OctagonAPSReceiver.m   [plain text]

/*
* Copyright (c) 2016 Apple Inc. All Rights Reserved.
*
* @APPLE_LICENSE_HEADER_START@
*
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* compliance with the License. Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this
* file.
*
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
*
* @APPLE_LICENSE_HEADER_END@
*/

#if OCTAGON

#import <objc/runtime.h>

#import "keychain/ckks/OctagonAPSReceiver.h"
#import "keychain/ckks/CKKS.h"
#import "keychain/ckks/CKKSCondition.h"
#import "keychain/ckks/CKKSNearFutureScheduler.h"
#import "keychain/ckks/CKKSAnalytics.h"
#import "keychain/analytics/SecMetrics.h"
#import "keychain/analytics/SecEventMetric.h"
#import "keychain/ot/ObjCImprovements.h"
#import <CloudKit/CloudKit_Private.h>
#include <utilities/SecAKSWrappers.h>

@implementation CKRecordZoneNotification (CKKSPushTracing)
- (void)setCkksPushTracingEnabled:(BOOL)ckksPushTracingEnabled {
objc_setAssociatedObject(self, "ckksPushTracingEnabled", ckksPushTracingEnabled ? @YES : @NO, OBJC_ASSOCIATION_RETAIN);
}

- (BOOL)ckksPushTracingEnabled {
return !![objc_getAssociatedObject(self, "ckksPushTracingEnabled") boolValue];
}

- (void)setCkksPushTracingUUID:(NSString*)ckksPushTracingUUID {
objc_setAssociatedObject(self, "ckksPushTracingUUID", ckksPushTracingUUID, OBJC_ASSOCIATION_RETAIN);
}

- (NSString*)ckksPushTracingUUID {
return objc_getAssociatedObject(self, "ckksPushTracingUUID");
}

- (void)setCkksPushReceivedDate:(NSDate*)ckksPushReceivedDate {
objc_setAssociatedObject(self, "ckksPushReceivedDate", ckksPushReceivedDate, OBJC_ASSOCIATION_RETAIN);
}

- (NSDate*)ckksPushReceivedDate {
return objc_getAssociatedObject(self, "ckksPushReceivedDate");
}
@end

@interface OctagonAPSReceiver()

@property CKKSNearFutureScheduler *clearStalePushNotifications;

@property NSString* namedDelegatePort;
@property NSMutableDictionary<NSString*, id<OctagonAPSConnection>>* environmentMap;

// If we receive notifications for a record zone that hasn't been registered yet, send them a their updates when they register
@property NSMutableSet<CKRecordZoneNotification*>* undeliveredUpdates;

// Same, but for cuttlefish containers (and only remember that a push was received; don't remember the pushes themselves)
@property NSMutableSet<NSString*>* undeliveredCuttlefishUpdates;

@property (nullable) id<CKKSZoneUpdateReceiverProtocol> zoneUpdateReceiver;
@property NSMapTable<NSString*, id<OctagonCuttlefishUpdateReceiver>>* octagonContainerMap;
@end

@implementation OctagonAPSReceiver

+ (instancetype)receiverForNamedDelegatePort:(NSString*)namedDelegatePort
apsConnectionClass:(Class<OctagonAPSConnection>)apsConnectionClass
{
@synchronized([self class]) {
NSMutableDictionary<NSString*, OctagonAPSReceiver*>* delegatePortMap = [self synchronizedGlobalDelegatePortMap];

OctagonAPSReceiver* recv = delegatePortMap[namedDelegatePort];

if(recv == nil) {
recv = [[OctagonAPSReceiver alloc] initWithNamedDelegatePort:namedDelegatePort
apsConnectionClass:apsConnectionClass];
delegatePortMap[namedDelegatePort] = recv;
}

return recv;
}
}

+ (void)resetGlobalDelegatePortMap
{
@synchronized (self) {
[self resettableSynchronizedGlobalDelegatePortMap:YES];
}
}

