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1 | /* |
2 | * Copyright (c) 2017 Apple Inc. All Rights Reserved. | |
3 | * | |
4 | * @APPLE_LICENSE_HEADER_START@ | |
5 | * | |
6 | * This file contains Original Code and/or Modifications of Original Code | |
7 | * as defined in and that are subject to the Apple Public Source License | |
8 | * Version 2.0 (the 'License'). You may not use this file except in | |
9 | * compliance with the License. Please obtain a copy of the License at | |
10 | * http://www.opensource.apple.com/apsl/ and read it before using this | |
11 | * file. | |
12 | * | |
13 | * The Original Code and all software distributed under the License are | |
14 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
15 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, | |
16 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
17 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. | |
18 | * Please see the License for the specific language governing rights and | |
19 | * limitations under the License. | |
20 | * | |
21 | * @APPLE_LICENSE_HEADER_END@ | |
22 | */ | |
23 | ||
24 | #import "CKKSKeychainView.h" | |
25 | #import "CKKSCurrentKeyPointer.h" | |
26 | #import "CKKSKey.h" | |
27 | #import "CKKSHealKeyHierarchyOperation.h" | |
28 | #import "CKKSGroupOperation.h" | |
29 | ||
30 | #if OCTAGON | |
31 | ||
32 | @interface CKKSHealKeyHierarchyOperation () | |
33 | @property NSBlockOperation* cloudkitModifyOperationFinished; | |
34 | @property CKOperationGroup* ckoperationGroup; | |
35 | @end | |
36 | ||
37 | @implementation CKKSHealKeyHierarchyOperation | |
38 | ||
39 | - (instancetype)init { | |
40 | return nil; | |
41 | } | |
42 | - (instancetype)initWithCKKSKeychainView:(CKKSKeychainView*)ckks ckoperationGroup:(CKOperationGroup*)ckoperationGroup { | |
43 | if(self = [super init]) { | |
44 | _ckks = ckks; | |
45 | _ckoperationGroup = ckoperationGroup; | |
46 | } | |
47 | return self; | |
48 | } | |
49 | ||
50 | - (void)groupStart { | |
51 | /* | |
52 | * We've been invoked because something is wonky with the key hierarchy. | |
53 | * | |
54 | * Attempt to figure out what it is, and what we can do about it. | |
55 | * | |
56 | * The answer "nothing, everything is terrible" is acceptable. | |
57 | */ | |
58 | ||
59 | __weak __typeof(self) weakSelf = self; | |
60 | ||
61 | CKKSKeychainView* ckks = self.ckks; | |
62 | if(!ckks) { | |
63 | ckkserror("ckksheal", ckks, "no CKKS object"); | |
64 | return; | |
65 | } | |
66 | ||
67 | if(self.cancelled) { | |
68 | ckksnotice("ckksheal", ckks, "CKKSHealKeyHierarchyOperation cancelled, quitting"); | |
69 | return; | |
70 | } | |
71 | ||
72 | // Synchronous, on some thread. Get back on the CKKS queue for SQL thread-safety. | |
73 | [ckks dispatchSync: ^bool{ | |
74 | if(self.cancelled) { | |
75 | ckksnotice("ckksheal", ckks, "CKKSHealKeyHierarchyOperation cancelled, quitting"); | |
76 | return false; | |
77 | } | |
78 | ||
79 | NSError* error = nil; | |
80 | ||
81 | CKKSCurrentKeySet* keyset = [[CKKSCurrentKeySet alloc] initForZone:ckks.zoneID]; | |
82 | ||
83 | bool changedCurrentTLK = false; | |
84 | bool changedCurrentClassA = false; | |
85 | bool changedCurrentClassC = false; | |
86 | ||
