CKKSLocalSynchronizeOperation.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@
*/

#import "keychain/ckks/CKKSKeychainView.h"
#import "keychain/ckks/CKKSGroupOperation.h"
#import "keychain/ckks/CKKSLocalSynchronizeOperation.h"
#import "keychain/ckks/CKKSFetchAllRecordZoneChangesOperation.h"
#import "keychain/ckks/CKKSScanLocalItemsOperation.h"
#import "keychain/ckks/CKKSMirrorEntry.h"
#import "keychain/ckks/CKKSIncomingQueueEntry.h"
#import "keychain/ckks/CloudKitCategories.h"
#import "keychain/categories/NSError+UsefulConstructors.h"
#import "keychain/ot/ObjCImprovements.h"

#if OCTAGON

@interface CKKSLocalSynchronizeOperation ()
@property int32_t restartCount;
@end

@implementation CKKSLocalSynchronizeOperation

- (instancetype)init {
return nil;
}
- (instancetype)initWithCKKSKeychainView:(CKKSKeychainView*)ckks
{
if(self = [super init]) {
_ckks = ckks;
_restartCount = 0;

[self addNullableDependency:ckks.holdLocalSynchronizeOperation];
}
return self;
}

- (void)groupStart {
WEAKIFY(self);

/*
* A local synchronize is very similar to a CloudKit synchronize, but it won't cause any (non-essential)
* CloudKit operations to occur.
*
* 1. Finish processing the outgoing queue. You can't be in-sync with cloudkit if you have an update that hasn't propagated.
* 2. Process anything in the incoming queue as normal.
* (Note that this might require the keybag to be unlocked.)
*
* 3. Take every item in the CKMirror, and check for its existence in the local keychain. If not present, add to the incoming queue.
* 4. Process the incoming queue again.
* 5. Scan the local keychain for items which exist locally but are not in CloudKit. Upload them.
* 6. If there are any such items in 4, restart the sync.
*/

CKKSKeychainView* ckks = self.ckks;

// Synchronous, on some thread. Get back on the CKKS queue for SQL thread-safety.
[ckks dispatchSyncWithSQLTransaction:^CKKSDatabaseTransactionResult{
if(self.cancelled) {
ckksnotice("ckksresync", ckks, "CKKSSynchronizeOperation cancelled, quitting");
return CKKSDatabaseTransactionRollback;
}

//ckks.lastLocalSynchronizeOperation = self;

uint32_t steps = 5;

ckksinfo("ckksresync", ckks, "Beginning local resynchronize (attempt %u)", self.restartCount);

CKOperationGroup* operationGroup = [CKOperationGroup CKKSGroupWithName:@"ckks-resync-local"];

// Step 1
CKKSOutgoingQueueOperation* outgoingOp = [ckks processOutgoingQueue: operationGroup];
outgoingOp.name = [NSString stringWithFormat: @"resync-step%u-outgoing", self.restartCount * steps + 1];
[self dependOnBeforeGroupFinished:outgoingOp];

// Step 2
CKKSIncomingQueueOperation* incomingOp = [[CKKSIncomingQueueOperation alloc] initWithDependencies:ckks.operationDependencies
intending:SecCKKSZoneKeyStateReady
errorState:SecCKKSZoneKeyStateUnhealthy
errorOnClassAFailure:true
handleMismatchedViewItems:false];

incomingOp.name = [NSString stringWithFormat: @"resync-step%u-incoming", self.restartCount * steps + 2];
[incomingOp addSuccessDependency:outgoingOp];
[self runBeforeGroupFinished:incomingOp];

// Step 3:
CKKSResultOperation* reloadOp = [[CKKSReloadAllItemsOperation alloc] initWithCKKSKeychainView:ckks];
reloadOp.name = [NSString stringWithFormat: @"resync-step%u-reload", self.restartCount * steps + 3];
[self runBeforeGroupFinished:reloadOp];

