OSX/sec/securityd/SecDbBackupManager.m

   1 /*
   2  * Copyright (c) 2018 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 "SecDbBackupManager.h"
  25
  26 NSString* const KeychainBackupsErrorDomain = @"com.apple.security.keychain.backups";
  27
  28 // oink oink
  29 @implementation SecDbBackupWrappedItemKey
  30 + (BOOL)supportsSecureCoding {
  31     return YES;
  32 }
  33 - (void)encodeWithCoder:(nonnull NSCoder *)coder {
  34     [coder encodeObject:self.wrappedKey forKey:@"wrappedKey"];
  35     [coder encodeObject:self.baguuid forKey:@"baguuid"];
  36 }
  37
  38 - (nullable instancetype)initWithCoder:(nonnull NSCoder *)coder {
  39     if (self = [super init]) {
  40         _wrappedKey = [coder decodeObjectOfClass:[NSData class] forKey:@"wrappedKey"];
  41         _baguuid = [coder decodeObjectOfClass:[NSData class] forKey:@"baguuid"];
  42     }
  43     return self;
  44 }
  45 @end
  46
  47 #if !SECDB_BACKUPS_ENABLED
  48
  49 @implementation SecDbBackupManager
  50
  51 + (instancetype)manager
  52 {
  53     return nil;
  54 }
  55
  56 - (void)verifyBackupIntegrity:(bool)lightweight
  57                    completion:(void (^)(NSDictionary<NSString*, NSString*>* results, NSError* _Nullable error))completion
  58 {
  59     completion(nil, [NSError errorWithDomain:KeychainBackupsErrorDomain
  60                                         code:SecDbBackupNotSupported
  61                                     userInfo:@{NSLocalizedDescriptionKey : @"platform doesn't do backups"}]);
  62 }
  63
  64 - (SecDbBackupWrappedItemKey* _Nullable)wrapItemKey:(id)key forKeyclass:(keyclass_t)keyclass error:(NSError**)error
  65 {
  66     return nil;
  67 }
  68
  69 @end
  70
  71 bool SecDbBackupCreateOrLoadBackupInfrastructure(CFErrorRef* error)
  72 {
  73     return true;
  74 }
  75
  76 #else   // SECDB_BACKUPS_ENABLED is true, roll out the code
  77
  78 #import "SecDbBackupManager_Internal.h"
  79 #include <CommonCrypto/CommonRandom.h>
  80 #import <Foundation/NSData_Private.h>
  81 #import "SecItemServer.h"
  82 #import "SecItemDb.h"
  83 #import "keychain/categories/NSError+UsefulConstructors.h"
  84 #import "sec_action.h"
  85 #import "SecItemServer.h"
  86 #include "utilities/der_plist.h"
  87
  88 // TODO: fire off metric on outcome
  89 bool SecDbBackupCreateOrLoadBackupInfrastructure(CFErrorRef* error)
  90 {
  91     NSError* localError;
  92     bool ok = [[SecDbBackupManager manager] createOrLoadBackupInfrastructure:&localError];
  93     if (!ok) {
  94         // Translate this to intelligible constant in C, but other errors can be passed along
  95         if (localError.code == SecDbBackupKeychainLocked) {
  96             *error = CFErrorCreate(kCFAllocatorDefault, kSecErrorDomain, errSecInteractionNotAllowed, NULL);
  97         } else {
  98             *error = (CFErrorRef)CFBridgingRetain(localError);
  99         }
 100     }
 101     return ok;
 102 }
 103
 104 // Reading from disk is relatively expensive. Keep wrapped key in memory and just delete the unwrapped copy on lock
 105 @interface InMemoryKCSK : NSObject
 106 @property aks_ref_key_t refKey;
 107 @property (nonatomic) NSData* wrappedKey;
 108 @property (nonatomic) SFECKeyPair* key;
 109 @end
 110
 111 @implementation InMemoryKCSK
 112 - (void)dealloc
 113 {
 114     if (_refKey) {
 115         free(_refKey);
 116     }
 117 }
 118
 119 + (instancetype)kcskWithRefKey:(aks_ref_key_t)refKey wrappedKey:(NSData*)wrappedKey key:(SFECKeyPair*)key
 120 {
 121     InMemoryKCSK* kcsk = [InMemoryKCSK new];
 122     kcsk.refKey = refKey;
 123     kcsk.wrappedKey = wrappedKey;
 124     kcsk.key = key;
 125     return kcsk;
 126 }
 127
 128 @end
 129
 130 @interface SecDbBackupManager () {
 131     dispatch_queue_t _queue;
 132     keybag_handle_t _handle;
 133     SecDbBackupBagIdentity* _bagIdentity;
 134     NSMutableDictionary<NSNumber*, InMemoryKCSK*>* _cachedKCSKs;
 135 }
 136 @end
 137
 138 @implementation SecDbBackupManager
 139
 140 #pragma mark - Misc Helpers
 141
 142 - (NSData*)getSHA256OfData:(NSData*)data
 143 {
 144     NSMutableData* digest = [[NSMutableData alloc] initWithLength:CC_SHA512_DIGEST_LENGTH];
 145     if (!CC_SHA512(data.bytes, (CC_LONG)data.length, digest.mutableBytes)) {
 146         return nil;
 147     }
 148     return digest;
 149 }
 150
 151 - (void)setBagIdentity:(SecDbBackupBagIdentity *)bagIdentity
 152 {
 153     _bagIdentity = bagIdentity;
 154 }
 155
 156 - (SecDbBackupBagIdentity*)bagIdentity
 157 {
 158     return _bagIdentity;
 159 }
 160
 161 - (bool)fillError:(NSError**)error code:(enum SecDbBackupErrorCode)code underlying:(NSError*)underlying description:(NSString*)format, ... NS_FORMAT_FUNCTION(4, 5)
 162 {
 163     if (error) {
 164         va_list ap;
 165         va_start(ap, format);
 166         NSString* desc = [[NSString alloc] initWithFormat:format arguments:ap];
 167         va_end(ap);
 168         if (underlying) {
 169             *error = [NSError errorWithDomain:KeychainBackupsErrorDomain code:code description:desc underlying:underlying];
 170         } else {
 171             *error = [NSError errorWithDomain:KeychainBackupsErrorDomain code:code description:desc];
 172         }
 173     }
 174
 175     // analyzer gets upset when a method taking an error** doesn't return a value
 176     return true;
 177 }
 178
 179 static SecDbBackupManager* staticManager;
 180 + (instancetype)manager
 181 {
 182     static dispatch_once_t onceToken;
 183     dispatch_once(&onceToken, ^{
 184         staticManager = [SecDbBackupManager new];
 185     });
 186     return staticManager;
 187 }
 188
 189 // Testing only please
 190 + (void)resetManager
 191 {
 192     if (staticManager) {
 193         staticManager = [SecDbBackupManager new];
 194     }
 195 }
 196
 197 - (instancetype)init
 198 {
 199     if (!checkV12DevEnabled()) {
 200         return nil;
 201     }
 202     if (self = [super init]) {