87 | if(keyset.error) { | |
88 | self.error = keyset.error; | |
89 | ckkserror("ckksheal", ckks, "couldn't load current key set, attempting to proceed: %@", keyset.error); | |
90 | } else { | |
91 | ckksnotice("ckksheal", ckks, "Key set is %@", keyset); | |
92 | } | |
93 | ||
94 | // There's all sorts of brokenness that could exist. For now, we check for: | |
95 | // | |
96 | // 1. Current key pointers are nil. | |
97 | // 2. Keys do not exist in local keychain (but TLK does) | |
98 | // 3. Keys do not exist in local keychain (including TLK) | |
99 | // | |
100 | ||
101 | if(keyset.currentTLKPointer && keyset.currentClassAPointer && keyset.currentClassCPointer && | |
102 | (!keyset.tlk || !keyset.classA || !keyset.classC)) { | |
103 | // Huh. No keys, but some current key pointers? Weird. | |
104 | // If we haven't done one yet, initiate a refetch of everything from cloudkit, and write down that we did so | |
105 | if(!ckks.keyStateMachineRefetched) { | |
106 | ckksnotice("ckksheal", ckks, "Have current key pointers, but no keys. This is exceptional; requesting full refetch"); | |
107 | [ckks _onqueueAdvanceKeyStateMachineToState:SecCKKSZoneKeyStateNeedFullRefetch withError:nil]; | |
108 | return true; | |
109 | } | |
110 | } | |
111 | ||
112 | // No current key records. That's... odd. | |
113 | if(!keyset.currentTLKPointer) { | |
114 | ckksnotice("ckksheal", ckks, "No current TLK pointer?"); | |
115 | keyset.currentTLKPointer = [[CKKSCurrentKeyPointer alloc] initForClass: SecCKKSKeyClassTLK currentKeyUUID:nil zoneID:ckks.zoneID encodedCKRecord:nil]; | |
116 | } | |
117 | if(!keyset.currentClassAPointer) { | |
118 | ckksnotice("ckksheal", ckks, "No current ClassA pointer?"); | |
119 | keyset.currentClassAPointer = [[CKKSCurrentKeyPointer alloc] initForClass: SecCKKSKeyClassA currentKeyUUID:nil zoneID:ckks.zoneID encodedCKRecord:nil]; | |
120 | } | |
121 | if(!keyset.currentClassCPointer) { | |
122 | ckksnotice("ckksheal", ckks, "No current ClassC pointer?"); | |
123 | keyset.currentClassCPointer = [[CKKSCurrentKeyPointer alloc] initForClass: SecCKKSKeyClassC currentKeyUUID:nil zoneID:ckks.zoneID encodedCKRecord:nil]; | |
124 | } | |
125 | ||
126 | ||
127 | if(keyset.currentTLKPointer.currentKeyUUID == nil || keyset.currentClassAPointer.currentKeyUUID == nil || keyset.currentClassCPointer.currentKeyUUID == nil || | |
128 | keyset.tlk == nil || keyset.classA == nil || keyset.classC == nil) { | |
129 | ||
130 | // The records exist, but are broken. Point them at something reasonable. | |
131 | NSArray<CKKSKey*>* keys = [CKKSKey allKeys:ckks.zoneID error:&error]; | |
132 | ||
133 | CKKSKey* newTLK = nil; | |
134 | CKKSKey* newClassAKey = nil; | |
135 | CKKSKey* newClassCKey = nil; | |
136 | ||
137 | NSMutableArray<CKRecord *>* recordsToSave = [[NSMutableArray alloc] init]; | |
138 | NSMutableArray<CKRecordID *>* recordIDsToDelete = [[NSMutableArray alloc] init]; | |
139 | ||
140 | // Find the current top local key. That's our new TLK. | |
141 | for(CKKSKey* key in keys) { | |
142 | CKKSKey* topKey = [key topKeyInAnyState: &error]; | |
143 | if(newTLK == nil) { | |
144 | newTLK = topKey; | |
145 | } else if(![newTLK.uuid isEqualToString: topKey.uuid]) { | |
