self fetchObjectWithUniqueID:TSPrivacyPreferencesSingletonKey];
+        if (!sharedInstance) {
+            sharedInstance = [[self alloc] initDefault];
+        }
+    });
+
+    return sharedInstance;
+}
+
+- (instancetype)initDefault
+{
+    return [self initWithShouldBlockOnIdentityChange:NO];
+}
+
+- (instancetype)initWithShouldBlockOnIdentityChange:(BOOL)shouldBlockOnIdentityChange
+{
+    self = [super initWithUniqueId:TSPrivacyPreferencesSingletonKey];
+    if (!self) {
+        return self;
+    }
+
+    _shouldBlockOnIdentityChange = shouldBlockOnIdentityChange;
+
+    return self;
+}
+
+@end
+
+NS_ASSUME_NONNULL_END

src/Messages/Interactions/TSErrorMessage.h

@@ -14,6 +14,7 @@ typedef NS_ENUM(int32_t, TSErrorMessageType) {
     TSErrorMessageInvalidMessage,
     TSErrorMessageDuplicateMessage,
     TSErrorMessageInvalidVersion,
+    TSErrorMessageNonBlockingIdentityChange,
 };
 
 -(instancetype)initWithCoder:(NSCoder *)coder NS_DESIGNATED_INITIALIZER;

src/Messages/Interactions/TSErrorMessage.m

@@ -65,6 +65,8 @@
             return NSLocalizedString(@"ERROR_MESSAGE_INVALID_KEY_EXCEPTION", @"");
         case TSErrorMessageWrongTrustedIdentityKey:
             return NSLocalizedString(@"ERROR_MESSAGE_WRONG_TRUSTED_IDENTITY_KEY", @"");
+        case TSErrorMessageNonBlockingIdentityChange:
+            return NSLocalizedString(@"ERROR_MESSAGE_NON_BLOCKING_IDENTITY_CHANGE", @"");
         default:
             return NSLocalizedString(@"ERROR_MESSAGE_UNKNOWN_ERROR", @"");
             break;

src/Protocols/UserPreferences.h

@@ -1,13 +0,0 @@
-//
-//  UserPreferences.h
-//  Pods
-//
-//  Created by Frederic Jacobs on 05/12/15.
-//
-//
-
-#import <Foundation/Foundation.h>
-
-@protocol UserPreferencesProtocol <NSObject>
-
-@end

src/Storage/AxolotlStore/TSStorageManager+IdentityKeyStore.m

@@ -1,9 +1,12 @@
 //  Created by Frederic Jacobs on 06/11/14.
 //  Copyright (c) 2014 Open Whisper Systems. All rights reserved.
 
+#import "NSDate+millisecondTimeStamp.h"
 #import "TSAccountManager.h"
+#import "TSContactThread.h"
+#import "TSErrorMessage.h"
+#import "TSPrivacyPreferences.h"
 #import "TSStorageManager+IdentityKeyStore.h"
-
 #import <25519/Curve25519.h>
 
 #define TSStorageManagerIdentityKeyStoreIdentityKey \
@@ -40,13 +43,36 @@
 }
 
 - (BOOL)isTrustedIdentityKey:(NSData *)identityKey recipientId:(NSString *)recipientId {
-    NSData *trusted = [self dataForKey:recipientId inCollection:TSStorageManagerTrustedKeysCollection];
+    NSData *existingKey = [self dataForKey:recipientId inCollection:TSStorageManagerTrustedKeysCollection];
+
+    if (!existingKey) {
+        return YES;
+    }
+
+    if ([existingKey isEqualToData:identityKey]) {
+        return YES;
+    }
 
-    return (trusted == nil || [trusted isEqualToData:identityKey]);
+    if (self.privacyPreferences.shouldBlockOnIdentityChange) {
+        return NO;
+    }
+
+    DDLogInfo(@"Updating identity key for recipient:%@", recipientId);
+    [self createIdentityChangeInfoMessageForRecipientId:recipientId];
+    [self saveRemoteIdentity:identityKey recipientId:recipientId];
+    return YES;
 }
 
 - (void)removeIdentityKeyForRecipient:(NSString *)receipientId {
     [self removeObjectForKey:receipientId inCollection:TSStorageManagerTrustedKeysCollection];
 }
 