 203         _queue = dispatch_queue_create("com.apple.security.secdbbackupmanager", DISPATCH_QUEUE_SERIAL_WITH_AUTORELEASE_POOL);
 204         _handle = bad_keybag_handle;
 205         _cachedKCSKs = [NSMutableDictionary new];
 206     }
 207     return self;
 208 }
 209
 210 - (SFECKeyPair*)getECKeyPairFromDERBytes:(void*)bytes length:(size_t)len error:(NSError**)error
 211 {
 212     if (!bytes || len == 0) {
 213         [self fillError:error code:SecDbBackupInvalidArgument underlying:nil description:@"Need valid byte buffer to make EC keypair from"];
 214         return nil;
 215     }
 216     CFTypeRef cftype = NULL;
 217     CFErrorRef cferr = NULL;
 218     const uint8_t* derp = der_decode_plist(kCFAllocatorDefault, NSPropertyListImmutable, &cftype, &cferr, bytes, bytes + len);
 219     free(bytes);
 220     if (derp == NULL || derp != (bytes + len) || cftype == NULL) {
 221         [self fillError:error code:SecDbBackupMalformedKCSKDataOnDisk underlying:CFBridgingRelease(cferr) description:@"Unable to parse der data"];
 222         return nil;
 223     }
 224
 225     return [[SFECKeyPair alloc] initWithData:(__bridge_transfer NSData*)cftype
 226                                    specifier:[[SFECKeySpecifier alloc] initWithCurve:SFEllipticCurveNistp384]
 227                                        error:error];
 228 }
 229
 230 #pragma mark - Fixup And Verification
 231
 232 - (void)verifyBackupIntegrity:(bool)lightweight
 233                    completion:(void (^)(NSDictionary<NSString*, NSString*>* _Nonnull, NSError * _Nullable))completion
 234 {
 235     NSError* error = nil;
 236     completion(@{@"summary" : @"Unimplemented"}, error);
 237 }
 238
 239 #pragma mark - Backup Bag Management
 240
 241 // Get the bag's UUID from AKS and the hash from provided data. This must always be the original bag's data
 242 - (SecDbBackupBagIdentity*)bagIdentityWithHandle:(keybag_handle_t)handle data:(NSData*)data error:(NSError**)error {
 243     assert(data);
 244     secnotice("SecDbBackup", "Getting bag identity");
 245     SecDbBackupBagIdentity* identity = [SecDbBackupBagIdentity new];
 246
 247     uuid_t uuid = {0};
 248     kern_return_t aksResult = aks_get_bag_uuid(handle, uuid);
 249     if (aksResult != kAKSReturnSuccess) {
 250         [self fillError:error code:SecDbBackupAKSFailure underlying:nil description:@"Unable to get keybag UUID (%d)", aksResult];
 251         return nil;
 252     }
 253     identity.baguuid = [NSData dataWithBytes:uuid length:16];
 254
 255     NSData* digest = [self getSHA256OfData:data];
 256     if (!digest) {
 257         [self fillError:error code:SecDbBackupCryptoFailure underlying:nil description:@"CC_SHA512 returned failure, can't get bag hash"];
 258         return nil;
 259     }
 260     identity.baghash = digest;
 261
 262     secnotice("SecDbBackup", "Obtained bag identity: %@", identity);
 263
 264     return identity;
 265 }
 266
 267 - (NSData*)createBackupBagSecret:(NSError**)error
 268 {
 269     uint8_t* data = calloc(1, BACKUPBAG_PASSPHRASE_LENGTH);
 270     if (!data) {
 271         return nil;     // Good luck allocating an error message
 272     }
 273
 274     CCRNGStatus rngResult = CCRandomGenerateBytes(data, BACKUPBAG_PASSPHRASE_LENGTH);
 275     if (rngResult != kCCSuccess) {
 276         [self fillError:error code:SecDbBackupCryptoFailure underlying:nil description:@"Unable to generate random bytes (%d)", rngResult];
 277         return nil;
 278     }
 279
 280     NSData* secret = [NSData _newZeroingDataWithBytesNoCopy:data length:BACKUPBAG_PASSPHRASE_LENGTH deallocator:NSDataDeallocatorNone];
 281     return secret;
 282 }
 283
 284 - (keybag_handle_t)onQueueCreateBackupBagWithSecret:(NSData*)secret error:(NSError**)error
 285 {
 286     dispatch_assert_queue(_queue);
 287
 288     keybag_handle_t handle = bad_keybag_handle;
 289     kern_return_t aksresult = aks_create_bag(secret.bytes, BACKUPBAG_PASSPHRASE_LENGTH, kAppleKeyStoreAsymmetricBackupBag, &handle);
 290     if (aksresult != kAKSReturnSuccess) {
 291         [self fillError:error code:SecDbBackupAKSFailure underlying:nil description:@"Unable to create keybag (%d)", aksresult];
 292         return bad_keybag_handle;
 293     }
 294
 295     // Make secret keys unavailable. Causes pubkeys to be destroyed so reload bag before use
 296     aksresult = aks_lock_bag(handle);
 297     if (aksresult != kAKSReturnSuccess) {   // This would be rather surprising
 298         [self fillError:error code:SecDbBackupAKSFailure underlying:nil description:@"Unable to lock keybag (%d)", aksresult];
 299         aks_unload_bag(handle);
 300         return bad_keybag_handle;
 301     }
 302
 303     return handle;
 304 }
 305
 306 - (BOOL)onQueueInTransaction:(SecDbConnectionRef)dbt saveBackupBag:(keybag_handle_t)handle asDefault:(BOOL)asDefault error:(NSError**)error
 307 {
 308     dispatch_assert_queue(_queue);
 309
 310     void* buf = NULL;
 311     int buflen = 0;
 312     kern_return_t aksResult = aks_save_bag(handle, &buf, &buflen);
 313     if (aksResult != kAKSReturnSuccess) {
 314         [self fillError:error code:SecDbBackupAKSFailure underlying:nil description:@"Unable to serialize keybag (%d)", aksResult];
 315         return NO;
 316     }
 317     NSData* bagData = [NSData dataWithBytesNoCopy:buf length:buflen];
 318
 319     SecDbBackupBagIdentity* bagIdentity = [self bagIdentityWithHandle:handle data:bagData error:error];
 320     if (!bagIdentity) {
 321         return NO;
 322     }
 323     SecDbBackupBag* bag = [SecDbBackupBag new];
 324     bag.bagIdentity = bagIdentity;
 325     bag.keybag = bagData;
 326
 327     __block CFErrorRef cfError = NULL;
 328     __block bool ok = true;
 329     if (asDefault) {
 330         ok &= SecDbPrepare(dbt, CFSTR("UPDATE backupbags SET defaultvalue = 0 WHERE defaultvalue = 1"), &cfError, ^(sqlite3_stmt *stmt) {
 331             ok &= SecDbStep(dbt, stmt, &cfError, ^(bool *stop) {
 332                 // FIXME: Should this be an error? Should something else happen?
