CKKSZone.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
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*
* @APPLE_LICENSE_HEADER_END@
*/

#include <AssertMacros.h>

#import <Foundation/Foundation.h>

#if OCTAGON
#import "CloudKitDependencies.h"
#import "keychain/ckks/CKKSAccountStateTracker.h"
#import "keychain/ckks/CloudKitCategories.h"
#import "keychain/categories/NSError+UsefulConstructors.h"
#import <CloudKit/CloudKit.h>
#import <CloudKit/CloudKit_Private.h>

#import "keychain/ot/ObjCImprovements.h"

#import "CKKSKeychainView.h"
#import "CKKSZone.h"

#include <utilities/debugging.h>

@interface CKKSZone()

@property CKDatabaseOperation<CKKSModifyRecordZonesOperation>* zoneCreationOperation;
@property CKDatabaseOperation<CKKSModifyRecordZonesOperation>* zoneDeletionOperation;
@property CKDatabaseOperation<CKKSModifySubscriptionsOperation>* zoneSubscriptionOperation;

@property NSOperationQueue* operationQueue;
@property CKKSResultOperation* accountLoggedInDependency;

@property NSHashTable<NSOperation*>* accountOperations;

// Make writable
@property bool halted;
@end

@implementation CKKSZone

- (instancetype)initWithContainer:(CKContainer*)container
zoneName:(NSString*)zoneName
accountTracker:(CKKSAccountStateTracker*)accountTracker
reachabilityTracker:(CKKSReachabilityTracker*)reachabilityTracker
zoneModifier:(CKKSZoneModifier*)zoneModifier
cloudKitClassDependencies:(CKKSCloudKitClassDependencies*)cloudKitClassDependencies
{
if(self = [super init]) {
_container = container;
_zoneName = zoneName;
_accountTracker = accountTracker;
_reachabilityTracker = reachabilityTracker;

_zoneModifier = zoneModifier;

_halted = false;

_database = [_container privateCloudDatabase];
_zone = [[CKRecordZone alloc] initWithZoneID: [[CKRecordZoneID alloc] initWithZoneName:zoneName ownerName:CKCurrentUserDefaultName]];

_accountStatus = CKKSAccountStatusUnknown;

_accountLoggedInDependency = [self createAccountLoggedInDependency:@"CloudKit account logged in."];

_accountOperations = [NSHashTable weakObjectsHashTable];

_cloudKitClassDependencies = cloudKitClassDependencies;

_queue = dispatch_queue_create([[NSString stringWithFormat:@"CKKSQueue.%@.zone.%@", container.containerIdentifier, zoneName] UTF8String], DISPATCH_QUEUE_SERIAL_WITH_AUTORELEASE_POOL);
_operationQueue = [[NSOperationQueue alloc] init];
}
return self;
}

- (CKKSResultOperation*)createAccountLoggedInDependency:(NSString*)message {
WEAKIFY(self);
CKKSResultOperation* accountLoggedInDependency = [CKKSResultOperation named:@"account-logged-in-dependency" withBlock:^{
STRONGIFY(self);
ckksnotice("ckkszone", self, "%@", message);
}];
accountLoggedInDependency.descriptionErrorCode = CKKSResultDescriptionPendingAccountLoggedIn;
return accountLoggedInDependency;
}

- (void)beginCloudKitOperation {
[self.accountTracker registerForNotificationsOfCloudKitAccountStatusChange:self];
}

- (void)resetSetup {
self.zoneCreated = false;
self.zoneSubscribed = false;
self.zoneCreatedError = nil;
self.zoneSubscribedError = nil;

self.zoneCreationOperation = nil;
self.zoneSubscriptionOperation = nil;
self.zoneDeletionOperation = nil;
}

- (CKRecordZoneID*)zoneID {
return [self.zone zoneID];
}

- (CKKSAccountStatus)accountStatusFromCKAccountInfo:(CKAccountInfo*)info
{
if(!info) {
return CKKSAccountStatusUnknown;
}
if(info.accountStatus == CKAccountStatusAvailable &&
info.hasValidCredentials) {
return CKKSAccountStatusAvailable;
} else {
return CKKSAccountStatusNoAccount;
}
}

