Class3BiometricAuthExtensionsKt

Added in 1.4.0-alpha02

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Kotlin |Java

public final class Class3BiometricAuthExtensionsKt

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Summary

Public methods
static final @NonNull BiometricPrompt.AuthenticationResult	authenticate(     @NonNull Class3BiometricAuthPrompt receiver,     @NonNull AuthPromptHost host,     BiometricPrompt.CryptoObject crypto ) Shows an authentication prompt to the user.
static final @NonNull BiometricPrompt.AuthenticationResult	authenticateWithClass3Biometrics(     @NonNull Fragment receiver,     BiometricPrompt.CryptoObject crypto,     @NonNull CharSequence title,     @NonNull CharSequence negativeButtonText,     CharSequence subtitle,     CharSequence description,     boolean confirmationRequired ) Prompts the user to authenticate with a Class 3 biometric (e.g. fingerprint, face, or iris).
static final @NonNull BiometricPrompt.AuthenticationResult	authenticateWithClass3Biometrics(     @NonNull FragmentActivity receiver,     BiometricPrompt.CryptoObject crypto,     @NonNull CharSequence title,     @NonNull CharSequence negativeButtonText,     CharSequence subtitle,     CharSequence description,     boolean confirmationRequired ) Prompts the user to authenticate with a Class 3 biometric (e.g. fingerprint, face, or iris).
static final @NonNull AuthPrompt	authenticateWithClass3Biometrics(     @NonNull Fragment receiver,     BiometricPrompt.CryptoObject crypto,     @NonNull CharSequence title,     @NonNull CharSequence negativeButtonText,     CharSequence subtitle,     CharSequence description,     boolean confirmationRequired,     Executor executor,     @NonNull AuthPromptCallback callback ) Prompts the user to authenticate with a Class 3 biometric (e.g. fingerprint, face, or iris).
static final @NonNull AuthPrompt	authenticateWithClass3Biometrics(     @NonNull FragmentActivity receiver,     BiometricPrompt.CryptoObject crypto,     @NonNull CharSequence title,     @NonNull CharSequence negativeButtonText,     CharSequence subtitle,     CharSequence description,     boolean confirmationRequired,     Executor executor,     @NonNull AuthPromptCallback callback ) Prompts the user to authenticate with a Class 3 biometric (e.g. fingerprint, face, or iris).

Public methods

authenticate

Artifact: androidx.biometric:biometric-ktx

View Source

public static final @NonNull BiometricPrompt.AuthenticationResult authenticate(
    @NonNull Class3BiometricAuthPrompt receiver,
    @NonNull AuthPromptHost host,
    BiometricPrompt.CryptoObject crypto
)

Shows an authentication prompt to the user.

import androidx.biometric.BiometricPrompt
import androidx.biometric.auth.AuthPromptErrorException
import androidx.biometric.auth.AuthPromptFailureException
import androidx.biometric.auth.AuthPromptHost
import androidx.biometric.auth.Class3BiometricAuthPrompt
import androidx.biometric.auth.authenticate

// To use Class3 authentication, we need to create a CryptoObject.
// First create a spec for the key to be generated.
val keyPurpose = KeyProperties.PURPOSE_ENCRYPT or KeyProperties.PURPOSE_DECRYPT
val keySpec =
    KeyGenParameterSpec.Builder(KEY_NAME, keyPurpose)
        .apply {
            setBlockModes(KeyProperties.BLOCK_MODE_CBC)
            setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_PKCS7)
            setUserAuthenticationRequired(true)

            // Require authentication for each use of the key.
            val timeout = 0
            // Set the key type according to the allowed auth types.
            val keyType =
                KeyProperties.AUTH_BIOMETRIC_STRONG or KeyProperties.AUTH_DEVICE_CREDENTIAL
            setUserAuthenticationParameters(timeout, keyType)
        }
        .build()

// Generate and store the key in the Android keystore.
KeyGenerator.getInstance(KeyProperties.KEY_ALGORITHM_AES, KEYSTORE_INSTANCE).run {
    init(keySpec)
    generateKey()
}