 333                 secwarning("SecDbBackup: Marking existing bag as non-default");
 334             });
 335         });
 336     }
 337     if (!ok) {
 338         return ok;
 339     }
 340     ok &= SecDbPrepare(dbt, CFSTR("INSERT INTO backupbags (backupUUID, backupbag, defaultvalue) VALUES (?,?,?)"), &cfError, ^(sqlite3_stmt *stmt) {
 341         ok &= SecDbBindObject(stmt, 1, (__bridge CFDataRef)bag.bagIdentity.baguuid, &cfError);
 342         ok &= SecDbBindObject(stmt, 2, (__bridge CFDataRef)bag.data, &cfError);
 343         ok &= SecDbBindInt(stmt, 3, asDefault ? 1 : 0, &cfError);
 344         ok &= SecDbStep(dbt, stmt, &cfError, NULL);
 345     });
 346
 347     if (!ok) {
 348         secerror("SecDbBackup: unable to save keybag to disk: %@", cfError);
 349         [self fillError:error code:SecDbBackupWriteFailure underlying:CFBridgingRelease(cfError) description:@"Unable to save keybag to disk"];
 350     }
 351
 352     return ok;
 353 }
 354
 355 - (keybag_handle_t)onQueueLoadBackupBag:(NSUUID*)uuid error:(NSError**)error {
 356     dispatch_assert_queue(_queue);
 357
 358     secnotice("SecDbBackup", "Attempting to load backup bag from disk");
 359
 360     __block CFErrorRef localErr = NULL;
 361     __block bool ok = true;
 362     __block NSData* readUUID;
 363     __block NSData* readBagData;
 364     __block unsigned found = 0;
 365     ok &= kc_with_dbt_non_item_tables(false, &localErr, ^bool(SecDbConnectionRef dbt) {
 366         NSString* sql = [NSString stringWithFormat:@"SELECT backupUUID, backupbag FROM backupbags WHERE %@", uuid ? @"backupUUID = ?" : @"defaultvalue = 1"];
 367         ok &= SecDbPrepare(dbt, (__bridge CFStringRef)sql, &localErr, ^(sqlite3_stmt *stmt) {
 368             if (uuid) {
 369                 unsigned char uuidbytes[UUIDBYTESLENGTH] = {0};
 370                 [uuid getUUIDBytes:uuidbytes];
 371                 ok &= SecDbBindBlob(stmt, 1, uuidbytes, UUIDBYTESLENGTH, SQLITE_TRANSIENT, &localErr);
 372             }
 373             ok &= SecDbStep(dbt, stmt, &localErr, ^(bool *stop) {
 374                 if (found > 0) {        // For uuids this should have violated constraints
 375                     secerror("Encountered more than one backup bag by %@", uuid ? @"backupUUID" : @"defaultvalue");
 376                     *stop = true;
 377                 }
 378                 readUUID = [[NSData alloc] initWithBytes:sqlite3_column_blob(stmt, 0) length:sqlite3_column_bytes(stmt, 0)];
 379                 readBagData = [[NSData alloc] initWithBytes:sqlite3_column_blob(stmt, 1) length:sqlite3_column_bytes(stmt, 1)];
 380                 ++found;
 381             });
 382         });
 383         return ok;
 384     });
 385
 386     if (!ok) {
 387         secerror("SecDbBackup: Unable to load backup bag from disk: %@", localErr);
 388         [self fillError:error code:SecDbBackupWriteFailure underlying:CFBridgingRelease(localErr) description:@"Unable to load backup bag from disk"];
 389         return bad_keybag_handle;
 390     }
 391
 392     if (!found) {
 393         [self fillError:error code:SecDbBackupNoBackupBagFound underlying:nil description:@"No backup bag found to load from disk"];
 394         return bad_keybag_handle;
 395     } else if (found > 1) {
 396         [self fillError:error
 397                    code:uuid ? SecDbBackupDuplicateBagFound : SecDbBackupMultipleDefaultBagsFound
 398              underlying:nil
 399                 description:@"More than one backup bag found"];
 400         return bad_keybag_handle;
 401     }
 402
 403     if (!readUUID ||  readUUID.length != UUIDBYTESLENGTH || !readBagData || !readBagData.length) {
 404         [self fillError:error code:SecDbBackupMalformedBagDataOnDisk underlying:nil description:@"bags read from disk malformed"];
 405         return bad_keybag_handle;
 406     }
 407
 408     SecDbBackupBag* readBag = [[SecDbBackupBag alloc] initWithData:readBagData];
 409     if (!readBag) {
 410         [self fillError:error code:SecDbBackupDeserializationFailure underlying:nil description:@"bag from disk does not deserialize"];
 411         return bad_keybag_handle;
 412     }
 413
 414     secnotice("SecDbBackup", "Successfully read backup bag from disk; loading and verifying. Read bag ID: %@", readBag.bagIdentity);
 415
 416     keybag_handle_t handle = bad_keybag_handle;
 417     kern_return_t aksResult = aks_load_bag(readBag.keybag.bytes, (int)readBag.keybag.length, &handle);
 418     if (aksResult != kAKSReturnSuccess) {
 419         [self fillError:error code:SecDbBackupAKSFailure underlying:nil description:@"Unable to load bag from disk (%d)", aksResult];
 420         return bad_keybag_handle;
 421     }
 422
 423     SecDbBackupBagIdentity* loadedID = [self bagIdentityWithHandle:handle data:readBag.keybag error:error];
 424     if (!loadedID) {
 425         aks_unload_bag(handle);
 426         return bad_keybag_handle;
 427     }
 428
 429     if (memcmp(loadedID.baguuid.bytes, readBag.bagIdentity.baguuid.bytes, UUIDBYTESLENGTH) ||
 430         memcmp(loadedID.baguuid.bytes, readUUID.bytes, UUIDBYTESLENGTH)) {
 431         [self fillError:error code:SecDbBackupUUIDMismatch underlying:nil description:@"Loaded UUID does not match UUIDs on disk"];
 432         aks_unload_bag(handle);
 433         return bad_keybag_handle;
 434     }
 435
 436     if (memcmp(loadedID.baghash.bytes, readBag.bagIdentity.baghash.bytes, CC_SHA512_DIGEST_LENGTH)) {
 437         [self fillError:error code:SecDbBackupDeserializationFailure underlying:nil description:@"Keybag hash does not match its identity's hash"];
 438         return bad_keybag_handle;
 439     }
 440
 441     // TODO: verify that bag is still signed, rdar://problem/46702467
 442
 443     secnotice("SecDbBackup", "Backup bag loaded and verified.");
 444
 445     // Must load readBag's identity because the hash from AKS is unstable.