- (void)cloudkitAccountStateChange:(CKAccountInfo* _Nullable)oldAccountInfo to:(CKAccountInfo*)currentAccountInfo
{
ckksnotice("ckkszone", self, "%@ Received notification of CloudKit account status change, moving from %@ to %@",
self.zoneID.zoneName,
oldAccountInfo,
currentAccountInfo);

// Filter for device2device encryption and cloudkit grey mode
CKKSAccountStatus oldStatus = [self accountStatusFromCKAccountInfo:oldAccountInfo];
CKKSAccountStatus currentStatus = [self accountStatusFromCKAccountInfo:currentAccountInfo];

if(oldStatus == currentStatus) {
ckksnotice("ckkszone", self, "Computed status of new CK account info is same as old status: %@", [CKKSAccountStateTracker stringFromAccountStatus:currentStatus]);
return;
}

switch(currentStatus) {
case CKKSAccountStatusAvailable: {
ckksnotice("ckkszone", self, "Logged into iCloud.");
[self handleCKLogin];

if(self.accountLoggedInDependency) {
[self.operationQueue addOperation:self.accountLoggedInDependency];
self.accountLoggedInDependency = nil;
};
}
break;

case CKKSAccountStatusNoAccount: {
ckksnotice("ckkszone", self, "Logging out of iCloud. Shutting down.");

if(!self.accountLoggedInDependency) {
self.accountLoggedInDependency = [self createAccountLoggedInDependency:@"CloudKit account logged in again."];
}

[self handleCKLogout];
}
break;

case CKKSAccountStatusUnknown: {
// We really don't expect to receive this as a notification, but, okay!
ckksnotice("ckkszone", self, "Account status has become undetermined. Pausing for %@", self.zoneID.zoneName);

if(!self.accountLoggedInDependency) {
self.accountLoggedInDependency = [self createAccountLoggedInDependency:@"CloudKit account logged in again."];
}

[self handleCKLogout];
}
break;
}
}

- (CKKSResultOperation*)handleCKLogin:(bool)zoneCreated zoneSubscribed:(bool)zoneSubscribed {
if(!SecCKKSIsEnabled()) {
ckksinfo("ckkszone", self, "Skipping CloudKit registration due to disabled CKKS");
return nil;
}

// If we've already started set up and that hasn't finished, complain
if([self.zoneSetupOperation isPending] || [self.zoneSetupOperation isExecuting]) {
ckksnotice("ckkszone", self, "Asked to handleCKLogin, but zoneSetupOperation appears to not be complete? %@ Continuing anyway", self.zoneSetupOperation);
}

self.zoneSetupOperation = [[CKKSGroupOperation alloc] init];
self.zoneSetupOperation.name = [NSString stringWithFormat:@"zone-setup-operation-%@", self.zoneName];

self.zoneCreated = zoneCreated;
self.zoneSubscribed = zoneSubscribed;

ckksnotice("ckkszone", self, "Setting up zone %@", self.zoneName);

WEAKIFY(self);

// First, check the account status. If it's sufficient, add the necessary CloudKit operations to this operation
__weak CKKSGroupOperation* weakZoneSetupOperation = self.zoneSetupOperation;
[self.zoneSetupOperation runBeforeGroupFinished:[CKKSResultOperation named:[NSString stringWithFormat:@"zone-setup-%@", self.zoneName] withBlock:^{
STRONGIFY(self);
__strong __typeof(self.zoneSetupOperation) zoneSetupOperation = weakZoneSetupOperation;
if(!self || !zoneSetupOperation) {
ckkserror("ckkszone", self, "received callback for released object");
return;
}

if(self.accountStatus != CKKSAccountStatusAvailable) {
ckkserror("ckkszone", self, "Zone doesn't believe it's logged in; quitting setup");
return;
}

