BiometricAuthenticator is a library that facilitates biometric authentication in Android applications using Jetpack Compose.

• Fingerprint and facial recognition authentication.
• Easy integration with Jetpack Compose.
• Customizable authentication dialog.

To include BiometricAuthenticator in your project, add the following dependency to your build.gradle file:

dependencies {
    implementation 'com.thinkup:biometric-authenticator-library:1.1'
}

To use BiometricAuthenticator, first ensure that your Activity extends FragmentActivity.

Here is a basic example of how to use BiometricAuthDialog to authenticate a user:

import com.thinkup.biometric_authenticator_library.components.BiometricAuthDialog

Column(
    modifier = Modifier
        .fillMaxWidth()
        .background(feedbackColor)
        .padding(24.dp),
    verticalArrangement = Arrangement.Center
) {
    Button(
        modifier = Modifier.fillMaxWidth(),
        onClick = { showDialog = !showDialog }) {
        Text(text = "LOGIN")
    }

    if (showDialog) {
        BiometricAuthDialog(
            context = context,
            prefKey = "KEY_FOR_LOGIN",
            title = "Enable biometrics",
            subtitle = "Do you want to allow the use of biometrics to access?",
            negativeButtonText = "Cancel",
            onSuccess = {
                showDialog = false
                feedbackColor = Color.Green
            },
            onFailed = {
                showDialog = false
                feedbackColor = Color.Red
            },
            onError = { errorCode, errString ->
                showDialog = false
                feedbackColor = Color.Red
            },
            onCanceled = {
                showDialog = false
                feedbackColor = Color.Red
            }
        )
    }
}

BiometricAuthDialog allows opening a biometric authentication dialog.

Parameters:

• context: The current context.
• prefKey: Key to store preferences.
• title: Dialog title.
• subtitle: Dialog subtitle.
• negativeButtonText: Text of the negative button.
• onSuccess: Lambda executed on successful authentication.
• onFailed: Lambda executed when authentication fails.
• onError: Lambda executed when an error occurs in the authentication, with parameters errorCode (error code) and errString (error message).
• onCanceled: Lambda executed if the user cancels the authentication.

Checks if the device supports and is set up for biometric authentication.

Parameters:

• prefKey: Key used to store the encrypted token.
• type: Type of biometric authentication (LOGIN or TRANSFER).

Return:

• BiometricAuthStatus: Status of the availability of biometric authentication.

Example:

val biometricStatus = biometricAuthenticator.checkBiometricAvailability("KEY_FOR_LOGIN", BiometricType.LOGIN)
if (biometricStatus == BiometricAuthStatus.READY) {
    // Proceed with authentication
} else {
    // Handle other states
}

Encrypts a token using biometric authentication for added security.

Parameters:

• token: The string to be encrypted.
• authResult: Result of the biometric authentication that contains the Cipher.
• prefKeyToken: Key to store the encrypted token in SharedPreferences.

Example:

biometricAuthenticator.encryptToken("mySensitiveToken", authResult, "KEY_FOR_LOGIN")

Decrypts a token encrypted using biometric authentication.

Parameters:

• authResult: Result of the biometric authentication that contains the Cipher.
• prefKey: Key to retrieve the encrypted token from SharedPreferences.

Return:

• String: Decrypted token.

Example:

val decryptedToken = biometricAuthenticator.decryptToken(authResult, "KEY_FOR_LOGIN")