 446     // This is the hash of the original saved bag and is anchored in the KCSKes.
 447     _bagIdentity = readBag.bagIdentity;
 448
 449     return handle;
 450 }
 451
 452 - (BOOL)onQueueReloadDefaultBackupBagWithError:(NSError**)error
 453 {
 454     if (_handle != bad_keybag_handle) {
 455         aks_unload_bag(_handle);
 456     }
 457
 458     _handle = [self onQueueLoadBackupBag:nil error:error];
 459     return _handle != bad_keybag_handle;
 460 }
 461
 462 #pragma mark - KCSK Management
 463
 464 - (SecDbBackupKeyClassSigningKey*)createKCSKForKeyClass:(keyclass_t)class withWrapper:(SFAESKey*)wrapper error:(NSError**)error
 465 {
 466     if (!wrapper) {
 467         [self fillError:error code:SecDbBackupInvalidArgument underlying:nil description:@"Need wrapper for KCSK"];
 468         return nil;
 469     }
 470
 471     SecDbBackupKeyClassSigningKey* kcsk = [SecDbBackupKeyClassSigningKey new];
 472     kcsk.keyClass = class;
 473
 474     SFECKeyPair* keypair = [[SFECKeyPair alloc] initRandomKeyPairWithSpecifier:[[SFECKeySpecifier alloc] initWithCurve:SFEllipticCurveNistp384]];
 475     kcsk.publicKey = [keypair.publicKey.keyData copy];
 476
 477     // Create a DER-encoded dictionary of bag identity
 478     void* der_blob;
 479     size_t der_len;
 480     CFErrorRef cfErr = NULL;
 481     NSDictionary* identDict = @{@"baguuid" : _bagIdentity.baguuid, @"baghash" : _bagIdentity.baghash};
 482     NSData* identData = (__bridge_transfer NSData*)CFPropertyListCreateDERData(NULL, (__bridge CFDictionaryRef)identDict, &cfErr);
 483     aks_operation_optional_params(NULL, 0, identData.bytes, identData.length, NULL, 0, &der_blob, &der_len);
 484
 485     // Create ref key with embedded bag identity DER data
 486     aks_ref_key_t refkey = NULL;
 487     kern_return_t aksResult = aks_ref_key_create(KEYBAG_DEVICE, class, key_type_sym, der_blob, der_len, &refkey);
 488     free(der_blob);
 489     if (aksResult != kAKSReturnSuccess) {
 490         [self fillError:error code:SecDbBackupAKSFailure underlying:nil
 491             description:@"Unable to create AKS ref key for KCSK class %d: %d", class, aksResult];
 492         return nil;
 493     }
 494
 495     size_t refkeyblobsize = 0;
 496     const uint8_t* refkeyblob = aks_ref_key_get_blob(refkey, &refkeyblobsize);
 497     kcsk.aksRefKey = [NSData dataWithBytes:refkeyblob length:refkeyblobsize];
 498
 499     size_t wrappedKeyLen = 0;
 500     void* wrappedKey = NULL;
 501     NSData* keypairAsData = keypair.keyData;
 502     aksResult = aks_ref_key_encrypt(refkey, NULL, 0, keypairAsData.bytes, keypairAsData.length, &wrappedKey, &wrappedKeyLen);
 503     if (aksResult != kAKSReturnSuccess) {
 504         [self fillError:error code:SecDbBackupAKSFailure underlying:nil
 505             description:@"Unable to encrypt KCSK class %d with AKS ref key: %d", class, aksResult];
 506         return nil;
 507     }
 508     aks_ref_key_free(&refkey);
 509     kcsk.aksWrappedKey = [NSData dataWithBytesNoCopy:wrappedKey length:wrappedKeyLen];
 510
 511     // Also add DER-encoded bag identity here
 512     SFAuthenticatedEncryptionOperation* op = [[SFAuthenticatedEncryptionOperation alloc] initWithKeySpecifier:[[SFAESKeySpecifier alloc] initWithBitSize:SFAESKeyBitSize256]];
 513     SFAuthenticatedCiphertext* backupwrapped = [op encrypt:keypair.keyData withKey:wrapper additionalAuthenticatedData:identData error:error];
 514     kcsk.backupWrappedKey = [NSKeyedArchiver archivedDataWithRootObject:backupwrapped requiringSecureCoding:YES error:error];
 515     if (!kcsk.backupWrappedKey) {
 516         return nil;
 517     }
 518
 519     return kcsk;
 520 }
 521
 522 - (BOOL)inTransaction:(SecDbConnectionRef)dbt writeKCSKToKeychain:(SecDbBackupKeyClassSigningKey*)kcsk error:(NSError**)error
 523 {
 524     __block bool ok = true;
 525     __block CFErrorRef cfError = NULL;
 526     NSString* sql = @"INSERT INTO backupkeyclasssigningkeys (keyclass, backupUUID, signingkey) VALUES (?, ?, ?)";
 527     ok &= SecDbPrepare(dbt, (__bridge CFStringRef)sql, &cfError, ^(sqlite3_stmt *stmt) {
 528         ok &= SecDbBindInt(stmt, 1, kcsk.keyClass, &cfError);
 529         ok &= SecDbBindObject(stmt, 2, (__bridge CFTypeRef)(self->_bagIdentity.baguuid), &cfError);
 530         ok &= SecDbBindObject(stmt, 3, (__bridge CFTypeRef)(kcsk.data), &cfError);
 531         ok &= SecDbStep(dbt, stmt, &cfError, NULL);
 532     });
 533
 534     if (!ok) {
 535         secerror("SecDbBackup: Unable to write KCSK for class %d to keychain: %@", kcsk.keyClass, cfError);
 536         [self fillError:error code:SecDbBackupWriteFailure underlying:CFBridgingRelease(cfError) description:@"Unable to write KCSK for class %d to keychain", kcsk.keyClass];
 537     }
 538
 539     return ok;
 540 }
 541
 542 - (InMemoryKCSK*)onQueueReadKCSKFromDiskForClass:(keyclass_t)keyclass error:(NSError**)error
 543 {
 544     __block bool ok = true;
 545     __block CFErrorRef cfError = NULL;
 546     __block NSData* readUUID;
 547     __block NSData* readKCSK;
 548     NSString* sql = @"SELECT backupUUID, signingkey FROM backupkeyclasssigningkeys WHERE keyclass = ?";
 549     ok &= kc_with_dbt_non_item_tables(NO, &cfError, ^bool(SecDbConnectionRef dbt) {
