Most visited

Recently visited

Results for

Summary: Ctors | Methods | Inherited Methods

KeyGenParameterSpec.Builder

public static final class KeyGenParameterSpec.Builder
extends Object

java.lang.Object
↳	android.security.keystore.KeyGenParameterSpec.Builder

Builder of KeyGenParameterSpec instances.

Summary

Public constructors
`Builder(String keystoreAlias, int purposes)` Creates a new instance of the `Builder`.

Public methods
`KeyGenParameterSpec`	`build()` Builds an instance of `KeyGenParameterSpec`.
`KeyGenParameterSpec.Builder`	`setAlgorithmParameterSpec(AlgorithmParameterSpec spec)` Sets the algorithm-specific key generation parameters.
`KeyGenParameterSpec.Builder`	`setAttestKeyAlias(String attestKeyAlias)` Sets the alias of the attestation key that will be used to sign the attestation certificate for the generated key pair, if an attestation challenge is set with `setAttestationChallenge(byte[])`.
`KeyGenParameterSpec.Builder`	`setAttestationChallenge(byte[] attestationChallenge)` Sets whether an attestation certificate will be generated for this key pair, and what challenge value will be placed in the certificate.
`KeyGenParameterSpec.Builder`	`setBlockModes(String... blockModes)` Sets the set of block modes (e.g., `GCM`, `CBC`) with which the key can be used when encrypting/decrypting.
`KeyGenParameterSpec.Builder`	`setCertificateNotAfter(Date date)` Sets the end of the validity period for the self-signed certificate of the generated key pair.
`KeyGenParameterSpec.Builder`	`setCertificateNotBefore(Date date)` Sets the start of the validity period for the self-signed certificate of the generated key pair.
`KeyGenParameterSpec.Builder`	`setCertificateSerialNumber(BigInteger serialNumber)` Sets the serial number used for the self-signed certificate of the generated key pair.
`KeyGenParameterSpec.Builder`	`setCertificateSubject(X500Principal subject)` Sets the subject used for the self-signed certificate of the generated key pair.
`KeyGenParameterSpec.Builder`	`setDevicePropertiesAttestationIncluded(boolean devicePropertiesAttestationIncluded)` Sets whether to include the base device properties in the attestation certificate.
`KeyGenParameterSpec.Builder`	`setDigests(String... digests)` Sets the set of digests algorithms (e.g., `SHA-256`, `SHA-384`) with which the key can be used.
`KeyGenParameterSpec.Builder`	`setEncryptionPaddings(String... paddings)` Sets the set of padding schemes (e.g., `PKCS7Padding`, `OAEPPadding`, `PKCS1Padding`, `NoPadding`) with which the key can be used when encrypting/decrypting.
`KeyGenParameterSpec.Builder`	`setInvalidatedByBiometricEnrollment(boolean invalidateKey)` Sets whether this key should be invalidated on biometric enrollment.
`KeyGenParameterSpec.Builder`	`setIsStrongBoxBacked(boolean isStrongBoxBacked)` Sets whether this key should be protected by a StrongBox security chip.
`KeyGenParameterSpec.Builder`	`setKeySize(int keySize)` Sets the size (in bits) of the key to be generated.
`KeyGenParameterSpec.Builder`	`setKeyValidityEnd(Date endDate)` Sets the time instant after which the key is no longer valid.
`KeyGenParameterSpec.Builder`	`setKeyValidityForConsumptionEnd(Date endDate)` Sets the time instant after which the key is no longer valid for decryption and verification.
`KeyGenParameterSpec.Builder`	`setKeyValidityForOriginationEnd(Date endDate)` Sets the time instant after which the key is no longer valid for encryption and signing.
`KeyGenParameterSpec.Builder`	`setKeyValidityStart(Date startDate)` Sets the time instant before which the key is not yet valid.
`KeyGenParameterSpec.Builder`	`setMaxUsageCount(int maxUsageCount)` Sets the maximum number of times the key is allowed to be used.
`KeyGenParameterSpec.Builder`	`setRandomizedEncryptionRequired(boolean required)` Sets whether encryption using this key must be sufficiently randomized to produce different ciphertexts for the same plaintext every time.
`KeyGenParameterSpec.Builder`	`setSignaturePaddings(String... paddings)` Sets the set of padding schemes (e.g., `PSS`, `PKCS#1`) with which the key can be used when signing/verifying.
`KeyGenParameterSpec.Builder`	`setUnlockedDeviceRequired(boolean unlockedDeviceRequired)` Sets whether the keystore requires the screen to be unlocked before allowing decryption using this key.
`KeyGenParameterSpec.Builder`	`setUserAuthenticationParameters(int timeout, int type)` Sets the duration of time (seconds) and authorization type for which this key is authorized to be used after the user is successfully authenticated.
`KeyGenParameterSpec.Builder`	`setUserAuthenticationRequired(boolean required)` Sets whether this key is authorized to be used only if the user has been authenticated.
`KeyGenParameterSpec.Builder`	`setUserAuthenticationValidWhileOnBody(boolean remainsValid)` Sets whether the key will remain authorized only until the device is removed from the user's body up to the limit of the authentication validity period (see `setUserAuthenticationValidityDurationSeconds(int)` and `setUserAuthenticationRequired(boolean)`).
`KeyGenParameterSpec.Builder`	`setUserAuthenticationValidityDurationSeconds(int seconds)` This method is deprecated. See `setUserAuthenticationParameters(int, int)`
`KeyGenParameterSpec.Builder`	`setUserConfirmationRequired(boolean required)` Sets whether this key is authorized to be used only for messages confirmed by the user.
`KeyGenParameterSpec.Builder`	`setUserPresenceRequired(boolean required)` Sets whether a test of user presence is required to be performed between the `Signature.initSign()` and `Signature.sign()` method calls.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeout, int nanos)` Causes the current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object, or some other thread interrupts the current thread, or a certain amount of real time has elapsed.
`final void`	`wait(long timeout)` Causes the current thread to wait until either another thread invokes the `notify()` method or the `notifyAll()` method for this object, or a specified amount of time has elapsed.
`final void`	`wait()` Causes the current thread to wait until another thread invokes the `notify()` method or the `notifyAll()` method for this object.

