androidx.security.crypto

Kotlin |Java

Classes

EncryptedFile	Class used to create and read encrypted files.
EncryptedSharedPreferences	An implementation of `SharedPreferences` that encrypts keys and values.
MasterKey	Wrapper for a master key used in the library.
MasterKeys	Convenient methods to create and obtain master keys in Android Keystore.

Top-level functions summary

EncryptedFile	`EncryptedFile(context: Context, file: File, masterKey: MasterKey, fileEncryptionScheme: EncryptedFile.FileEncryptionScheme = FileEncryptionScheme.AES256_GCM_HKDF_4KB, keysetPrefName: String? = null, keysetAlias: String? = null)` Creates an EncryptedFile
SharedPreferences	`EncryptedSharedPreferences(context: Context, fileName: String, masterKey: MasterKey, prefKeyEncryptionScheme: EncryptedSharedPreferences.PrefKeyEncryptionScheme = PrefKeyEncryptionScheme.AES256_SIV, prefValueEncryptionScheme: EncryptedSharedPreferences.PrefValueEncryptionScheme = PrefValueEncryptionScheme.AES256_GCM)` Opens an instance of encrypted SharedPreferences
MasterKey	`MasterKey(context: Context, keyAlias: String = MasterKey.DEFAULT_MASTER_KEY_ALIAS, keyScheme: MasterKey.KeyScheme = MasterKey.KeyScheme.AES256_GCM, authenticationRequired: Boolean = false, userAuthenticationValidityDurationSeconds: Int = MasterKey.getDefaultAuthenticationValidityDurationSeconds(), requestStrongBoxBacked: Boolean = false)` Creates a MasterKey with the provided parameters.

Top-level functions

EncryptedFile

fun EncryptedFile(
    context: Context, 
    file: File, 
    masterKey: MasterKey, 
    fileEncryptionScheme: EncryptedFile.FileEncryptionScheme = FileEncryptionScheme.AES256_GCM_HKDF_4KB, 
    keysetPrefName: String? = null, 
    keysetAlias: String? = null
): EncryptedFile

Creates an EncryptedFile

Parameters
context: Context	The context to work with.
file: File	The backing File.
masterKey: MasterKey	The MasterKey that should be used.
fileEncryptionScheme: EncryptedFile.FileEncryptionScheme = FileEncryptionScheme.AES256_GCM_HKDF_4KB	The FileEncryptionScheme to use, defaulting to FileEncryptionScheme.AES256_GCM_HKDF_4KB.
keysetPrefName: String? = null	The `SharedPreferences` file to store the keyset for this EncryptedFile.
keysetAlias: String? = null	The alias in the `SharedPreferences` file to store the keyset for this EncryptedFile.

EncryptedSharedPreferences

fun EncryptedSharedPreferences(
    context: Context, 
    fileName: String, 
    masterKey: MasterKey, 
    prefKeyEncryptionScheme: EncryptedSharedPreferences.PrefKeyEncryptionScheme = PrefKeyEncryptionScheme.AES256_SIV, 
    prefValueEncryptionScheme: EncryptedSharedPreferences.PrefValueEncryptionScheme = PrefValueEncryptionScheme.AES256_GCM
): SharedPreferences

Opens an instance of encrypted SharedPreferences

Parameters
fileName: String	The name of the file to open; can not contain path separators.
masterKey: MasterKey	The master key to use.
prefKeyEncryptionScheme: EncryptedSharedPreferences.PrefKeyEncryptionScheme = PrefKeyEncryptionScheme.AES256_SIV	The scheme to use for encrypting keys.
prefValueEncryptionScheme: EncryptedSharedPreferences.PrefValueEncryptionScheme = PrefValueEncryptionScheme.AES256_GCM	The scheme to use for encrypting values.

Return
The SharedPreferences instance that encrypts all data.

MasterKey

fun MasterKey(
    context: Context, 
    keyAlias: String = MasterKey.DEFAULT_MASTER_KEY_ALIAS, 
    keyScheme: MasterKey.KeyScheme = MasterKey.KeyScheme.AES256_GCM, 
    authenticationRequired: Boolean = false, 
    userAuthenticationValidityDurationSeconds: Int = MasterKey.getDefaultAuthenticationValidityDurationSeconds(), 
    requestStrongBoxBacked: Boolean = false
): MasterKey

Creates a MasterKey with the provided parameters.

Parameters
context: Context	The context to work with.
keyAlias: String = MasterKey.DEFAULT_MASTER_KEY_ALIAS	The alias to use for the `MasterKey`.
keyScheme: MasterKey.KeyScheme = MasterKey.KeyScheme.AES256_GCM	The MasterKey.KeyScheme to have the `MasterKey` use.
authenticationRequired: Boolean = false	`true` if the user must authenticate for the `MasterKey` to be used.
userAuthenticationValidityDurationSeconds: Int = MasterKey.getDefaultAuthenticationValidityDurationSeconds()	Duration in seconds that the `MasterKey` is valid for after the user has authenticated. Must be a value > 0.
requestStrongBoxBacked: Boolean = false	`true` if the key should be stored in Strong Box, if possible.