 550         ok &= SecDbPrepare(dbt, (__bridge CFStringRef)sql, &cfError, ^(sqlite3_stmt *stmt) {
 551             ok &= SecDbBindInt(stmt, 1, keyclass, &cfError);
 552             ok &= SecDbStep(dbt, stmt, &cfError, ^(bool *stop) {
 553                 readUUID = [[NSData alloc] initWithBytes:sqlite3_column_blob(stmt, 0) length:sqlite3_column_bytes(stmt, 0)];
 554                 readKCSK = [[NSData alloc] initWithBytes:sqlite3_column_blob(stmt, 1) length:sqlite3_column_bytes(stmt, 1)];
 555             });
 556         });
 557         return ok;
 558     });
 559     if (!readKCSK || !readUUID) {
 560         [self fillError:error code:SecDbBackupNoKCSKFound underlying:nil description:@"KCSK for class %d not on disk", keyclass];
 561         return nil;
 562     }
 563
 564     SecDbBackupKeyClassSigningKey* kcsk = [[SecDbBackupKeyClassSigningKey alloc] initWithData:readKCSK];
 565     if (!kcsk) {
 566         [self fillError:error code:SecDbBackupMalformedKCSKDataOnDisk underlying:nil description:@"Retrieved KCSK blob but it didn't become a KCSK"];
 567         return nil;
 568     }
 569
 570     aks_ref_key_t refkey = NULL;
 571     kern_return_t aksResult = aks_ref_key_create_with_blob(KEYBAG_DEVICE, kcsk.aksRefKey.bytes, kcsk.aksRefKey.length, &refkey);
 572     if (aksResult != kAKSReturnSuccess) {
 573         [self fillError:error
 574                    code:SecDbBackupAKSFailure
 575              underlying:nil
 576             description:@"Failed to create refkey from KCSK blob for class %d: %d", keyclass, aksResult];
 577         return nil;
 578     }
 579
 580     size_t externalDataLen = 0;
 581     const uint8_t* externalData = aks_ref_key_get_external_data(refkey, &externalDataLen);
 582     NSData* derBagIdent = [NSData dataWithBytes:externalData length:externalDataLen];
 583     CFErrorRef cfErr = NULL;
 584     NSDictionary* identData = (__bridge_transfer NSDictionary*)CFPropertyListCreateWithDERData(NULL, (__bridge CFDataRef)derBagIdent, 0, NULL, &cfErr);
 585     if (!identData || ![_bagIdentity.baghash isEqualToData:identData[@"baghash"]] || ![_bagIdentity.baguuid isEqualToData:identData[@"baguuid"]]) {
 586         secerror("SecDbBackup: KCSK ref key embedded bag identity does not match loaded bag. %@ vs %@", identData, _bagIdentity);
 587         [self fillError:error code:SecDbBackupMalformedKCSKDataOnDisk underlying:CFBridgingRelease(cfErr) description:@"KCSK ref key embedded bag identity does not match loaded bag."];
 588         return nil;
 589     }
 590
 591     // AKS refkey claims in its external data to belong to our backup bag. Let's see if the claim holds up: use the key.
 592     void* keypairBytes = NULL;
 593     size_t keypairLength = 0;
 594     aksResult = aks_ref_key_decrypt(refkey, NULL, 0, kcsk.aksWrappedKey.bytes, kcsk.aksWrappedKey.length, &keypairBytes, &keypairLength);
 595     if (aksResult == kSKSReturnNoPermission) {
 596         [self fillError:error code:SecDbBackupKeychainLocked underlying:nil description:@"Unable to unwrap KCSK private key for class %d. Locked", keyclass];
 597         return nil;
 598     } else if (aksResult != kAKSReturnSuccess) {
 599         // Failure could indicate key was corrupted or tampered with
 600         [self fillError:error
 601                    code:SecDbBackupAKSFailure
 602              underlying:nil
 603             description:@"AKS did not unwrap KCSK private key for class %d: %d", keyclass, aksResult];
 604         return nil;
 605     }
 606
 607     SFECKeyPair* keypair = [self getECKeyPairFromDERBytes:keypairBytes length:keypairLength error:error];
 608     return keypair ? [InMemoryKCSK kcskWithRefKey:refkey wrappedKey:kcsk.aksWrappedKey key:keypair] : nil;
 609 }
 610
 611 - (SFECKeyPair*)onQueueFetchKCSKForKeyclass:(keyclass_t)keyclass error:(NSError**)error
 612 {
 613     assert(error);
 614     assert(_bagIdentity);
 615     assert(_handle != bad_keybag_handle);
 616
 617     InMemoryKCSK* cached = _cachedKCSKs[@(keyclass)];
 618     if (cached.key) {
 619         return cached.key;
 620     }
 621
 622     if (cached) {
 623         secnotice("SecDbBackup", "Cached but wrapped KCSK found for class %d, unwrapping", keyclass);
 624         void* keybytes = NULL;
 625         size_t keylen = 0;
 626         kern_return_t aksResult = aks_ref_key_decrypt(cached.refKey, NULL, 0, cached.wrappedKey.bytes, cached.wrappedKey.length, &keybytes, &keylen);
 627         if (aksResult == kAKSReturnSuccess) {
 628             cached.key = [self getECKeyPairFromDERBytes:keybytes length:keylen error:error];
 629             return cached.key;
 630         } else {
 631             secerror("SecDbBackup: Cached KCSK isn't unwrapping key material. This is a bug.");
 632         }
 633     }
 634
 635     secnotice("SecDbBackup", "No cached KCSK for class %d, reading from disk", keyclass);
 636     cached = [self onQueueReadKCSKFromDiskForClass:keyclass error:error];
 637     if (!cached.key) {
 638         secerror("SecDbBackup: Failed to obtain KCSK for class %d: %@", keyclass, *error);
 639         if ((*error).code != SecDbBackupKeychainLocked) {
 640             seccritical("SecDbBackup: KCSK unavailable, cannot backup-wrap class %d items. Need to perform recovery.", keyclass);
 641             // TODO: We're borked. Need to recover from this.