Public constructors

Builder

public Builder (String keystoreAlias, 
                int purposes)

Creates a new instance of the Builder.

Parameters

Parameters
`keystoreAlias`	`String`: alias of the entry in which the generated key will appear in Android KeyStore. Must not be empty. This value cannot be `null`.
`purposes`	`int`: set of purposes (e.g., encrypt, decrypt, sign) for which the key can be used. Attempts to use the key for any other purpose will be rejected. If the set of purposes for which the key can be used does not contain `KeyProperties#PURPOSE_SIGN`, the self-signed certificate generated by `KeyPairGenerator` of `AndroidKeyStore` provider will contain an invalid signature. This is OK if the certificate is only used for obtaining the public key from Android KeyStore. See `KeyProperties`.`PURPOSE` flags. Value is either `0` or a combination of `KeyProperties.PURPOSE_ENCRYPT`, `KeyProperties.PURPOSE_DECRYPT`, `KeyProperties.PURPOSE_SIGN`, `KeyProperties.PURPOSE_VERIFY`, `KeyProperties.PURPOSE_WRAP_KEY`, `KeyProperties.PURPOSE_AGREE_KEY`, and `KeyProperties.PURPOSE_ATTEST_KEY`

keystoreAlias

String: alias of the entry in which the generated key will appear in Android KeyStore. Must not be empty. This value cannot be null.

purposes

int: set of purposes (e.g., encrypt, decrypt, sign) for which the key can be used. Attempts to use the key for any other purpose will be rejected.

If the set of purposes for which the key can be used does not contain KeyProperties#PURPOSE_SIGN, the self-signed certificate generated by KeyPairGenerator of AndroidKeyStore provider will contain an invalid signature. This is OK if the certificate is only used for obtaining the public key from Android KeyStore.

See KeyProperties.PURPOSE flags. Value is either 0 or a combination of KeyProperties.PURPOSE_ENCRYPT, KeyProperties.PURPOSE_DECRYPT, KeyProperties.PURPOSE_SIGN, KeyProperties.PURPOSE_VERIFY, KeyProperties.PURPOSE_WRAP_KEY, KeyProperties.PURPOSE_AGREE_KEY, and KeyProperties.PURPOSE_ATTEST_KEY

Public methods

build

public KeyGenParameterSpec build ()

Builds an instance of KeyGenParameterSpec.