NSBlockOperation* setupCompleteOperation = [NSBlockOperation blockOperationWithBlock:^{
STRONGIFY(self);
if(!self) {
secerror("ckkszone: received callback for released object");
return;
}

ckksnotice("ckkszone", self, "%@: Setup complete", self.zoneName);
}];
setupCompleteOperation.name = @"zone-setup-complete-operation";

// We have an account, so fetch the push environment and bring up APS
[self.container serverPreferredPushEnvironmentWithCompletionHandler: ^(NSString *apsPushEnvString, NSError *error) {
STRONGIFY(self);
if(!self) {
secerror("ckkszone: received callback for released object");
return;
}

if(error || (apsPushEnvString == nil)) {
ckkserror("ckkszone", self, "Received error fetching preferred push environment (%@). Keychain syncing is highly degraded: %@", apsPushEnvString, error);
} else {
OctagonAPSReceiver* aps = [OctagonAPSReceiver receiverForEnvironment:apsPushEnvString
namedDelegatePort:SecCKKSAPSNamedPort
apsConnectionClass:self.cloudKitClassDependencies.apsConnectionClass];
[aps registerReceiver:self forZoneID:self.zoneID];
}
}];

if(!zoneCreated || !zoneSubscribed) {
ckksnotice("ckkszone", self, "Asking to create and subscribe to CloudKit zone '%@'", self.zoneName);
CKKSZoneModifyOperations* zoneOps = [self.zoneModifier createZone:self.zone];

CKKSResultOperation* handleModificationsOperation = [CKKSResultOperation named:@"handle-modification" withBlock:^{
STRONGIFY(self);
if([zoneOps.savedRecordZones containsObject:self.zone]) {
ckksnotice("ckkszone", self, "Successfully created '%@'", self.zoneName);
self.zoneCreated = true;
} else {
ckksnotice("ckkszone", self, "Failed to create '%@'", self.zoneName);
self.zoneCreatedError = zoneOps.zoneModificationOperation.error;
}

bool createdSubscription = false;
for(CKSubscription* subscription in zoneOps.savedSubscriptions) {
if([subscription.zoneID isEqual:self.zoneID]) {
createdSubscription = true;
break;
}
}

if(createdSubscription) {
ckksnotice("ckkszone", self, "Successfully subscribed '%@'", self.zoneName);
self.zoneSubscribed = true;
} else {
ckksnotice("ckkszone", self, "Failed to subscribe to '%@'", self.zoneName);
self.zoneSubscribedError = zoneOps.zoneSubscriptionOperation.error;
}
}];
[setupCompleteOperation addDependency:zoneOps.zoneModificationOperation];
[handleModificationsOperation addDependency:zoneOps.zoneModificationOperation];
[handleModificationsOperation addDependency:zoneOps.zoneSubscriptionOperation];
[zoneSetupOperation runBeforeGroupFinished:handleModificationsOperation];
} else {
ckksnotice("ckkszone", self, "no need to create or subscribe to the zone '%@'", self.zoneName);
}

[self.zoneSetupOperation runBeforeGroupFinished:setupCompleteOperation];
}]];

[self scheduleAccountStatusOperation:self.zoneSetupOperation];
return self.zoneSetupOperation;
}

- (CKKSResultOperation*)deleteCloudKitZoneOperation:(CKOperationGroup* _Nullable)ckoperationGroup {
if(!SecCKKSIsEnabled()) {
ckksnotice("ckkszone", self, "Skipping CloudKit reset due to disabled CKKS");
return nil;
}

WEAKIFY(self);

// We want to delete this zone and this subscription from CloudKit.

// Step 1: cancel setup operations (if they exist)
[self.accountLoggedInDependency cancel];
[self.zoneSetupOperation cancel];
[self.zoneCreationOperation cancel];
[self.zoneSubscriptionOperation cancel];

// Step 2: Try to delete the zone

CKKSZoneModifyOperations* zoneOps = [self.zoneModifier deleteZone:self.zoneID];

CKKSResultOperation* afterModification = [CKKSResultOperation named:@"after-modification" withBlockTakingSelf:^(CKKSResultOperation * _Nonnull op) {
STRONGIFY(self);

bool fatalError = false;