+ (NSMutableDictionary<NSString*, OctagonAPSReceiver*>*)synchronizedGlobalDelegatePortMap
{
return [self resettableSynchronizedGlobalDelegatePortMap:NO];
}

+ (NSMutableDictionary<NSString*, OctagonAPSReceiver*>*)resettableSynchronizedGlobalDelegatePortMap:(BOOL)reset
{
static NSMutableDictionary<NSString*, OctagonAPSReceiver*>* delegatePortMap = nil;

if(delegatePortMap == nil || reset) {
delegatePortMap = [[NSMutableDictionary alloc] init];
}

return delegatePortMap;
}

- (NSArray<NSString *>*)registeredPushEnvironments
{
__block NSArray<NSString*>* environments = nil;
dispatch_sync([OctagonAPSReceiver apsDeliveryQueue], ^{
environments = [self.environmentMap allKeys];
});
return environments;
}

+ (dispatch_queue_t)apsDeliveryQueue {
static dispatch_queue_t aps_dispatch_queue;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
aps_dispatch_queue = dispatch_queue_create("aps-callback-queue", DISPATCH_QUEUE_SERIAL_WITH_AUTORELEASE_POOL);
});
return aps_dispatch_queue;
}

- (BOOL) haveStalePushes
{
__block BOOL haveStalePushes = NO;
dispatch_sync([OctagonAPSReceiver apsDeliveryQueue], ^{
haveStalePushes = (self.undeliveredUpdates.count || self.undeliveredCuttlefishUpdates.count);
});
return haveStalePushes;
}

- (NSArray<NSString*>*)cuttlefishPushTopics
{
NSString* cuttlefishTopic = [kCKPushTopicPrefix stringByAppendingString:@"com.apple.security.cuttlefish"];

// Currently cuttlefish pushes are sent to TPH. System XPC services can't properly register to be woken
// at push time, so receive them for it.
NSString* tphTopic = [kCKPushTopicPrefix stringByAppendingString:@"com.apple.TrustedPeersHelper"];

return @[cuttlefishTopic, tphTopic];
}

- (instancetype)initWithNamedDelegatePort:(NSString*)namedDelegatePort
apsConnectionClass:(Class<OctagonAPSConnection>)apsConnectionClass
{
return [self initWithNamedDelegatePort:namedDelegatePort
apsConnectionClass:apsConnectionClass
stalePushTimeout:5*60*NSEC_PER_SEC];
}

- (instancetype)initWithNamedDelegatePort:(NSString*)namedDelegatePort
apsConnectionClass:(Class<OctagonAPSConnection>)apsConnectionClass
stalePushTimeout:(uint64_t)stalePushTimeout
{
if((self = [super init])) {
_apsConnectionClass = apsConnectionClass;

_undeliveredUpdates = [NSMutableSet set];
_undeliveredCuttlefishUpdates = [[NSMutableSet alloc] init];

_namedDelegatePort = namedDelegatePort;

_environmentMap = [NSMutableDictionary dictionary];

_octagonContainerMap = [NSMapTable strongToWeakObjectsMapTable];
_zoneUpdateReceiver = nil;

WEAKIFY(self);
void (^clearPushBlock)(void) = ^{
dispatch_async([OctagonAPSReceiver apsDeliveryQueue], ^{
NSMutableSet<CKRecordZoneNotification*> *droppedUpdates;
STRONGIFY(self);
if (self == nil) {
return;
}

droppedUpdates = self.undeliveredUpdates;

self.undeliveredUpdates = [NSMutableSet set];
[self.undeliveredCuttlefishUpdates removeAllObjects];

[self reportDroppedPushes:droppedUpdates];
});
};

_clearStalePushNotifications = [[CKKSNearFutureScheduler alloc] initWithName: @"clearStalePushNotifications"
delay:stalePushTimeout
keepProcessAlive:false
dependencyDescriptionCode:CKKSResultDescriptionNone
block:clearPushBlock];
}
return self;
}

- (void)registerForEnvironment:(NSString*)environmentName
{
WEAKIFY(self);