Returns
`KeyGenParameterSpec`	This value cannot be `null`.

setAlgorithmParameterSpec

public KeyGenParameterSpec.Builder setAlgorithmParameterSpec (AlgorithmParameterSpec spec)

Sets the algorithm-specific key generation parameters. For example, for RSA keys this may be an instance of RSAKeyGenParameterSpec whereas for EC keys this may be an instance of ECGenParameterSpec.

These key generation parameters must match other explicitly set parameters (if any), such as key size.

Parameters
`spec`	`AlgorithmParameterSpec`: This value cannot be `null`.

Returns
`KeyGenParameterSpec.Builder`

setAttestKeyAlias

public KeyGenParameterSpec.Builder setAttestKeyAlias (String attestKeyAlias)

Sets the alias of the attestation key that will be used to sign the attestation certificate for the generated key pair, if an attestation challenge is set with setAttestationChallenge(byte[]). If an attestKeyAlias is set but no challenge, KeyPairGenerator.initialize(int) will throw InvalidAlgorithmParameterException.

If the attestKeyAlias is set to null (the default), Android Keystore will select an appropriate system-provided attestation signing key. If not null, the alias must reference an Android Keystore Key that was created with KeyProperties.PURPOSE_ATTEST_KEY, or key generation will throw InvalidAlgorithmParameterException.

Parameters
`attestKeyAlias`	`String`: the alias of the attestation key to be used to sign the attestation certificate. This value may be `null`.

Returns
`KeyGenParameterSpec.Builder`

setAttestationChallenge

public KeyGenParameterSpec.Builder setAttestationChallenge (byte[] attestationChallenge)

Sets whether an attestation certificate will be generated for this key pair, and what challenge value will be placed in the certificate. The attestation certificate chain can be retrieved with with KeyStore.getCertificateChain(String).

If attestationChallenge is not null, the public key certificate for this key pair will contain an extension that describes the details of the key's configuration and authorizations, including the attestationChallenge value. If the key is in secure hardware, and if the secure hardware supports attestation, the certificate will be signed by a chain of certificates rooted at a trustworthy CA key. Otherwise the chain will be rooted at an untrusted certificate.

The purpose of the challenge value is to enable relying parties to verify that the key was created in response to a specific request. If attestation is desired but no challenged is needed, any non-null value may be used, including an empty byte array.

If attestationChallenge is null, and this spec is used to generate an asymmetric (RSA or EC) key pair, the public key certificate will be self-signed if the key has purpose KeyProperties.PURPOSE_SIGN. If the key does not have purpose KeyProperties.PURPOSE_SIGN, it is not possible to use the key to sign a certificate, so the public key certificate will contain a dummy signature.

Symmetric keys, such as AES and HMAC keys, do not have public key certificates. If a KeyGenParameterSpec.getAttestationChallenge() returns non-null and the spec is used to generate a symmetric (AES or HMAC) key, KeyGenerator.generateKey() will throw InvalidAlgorithmParameterException.

Parameters
`attestationChallenge`	`byte`

Returns
`KeyGenParameterSpec.Builder`

setBlockModes

public KeyGenParameterSpec.Builder setBlockModes (String... blockModes)

Sets the set of block modes (e.g., GCM, CBC) with which the key can be used when encrypting/decrypting. Attempts to use the key with any other block modes will be rejected.

This must be specified for symmetric encryption/decryption keys.

See KeyProperties.BLOCK_MODE constants.

Parameters
`blockModes`	`String`: Value is `KeyProperties.BLOCK_MODE_ECB`, `KeyProperties.BLOCK_MODE_CBC`, `KeyProperties.BLOCK_MODE_CTR`, or `KeyProperties.BLOCK_MODE_GCM`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setCertificateNotAfter

public KeyGenParameterSpec.Builder setCertificateNotAfter (Date date)

Sets the end of the validity period for the self-signed certificate of the generated key pair.

By default, this date is Jan 1 2048.

Parameters
`date`	`Date`: This value cannot be `null`.

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setCertificateNotBefore

public KeyGenParameterSpec.Builder setCertificateNotBefore (Date date)

Sets the start of the validity period for the self-signed certificate of the generated key pair.

By default, this date is Jan 1 1970.

Parameters
`date`	`Date`: This value cannot be `null`.

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setCertificateSerialNumber

public KeyGenParameterSpec.Builder setCertificateSerialNumber (BigInteger serialNumber)

Sets the serial number used for the self-signed certificate of the generated key pair.

By default, the serial number is 1.