 642         }
 643     }
 644     _cachedKCSKs[@(keyclass)] = cached;
 645     return cached.key;
 646 }
 647
 648 #pragma mark - Recovery Set Management
 649
 650 - (BOOL)onQueueInTransaction:(SecDbConnectionRef)dbt writeRecoverySetToKeychain:(SecDbBackupRecoverySet*)set error:(NSError**)error
 651 {
 652     dispatch_assert_queue(_queue);
 653     __block bool ok = true;
 654     __block CFErrorRef cfError = NULL;
 655
 656     NSString* sql = @"INSERT INTO backuprecoverysets (backupUUID, recoverytype, recoveryset) VALUES (?, ?, ?)";
 657     ok &= SecDbPrepare(dbt, (__bridge CFStringRef)sql, &cfError, ^(sqlite3_stmt *stmt) {
 658         ok &= SecDbBindObject(stmt, 1, (__bridge CFDataRef)set.bagIdentity.baguuid, &cfError);
 659         ok &= SecDbBindObject(stmt, 2, (__bridge CFNumberRef)@(set.recoveryType), &cfError);
 660         ok &= SecDbBindObject(stmt, 3, (__bridge CFDataRef)set.data, &cfError);
 661         ok &= SecDbStep(dbt, stmt, &cfError, NULL);
 662     });
 663
 664     if (!ok) {
 665         secerror("SecDbBackup: Unable to write recovery set to keychain: %@", cfError);
 666         [self fillError:error code:SecDbBackupWriteFailure underlying:CFBridgingRelease(cfError) description:@"Unable to write recovery set to keychain"];
 667     }
 668
 669     return ok;
 670 }
 671
 672 - (SecDbBackupRecoverySet*)onQueueInTransaction:(SecDbConnectionRef)dbt createRecoverySetWithBagSecret:(NSData*)secret
 673                      forType:(SecDbBackupRecoveryType)type error:(NSError**)error
 674 {
 675     dispatch_assert_queue(_queue);
 676     if (!secret) {
 677         [self fillError:error code:SecDbBackupInvalidArgument underlying:nil description:@"Can't create recovery set without secret"];
 678         return nil;
 679     }
 680
 681     SecDbBackupRecoverySet* set;
 682     switch (type) {
 683         case SecDbBackupRecoveryTypeAKS:
 684             set = [self inTransaction:dbt createAKSTypeRecoverySetWithBagSecret:secret handle:_handle error:error];
 685             break;
 686         case SecDbBackupRecoveryTypeCylon:
 687             secerror("SecDbBackup: Cylon recovery type not yet implemented");
 688             [self fillError:error code:SecDbBackupUnknownOption underlying:nil description:@"Recovery type Cylon not yet implemented"];
 689             break;
 690         case SecDbBackupRecoveryTypeRecoveryKey:
 691             secerror("SecDbBackup: RecoveryKey recovery type not yet implemented");
 692             [self fillError:error code:SecDbBackupUnknownOption underlying:nil description:@"Recovery type RecoveryKey not yet implemented"];
 693             break;
 694         default:
 695             secerror("SecDbBackup: Unknown type %ld", (long)type);
 696             [self fillError:error code:SecDbBackupUnknownOption underlying:nil description:@"Recovery type %li unknown", (long)type];
 697             break;
 698     }
 699
 700     return set;
 701 }
 702
 703 - (SecDbBackupRecoverySet*)inTransaction:(SecDbConnectionRef)dbt createAKSTypeRecoverySetWithBagSecret:(NSData*)secret handle:(keybag_handle_t)handle error:(NSError**)error
 704 {
 705     SecDbBackupRecoverySet* set = [SecDbBackupRecoverySet new];
 706     set.recoveryType = SecDbBackupRecoveryTypeAKS;
 707     set.bagIdentity = _bagIdentity;
 708
 709     NSError* cryptoError;
 710     SFAESKeySpecifier* specifier = [[SFAESKeySpecifier alloc] initWithBitSize:SFAESKeyBitSize256];
 711     SFAESKey* KCSKSecret = [[SFAESKey alloc] initRandomKeyWithSpecifier:specifier error:&cryptoError];
 712     if (!KCSKSecret) {
 713         [self fillError:error code:SecDbBackupCryptoFailure underlying:cryptoError description:@"Unable to create AKS recovery set"];
 714         return nil;
 715     }
 716
 717     // We explicitly do NOT want akpu. For the rest, create and write all KCSKs
 718     for (NSNumber* class in @[@(key_class_ak), @(key_class_ck), @(key_class_dk), @(key_class_aku), @(key_class_cku), @(key_class_dku)]) {
 719         SecDbBackupKeyClassSigningKey* kcsk = [self createKCSKForKeyClass:[class intValue] withWrapper:KCSKSecret error:error];
 720         if (!kcsk) {
 721             secerror("SecDbBackup: Unable to create KCSK for class %@: %@", class, *error);
 722             return nil;
 723         }
 724         if (![self inTransaction:dbt writeKCSKToKeychain:kcsk error:error]) {
 725             secerror("SecDbBackup: Unable to write KCSK for class %@ to keychain: %@", class, *error);
 726             return nil;
 727         }
 728     }
 729
 730     SFAESKey* recoverykey = [[SFAESKey alloc] initRandomKeyWithSpecifier:specifier error:&cryptoError];
 731     if (!recoverykey) {
 732         [self fillError:error code:SecDbBackupCryptoFailure underlying:cryptoError description:@"Unable to create recovery key"];
 733         return nil;
 734     }
 735
 736     SFAuthenticatedEncryptionOperation* op = [[SFAuthenticatedEncryptionOperation alloc]
 737                                               initWithKeySpecifier:[[SFAESKeySpecifier alloc]
 738                                                                     initWithBitSize:SFAESKeyBitSize256]];
 739     SFAuthenticatedCiphertext* wrappedsecret = [op encrypt:secret withKey:recoverykey error:&cryptoError];
 740     if (!wrappedsecret) {
 741         secerror("SecDbBackup: Unable to wrap keybag secret: %@", cryptoError);
 742         [self fillError:error code:SecDbBackupCryptoFailure underlying:cryptoError description:@"Unable to wrap keybag secret"];
 743         return nil;
 744     }
 745     set.wrappedBagSecret = [NSKeyedArchiver archivedDataWithRootObject:wrappedsecret requiringSecureCoding:YES error:error];
 746
 747     SFAuthenticatedCiphertext* wrappedkcsksecret = [op encrypt:KCSKSecret.keyData withKey:recoverykey error:&cryptoError];
 748     if (!wrappedkcsksecret) {
 749         secerror("SecDbBackup: Unable to wrap KCSK secret: %@", cryptoError);
 750         [self fillError:error code:SecDbBackupCryptoFailure underlying:cryptoError description:@"Unable to wrap KCSK secret"];
 751         return nil;
 752     }
 753     set.wrappedKCSKSecret = [NSKeyedArchiver archivedDataWithRootObject:wrappedkcsksecret requiringSecureCoding:YES error:error];
 754
 755     NSMutableData* wrappedrecoverykey = [[NSMutableData alloc] initWithLength:APPLE_KEYSTORE_MAX_SYM_WRAPPED_KEY_LEN];
 756     if (![SecAKSObjCWrappers aksEncryptWithKeybag:KEYBAG_DEVICE keyclass:key_class_aku plaintext:recoverykey.keyData outKeyclass:nil ciphertext:wrappedrecoverykey error:&cryptoError]) {