// Step 4
CKKSIncomingQueueOperation* incomingResyncOp = [[CKKSIncomingQueueOperation alloc] initWithDependencies:ckks.operationDependencies
intending:SecCKKSZoneKeyStateReady
errorState:SecCKKSZoneKeyStateUnhealthy
errorOnClassAFailure:true
handleMismatchedViewItems:false];

incomingResyncOp.name = [NSString stringWithFormat: @"resync-step%u-incoming-again", self.restartCount * steps + 4];
[incomingResyncOp addSuccessDependency: reloadOp];
[self runBeforeGroupFinished:incomingResyncOp];

// Step 5
CKKSScanLocalItemsOperation* scan = [[CKKSScanLocalItemsOperation alloc] initWithDependencies:ckks.operationDependencies
ckks:ckks
intending:SecCKKSZoneKeyStateReady
errorState:SecCKKSZoneKeyStateError
ckoperationGroup:operationGroup];
scan.name = [NSString stringWithFormat: @"resync-step%u-scan", self.restartCount * steps + 5];
[scan addSuccessDependency: incomingResyncOp];
[self runBeforeGroupFinished: scan];

// Step 6
CKKSResultOperation* restart = [[CKKSResultOperation alloc] init];
restart.name = [NSString stringWithFormat: @"resync-step%u-consider-restart", self.restartCount * steps + 6];
[restart addExecutionBlock:^{
STRONGIFY(self);
if(!self) {
ckkserror("ckksresync", ckks, "received callback for released object");
return;
}

NSError* error = nil;
NSArray<NSString*>* iqes = [CKKSIncomingQueueEntry allUUIDs:ckks.zoneID error:&error];
if(error) {
ckkserror("ckksresync", ckks, "Couldn't fetch IQEs: %@", error);
}

if(scan.recordsFound > 0 || iqes.count > 0) {
if(self.restartCount >= 3) {
// we've restarted too many times. Fail and stop.
ckkserror("ckksresync", ckks, "restarted synchronization too often; Failing");
self.error = [NSError errorWithDomain:@"securityd"
code:2
userInfo:@{NSLocalizedDescriptionKey: @"resynchronization restarted too many times; churn in database?"}];
} else {
// restart the sync operation.
self.restartCount += 1;
ckkserror("ckksresync", ckks, "restarting synchronization operation due to new local items");
[self groupStart];
}
}
}];

[restart addSuccessDependency: scan];
[self runBeforeGroupFinished: restart];

return CKKSDatabaseTransactionCommit;
}];
}

@end;

#pragma mark - CKKSReloadAllItemsOperation

@implementation CKKSReloadAllItemsOperation

- (instancetype)init {
return nil;
}
- (instancetype)initWithCKKSKeychainView:(CKKSKeychainView*)ckks
{
if(self = [super init]) {
_ckks = ckks;
}
return self;
}

- (void)main {
CKKSKeychainView* strongCKKS = self.ckks;

[strongCKKS dispatchSyncWithSQLTransaction:^CKKSDatabaseTransactionResult{
NSError* error = nil;
NSArray<CKKSMirrorEntry*>* mirrorItems = [CKKSMirrorEntry all:strongCKKS.zoneID error:&error];

if(error) {
ckkserror("ckksresync", strongCKKS, "Couldn't fetch mirror items: %@", error);
self.error = error;
return CKKSDatabaseTransactionRollback;
}

// Reload all entries back into the local keychain
// We _could_ scan for entries, but that'd be expensive
// In 36044942, we used to store only the CKRecord system fields in the ckrecord. To work around this, make a whole new CKRecord from the item.
for(CKKSMirrorEntry* ckme in mirrorItems) {
CKRecord* ckmeRecord = [ckme.item CKRecordWithZoneID:strongCKKS.zoneID];
if(!ckmeRecord) {
ckkserror("ckksresync", strongCKKS, "Couldn't make CKRecord for item: %@", ckme);
continue;
}

[strongCKKS _onqueueCKRecordChanged:ckmeRecord resync:true];
}

return CKKSDatabaseTransactionCommit;
}];
}
@end
#endif