Parameters
`serialNumber`	`BigInteger`: This value cannot be `null`.

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setCertificateSubject

public KeyGenParameterSpec.Builder setCertificateSubject (X500Principal subject)

Sets the subject used for the self-signed certificate of the generated key pair.

By default, the subject is CN=fake.

Parameters
`subject`	`X500Principal`: This value cannot be `null`.

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setDevicePropertiesAttestationIncluded

public KeyGenParameterSpec.Builder setDevicePropertiesAttestationIncluded (boolean devicePropertiesAttestationIncluded)

Sets whether to include the base device properties in the attestation certificate.

If attestationChallenge is not null, the public key certificate for this key pair will contain an extension that describes the details of the key's configuration and authorizations, including the device properties values (brand, device, manufacturer, model, product). These should be the same as in (Build#BRAND, Build#DEVICE, Build#MANUFACTURER, Build#MODEL, Build#PRODUCT). The attestation certificate chain can be retrieved with KeyStore.getCertificateChain(String).

If attestationChallenge is null, the public key certificate for this key pair will not contain the extension with the requested attested values.

KeyGenerator.generateKey() will throw ProviderException if device properties attestation fails or is not supported.

Parameters
`devicePropertiesAttestationIncluded`	`boolean`

Returns
`KeyGenParameterSpec.Builder`

setDigests

public KeyGenParameterSpec.Builder setDigests (String... digests)

Sets the set of digests algorithms (e.g., SHA-256, SHA-384) with which the key can be used. Attempts to use the key with any other digest algorithm will be rejected.

This must be specified for signing/verification keys and RSA encryption/decryption keys used with RSA OAEP padding scheme because these operations involve a digest. For HMAC keys, the default is the digest associated with the key algorithm (e.g., SHA-256 for key algorithm HmacSHA256). HMAC keys cannot be authorized for more than one digest.

For private keys used for TLS/SSL client or server authentication it is usually necessary to authorize the use of no digest (KeyProperties#DIGEST_NONE). This is because TLS/SSL stacks typically generate the necessary digest(s) themselves and then use a private key to sign it.

See KeyProperties.DIGEST constants.

Parameters
`digests`	`String`: Value is `KeyProperties.DIGEST_NONE`, `KeyProperties.DIGEST_MD5`, `KeyProperties.DIGEST_SHA1`, `KeyProperties.DIGEST_SHA224`, `KeyProperties.DIGEST_SHA256`, `KeyProperties.DIGEST_SHA384`, or `KeyProperties.DIGEST_SHA512`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setEncryptionPaddings

public KeyGenParameterSpec.Builder setEncryptionPaddings (String... paddings)

Sets the set of padding schemes (e.g., PKCS7Padding, OAEPPadding, PKCS1Padding, NoPadding) with which the key can be used when encrypting/decrypting. Attempts to use the key with any other padding scheme will be rejected.

This must be specified for keys which are used for encryption/decryption.

For RSA private keys used by TLS/SSL servers to authenticate themselves to clients it is usually necessary to authorize the use of no/any padding (KeyProperties#ENCRYPTION_PADDING_NONE) and/or PKCS#1 encryption padding (KeyProperties#ENCRYPTION_PADDING_RSA_PKCS1). This is because RSA decryption is required by some cipher suites, and some stacks request decryption using no padding whereas others request PKCS#1 padding.

See KeyProperties.ENCRYPTION_PADDING constants.

Parameters
`paddings`	`String`: Value is `KeyProperties.ENCRYPTION_PADDING_NONE`, `KeyProperties.ENCRYPTION_PADDING_PKCS7`, `KeyProperties.ENCRYPTION_PADDING_RSA_PKCS1`, or `KeyProperties.ENCRYPTION_PADDING_RSA_OAEP`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setInvalidatedByBiometricEnrollment

public KeyGenParameterSpec.Builder setInvalidatedByBiometricEnrollment (boolean invalidateKey)

Sets whether this key should be invalidated on biometric enrollment. This applies only to keys which require user authentication (see setUserAuthenticationRequired(boolean)) and if no positive validity duration has been set (see setUserAuthenticationValidityDurationSeconds(int), meaning the key is valid for biometric authentication only.

By default, invalidateKey is true, so keys that are valid for biometric authentication only are irreversibly invalidated when a new biometric is enrolled, or when all existing biometrics are deleted. That may be changed by calling this method with invalidateKey set to false.

