at.favre.lib.armadillo

Interface ArmadilloSharedPreferences

All Superinterfaces:

android.content.SharedPreferences

All Known Implementing Classes:

SecureSharedPreferences

public interface ArmadilloSharedPreferences
extends android.content.SharedPreferences

Extending the SharedPreferences interface this exports additional APIs specific to armadillo.

Nested Class Summary

Nested classes/interfaces inherited from interface android.content.SharedPreferences

android.content.SharedPreferences.Editor, android.content.SharedPreferences.OnSharedPreferenceChangeListener

Method Summary

Modifier and Type	Method and Description
void	changePassword(char[] newPassword) Changes the user provided password to the new given password.
void	changePassword(char[] newPassword, KeyStretchingFunction function) Changes the user provided password to the new given password and sets a new stretching function.
void	close() Clears most of the internal state and makes the instance unusable.
boolean	isValidPassword() Determines whether the user-provided password used to initialises Armadillo is the right one or not.

Methods inherited from interface android.content.SharedPreferences

contains, edit, getAll, getBoolean, getFloat, getInt, getLong, getString, getStringSet, registerOnSharedPreferenceChangeListener, unregisterOnSharedPreferenceChangeListener

Method Detail

isValidPassword

boolean isValidPassword()

Determines whether the user-provided password used to initialises Armadillo is the right one or not.

Armadillo.Builder.supportVerifyPassword(boolean) has to be enabled to be able to use this method.

In order to verify the password, a known value is stored encrypted with the password the first time that Armadillo is initialised. When this method is called, it tries to decrypt this value and compares it to the original value. If the values match the validation succeeds, otherwise, it fails.

Warning: Depending on the use key stretching function this is a very expensive call, do it in a background thread.

Returns:

true is the password is valid, false otherwise

Throws:

java.lang.UnsupportedOperationException - when support verify password is not enabled

changePassword

void changePassword(char[] newPassword,
                    KeyStretchingFunction function)

Changes the user provided password to the new given password and sets a new stretching function. This will immediately reencrypt all the key/value entries with the new password and the data won't be accessible with the old one anymore. This process is atomic, if an exception happens during it, nothing will change.

This method can be used to switch from a generated key to a key derived from user-provided password.

A null or zero length password will reset the password (as if no user-provided password is set).

Warning: Depending on the use key stretching function and count of saved data this is a very expensive call, do it in a background thread.

Parameters:

newPassword - which will be additionally used to create the key for the encryption

function - set a new function to be used the encrypt with new password. It will be ignored if null is passed.

changePassword

void changePassword(char[] newPassword)

Changes the user provided password to the new given password. This will immediately reencrypt all the key/value entries with the new password and the data won't be accessible with the old one anymore. This process is atomic, if an exception happens during it, nothing will change.

This method can be used to switch from a generated key to a key derived from user-provided password.

A null or zero length password will reset the password (as if no user-provided password is set).

Warning: Depending on the use key stretching function and count of saved data this is a very expensive call, do it in a background thread.

Parameters:

newPassword - which will be additionally used to create the key for the encryption

close

void close()

Clears most of the internal state and makes the instance unusable. User-provided password is cleared.