146 | ckkserror("ckksheal", ckks, "key hierarchy has split: there's two top keys. Currently we don't handle this situation."); | |
147 | [ckks _onqueueAdvanceKeyStateMachineToState: SecCKKSZoneKeyStateError withError: [NSError errorWithDomain:@"securityd" | |
148 | code:0 | |
149 | userInfo:@{NSLocalizedDescriptionKey: | |
150 | [NSString stringWithFormat:@"Key hierarchy has split: %@ and %@ are roots", newTLK, topKey]}]]; | |
151 | return true; | |
152 | } | |
153 | } | |
154 | ||
155 | if(![ckks checkTLK: newTLK error: &error]) { | |
156 | // Was this error "I've never seen that TLK before in my life"? If so, enter the "wait for TLK sync" state. | |
157 | if(error && [error.domain isEqualToString: @"securityd"] && error.code == errSecItemNotFound) { | |
158 | ckksnotice("ckksheal", ckks, "Received a TLK which we don't have in the local keychain(%@). Entering waitfortlk.", newTLK); | |
159 | [ckks _onqueueAdvanceKeyStateMachineToState:SecCKKSZoneKeyStateWaitForTLK withError:nil]; | |
160 | return true; | |
161 | } else if(error && [ckks.lockStateTracker isLockedError:error]) { | |
162 | ckksnotice("ckkskey", ckks, "Received a TLK(%@), but keybag appears to be locked. Entering WaitForUnlock.", newTLK); | |
163 | [ckks _onqueueAdvanceKeyStateMachineToState:SecCKKSZoneKeyStateWaitForUnlock withError:nil]; | |
164 | return true; | |
165 | ||
166 | } else { | |
167 | // Otherwise, something has gone horribly wrong. enter error state. | |
168 | ckkserror("ckksheal", ckks, "CKKS claims %@ is not a valid TLK: %@", newTLK, error); | |
169 | NSError* newError = nil; | |
170 | if(error) { | |
171 | newError = [NSError errorWithDomain:@"securityd" | |
172 | code:0 | |
173 | userInfo:@{NSLocalizedDescriptionKey: @"invalid TLK from CloudKit", NSUnderlyingErrorKey: error}]; | |
174 | } else { | |
175 | newError = [NSError errorWithDomain:@"securityd" | |
176 | code:0 | |
177 | userInfo:@{NSLocalizedDescriptionKey: @"invalid TLK from CloudKit"}]; | |
178 | } | |
179 | [ckks _onqueueAdvanceKeyStateMachineToState:SecCKKSZoneKeyStateError withError:newError]; | |
180 | return true; | |
181 | } | |
182 | } | |
183 | ||
184 | // We have our new TLK. | |
185 | keyset.currentTLKPointer.currentKeyUUID = newTLK.uuid; | |
186 | changedCurrentTLK = true; | |
187 | ||
188 | // Find some class A and class C keys directly under this one. | |
189 | for(CKKSKey* key in keys) { | |
190 | if([key.parentKeyUUID isEqualToString: newTLK.uuid]) { | |
191 | if((keyset.currentClassAPointer.currentKeyUUID == nil || keyset.classA == nil) && | |
192 | [key.keyclass isEqualToString: SecCKKSKeyClassA]) { | |
193 | keyset.currentClassAPointer.currentKeyUUID = key.uuid; | |
194 | changedCurrentClassA = true; | |
195 | } | |
196 | ||
197 | if((keyset.currentClassCPointer.currentKeyUUID == nil || keyset.classC == nil) && | |
198 | [key.keyclass isEqualToString: SecCKKSKeyClassC]) { | |
199 | keyset.currentClassCPointer.currentKeyUUID = key.uuid; | |
200 | changedCurrentClassC = true; | |
201 | } | |
202 | } | |
203 | } | |
204 | ||
205 | if(!keyset.currentClassAPointer.currentKeyUUID) { | |
206 | newClassAKey = [CKKSKey randomKeyWrappedByParent:newTLK error:&error]; | |