Invalidating keys on enrollment of a new biometric or unenrollment of all biometrics improves security by ensuring that an unauthorized person who obtains the password can't gain the use of biometric-authenticated keys by enrolling their own biometric. However, invalidating keys makes key-dependent operations impossible, requiring some fallback procedure to authenticate the user and set up a new key.

Parameters
`invalidateKey`	`boolean`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setIsStrongBoxBacked

public KeyGenParameterSpec.Builder setIsStrongBoxBacked (boolean isStrongBoxBacked)

Sets whether this key should be protected by a StrongBox security chip.

Parameters
`isStrongBoxBacked`	`boolean`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setKeySize

public KeyGenParameterSpec.Builder setKeySize (int keySize)

Sets the size (in bits) of the key to be generated. For instance, for RSA keys this sets the modulus size, for EC keys this selects a curve with a matching field size, and for symmetric keys this sets the size of the bitstring which is their key material.

The default key size is specific to each key algorithm. If key size is not set via this method, it should be looked up from the algorithm-specific parameters (if any) provided via setAlgorithmParameterSpec.

Parameters
`keySize`	`int`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setKeyValidityEnd

public KeyGenParameterSpec.Builder setKeyValidityEnd (Date endDate)

Sets the time instant after which the key is no longer valid.

By default, the key is valid at any instant.

Parameters
`endDate`	`Date`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

See also:

setKeyValidityForConsumptionEnd

public KeyGenParameterSpec.Builder setKeyValidityForConsumptionEnd (Date endDate)

Sets the time instant after which the key is no longer valid for decryption and verification.

By default, the key is valid at any instant.

Parameters
`endDate`	`Date`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

See also:

setKeyValidityForOriginationEnd(Date)

setKeyValidityForOriginationEnd

public KeyGenParameterSpec.Builder setKeyValidityForOriginationEnd (Date endDate)

Sets the time instant after which the key is no longer valid for encryption and signing.

By default, the key is valid at any instant.

Parameters
`endDate`	`Date`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

See also:

setKeyValidityForConsumptionEnd(Date)

setKeyValidityStart

public KeyGenParameterSpec.Builder setKeyValidityStart (Date startDate)

Sets the time instant before which the key is not yet valid.

By default, the key is valid at any instant.

Parameters
`startDate`	`Date`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

See also:

setKeyValidityEnd(Date)

setMaxUsageCount

public KeyGenParameterSpec.Builder setMaxUsageCount (int maxUsageCount)

Sets the maximum number of times the key is allowed to be used. After every use of the key, the use counter will decrease. This authorization applies only to secret key and private key operations. Public key operations are not restricted. For example, after successfully encrypting and decrypting data using methods such as Cipher#doFinal(), the use counter of the secret key will decrease. After successfully signing data using methods such as Signature#sign(), the use counter of the private key will decrease. When the use counter is depleted, the key will be marked for deletion by Android Keystore and any subsequent attempt to use the key will throw KeyPermanentlyInvalidatedException. There is no key to be loaded from the Android Keystore once the exhausted key is permanently deleted, as if the key never existed before.

By default, there is no restriction on the usage of key.

Some secure hardware may not support this feature at all, in which case it will be enforced in software, some secure hardware may support it but only with maxUsageCount = 1, and some secure hardware may support it with larger value of maxUsageCount.

The PackageManger feature flags: PackageManager.FEATURE_KEYSTORE_SINGLE_USE_KEY and PackageManager.FEATURE_KEYSTORE_LIMITED_USE_KEY can be used to check whether the secure hardware cannot enforce this feature, can only enforce it with maxUsageCount = 1, or can enforce it with larger value of maxUsageCount.

Parameters
`maxUsageCount`	`int`: maximum number of times the key is allowed to be used or `KeyProperties#UNRESTRICTED_USAGE_COUNT` if there is no restriction on the usage.

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setRandomizedEncryptionRequired

public KeyGenParameterSpec.Builder setRandomizedEncryptionRequired (boolean required)

Sets whether encryption using this key must be sufficiently randomized to produce different ciphertexts for the same plaintext every time. The formal cryptographic property being required is indistinguishability under chosen-plaintext attack (IND-CPA). This property is important because it mitigates several classes of weaknesses due to which ciphertext may leak information about plaintext. For example, if a given plaintext always produces the same ciphertext, an attacker may see the repeated ciphertexts and be able to deduce something about the plaintext.