// APS might be slow. This doesn't need to happen immediately, so let it happen later.
dispatch_async([OctagonAPSReceiver apsDeliveryQueue], ^{
STRONGIFY(self);
if(!self) {
return;
}

id<OctagonAPSConnection> apsConnection = self.environmentMap[environmentName];
if(apsConnection) {
// We've already set one of these up.
return;
}

apsConnection = [[self.apsConnectionClass alloc] initWithEnvironmentName:environmentName namedDelegatePort:self.namedDelegatePort queue:[OctagonAPSReceiver apsDeliveryQueue]];
self.environmentMap[environmentName] = apsConnection;

apsConnection.delegate = self;

// The following string should match: [[NSBundle mainBundle] bundleIdentifier]
NSString* ckksTopic = [kCKPushTopicPrefix stringByAppendingString:@"com.apple.securityd"];

#if TARGET_OS_WATCH
// Watches treat CKKS as opportunistic, and Octagon as normal priority.
apsConnection.enabledTopics = [self cuttlefishPushTopics];
apsConnection.opportunisticTopics = @[ckksTopic];
#else
apsConnection.enabledTopics = [[self cuttlefishPushTopics] arrayByAddingObject:ckksTopic];
#if TARGET_OS_OSX
apsConnection.darkWakeTopics = self.apsConnection.enabledTopics;
#endif // TARGET_OS_OSX

#endif // TARGET_OS_WATCH
});
}

// Report that pushes we are dropping
- (void)reportDroppedPushes:(NSSet<CKRecordZoneNotification*>*)notifications
{
bool hasBeenUnlocked = false;
CFErrorRef error = NULL;

/*
* Let server know that device is not unlocked yet
*/

(void)SecAKSGetHasBeenUnlocked(&hasBeenUnlocked, &error);
CFReleaseNull(error);

NSString *eventName = @"CKKS APNS Push Dropped";
if (!hasBeenUnlocked) {
eventName = @"CKKS APNS Push Dropped - never unlocked";
}

for (CKRecordZoneNotification *notification in notifications) {
if (notification.ckksPushTracingEnabled) {
ckksnotice_global("apsnotification", "Submitting initial CKEventMetric due to notification %@", notification);

SecEventMetric *metric = [[SecEventMetric alloc] initWithEventName:@"APNSPushMetrics"];
metric[@"push_token_uuid"] = notification.ckksPushTracingUUID;
metric[@"push_received_date"] = notification.ckksPushReceivedDate;

metric[@"push_event_name"] = eventName;

[[SecMetrics managerObject] submitEvent:metric];
}
}
}

- (CKKSCondition*)registerCKKSReceiver:(id<CKKSZoneUpdateReceiverProtocol>)receiver
{
CKKSCondition* finished = [[CKKSCondition alloc] init];

WEAKIFY(self);
dispatch_async([OctagonAPSReceiver apsDeliveryQueue], ^{
STRONGIFY(self);
if(!self) {
ckkserror_global("octagonpush", "received registration for released OctagonAPSReceiver");
return;
}

ckksnotice_global("octagonpush", "Registering new CKKS push receiver: %@", receiver);

self.zoneUpdateReceiver = receiver;

NSMutableSet<CKRecordZoneNotification*>* currentPendingMessages = [self.undeliveredUpdates copy];
[self.undeliveredUpdates removeAllObjects];

for(CKRecordZoneNotification* message in currentPendingMessages.allObjects) {
// Now, send the receiver its notification!
ckkserror_global("octagonpush", "sending stored push(%@) to newly-registered receiver: %@", message, receiver);
[receiver notifyZoneChange:message];
}

[finished fulfill];
});

return finished;
}

- (CKKSCondition*)registerCuttlefishReceiver:(id<OctagonCuttlefishUpdateReceiver>)receiver
forContainerName:(NSString*)containerName
{
CKKSCondition* finished = [[CKKSCondition alloc] init];