// Prepare the crypto object to use for authentication.
val cipher =
    Cipher.getInstance(
            "${KeyProperties.KEY_ALGORITHM_AES}/${KeyProperties.BLOCK_MODE_CBC}/" +
                KeyProperties.ENCRYPTION_PADDING_PKCS7
        )
        .apply {
            val keyStore = KeyStore.getInstance(KEYSTORE_INSTANCE).apply { load(null) }
            init(Cipher.ENCRYPT_MODE, keyStore.getKey(KEY_NAME, null) as SecretKey)
        }

val cryptoObject = BiometricPrompt.CryptoObject(cipher)
val payload = "A message to encrypt".toByteArray(Charset.defaultCharset())

// Construct AuthPrompt with localized Strings to be displayed to UI.
val authPrompt =
    Class3BiometricAuthPrompt.Builder(title, negativeButtonText)
        .apply {
            setSubtitle(subtitle)
            setDescription(description)
            setConfirmationRequired(true)
        }
        .build()

try {
    val authResult = authPrompt.authenticate(AuthPromptHost(this), cryptoObject)

    // Encrypt a payload using the result of crypto-based auth.
    val encryptedPayload = authResult.cryptoObject?.cipher?.doFinal(payload)

    // Use the encrypted payload somewhere interesting.
    sendEncryptedPayload(encryptedPayload)
} catch (e: AuthPromptErrorException) {
    // Handle irrecoverable error during authentication.
    // Possible values for AuthPromptErrorException.errorCode are listed in the @IntDef,
    // androidx.biometric.BiometricPrompt.AuthenticationError.
} catch (e: AuthPromptFailureException) {
    // Handle auth failure due biometric credentials being rejected.
}

Parameters
@NonNull AuthPromptHost host	A wrapper for the component that will host the prompt.
BiometricPrompt.CryptoObject crypto	A cryptographic object to be associated with this authentication.

Returns
@NonNull BiometricPrompt.AuthenticationResult	AuthenticationResult for a successful authentication.

Throws
androidx.biometric.auth.AuthPromptErrorException	when an unrecoverable error has been encountered and authentication has stopped.
androidx.biometric.auth.AuthPromptFailureException	when an authentication attempt by the user has been rejected.

See also
authenticate	(AuthPromptHost, AuthPromptCallback)

authenticateWithClass3Biometrics

Artifact: androidx.biometric:biometric-ktx

View Source

public static final @NonNull BiometricPrompt.AuthenticationResult authenticateWithClass3Biometrics(
    @NonNull Fragment receiver,
    BiometricPrompt.CryptoObject crypto,
    @NonNull CharSequence title,
    @NonNull CharSequence negativeButtonText,
    CharSequence subtitle,
    CharSequence description,
    boolean confirmationRequired
)

Prompts the user to authenticate with a Class 3 biometric (e.g. fingerprint, face, or iris).

Parameters
BiometricPrompt.CryptoObject crypto	A cryptographic object to be associated with this authentication.
@NonNull CharSequence title	The title to be displayed on the prompt.
@NonNull CharSequence negativeButtonText	The label for the negative button on the prompt.
CharSequence subtitle	An optional subtitle to be displayed on the prompt.
CharSequence description	An optional description to be displayed on the prompt.
boolean confirmationRequired	Whether user confirmation should be required for passive biometrics.

Returns
@NonNull BiometricPrompt.AuthenticationResult	AuthenticationResult for a successful authentication.

Throws
androidx.biometric.auth.AuthPromptErrorException	when an unrecoverable error has been encountered and authentication has stopped.
androidx.biometric.auth.AuthPromptFailureException	when an authentication attempt by the user has been rejected.