By default, IND-CPA is required.

When IND-CPA is required:

encryption/decryption transformation which do not offer IND-CPA, such as ECB with a symmetric encryption algorithm, or RSA encryption/decryption without padding, are prohibited;
in block modes which use an IV, such as GCM, CBC, and CTR, caller-provided IVs are rejected when encrypting, to ensure that only random IVs are used.

Before disabling this requirement, consider the following approaches instead:

If you are generating a random IV for encryption and then initializing a Cipher using the IV, the solution is to let the Cipher generate a random IV instead. This will occur if the Cipher is initialized for encryption without an IV. The IV can then be queried via Cipher#getIV().
If you are generating a non-random IV (e.g., an IV derived from something not fully random, such as the name of the file being encrypted, or transaction ID, or password, or a device identifier), consider changing your design to use a random IV which will then be provided in addition to the ciphertext to the entities which need to decrypt the ciphertext.
If you are using RSA encryption without padding, consider switching to encryption padding schemes which offer IND-CPA, such as PKCS#1 or OAEP.

Parameters
`required`	`boolean`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setSignaturePaddings

public KeyGenParameterSpec.Builder setSignaturePaddings (String... paddings)

Sets the set of padding schemes (e.g., PSS, PKCS#1) with which the key can be used when signing/verifying. Attempts to use the key with any other padding scheme will be rejected.

This must be specified for RSA keys which are used for signing/verification.

See KeyProperties.SIGNATURE_PADDING constants.

Parameters
`paddings`	`String`: Value is `KeyProperties.SIGNATURE_PADDING_RSA_PKCS1`, or `KeyProperties.SIGNATURE_PADDING_RSA_PSS`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setUnlockedDeviceRequired

public KeyGenParameterSpec.Builder setUnlockedDeviceRequired (boolean unlockedDeviceRequired)

Sets whether the keystore requires the screen to be unlocked before allowing decryption using this key. If this is set to true, any attempt to decrypt or sign using this key while the screen is locked will fail. A locked device requires a PIN, password, biometric, or other trusted factor to access. While the screen is locked, the key can still be used for encryption or signature verification.

Parameters
`unlockedDeviceRequired`	`boolean`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setUserAuthenticationParameters

public KeyGenParameterSpec.Builder setUserAuthenticationParameters (int timeout, 
                int type)

Sets the duration of time (seconds) and authorization type for which this key is authorized to be used after the user is successfully authenticated. This has effect if the key requires user authentication for its use (see setUserAuthenticationRequired(boolean)).

By default, if user authentication is required, it must take place for every use of the key.

These cryptographic operations will throw UserNotAuthenticatedException during initialization if the user needs to be authenticated to proceed. This situation can be resolved by the user authenticating with the appropriate biometric or credential as required by the key. See BiometricPrompt.Builder#setAllowedAuthenticators(int) and BiometricManager.Authenticators.

Once resolved, initializing a new cryptographic operation using this key (or any other key which is authorized to be used for a fixed duration of time after user authentication) should succeed provided the user authentication flow completed successfully.

Parameters
`timeout`	`int`: duration in seconds or `0` if user authentication must take place for every use of the key. Value is 0 or greater
`type`	`int`: set of authentication types which can authorize use of the key. See `KeyProperties`.`AUTH` flags. Value is either `0` or a combination of `KeyProperties.AUTH_BIOMETRIC_STRONG`, and `KeyProperties.AUTH_DEVICE_CREDENTIAL`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

See also:

setUserAuthenticationRequired

public KeyGenParameterSpec.Builder setUserAuthenticationRequired (boolean required)

Sets whether this key is authorized to be used only if the user has been authenticated.

By default, the key is authorized to be used regardless of whether the user has been authenticated.

When user authentication is required:

The key can only be generated if secure lock screen is set up (see KeyguardManager#isDeviceSecure()). Additionally, if the key requires that user authentication takes place for every use of the key (see setUserAuthenticationValidityDurationSeconds(int)), at least one biometric must be enrolled (see BiometricManager#canAuthenticate()).
The use of the key must be authorized by the user by authenticating to this Android device using a subset of their secure lock screen credentials such as password/PIN/pattern or biometric. More information.
The key will become irreversibly invalidated once the secure lock screen is disabled (reconfigured to None, Swipe or other mode which does not authenticate the user) or when the secure lock screen is forcibly reset (e.g., by a Device Administrator). Additionally, if the key requires that user authentication takes place for every use of the key, it is also irreversibly invalidated once a new biometric is enrolled or once\ no more biometrics are enrolled, unless setInvalidatedByBiometricEnrollment(boolean) is used to allow validity after enrollment. Attempts to initialize cryptographic operations using such keys will throw KeyPermanentlyInvalidatedException.