 757         secerror("SecDbBackup: Unable to wrap recovery key to AKS: %@", cryptoError);
 758         [self fillError:error code:SecDbBackupAKSFailure underlying:cryptoError description:@"Unable to wrap recovery key to AKS"];
 759         return nil;
 760     }
 761     set.wrappedRecoveryKey = [wrappedrecoverykey copy];
 762
 763     return set;
 764 }
 765
 766 #pragma mark - Backup System Initialization / Maintenance
 767
 768 - (BOOL)createOrLoadBackupInfrastructure:(NSError**)error {
 769     assert(error);
 770     __block BOOL ok = true;
 771     __block NSError* localError;
 772     dispatch_sync(_queue, ^{
 773         ok = [self onQueueCreateOrLoadBackupInfrastructure:&localError];
 774     });
 775
 776     if (localError) {
 777         *error = localError;
 778     }
 779     return ok;
 780 }
 781
 782 // TODO: if this creates the infrastructure, kick off a fixup routine
 783 // TODO: if not, make sure we actually delete stuff. Nested transactions are not a thing (use checkpointing or delete explicitly)
 784
 785 - (BOOL)onQueueCreateOrLoadBackupInfrastructure:(NSError**)error {
 786     dispatch_assert_queue(_queue);
 787     assert(error);
 788     if (self->_handle != bad_keybag_handle) {
 789         return true;
 790     }
 791
 792     self->_handle = [self onQueueLoadBackupBag:nil error:error];
 793     if (self->_handle != bad_keybag_handle) {
 794         secnotice("SecDbBackup", "Keybag found and loaded");
 795         return true;
 796     } else if (self->_handle == bad_keybag_handle && (*error).code != SecDbBackupNoBackupBagFound) {
 797         return false;
 798     }
 799     *error = nil;
 800
 801     __block BOOL ok = YES;
 802     __block CFErrorRef cfError = NULL;
 803     __block NSError* localError;
 804     secnotice("SecDbBackup", "CreateOrLoad: No backup bag found, attempting to create new infrastructure");
 805     if (ok && !SecAKSDoWithUserBagLockAssertion(&cfError, ^{
 806         ok &= kc_with_dbt_non_item_tables(YES, &cfError, ^bool(SecDbConnectionRef dbt) {
 807             ok &= kc_transaction(dbt, &cfError, ^bool{
 808                 NSData* secret = [self createBackupBagSecret:&localError];
 809                 if (!secret) {
 810                     return false;
 811                 }
 812
 813                 self->_handle = [self onQueueCreateBackupBagWithSecret:secret error:&localError];
 814                 if (self->_handle == bad_keybag_handle) {
 815                     return false;
 816                 }
 817                 secnotice("SecDbBackup", "CreateOrLoad: Successfully created backup bag");
 818
 819                 if (![self onQueueInTransaction:dbt saveBackupBag:self->_handle asDefault:YES error:&localError]) {
 820                     return false;
 821                 }
 822                 secnotice("SecDbBackup", "CreateOrLoad: Successfully saved backup bag");
 823
 824                 if (![self onQueueReloadDefaultBackupBagWithError:&localError]) {
 825                     return false;
 826                 }
 827                 secnotice("SecDbBackup", "CreateOrLoad: Successfully reloaded backup bag");
 828
 829                 SecDbBackupRecoverySet* set = [self onQueueInTransaction:dbt
 830                                           createRecoverySetWithBagSecret:secret
 831                                                                  forType:SecDbBackupRecoveryTypeAKS
 832                                                                    error:&localError];
 833                 if (!set) {
 834                 secnotice("SecDbBackup", "CreateOrLoad: Successfully created recovery set");
 835                     return false;
 836                 }
 837
 838                 if (![self onQueueInTransaction:dbt writeRecoverySetToKeychain:set error:&localError]) {
 839                     return false;
 840                 }
 841                 secnotice("SecDbBackup", "CreateOrLoad: Successfully saved recovery set");
 842
 843                 return true;
 844             });
 845             return ok;
 846         });
 847     })) {   // could not perform action with lock assertion
 848         static dispatch_once_t once;
 849         static sec_action_t action;
 850         dispatch_once(&once, ^{
 851             action = sec_action_create("keybag_locked_during_backup_setup_complaint", 5);
 852             sec_action_set_handler(action, ^{
 853                 secerror("SecDbBackup: Cannot obtain AKS lock assertion so cannot setup backup infrastructure");
 854             });
 855         });
 856         sec_action_perform(action);
 857         [self fillError:&localError code:SecDbBackupKeychainLocked underlying:nil
 858             description:@"Unable to initialize backup infrastructure, keychain locked"];
 859         ok = NO;
 860     }
 861
 862     if (!ok) {
 863         self->_bagIdentity = nil;
 864         aks_unload_bag(self->_handle);
 865         self->_handle = bad_keybag_handle;
 866     }
 867
 868     if (ok) {
 869         secnotice("SecDbBackup", "Hurray! Successfully created backup infrastructure");
 870     } else {
 871         assert(localError || cfError);
 872         if (localError) {
 873             secerror("SecDbBackup: Could not initialize backup infrastructure: %@", localError);
 874             *error = localError;
 875         } else if (cfError) {
 876             secerror("SecDbBackup: Could not initialize backup infrastructure: %@", cfError);
 877             [self fillError:error code:SecDbBackupSetupFailure underlying:CFBridgingRelease(cfError)
 878                 description:@"Unable to initialize backup infrastructure"];
 879         } else {
 880             secerror("SecDbBackup: Could not initialize backup infrastructure but have no error");
 881             [self fillError:error code:SecDbBackupSetupFailure underlying:nil
 882                 description:@"Unable to initialize backup infrastructure (not sure why)"];
 883         }
 884         CFReleaseNull(cfError);
 885     }
 886
 887     return ok;
 888 }
 889
 890 #pragma mark - Item Encryption
 891
 892 - (SecDbBackupWrappedItemKey*)wrapItemKey:(SFAESKey*)key forKeyclass:(keyclass_t)keyclass error:(NSError**)error
 893 {
 894     assert(error);
 895     if (keyclass == key_class_akpu) {
 896         secwarning("SecDbBackup: Don't tempt me Frodo!");
 897         [self fillError:error code:SecDbBackupInvalidArgument underlying:nil description:@"Do not call wrapItemKey with class akpu"];
