MasterKey

Artifact: androidx.security:security-crypto

View Source

Added in 1.1.0-alpha07

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Kotlin |Java

public final class MasterKey

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Wrapper for a master key used in the library.

On Android M (API 23) and above, this is class references a key that's stored in the Android Keystore. On Android L (API 21, 22), there isn't a master key.

Summary

Nested types
public final class MasterKey.Builder Builder for generating a MasterKey.
public enum MasterKey.KeyScheme Algorithm/Cipher choices used for the master key.

Constants
static final int	DEFAULT_AES_GCM_MASTER_KEY_SIZE = 256 The default and recommended size for the master key.
static final String	DEFAULT_MASTER_KEY_ALIAS = "_androidx_security_master_key_" The default master key alias.

Public methods
static int	getDefaultAuthenticationValidityDurationSeconds() The default validity period for authentication in seconds.
int	getUserAuthenticationValidityDurationSeconds() Gets the duration in seconds that the key is unlocked for following user authentication.
boolean	isKeyStoreBacked() Checks if this key is backed by the Android Keystore.
boolean	isStrongBoxBacked() Gets whether the key is backed by strong box.
boolean	isUserAuthenticationRequired() Gets whether user authentication is required to use this key.
@NonNull String	toString()

Constants

DEFAULT_AES_GCM_MASTER_KEY_SIZE

Added in 1.1.0-alpha07

public static final int DEFAULT_AES_GCM_MASTER_KEY_SIZE = 256

The default and recommended size for the master key.

DEFAULT_MASTER_KEY_ALIAS

Added in 1.1.0-alpha07

public static final String DEFAULT_MASTER_KEY_ALIAS = "_androidx_security_master_key_"

The default master key alias.

Public methods

getDefaultAuthenticationValidityDurationSeconds

Added in 1.1.0-alpha07

public static int getDefaultAuthenticationValidityDurationSeconds()

The default validity period for authentication in seconds.

getUserAuthenticationValidityDurationSeconds

Added in 1.1.0-alpha07

public int getUserAuthenticationValidityDurationSeconds()

Gets the duration in seconds that the key is unlocked for following user authentication.

The value returned for this method is only meaningful on Android M+ (API 23) when isUserAuthenticationRequired returns true.

Returns
int	The duration the key is unlocked for in seconds.

isKeyStoreBacked

Added in 1.1.0-alpha07

public boolean isKeyStoreBacked()

Checks if this key is backed by the Android Keystore.

Returns
boolean	true if the key is in Android Keystore, false otherwise. This method always returns false when called on Android Lollipop (API 21 and 22).

isStrongBoxBacked

Added in 1.1.0-alpha07

public boolean isStrongBoxBacked()

Gets whether the key is backed by strong box.

isUserAuthenticationRequired

Added in 1.1.0-alpha07

public boolean isUserAuthenticationRequired()

Gets whether user authentication is required to use this key.

This method always returns false on Android L (API 21 + 22).

toString

public @NonNull String toString()