207 | [newClassAKey saveKeyMaterialToKeychain:&error]; | |
208 | ||
209 | if(error) { | |
210 | ckkserror("ckksheal", ckks, "couldn't create new classA key: %@", error); | |
211 | [ckks _onqueueAdvanceKeyStateMachineToState:SecCKKSZoneKeyStateError withError:[NSError errorWithDomain: @"securityd" code:0 userInfo:@{NSLocalizedDescriptionKey: @"couldn't create new classA key", NSUnderlyingErrorKey: error}]]; | |
212 | } | |
213 | ||
214 | keyset.currentClassAPointer.currentKeyUUID = newClassAKey.uuid; | |
215 | changedCurrentClassA = true; | |
216 | } | |
217 | if(!keyset.currentClassCPointer.currentKeyUUID) { | |
218 | newClassCKey = [CKKSKey randomKeyWrappedByParent:newTLK error:&error]; | |
219 | [newClassCKey saveKeyMaterialToKeychain:&error]; | |
220 | ||
221 | if(error) { | |
222 | ckkserror("ckksheal", ckks, "couldn't create new classC key: %@", error); | |
223 | [ckks _onqueueAdvanceKeyStateMachineToState:SecCKKSZoneKeyStateError withError:[NSError errorWithDomain: @"securityd" code:0 userInfo:@{NSLocalizedDescriptionKey: @"couldn't create new classC key", NSUnderlyingErrorKey: error}]]; | |
224 | } | |
225 | ||
226 | keyset.currentClassCPointer.currentKeyUUID = newClassCKey.uuid; | |
227 | changedCurrentClassC = true; | |
228 | } | |
229 | ||
230 | // Note: we never make a new TLK here. So, don't save it back to CloudKit. | |
231 | //if(newTLK) { | |
232 | // [recordsToSave addObject: [newTLK CKRecordWithZoneID: ckks.zoneID]]; | |
233 | //} | |
234 | if(newClassAKey) { | |
235 | [recordsToSave addObject: [newClassAKey CKRecordWithZoneID: ckks.zoneID]]; | |
236 | } | |
237 | if(newClassCKey) { | |
238 | [recordsToSave addObject: [newClassCKey CKRecordWithZoneID: ckks.zoneID]]; | |
239 | } | |
240 | ||
241 | if(changedCurrentTLK) { | |
242 | [recordsToSave addObject: [keyset.currentTLKPointer CKRecordWithZoneID: ckks.zoneID]]; | |
243 | } | |
244 | if(changedCurrentClassA) { | |
245 | [recordsToSave addObject: [keyset.currentClassAPointer CKRecordWithZoneID: ckks.zoneID]]; | |
246 | } | |
247 | if(changedCurrentClassC) { | |
248 | [recordsToSave addObject: [keyset.currentClassCPointer CKRecordWithZoneID: ckks.zoneID]]; | |
249 | } | |
250 | ||
251 | ckksinfo("ckksheal", ckks, "Saving new keys %@ to cloudkit %@", recordsToSave, ckks.database); | |
252 | ||
253 | // Use the spare operation trick to wait for the CKModifyRecordsOperation to complete | |
254 | self.cloudkitModifyOperationFinished = [NSBlockOperation named:@"heal-cloudkit-modify-operation-finished" withBlock:^{}]; | |
255 | [self dependOnBeforeGroupFinished: self.cloudkitModifyOperationFinished]; | |
256 | ||
257 | CKModifyRecordsOperation* modifyRecordsOp = nil; | |
258 | ||
259 | // Get the CloudKit operation ready... | |
260 | modifyRecordsOp = [[CKModifyRecordsOperation alloc] initWithRecordsToSave:recordsToSave recordIDsToDelete:recordIDsToDelete]; | |
261 | modifyRecordsOp.atomic = YES; | |
262 | modifyRecordsOp.longLived = NO; // The keys are only in memory; mark this explicitly not long-lived | |
263 | modifyRecordsOp.timeoutIntervalForRequest = 2; | |
264 | modifyRecordsOp.qualityOfService = NSQualityOfServiceUtility; // relatively important. Use Utility. | |
265 | modifyRecordsOp.group = self.ckoperationGroup; | |