 898         return nil;
 899     }
 900
 901     if (![self createOrLoadBackupInfrastructure:error]) {
 902         if ((*error).domain != (__bridge NSString*)kSecErrorDomain || (*error).code != errSecInteractionNotAllowed) {
 903             secerror("SecDbBackup: Could not create/load backup infrastructure: %@", *error);
 904         }
 905         return nil;
 906     }
 907
 908     __block SecDbBackupWrappedItemKey* backupWrappedKey;
 909
 910     __block NSMutableData* wrappedKey = [NSMutableData dataWithLength:APPLE_KEYSTORE_MAX_ASYM_WRAPPED_KEY_LEN];
 911     __block NSError* localError;
 912     dispatch_sync(_queue, ^{
 913         if (![self onQueueCreateOrLoadBackupInfrastructure:&localError]) {
 914             return;
 915         }
 916         if (![SecAKSObjCWrappers aksEncryptWithKeybag:self->_handle
 917                                              keyclass:keyclass
 918                                             plaintext:key.keyData
 919                                           outKeyclass:nil
 920                                            ciphertext:wrappedKey
 921                                                 error:&localError]) {
 922             return;
 923         }
 924         SFSignedData* wrappedAndSigned = [self onQueueSignData:wrappedKey withKCSKForKeyclass:keyclass error:&localError];
 925         if (!wrappedAndSigned) {
 926             if (localError.code != SecDbBackupKeychainLocked) {
 927                 secerror("SecDbBackup: Unable to sign item for class %d: %@", keyclass, localError);
 928                 return;
 929             }
 930         }
 931         backupWrappedKey = [SecDbBackupWrappedItemKey new];
 932         backupWrappedKey.wrappedKey = [NSKeyedArchiver archivedDataWithRootObject:wrappedAndSigned requiringSecureCoding:YES error:&localError];
 933         backupWrappedKey.baguuid = self->_bagIdentity.baguuid;
 934     });
 935
 936     if (localError) {
 937         secerror("SecDbBackup: Unable to wrap-and-sign item of class %d: %@", keyclass, localError);
 938         *error = localError;
 939         return nil;
 940     }
 941
 942     return backupWrappedKey;
 943 }
 944
 945 - (SFSignedData*)onQueueSignData:(NSMutableData*)data withKCSKForKeyclass:(keyclass_t)keyclass error:(NSError**)error
 946 {
 947     SFECKeyPair* kcsk = [self onQueueFetchKCSKForKeyclass:keyclass error:error];
 948     if (!kcsk) {
 949         return nil;
 950     }
 951
 952     SFEC_X962SigningOperation* op = [[SFEC_X962SigningOperation alloc] initWithKeySpecifier:[[SFECKeySpecifier alloc] initWithCurve:SFEllipticCurveNistp384]];
 953     return [op sign:data withKey:kcsk error:error];
 954 }
 955
 956 #pragma mark - Testing Helpers
 957
 958 - (keybag_handle_t)createBackupBagWithSecret:(NSData*)secret error:(NSError**)error
 959 {
 960     assert(error);
 961     __block keybag_handle_t handle = bad_keybag_handle;
 962     __block NSError* localError;
 963     dispatch_sync(_queue, ^{
 964         handle = [self onQueueCreateBackupBagWithSecret:secret error:&localError];
 965     });
 966     if (localError) {
 967         *error = localError;
 968     } else if (handle == bad_keybag_handle) {
 969         [self fillError:error code:SecDbBackupTestCodeFailure underlying:nil description:@"Unable to create backup bag, but no reason"];
 970     }
 971     return handle;
 972 }
 973
 974 - (BOOL)saveBackupBag:(keybag_handle_t)handle asDefault:(BOOL)asDefault error:(NSError**)error
 975 {
 976     assert(error);
 977     __block bool ok = true;
 978     __block NSError* localErr;
 979     __block CFErrorRef cfError = NULL;
 980     dispatch_sync(_queue, ^{
 981         ok &= kc_with_dbt_non_item_tables(YES, &cfError, ^bool(SecDbConnectionRef dbt) {
 982             ok &= kc_transaction(dbt, &cfError, ^bool{
 983                 ok &= [self onQueueInTransaction:dbt saveBackupBag:handle asDefault:asDefault error:&localErr];
 984                 return ok;
 985             });
 986             return ok;
 987         });
 988     });
 989
 990     if (!ok) {
 991         if (cfError) {
 992             [self fillError:error code:SecDbBackupTestCodeFailure underlying:CFBridgingRelease(cfError) description:@"Unable to save keybag to disk"];
 993         } else if (localErr) {
 994             *error = localErr;
 995         } else if (!localErr) {
 996             [self fillError:error code:SecDbBackupTestCodeFailure underlying:nil description:@"Unable to save keybag to disk but who knows why"];
 997         }
 998     }
 999     return ok;
1000 }
1001
1002 - (keybag_handle_t)loadBackupBag:(NSUUID*)uuid error:(NSError**)error {
1003     __block keybag_handle_t handle = bad_keybag_handle;
1004     __block NSError* localError;
1005     dispatch_sync(_queue, ^{
1006         handle = [self onQueueLoadBackupBag:uuid error:&localError];
1007     });
1008     if (error && localError) {
1009         *error = localError;
1010     }
1011     return handle;
1012 }
1013
1014 - (SecDbBackupRecoverySet*)createRecoverySetWithBagSecret:(NSData*)secret forType:(SecDbBackupRecoveryType)type error:(NSError**)error
1015 {
1016     __block SecDbBackupRecoverySet* set;
1017     __block BOOL ok = YES;
1018     __block NSError* localError;
1019     __block CFErrorRef cfError = NULL;
1020     dispatch_sync(_queue, ^{
1021         ok &= kc_with_dbt_non_item_tables(true, &cfError, ^bool(SecDbConnectionRef dbt) {
1022             ok &= kc_transaction(dbt, &cfError, ^bool{
1023                 set = [self onQueueInTransaction:dbt createRecoverySetWithBagSecret:secret forType:type error:&localError];
1024                 return set != nil;
1025             });
1026             return ok;
1027         });
1028     });
1029     if (error && cfError) {
1030         *error = CFBridgingRelease(cfError);
1031     } else if (error && localError) {
1032         *error = localError;
1033     }
1034     CFReleaseNull(cfError);
1035
1036     return set;
1037 }
1038
1039 - (SFECKeyPair*)fetchKCSKForKeyclass:(keyclass_t)keyclass error:(NSError**)error
1040 {
1041     __block SFECKeyPair* keypair;
1042     __block NSError* localError;
1043     dispatch_sync(_queue, ^{
1044         keypair = [self onQueueFetchKCSKForKeyclass:keyclass error:&localError];
1045     });
1046     if (localError && error) {
1047         *error = localError;
1048     }
1049
1050     return keypair;
1051 }
1052
1053 @end
1054
1055 #endif // SECDB_BACKUPS_ENABLED