Class2BiometricAuthExtensionsKt

public static final @NonNull BiometricPrompt.AuthenticationResult authenticate(
    @NonNull Class2BiometricAuthPrompt receiver,
    @NonNull AuthPromptHost host
)

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.Class2BiometricAuthPrompt
import androidx.biometric.auth.authenticate

val payload = "A message to encrypt".toByteArray(Charset.defaultCharset())

// Construct AuthPrompt with localized Strings to be displayed to UI.
val authPrompt =
    Class2BiometricAuthPrompt.Builder(title, negativeButtonText)
        .apply {
            setSubtitle(subtitle)
            setDescription(description)
            setConfirmationRequired(true)
        }
        .build()

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

    // 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.
}

public static final @NonNull BiometricPrompt.AuthenticationResult authenticateWithClass2Biometrics(
    @NonNull Fragment receiver,
    @NonNull CharSequence title,
    @NonNull CharSequence negativeButtonText,
    CharSequence subtitle,
    CharSequence description,
    boolean confirmationRequired
)

Prompts the user to authenticate with a Class 2 biometric (e.g. fingerprint, face, or iris).

Note that Class 3 biometrics are guaranteed to meet the requirements for Class 2 and thus will also be accepted.

public static final @NonNull BiometricPrompt.AuthenticationResult authenticateWithClass2Biometrics(
    @NonNull FragmentActivity receiver,
    @NonNull CharSequence title,
    @NonNull CharSequence negativeButtonText,
    CharSequence subtitle,
    CharSequence description,
    boolean confirmationRequired
)

Prompts the user to authenticate with a Class 2 biometric (e.g. fingerprint, face, or iris).

Note that Class 3 biometrics are guaranteed to meet the requirements for Class 2 and thus will also be accepted.

public static final @NonNull AuthPrompt startClass2BiometricAuthentication(
    @NonNull Fragment receiver,
    @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 2 biometric (e.g. fingerprint, face, or iris).

Note that Class 3 biometrics are guaranteed to meet the requirements for Class 2 and thus will also be accepted.

public static final @NonNull AuthPrompt startClass2BiometricAuthentication(
    @NonNull FragmentActivity receiver,
    @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 2 biometric (e.g. fingerprint, face, or iris).

Note that Class 3 biometrics are guaranteed to meet the requirements for Class 2 and thus will also be accepted.