266 | ckksnotice("ckksheal", ckks, "Operation group is %@", self.ckoperationGroup); | |
267 | ||
268 | modifyRecordsOp.perRecordCompletionBlock = ^(CKRecord *record, NSError * _Nullable error) { | |
269 | __strong __typeof(weakSelf) strongSelf = weakSelf; | |
270 | __strong __typeof(strongSelf.ckks) blockCKKS = strongSelf.ckks; | |
271 | ||
272 | // These should all fail or succeed as one. Do the hard work in the records completion block. | |
273 | if(!error) { | |
274 | ckksnotice("ckksheal", blockCKKS, "Successfully completed upload for %@", record.recordID.recordName); | |
275 | } else { | |
276 | ckkserror("ckksheal", blockCKKS, "error on row: %@ %@", error, record); | |
277 | } | |
278 | }; | |
279 | ||
280 | modifyRecordsOp.modifyRecordsCompletionBlock = ^(NSArray<CKRecord *> *savedRecords, NSArray<CKRecordID *> *deletedRecordIDs, NSError *error) { | |
281 | __strong __typeof(weakSelf) strongSelf = weakSelf; | |
282 | __strong __typeof(strongSelf.ckks) strongCKKS = strongSelf.ckks; | |
283 | if(!strongSelf) { | |
284 | secerror("ckks: received callback for released object"); | |
285 | return; | |
286 | } | |
287 | ||
288 | ckksnotice("ckksheal", strongCKKS, "Completed Key Heal CloudKit operation with error: %@", error); | |
289 | ||
290 | [strongCKKS dispatchSync: ^bool{ | |
291 | if(error == nil) { | |
292 | // Success. Persist the keys to the CKKS database. | |
293 | ||
294 | // Save the new CKRecords to the before persisting to database | |
295 | for(CKRecord* record in savedRecords) { | |
296 | if([newTLK matchesCKRecord: record]) { | |
297 | newTLK.storedCKRecord = record; | |
298 | } else if([newClassAKey matchesCKRecord: record]) { | |
299 | newClassAKey.storedCKRecord = record; | |
300 | } else if([newClassCKey matchesCKRecord: record]) { | |
301 | newClassCKey.storedCKRecord = record; | |
302 | ||
303 | } else if([keyset.currentTLKPointer matchesCKRecord: record]) { | |
304 | keyset.currentTLKPointer.storedCKRecord = record; | |
305 | } else if([keyset.currentClassAPointer matchesCKRecord: record]) { | |
306 | keyset.currentClassAPointer.storedCKRecord = record; | |
307 | } else if([keyset.currentClassCPointer matchesCKRecord: record]) { | |
308 | keyset.currentClassCPointer.storedCKRecord = record; | |
309 | } | |
310 | } | |
311 | ||
312 | NSError* localerror = nil; | |
313 | ||
314 | [newTLK saveToDatabaseAsOnlyCurrentKeyForClassAndState: &localerror]; | |
315 | [newClassAKey saveToDatabaseAsOnlyCurrentKeyForClassAndState: &localerror]; | |
316 | [newClassCKey saveToDatabaseAsOnlyCurrentKeyForClassAndState: &localerror]; | |
317 | ||
318 | [keyset.currentTLKPointer saveToDatabase: &localerror]; | |
319 | [keyset.currentClassAPointer saveToDatabase: &localerror]; | |
320 | [keyset.currentClassCPointer saveToDatabase: &localerror]; | |
321 | ||
322 | if(localerror != nil) { | |
323 | ckkserror("ckksheal", strongCKKS, "couldn't save new key hierarchy to database; this is very bad: %@", localerror); | |
324 | [strongCKKS _onqueueAdvanceKeyStateMachineToState: SecCKKSZoneKeyStateError withError: localerror]; | |
325 | return false; | |
326 | } else { | |
327 | // Everything is groovy. HOWEVER, we might still not have processed the keys. Ask for that! | |
