FZAKeyManager Class Reference
| Inherits from | NSObject |
| Declared in | FZAKeyManager.h |
Overview
FZAKeyManager is an abstract class for creating and managing encryption keys.
This class should be inherited to provide cryptographic storage appropriate to the platform on which the library is running.
Tasks
-
– hasKey -
– clearPasswordAndSaltClear existing key chain items for password and salt.
-
– randomDataOfLength:Create some random data.
-
– keyFromPassword:salt:Generate a key from a password.
-
– storeKeyDerivedFromPassword:salt:error:Set a new key derived from a password supplied by the user.
-
– keyRetrieve and return the key from cryptographic storage.
-
+ newKeyManagerReturn a new subclass of this class, appropriate to the current platform.
Instance Methods
clearPasswordAndSalt
Clear existing key chain items for password and salt.
- (void)clearPasswordAndSaltDeclared In
FZAKeyManager.hkey
Retrieve and return the key from cryptographic storage.
- (NSData *)keyDiscussion
%warning%
Warning: This method must be overridden by subclasses.
Declared In
FZAKeyManager.hkeyFromPassword:salt:
Generate a key from a password.
- (NSData *)keyFromPassword:(NSString *)password salt:(NSData *)saltParameters
- password
The string to use as the password.
- salt
The salt data to use.
Return Value
A data key.
Discussion
This function is repeatable, in that the same password and salt always creates the same key. The key derived from the password is only stored on the local device, where the target data is already available in the clear - it never appears in the sync folder.
Declared In
FZAKeyManager.hrandomDataOfLength:
Create some random data.
- (NSData *)randomDataOfLength:(NSInteger)lengthParameters
- length
The number of bytes of randomness needed.
Return Value
The random data.
Discussion
%warning%
Warning: This method must be overridden by subclasses.
Declared In
FZAKeyManager.hstoreKeyDerivedFromPassword:salt:error:
Set a new key derived from a password supplied by the user.
- (BOOL)storeKeyDerivedFromPassword:(NSString *)password salt:(NSData *)salt error:(NSError **)errorParameters
- password
The string to use as the password.
- salt
Some random data fed into the key derivation function.
- error
Any error that occurs.
Return Value
YES if the key was stored succcessfully, NO if not (error will be set).
Discussion
This key gets stored into whatever cryptographic storage is available on the target platform.
%warning%
Warning: This method must be overridden by subclasses.
Declared In
FZAKeyManager.h