setup-android-wallet-sdk

Requirements

• Android 9+ (API level 28+)
• Android Studio
• Kotlin

Prerequisites

• Create an application to obtain a base URL. The SDK uses this base URL to interact with the LoginID authentication service.
• Create an API key with at least the external:verify scope. You’ll need this to request authorization tokens from your backend.

Before installing the SDK, configure the association between your Android application and your website using a Digital Asset Links file.

Configure Digital Asset Links

Android uses a Digital Asset Links file named assetlinks.json to verify the association between your application and your website.

Find Your Package Name

You can find your application's package name in the app module's build.gradle.kts file under defaultConfig:

android {
    defaultConfig {
        applicationId = "<PACKAGE_NAME>"
    }
}

Generate the SHA-256 Certificate Fingerprint

Use the keytool utility included with the Java Development Kit to retrieve the SHA-256 fingerprint of your application's signing certificate:

keytool -list -v \
  -keystore KEYSTORE_PATH \
  -alias KEYSTORE_ALIAS \
  -storepass KEYSTORE_PASSWORD \
  -keypass KEY_PASSWORD

Replace the following values:

• KEYSTORE_PATH with the path to your keystore
• KEYSTORE_ALIAS with the signing-key alias
• KEYSTORE_PASSWORD with the keystore password
• KEY_PASSWORD with the signing-key password

The command output includes the certificate's SHA-256 fingerprint.

Local Development

For local development, you can use the default Android debug keystore with the following values:

• KEYSTORE_ALIAS: androiddebugkey
• KEYSTORE_PASSWORD: android
• KEY_PASSWORD: android

Use a dedicated signing key for production applications. For applications distributed through Google Play, you can find the app-signing certificate fingerprint in the Google Play Console.

Register the Fingerprint

Register your application's SHA-256 certificate fingerprint in your LoginID application's FIDO2 section before continuing. For instructions, see Adding Android Fingerprint.

Host the assetlinks.json File

Create an assetlinks.json file containing your application's package name and SHA-256 certificate fingerprint:

[
  {
    "relation": [
      "delegate_permission/common.get_login_creds"
    ],
    "target": {
      "namespace": "android_app",
      "package_name": "<PACKAGE_NAME>",
      "sha256_cert_fingerprints": [
        "<SHA256_FINGERPRINT>"
      ]
    }
  }
]

Replace <PACKAGE_NAME> and <SHA256_FINGERPRINT> with your application's values.

Host the file at the following location:

https://<WEBSITE_DOMAIN>/.well-known/assetlinks.json

The file must be publicly accessible over HTTPS.

Declare the Association in Your Android Application

Add an asset_statements resource to res/values/strings.xml:

<resources>
    <string name="asset_statements" translatable="false">
        [{
            \"include\": \"https://<WEBSITE_DOMAIN>/.well-known/assetlinks.json\"
        }]
    </string>
</resources>

Then add the corresponding <meta-data> element inside the <application> element of your AndroidManifest.xml file:

<manifest xmlns:android="http://schemas.android.com/apk/res/android">
    <application>
        <meta-data
            android:name="asset_statements"
            android:resource="@string/asset_statements" />
    </application>
</manifest>

Set Up the SDK

Add the SDK dependency

First, ensure you have the Maven Central repository in your project's settings.gradle.kts file:

dependencyResolutionManagement {
  repositories {
      google()
      mavenCentral()
  }
}

Next, add the SDK and required dependencies to your app module's build.gradle.kts:

dependencies {
  // LoginID SDK
  implementation("io.loginid:undefined:1.0.1")
}

Initialize the SDK

Kotlin

import io.loginid.LoginIDAuth

class MyApplication : Application() {
  val lid = LoginIDAuth(<LOGINID_BASE_URL>)

  override fun onCreate() {
      super.onCreate()

      // Additional setup...
  }
}

info

You can view the source code here.