This authorization applies only to secret key and private key operations. Public key operations are not restricted.

Parameters
`required`	`boolean`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

See also:

setUserAuthenticationValidWhileOnBody

public KeyGenParameterSpec.Builder setUserAuthenticationValidWhileOnBody (boolean remainsValid)

Sets whether the key will remain authorized only until the device is removed from the user's body up to the limit of the authentication validity period (see setUserAuthenticationValidityDurationSeconds(int) and setUserAuthenticationRequired(boolean)). Once the device has been removed from the user's body, the key will be considered unauthorized and the user will need to re-authenticate to use it. For keys without an authentication validity period this parameter has no effect.

Similarly, on devices that do not have an on-body sensor, this parameter will have no effect; the device will always be considered to be "on-body" and the key will therefore remain authorized until the validity period ends.

Parameters
`remainsValid`	`boolean`: if `true`, and if the device supports on-body detection, key will be invalidated when the device is removed from the user's body or when the authentication validity expires, whichever occurs first.

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setUserAuthenticationValidityDurationSeconds

public KeyGenParameterSpec.Builder setUserAuthenticationValidityDurationSeconds (int seconds)

This method is deprecated.
See setUserAuthenticationParameters(int, int)

Sets the duration of time (seconds) for which this key is authorized to be used after the user is successfully authenticated. This has effect if the key requires user authentication for its use (see setUserAuthenticationRequired(boolean)).

By default, if user authentication is required, it must take place for every use of the key.

Cryptographic operations involving keys which require user authentication to take place for every operation can only use biometric authentication. This is achieved by initializing a cryptographic operation (Signature, Cipher, Mac) with the key, wrapping it into a BiometricPrompt.CryptoObject, invoking BiometricPrompt.authenticate with CryptoObject, and proceeding with the cryptographic operation only if the authentication flow succeeds.

Cryptographic operations involving keys which are authorized to be used for a duration of time after a successful user authentication event can only use secure lock screen authentication. These cryptographic operations will throw UserNotAuthenticatedException during initialization if the user needs to be authenticated to proceed. This situation can be resolved by the user unlocking the secure lock screen of the Android or by going through the confirm credential flow initiated by KeyguardManager#createConfirmDeviceCredentialIntent(CharSequence, CharSequence). Once resolved, initializing a new cryptographic operation using this key (or any other key which is authorized to be used for a fixed duration of time after user authentication) should succeed provided the user authentication flow completed successfully.

Parameters
`seconds`	`int`: duration in seconds or `-1` if user authentication must take place for every use of the key. Value is -1 or greater

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

See also:

setUserConfirmationRequired

public KeyGenParameterSpec.Builder setUserConfirmationRequired (boolean required)

Sets whether this key is authorized to be used only for messages confirmed by the user. Confirmation is separate from user authentication (see setUserAuthenticationRequired(boolean)). Keys can be created that require confirmation but not user authentication, or user authentication but not confirmation, or both. Confirmation verifies that some user with physical possession of the device has approved a displayed message. User authentication verifies that the correct user is present and has authenticated.

This authorization applies only to secret key and private key operations. Public key operations are not restricted. See ConfirmationPrompt class for more details about user confirmations.

Parameters
`required`	`boolean`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.

setUserPresenceRequired

public KeyGenParameterSpec.Builder setUserPresenceRequired (boolean required)

Sets whether a test of user presence is required to be performed between the Signature.initSign() and Signature.sign() method calls. It requires that the KeyStore implementation have a direct way to validate the user presence for example a KeyStore hardware backed strongbox can use a button press that is observable in hardware. A test for user presence is tangential to authentication. The test can be part of an authentication step as long as this step can be validated by the hardware protecting the key and cannot be spoofed. For example, a physical button press can be used as a test of user presence if the other pins connected to the button are not able to simulate a button press.There must be no way for the primary processor to fake a button press, or that button must not be used as a test of user presence.

Parameters
`required`	`boolean`

Returns
`KeyGenParameterSpec.Builder`	This value cannot be `null`.