WEAKIFY(self);
dispatch_async([OctagonAPSReceiver apsDeliveryQueue], ^{
STRONGIFY(self);
if(!self) {
ckkserror_global("octagonpush", "received registration for released OctagonAPSReceiver");
return;
}

[self.octagonContainerMap setObject:receiver forKey:containerName];
if([self.undeliveredCuttlefishUpdates containsObject:containerName]) {
[self.undeliveredCuttlefishUpdates removeObject:containerName];

// Now, send the receiver its fake notification!
ckkserror_global("octagonpush", "sending fake push to newly-registered cuttlefish receiver(%@): %@", containerName, receiver);
[receiver notifyContainerChange:nil];
}

[finished fulfill];
});

return finished;
}

#pragma mark - APS Delegate callbacks

- (void)connection:(APSConnection *)connection didReceivePublicToken:(NSData *)publicToken {
// no-op.
ckksnotice_global("octagonpush", "OctagonAPSDelegate initiated: %@", connection);
}

- (void)connection:(APSConnection *)connection didReceiveToken:(NSData *)token forTopic:(NSString *)topic identifier:(NSString *)identifier {
ckksnotice_global("octagonpush", "Received per-topic push token \"%@\" for topic \"%@\" identifier \"%@\" on connection %@", token, topic, identifier, connection);
}

- (void)connection:(APSConnection *)connection didReceiveIncomingMessage:(APSIncomingMessage *)message {
ckksnotice_global("octagonpush", "OctagonAPSDelegate received a message(%@): %@ ", message.topic, message.userInfo);

// Report back through APS that we received a message
if(message.tracingEnabled) {
[connection confirmReceiptForMessage:message];
}

// Separate and handle cuttlefish notifications
if(message.userInfo[@"cf"] != nil) {
NSDictionary* cfInfo = message.userInfo[@"cf"];
NSString* container = cfInfo[@"c"];

ckksnotice_global("octagonpush", "Received a cuttlefish push to container %@", container);
[[CKKSAnalytics logger] setDateProperty:[NSDate date] forKey:CKKSAnalyticsLastOctagonPush];

if(container) {
id<OctagonCuttlefishUpdateReceiver> receiver = [self.octagonContainerMap objectForKey:container];

if(receiver) {
[receiver notifyContainerChange:message];
} else {
ckkserror_global("octagonpush", "received cuttlefish push for unregistered container: %@", container);
[self.undeliveredCuttlefishUpdates addObject:container];
[self.clearStalePushNotifications trigger];
}
} else {
// APS stripped the container. Send a push to all registered containers.
@synchronized(self.octagonContainerMap) {
for(id<OctagonCuttlefishUpdateReceiver> receiver in [self.octagonContainerMap objectEnumerator]) {
[receiver notifyContainerChange:nil];
}
}
}

return;
}

CKNotification* notification = [CKNotification notificationFromRemoteNotificationDictionary:message.userInfo];

if(notification.notificationType == CKNotificationTypeRecordZone) {
CKRecordZoneNotification* rznotification = (CKRecordZoneNotification*) notification;
rznotification.ckksPushTracingEnabled = message.tracingEnabled;
rznotification.ckksPushTracingUUID = message.tracingUUID ? [[[NSUUID alloc] initWithUUIDBytes:message.tracingUUID.bytes] UUIDString] : nil;
rznotification.ckksPushReceivedDate = [NSDate date];

[[CKKSAnalytics logger] setDateProperty:[NSDate date] forKey:CKKSAnalyticsLastCKKSPush];

// Find receiever in map
id<CKKSZoneUpdateReceiverProtocol> recv = self.zoneUpdateReceiver;
if(recv) {
[recv notifyZoneChange:rznotification];
} else {
ckkserror_global("ckkspush", "received push for unregistered receiver: %@", rznotification);
[self.undeliveredUpdates addObject:rznotification];
[self.clearStalePushNotifications trigger];
}
} else {
ckkserror_global("ckkspush", "unexpected notification: %@", notification);
}
}

@end

#endif // OCTAGON