VPNUStorage
Special class which can be used to save account-specific information on disk.
Discussion
Use this class if you want to save any information which is specific for an account described by VPNUAccountUserInfo. This class also provides an interface to save data securely using methods which use encryption and decryption.
The class uses NSUserDefaults internally. If you clear the defaults associated with the intance of this class (generally standardUserDefaults), all stored values (including encrypted) will be lost.
Extends: NSObject
Declared in: VPNUStorage.h
Class Methods
defaultStorage
+ (instancetype)defaultStorage;
Returns the shared storage object.
Discussion
The shared storage is created internally with standardUserDefaults instance of NSUserDefaults class. If you want to use any custom NSUserDefaults object, you can initialize your own instance of VPNUStorage using initWithUserDefaults: covinience initializer.
Instance Methods
initWithUserDefaults:
- (instancetype)initWithUserDefaults:(NSUserDefaults *)userDefaults NS_DESIGNATED_INITIALIZER;
Initializes and return a newly created VPNUStorage instance which uses a custom NSUserDefaults object.
Parameters
- userDefaults
- A custom NSUserDefaults object.
Discussion
This method is a convenience constructor.
Use this method only if you know what you are doing. Generally you want to use standardUserDefaults instance of NSUserDefaults class - simply use the defaultStorage class method (the latter is generally preferred).
readObjectForKey:
- (id)readObjectForKey:(NSString *)key;
Returns the object associated with the provided key.
Parameters
- key
- The key with which to associate with the object. Cannot be nil.
readObjectForKey:forAccount:
- (id)readObjectForKey:(NSString *)key forAccount:(VPNUAccountUserInfo *)account;
Returns the object associated with the provided key and account.
Parameters
- key
- The key with which to associate with the object. Cannot be nil.
- account
- The account with which to associate with the given key.
readWithDecryptionObjectForKey:
- (id)readWithDecryptionObjectForKey:(NSString *)key;
Decrypts and returns the object associated with the provided key.
Parameters
- key
- The key with which to associate with the object. Cannot be nil.
Discussion
This method generates an exception if no encryption key was provided using setEncryptionKey: method.
readWithDecryptionObjectForKey:forAccount:
- (id)readWithDecryptionObjectForKey:(NSString *)key forAccount:(VPNUAccountUserInfo *)account;
Decrypts and returns the object associated with the provided key and account.
Parameters
- key
- The key with which to associate with the object. Cannot be nil.
- account
- The account with which to associate with the given key.
Discussion
This method generates an exception if no encryption key was provided using setEncryptionKey: method.
setEncryptionKey:
- (void)setEncryptionKey:(NSString *)key;
Sets the provided string as the encryption and decryption key used by secure methods.
Parameters
- key
- Encryption key to be used for encryption. Cannot be nil.
Discussion
The provided string is later used internally when the methods with pattern storeWithEncryptionObject:forKey: and readWithDecryptionObjectForKey: are called. It is recommended to use an arbitrary, comparatively large and permutated string for this value. Generally you are discouraged to use a user's login or password or any meaningful string as an encryption key.
Set the key only once before making any calls to the instance. Otherwise the correctness of encryption and decryption is not guaranteed.
Encryption key should be the same between the launches of your host application. If you change the key, all previously saved values will be inaccessible until you set the key back to the previous value.
storeObject:forKey:
- (void)storeObject:(id)object forKey:(NSString *)key;
Stores provided object for the specified key.
Parameters
- object
- The object to store.
- key
- The key with which to associate with the object. Cannot be nil.
Discussion
The object parameter can be only property list objects: NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary.
storeObject:forKey:forAccount:
- (void)storeObject:(id)object forKey:(NSString *)key forAccount:(VPNUAccountUserInfo *)account;
Stores provided key-value pair (key and object) for the specified account.
Parameters
- object
- The object to store.
- key
- The key with which to associate with the object. Cannot be nil.
- account
- The account with which to associate with the given key-value pair.
Discussion
The object parameter can be only property list objects: NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary.
storeWithEncryptionObject:forKey:
- (void)storeWithEncryptionObject:(id)object forKey:(NSString *)key;
Encrypts and stores provided object for the specified key.
Parameters
- object
- The object to store. Cannot be nil.
- key
- The key with which to associate with the object. Cannot be nil.
Discussion
This method generates an exception if no encryption key was provided using setEncryptionKey: method. The object parameter can be only property list objects: NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary.
storeWithEncryptionObject:forKey:forAccount:
- (void)storeWithEncryptionObject:(id)object forKey:(NSString *)key forAccount:(VPNUAccountUserInfo *)account;
Encrypts and stores provided key-value pair (key and object) for the specified account.
Parameters
- object
- The object to store. Cannot be nil.
- key
- The key with which to associate with the object. Cannot be nil.
- account
- The account with which to associate with the given key-value pair.
Discussion
This method generates an exception if no encryption key was provided using setEncryptionKey: method. The object parameter can be only property list objects: NSData, NSString, NSNumber, NSDate, NSArray, or NSDictionary.