See also
Class3BiometricAuthPrompt

authenticateWithClass3Biometrics

Artifact: androidx.biometric:biometric-ktx

View Source

public static final @NonNull BiometricPrompt.AuthenticationResult authenticateWithClass3Biometrics(
    @NonNull FragmentActivity receiver,
    BiometricPrompt.CryptoObject crypto,
    @NonNull CharSequence title,
    @NonNull CharSequence negativeButtonText,
    CharSequence subtitle,
    CharSequence description,
    boolean confirmationRequired
)

Prompts the user to authenticate with a Class 3 biometric (e.g. fingerprint, face, or iris).

Parameters
BiometricPrompt.CryptoObject crypto	A cryptographic object to be associated with this authentication.
@NonNull CharSequence title	The title to be displayed on the prompt.
@NonNull CharSequence negativeButtonText	The label for the negative button on the prompt.
CharSequence subtitle	An optional subtitle to be displayed on the prompt.
CharSequence description	An optional description to be displayed on the prompt.
boolean confirmationRequired	Whether user confirmation should be required for passive biometrics.

Returns
@NonNull BiometricPrompt.AuthenticationResult	AuthenticationResult for a successful authentication.

Throws
androidx.biometric.auth.AuthPromptErrorException	when an unrecoverable error has been encountered and authentication has stopped.
androidx.biometric.auth.AuthPromptFailureException	when an authentication attempt by the user has been rejected.

See also
Class3BiometricAuthPrompt

authenticateWithClass3Biometrics

Artifact: androidx.biometric:biometric-ktx

View Source

Added in 1.4.0-alpha02

public static final @NonNull AuthPrompt authenticateWithClass3Biometrics(
    @NonNull Fragment receiver,
    BiometricPrompt.CryptoObject crypto,
    @NonNull CharSequence title,
    @NonNull CharSequence negativeButtonText,
    CharSequence subtitle,
    CharSequence description,
    boolean confirmationRequired,
    Executor executor,
    @NonNull AuthPromptCallback callback
)

Prompts the user to authenticate with a Class 3 biometric (e.g. fingerprint, face, or iris).

Parameters
BiometricPrompt.CryptoObject crypto	A cryptographic object to be associated with this authentication.
@NonNull CharSequence title	The title to be displayed on the prompt.
@NonNull CharSequence negativeButtonText	The label for the negative button on the prompt.
CharSequence subtitle	An optional subtitle to be displayed on the prompt.
CharSequence description	An optional description to be displayed on the prompt.
boolean confirmationRequired	Whether user confirmation should be required for passive biometrics.
Executor executor	An executor for callback methods. If null, these will run on the main thread.
@NonNull AuthPromptCallback callback	The object that will receive and process authentication events.

Returns
@NonNull AuthPrompt	An AuthPrompt handle to the shown prompt.

See also
Class3BiometricAuthPrompt

authenticateWithClass3Biometrics

Artifact: androidx.biometric:biometric-ktx

View Source

Added in 1.4.0-alpha02

public static final @NonNull AuthPrompt authenticateWithClass3Biometrics(
    @NonNull FragmentActivity receiver,
    BiometricPrompt.CryptoObject crypto,
    @NonNull CharSequence title,
    @NonNull CharSequence negativeButtonText,
    CharSequence subtitle,
    CharSequence description,
    boolean confirmationRequired,
    Executor executor,
    @NonNull AuthPromptCallback callback
)

Prompts the user to authenticate with a Class 3 biometric (e.g. fingerprint, face, or iris).

Parameters
BiometricPrompt.CryptoObject crypto	A cryptographic object to be associated with this authentication.
@NonNull CharSequence title	The title to be displayed on the prompt.
@NonNull CharSequence negativeButtonText	The label for the negative button on the prompt.
CharSequence subtitle	An optional subtitle to be displayed on the prompt.
CharSequence description	An optional description to be displayed on the prompt.
boolean confirmationRequired	Whether user confirmation should be required for passive biometrics.
Executor executor	An executor for callback methods. If null, these will run on the main thread.
@NonNull AuthPromptCallback callback	The object that will receive and process authentication events.

Returns
@NonNull AuthPrompt	An AuthPrompt handle to the shown prompt.

See also
Class3BiometricAuthPrompt