+- (void)createIdentityChangeInfoMessageForRecipientId:(NSString *)recipientId
+{
+    TSContactThread *contactThread = [TSContactThread getOrCreateThreadWithContactId:recipientId];
+    [[[TSErrorMessage alloc] initWithTimestamp:[NSDate ows_millisecondTimeStamp]
+                                      inThread:contactThread
+                             failedMessageType:TSErrorMessageNonBlockingIdentityChange] save];
+}
+
 @end

src/Storage/TSStorageManager.h

@@ -14,6 +14,7 @@
 @class ECKeyPair;
 @class PreKeyRecord;
 @class SignedPreKeyRecord;
+@class TSPrivacyPreferences;
 
 extern NSString *const TSUIDatabaseConnectionDidUpdateNotification;
 
@@ -46,5 +47,6 @@ extern NSString *const TSUIDatabaseConnectionDidUpdateNotification;
 - (void)purgeCollection:(NSString *)collection;
 
 @property (nonatomic, readonly) YapDatabaseConnection *dbConnection;
+@property (nonatomic, readonly) TSPrivacyPreferences *privacyPreferences;
 
 @end

src/Storage/TSStorageManager.m

@@ -10,6 +10,7 @@
 #import "TSDatabaseSecondaryIndexes.h"
 #import "TSDatabaseView.h"
 #import "TSInteraction.h"
+#import "TSPrivacyPreferences.h"
 #import "TSThread.h"
 #import <25519/Randomness.h>
 #import <SAMKeychain/SAMKeychain.h>
@@ -73,18 +74,19 @@ static NSString *keychainDBPassAccount    = @"TSDatabasePass";
 @implementation TSStorageManager
 
 + (instancetype)sharedManager {
-    static TSStorageManager *sharedMyManager = nil;
+    static TSStorageManager *sharedManager = nil;
     static dispatch_once_t onceToken;
     dispatch_once(&onceToken, ^{
-      sharedMyManager = [[self alloc] init];
+        sharedManager = [[self alloc] initDefault];
 #if TARGET_OS_IPHONE
-      [sharedMyManager protectSignalFiles];
+        [sharedManager protectSignalFiles];
 #endif
     });
-    return sharedMyManager;
+    return sharedManager;
 }
 
-- (instancetype)init {
+- (instancetype)initDefault
+{
     self = [super init];
 
     YapDatabaseOptions *options = [[YapDatabaseOptions alloc] init];
@@ -178,6 +180,11 @@ static NSString *keychainDBPassAccount    = @"TSDatabasePass";
     return self.database.newConnection;
 }
 
+- (TSPrivacyPreferences *)privacyPreferences
+{
+    return [TSPrivacyPreferences sharedInstance];
+}
+
 - (BOOL)userSetPassword {
     return FALSE;
 }

tests/Storage/TSStorageIdentityKeyStoreTests.m

@@ -9,9 +9,10 @@
 #import <XCTest/XCTest.h>
 #import <25519/Curve25519.h>
 
-#import "TSStorageManager.h"
-#import "TSStorageManager+IdentityKeyStore.h"
 #import "SecurityUtils.h"
+#import "TSPrivacyPreferences.h"
+#import "TSStorageManager+IdentityKeyStore.h"
+#import "TSStorageManager.h"
 
 @interface TSStorageIdentityKeyStoreTests : XCTestCase
 
@@ -47,7 +48,12 @@
 }
 
 
-- (void)testChangedKey {
+- (void)testChangedKeyWithBlockingIdentityChanges
+{
+    TSPrivacyPreferences *preferences = [TSPrivacyPreferences sharedInstance];
+    preferences.shouldBlockOnIdentityChange = YES;
+    [preferences save];
+
     NSData *newKey = [SecurityUtils generateRandomBytes:32];
     NSString *recipientId = @"test@gmail.com";
 
@@ -60,6 +66,25 @@
     XCTAssertFalse([[TSStorageManager sharedManager] isTrustedIdentityKey:otherKey recipientId:recipientId]);
 }
 
+
+- (void)testChangedKeyWIthNonBlockingIdentityChanges
+{
+    TSPrivacyPreferences *preferences = [TSPrivacyPreferences sharedInstance];
+    preferences.shouldBlockOnIdentityChange = NO;
+    [preferences save];
+
+    NSData *newKey = [SecurityUtils generateRandomBytes:32];
+    NSString *recipientId = @"test@gmail.com";
+
+    [[TSStorageManager sharedManager] saveRemoteIdentity:newKey recipientId:recipientId];
+
+    XCTAssert([[TSStorageManager sharedManager] isTrustedIdentityKey:newKey recipientId:recipientId]);
+
+    NSData *otherKey = [SecurityUtils generateRandomBytes:32];
+
+    XCTAssertTrue([[TSStorageManager sharedManager] isTrustedIdentityKey:otherKey recipientId:recipientId]);
+}
+
 - (void)testIdentityKey {
     [[TSStorageManager sharedManager] generateNewIdentityKey];