Summary: Ctors | Methods | Inherited Methods

MasterKey.Builder

Kotlin |Java

public static final class MasterKey.Builder
extends Object

java.lang.Object
↳	androidx.security.crypto.MasterKey.Builder

Builder for generating a MasterKey.

Summary

Public constructors
`Builder(Context context)` Creates a builder for a `MasterKey` using the default alias of `MasterKey.DEFAULT_MASTER_KEY_ALIAS`.
`Builder(Context context, String keyAlias)` Creates a builder for a `MasterKey`.

Public methods
`MasterKey`	`build()` Builds a `MasterKey` from this builder.
`MasterKey.Builder`	`setKeyGenParameterSpec(KeyGenParameterSpec keyGenParameterSpec)` Sets a custom `KeyGenParameterSpec` to use as the basis of the master key.
`MasterKey.Builder`	`setKeyScheme(MasterKey.KeyScheme keyScheme)` Sets a `MasterKey.KeyScheme` to be used for the master key.
`MasterKey.Builder`	`setRequestStrongBoxBacked(boolean requestStrongBoxBacked)` Sets whether or not to request this key is strong box backed.
`MasterKey.Builder`	`setUserAuthenticationRequired(boolean authenticationRequired)` When used with `setKeyScheme(KeyScheme)`, sets that the built master key should require the user to authenticate before it's unlocked, probably using the androidx.biometric library.
`MasterKey.Builder`	`setUserAuthenticationRequired(boolean authenticationRequired, int userAuthenticationValidityDurationSeconds)` When used with `setKeyScheme(KeyScheme)`, sets that the built master key should require the user to authenticate before it's unlocked, probably using the androidx.biometric library, and that the key should remain unlocked for the provided duration.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()`
`boolean`	`equals(Object arg0)`
`void`	`finalize()`
`final Class<?>`	`getClass()`
`int`	`hashCode()`
`final void`	`notify()`
`final void`	`notifyAll()`
`String`	`toString()`
`final void`	`wait(long arg0, int arg1)`
`final void`	`wait(long arg0)`
`final void`	`wait()`

Public constructors

Builder

public Builder (Context context)

Creates a builder for a MasterKey using the default alias of MasterKey.DEFAULT_MASTER_KEY_ALIAS.

Parameters
`context`	`Context`: The context to use with this master key.

Builder

public Builder (Context context, 
                String keyAlias)

Creates a builder for a MasterKey.

Parameters
`context`	`Context`: The context to use with this master key.
`keyAlias`	`String`

Public methods

build

public MasterKey build ()

Builds a MasterKey from this builder.

Returns
`MasterKey`	The master key.

Throws
`GeneralSecurityException`
`IOException`

setKeyGenParameterSpec

public MasterKey.Builder setKeyGenParameterSpec (KeyGenParameterSpec keyGenParameterSpec)

Sets a custom KeyGenParameterSpec to use as the basis of the master key. NOTE: Either this method OR setKeyScheme(KeyScheme) should be used to set the parameters to use for building the master key. Calling either function after the other will throw an IllegalArgumentException.

Parameters
`keyGenParameterSpec`	`KeyGenParameterSpec`: The key spec to use.

Returns
`MasterKey.Builder`	This builder.

setKeyScheme

public MasterKey.Builder setKeyScheme (MasterKey.KeyScheme keyScheme)

Sets a MasterKey.KeyScheme to be used for the master key. This uses a default KeyGenParameterSpec associated with the provided KeyScheme. NOTE: Either this method OR setKeyGenParameterSpec(KeyGenParameterSpec) should be used to set the parameters to use for building the master key. Calling either function after the other will throw an IllegalArgumentException.

Parameters
`keyScheme`	`MasterKey.KeyScheme`: The KeyScheme to use.

Returns
`MasterKey.Builder`	This builder.

setRequestStrongBoxBacked

public MasterKey.Builder setRequestStrongBoxBacked (boolean requestStrongBoxBacked)

Sets whether or not to request this key is strong box backed. This setting is only applicable on Build.VERSION_CODES.P and above, and only on devices that support Strongbox.

Parameters
`requestStrongBoxBacked`	`boolean`: Whether to request to use strongbox

Returns
`MasterKey.Builder`	This builder.

setUserAuthenticationRequired

public MasterKey.Builder setUserAuthenticationRequired (boolean authenticationRequired)

When used with setKeyScheme(KeyScheme), sets that the built master key should require the user to authenticate before it's unlocked, probably using the androidx.biometric library. This method sets the validity duration of the key to MasterKey.getDefaultAuthenticationValidityDurationSeconds().

Parameters
`authenticationRequired`	`boolean`: Whether user authentication should be required to use the key.

Returns
`MasterKey.Builder`	This builder.

setUserAuthenticationRequired

public MasterKey.Builder setUserAuthenticationRequired (boolean authenticationRequired, 
                int userAuthenticationValidityDurationSeconds)

When used with setKeyScheme(KeyScheme), sets that the built master key should require the user to authenticate before it's unlocked, probably using the androidx.biometric library, and that the key should remain unlocked for the provided duration.

Parameters
`authenticationRequired`	`boolean`: Whether user authentication should be required to use the key.
`userAuthenticationValidityDurationSeconds`	`int`: Duration in seconds that the key should remain unlocked following user authentication. Value is 1 or greater.

Returns
`MasterKey.Builder`	This builder.