CKKSReencryptOutgoingItemsOperation.m   [plain text]

/*
* Copyright (c) 2016 Apple Inc. All Rights Reserved.
*
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*
* 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.
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#import "keychain/ckks/CKKS.h"
#import "keychain/ckks/CKKSKeychainView.h"
#import "keychain/ckks/CKKSCurrentKeyPointer.h"
#import "keychain/ckks/CKKSKey.h"
#import "keychain/ckks/CKKSOutgoingQueueEntry.h"
#import "keychain/ckks/CKKSReencryptOutgoingItemsOperation.h"
#import "keychain/ckks/CKKSItemEncrypter.h"
#import "keychain/ckks/CloudKitCategories.h"
#import "keychain/categories/NSError+UsefulConstructors.h"

#if OCTAGON

// Note: reencryption is not, strictly speaking, a CloudKit operation. However, we preserve this to pass it back to the outgoing queue operation we'll create
@interface CKKSReencryptOutgoingItemsOperation ()
@property CKOperationGroup* ckoperationGroup;
@end

@implementation CKKSReencryptOutgoingItemsOperation

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

[self addNullableDependency:ckks.keyStateReadyDependency];
[self addNullableDependency:ckks.holdReencryptOutgoingItemsOperation];

// We also depend on the key hierarchy being reasonable
[self addNullableDependency:ckks.keyStateReadyDependency];

}
return self;
}

- (void) main {
CKKSKeychainView* ckks = self.ckks;
if(!ckks) {
ckkserror("ckksreencrypt", ckks, "no CKKS object");
return;
}

[ckks dispatchSync: ^bool{
if(self.cancelled) {
ckksnotice("ckksreencrypt", ckks, "CKKSReencryptOutgoingItemsOperation cancelled, quitting");
return false;
}

ckks.lastReencryptOutgoingItemsOperation = self;

NSError* error = nil;
bool newItems = false;

NSArray<CKKSOutgoingQueueEntry*>* oqes = [CKKSOutgoingQueueEntry allInState: SecCKKSStateReencrypt zoneID:ckks.zoneID error:&error];
if(error) {
ckkserror("ckksreencrypt", ckks, "Error fetching oqes from database: %@", error);
self.error = error;
return false;
}

for(CKKSOutgoingQueueEntry* oqe in oqes) {
// If there's already a 'new' item replacing this one, drop the reencryption on the floor
CKKSOutgoingQueueEntry* newOQE = [CKKSOutgoingQueueEntry tryFromDatabase:oqe.uuid state:SecCKKSStateNew zoneID:oqe.item.zoneID error:&error];
if(error) {
ckkserror("ckksreencrypt", ckks, "Couldn't load 'new' OQE to determine status: %@", error);
self.error = error;
error = nil;
continue;
}
if(newOQE) {
ckksnotice("ckksreencrypt", ckks, "Have a new OQE superceding %@ (%@), skipping", oqe, newOQE);
// Don't use the state transition here, either, since this item isn't really changing states
[oqe deleteFromDatabase:&error];
if(error) {
ckkserror("ckksreencrypt", ckks, "Couldn't delete reencrypting OQE(%@) from database: %@", oqe, error);
self.error = error;
error = nil;
continue;
}
continue;
}

ckksnotice("ckksreencrypt", ckks, "Reencrypting item %@", oqe);

NSDictionary* item = [CKKSItemEncrypter decryptItemToDictionary: oqe.item error:&error];
if(error) {
if ([error.domain isEqualToString:@"securityd"] && error.code == errSecItemNotFound) {
ckkserror("ckksreencrypt", ckks, "Coudn't find key in keychain; attempting to poke key hierarchy: %@", error);
[ckks.pokeKeyStateMachineScheduler trigger];
} else {
ckkserror("ckksreencrypt", ckks, "Couldn't decrypt item %@: %@", oqe, error);
}
self.error = error;
error = nil;
continue;
}

// Pick a key whose class matches the keyclass that this item
CKKSKey* originalKey = [CKKSKey fromDatabase: oqe.item.parentKeyUUID zoneID:ckks.zoneID error:&error];
if(error) {
ckkserror("ckksreencrypt", ckks, "Couldn't fetch key (%@) for item %@: %@", oqe.item.parentKeyUUID, oqe, error);
self.error = error;
error = nil;
continue;
}

CKKSKey* newkey = [CKKSKey currentKeyForClass: originalKey.keyclass zoneID:ckks.zoneID error:&error];
[newkey ensureKeyLoaded: &error];
if(error) {
ckkserror("ckksreencrypt", ckks, "Couldn't fetch the current key for class %@: %@", originalKey.keyclass, error);
self.error = error;
error = nil;
continue;
}

CKKSMirrorEntry* ckme = [CKKSMirrorEntry tryFromDatabase:oqe.item.uuid zoneID:ckks.zoneID error:&error];
if(error) {
ckkserror("ckksreencrypt", ckks, "Couldn't fetch ckme (%@) for item %@: %@", oqe.item.parentKeyUUID, oqe, error);
self.error = error;
error = nil;
continue;
}

CKKSItem* encryptedItem = [CKKSItemEncrypter encryptCKKSItem:oqe.item
dataDictionary:item
updatingCKKSItem:ckme.item
parentkey:newkey
error:&error];

if(error) {
ckkserror("ckksreencrypt", ckks, "Couldn't encrypt under the new key %@: %@", newkey, error);
self.error = error;
error = nil;
continue;
}

CKKSOutgoingQueueEntry* replacement = [[CKKSOutgoingQueueEntry alloc] initWithCKKSItem:encryptedItem
action:oqe.action
state:SecCKKSStateNew
waitUntil:nil
accessGroup:oqe.accessgroup];

// Don't use the CKKSKeychainView state change here, since we're doing a wholesale item swap.
[oqe deleteFromDatabase:&error];
[replacement saveToDatabase:&error];
if(error) {
ckkserror("ckksreencrypt", ckks, "Couldn't save newly-encrypted oqe %@: %@", replacement, error);
self.error = error;
error = nil;
continue;
}

newItems = true;
}

if(newItems) {
[ckks processOutgoingQueue:self.ckoperationGroup];
}
return true;
}];
}

@end;

#endif