NSError* operationError = zoneOps.zoneModificationOperation.error;
bool removed = [zoneOps.deletedRecordZoneIDs containsObject:self.zoneID];

if(!removed && operationError) {
// Okay, but if this error is either 'ZoneNotFound' or 'UserDeletedZone', that's fine by us: the zone is deleted.
NSDictionary* partialErrors = operationError.userInfo[CKPartialErrorsByItemIDKey];
if([operationError.domain isEqualToString:CKErrorDomain] && operationError.code == CKErrorPartialFailure && partialErrors) {
for(CKRecordZoneID* errorZoneID in partialErrors.allKeys) {
NSError* errorZone = partialErrors[errorZoneID];

if(errorZone && [errorZone.domain isEqualToString:CKErrorDomain] &&
(errorZone.code == CKErrorZoneNotFound || errorZone.code == CKErrorUserDeletedZone)) {
ckksnotice("ckkszone", self, "Attempted to delete zone %@, but it's already missing. This is okay: %@", errorZoneID, errorZone);
} else {
fatalError = true;
}
}

} else {
fatalError = true;
}

ckksnotice("ckkszone", self, "deletion of record zone %@ completed with error: %@", self.zoneID, operationError);

if(fatalError) {
op.error = operationError;
}
} else {
ckksnotice("ckkszone", self, "deletion of record zone %@ completed successfully", self.zoneID);
}
}];

[afterModification addDependency:zoneOps.zoneModificationOperation];
return afterModification;
}

- (void)notifyZoneChange: (CKRecordZoneNotification*) notification {
ckksnotice("ckkszone", self, "received a notification for CK zone change, ignoring");
}

- (void)handleCKLogin {
ckksinfo("ckkszone", self, "received a notification of CK login");
self.accountStatus = CKKSAccountStatusAvailable;
}

- (void)handleCKLogout {
ckksinfo("ckkszone", self, "received a notification of CK logout");
self.accountStatus = CKKSAccountStatusNoAccount;
[self resetSetup];
}

- (bool)scheduleOperation: (NSOperation*) op {
if(self.halted) {
ckkserror("ckkszone", self, "attempted to schedule an operation on a halted zone, ignoring");
return false;
}

[op addNullableDependency:self.accountLoggedInDependency];

[self.operationQueue addOperation: op];
return true;
}

- (void)cancelAllOperations {
[self.operationQueue cancelAllOperations];
}

- (void)waitUntilAllOperationsAreFinished {
[self.operationQueue waitUntilAllOperationsAreFinished];
}

- (void)waitForOperationsOfClass:(Class) operationClass {
NSArray* operations = [self.operationQueue.operations copy];
for(NSOperation* op in operations) {
if([op isKindOfClass:operationClass]) {
[op waitUntilFinished];
}
}
}

- (bool)scheduleAccountStatusOperation: (NSOperation*) op {
if(self.halted) {
ckkserror("ckkszone", self, "attempted to schedule an account operation on a halted zone, ignoring");
return false;
}

// Always succeed. But, account status operations should always proceed in-order.
[op linearDependencies:self.accountOperations];
[self.operationQueue addOperation: op];
return true;
}

// to be used rarely, if at all
- (bool)scheduleOperationWithoutDependencies:(NSOperation*)op {
if(self.halted) {
ckkserror("ckkszone", self, "attempted to schedule an non-dependent operation on a halted zone, ignoring");
return false;
}

[self.operationQueue addOperation: op];
return true;
}

- (void) dispatchSync: (bool (^)(void)) block {
// important enough to block this thread.
__block bool ok = false;
dispatch_sync(self.queue, ^{
if(self.halted) {
ckkserror("ckkszone", self, "CKKSZone not dispatchSyncing a block (due to being halted)");
return;
}

ok = block();
if(!ok) {
ckkserror("ckkszone", self, "CKKSZone block returned false");
}
});
}

- (void)halt {
// Synchronously set the 'halted' bit
dispatch_sync(self.queue, ^{
self.halted = true;
});

// Bring all operations down, too
[self cancelAllOperations];
}

@end

#endif /* OCTAGON */