328 | [strongCKKS _onqueueKeyStateMachineRequestProcess]; | |
329 | [strongCKKS _onqueueAdvanceKeyStateMachineToState: SecCKKSZoneKeyStateReady withError: nil]; | |
330 | } | |
331 | } else { | |
332 | // ERROR. This isn't a total-failure error state, but one that should kick off a healing process. | |
333 | ckkserror("ckksheal", strongCKKS, "couldn't save new key hierarchy to CloudKit: %@", error); | |
334 | [strongCKKS _onqueueAdvanceKeyStateMachineToState: SecCKKSZoneKeyStateNewTLKsFailed withError: nil]; | |
335 | } | |
336 | return true; | |
337 | }]; | |
338 | ||
339 | // Notify that we're done | |
340 | [strongSelf.operationQueue addOperation: strongSelf.cloudkitModifyOperationFinished]; | |
341 | }; | |
342 | ||
343 | [ckks.database addOperation: modifyRecordsOp]; | |
344 | return true; | |
345 | } | |
346 | ||
347 | [keyset.tlk loadKeyMaterialFromKeychain:&error]; | |
348 | if(error && [ckks.lockStateTracker isLockedError:error]) { | |
349 | ckksnotice("ckkskey", ckks, "Failed to load TLK from keychain, keybag is locked. Entering WaitForUnlock: %@", error); | |
350 | [ckks _onqueueAdvanceKeyStateMachineToState:SecCKKSZoneKeyStateWaitForUnlock withError:nil]; | |
351 | return false; | |
352 | } else if(error) { | |
353 | ckkserror("ckksheal", ckks, "No TLK in keychain, triggering move to bad state: %@", error); | |
354 | [ckks _onqueueAdvanceKeyStateMachineToState: SecCKKSZoneKeyStateWaitForTLK withError: nil]; | |
355 | return false; | |
356 | } | |
357 | ||
358 | if(![self ensureKeyPresent:keyset.classA]) { | |
359 | return false; | |
360 | } | |
361 | ||
362 | if(![self ensureKeyPresent:keyset.classC]) { | |
363 | return false; | |
364 | } | |
365 | ||
366 | // Seems good to us. Check if we're ready? | |
367 | [ckks _onqueueAdvanceKeyStateMachineToState: SecCKKSZoneKeyStateReady withError: nil]; | |
368 | ||
369 | return true; | |
370 | }]; | |
371 | } | |
372 | ||
373 | - (bool)ensureKeyPresent:(CKKSKey*)key { | |
374 | NSError* error = nil; | |
375 | CKKSKeychainView* ckks = self.ckks; | |
376 | ||
377 | [key loadKeyMaterialFromKeychain:&error]; | |
378 | if(error) { | |
379 | ckkserror("ckksheal", ckks, "Couldn't load classC key from keychain. Attempting recovery: %@", error); | |
380 | error = nil; | |
381 | [key unwrapViaKeyHierarchy: &error]; | |
382 | if(error) { | |
383 | ckkserror("ckksheal", ckks, "Couldn't unwrap class C key using key hierarchy. Keys are broken, quitting: %@", error); | |
384 | [ckks _onqueueAdvanceKeyStateMachineToState: SecCKKSZoneKeyStateError withError: error]; | |
385 | self.error = error; | |
386 | return false; | |
387 | } | |
388 | [key saveKeyMaterialToKeychain:&error]; | |
389 | if(error) { | |
390 | ckkserror("ckksheal", ckks, "Couldn't save class C key to keychain: %@", error); | |
391 | [ckks _onqueueAdvanceKeyStateMachineToState: SecCKKSZoneKeyStateError withError: error]; | |
392 | self.error = error; | |
393 | return false; | |
394 | } | |
395 | } | |
396 | return true; | |
397 | } | |
398 | ||
399 | - (void)cancel { | |
400 | [self.cloudkitModifyOperationFinished cancel]; | |
401 | [super cancel]; | |
402 | } | |
403 | ||
404 | @end; | |
405 | ||
406 | #endif |