iCloud sync keychain

Question

In my app, I want to be able to sync a configuration that gets created by the user. I wanted to use iCloud to sync that configuration so that it is always the same on all de

Answer 1

These are the utility methods I've made for keychain. kSecAttrSynchronizable is what makes iCloud Sync work. Hope they help.

• Keychain Query.
• Remove item
• Delete item
• Save item

• Load item

  + (NSMutableDictionary *)getKeychainQuery:(NSString *)service {
      return [NSMutableDictionary dictionaryWithObjectsAndKeys:
              (__bridge id)kSecClassGenericPassword, (__bridge id)kSecClass,
              service, (__bridge id)kSecAttrService,
              service, (__bridge id)kSecAttrAccount,
              service, (__bridge id)kSecAttrSynchronizable,
              (__bridge id)kSecAttrAccessibleAfterFirstUnlock, (__bridge id)kSecAttrAccessible,
              nil];
  }
  
  + (void)save:(NSString *)service data:(id)data {
      NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
      SecItemDelete((__bridge CFDictionaryRef)keychainQuery);
      [keychainQuery setObject:[NSKeyedArchiver archivedDataWithRootObject:data] forKey:(__bridge id)kSecValueData];
      SecItemAdd((__bridge CFDictionaryRef)keychainQuery, NULL);
  }
  
  + (void)remove:(NSString *)service {
       NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
       SecItemDelete((__bridge CFDictionaryRef)keychainQuery);
  }
  
  +(NSString *)keychainItem:(NSString *)service{
      id data = [self load:service];
  
      if([data isKindOfClass:[NSString class]]){
          return data;
      }
      return @"";
  }
  
  + (id)load:(NSString *)service {
      id ret = nil;
      NSMutableDictionary *keychainQuery = [self getKeychainQuery:service];
      [keychainQuery setObject:(id)kCFBooleanTrue forKey:(__bridge id)kSecReturnData];
      [keychainQuery setObject:(__bridge id)kSecMatchLimitOne forKey:(__bridge id)kSecMatchLimit];
      CFDataRef keyData = NULL;
      if (SecItemCopyMatching((__bridge CFDictionaryRef)keychainQuery, (CFTypeRef *)&keyData) == noErr) {
          @try {
              ret = [NSKeyedUnarchiver unarchiveObjectWithData:(__bridge NSData *)keyData];
          }
          @catch (NSException *e) {
              NSLog(@"Unarchive of %@ failed: %@", service, e);
           }
          @finally {}
      }
      if (keyData) CFRelease(keyData);
      return ret;
  }