BiometricAuthenticatorConfig

Configuration class for biometric authenticators that defines UI prompts, key generation, and hardware preferences.

This DSL-style configuration class provides comprehensive control over biometric authentication behavior, including user interface presentation, cryptographic key generation parameters, and hardware security preferences. The configuration follows a builder pattern allowing flexible customization while providing sensible defaults for most biometric authentication scenarios.

Key configuration areas:

• UI Presentation: Customizable biometric prompt appearance and messaging

• Key Generation: Hardware-backed cryptographic key parameters and specifications

• Hardware Preferences: StrongBox support and security enclave utilization

• Logging: Configurable logging for debugging and monitoring biometric operations

• Biometric Management: Integration with Android BiometricManager APIs

Default configuration provides:

• Standard logging through the SDK logger

• Software-backed key generation (StrongBox disabled by default)

• Empty prompt configuration (requires customization)

• Default Android Keystore key generation parameters

• Automatic BiometricManager initialization

Example usage:

val authenticator = BiometricOnlyAuthenticator {
    strongBoxPreferred = true

    promptInfo {
        setTitle("Authenticate with Biometric")
        setSubtitle("Use your fingerprint or face")
        setDescription("This verifies your identity for secure access")
        setNegativeButtonText("Cancel")
    }

    keyGenParameterSpec {
        setUserAuthenticationRequired(true)
        setUserAuthenticationValidityDurationSeconds(0) // Require auth for each use
        setInvalidatedByBiometricEnrollment(true)
    }

    logger = Logger.create("BiometricAuth")
}

Security considerations:

• StrongBox provides highest security but limited device support

• Key invalidation on biometric changes prevents unauthorized access

• User authentication requirements ensure fresh biometric verification

• Logging should be disabled or filtered in production builds

Hardware compatibility:

• Requires Android 6.0+ (API 23) for basic biometric support

• Android 9.0+ (API 28) recommended for BiometricPrompt APIs

• StrongBox requires Android 9.0+ and compatible hardware

• Biometric sensors (fingerprint, face, iris) must be available

See also