Tutorial: Prepare your Android mobile app for native authentication

Άρθρο
05/30/2024

This tutorial demonstrates how to add Microsoft Authentication Library (MSAL) native authentication SDK to an Android mobile app.

In this tutorial, you learn how to:

Add MSAL dependencies.
Create a configuration file.
Create MSAL SDK instance.

Prerequisites

If you haven't already, follow the instructions in Sign in users in sample Android (Kotlin) mobile app by using native authentication and register an app in your external tenant. Make sure you complete the following steps:
- Register an application.
- Enable public client and native authentication flows.
- Grant API permissions.
- Create a user flow.
- Associate the app with the user flow.
An Android project. If you don't have an Android project, create it.

Add MSAL dependencies

Open your project in Android Studio or create a new project.

Open your application's build.gradle and add the following dependencies:

allprojects {
    repositories {
        //Needed for com.microsoft.device.display:display-mask library
        maven {
            url 'https://pkgs.dev.azure.com/MicrosoftDeviceSDK/DuoSDK-Public/_packaging/Duo-SDK-Feed/maven/v1'
            name 'Duo-SDK-Feed'
        }
        mavenCentral()
        google()
    }
}
//...

dependencies { 
    implementation 'com.microsoft.identity.client:msal:5.+'
    //...
}

In Android Studio, select File > Sync Project with Gradle Files.

Create a configuration file

You pass the required tenant identifiers, such as the application (client) ID, to the MSAL SDK through a JSON configuration setting.

Use these steps to create configuration file:

In Android Studio's project pane, navigate to app\src\main\res.
Right-click res and select New > Directory. Enter raw as the new directory name and select OK.
In app\src\main\res\raw, create a new JSON file called auth_config_native_auth.json.

In the auth_config_native_auth.json file, add the following MSAL configurations:

{ 
  "client_id": "Enter_the_Application_Id_Here", 
  "authorities": [ 
    { 
      "type": "CIAM", 
      "authority_url": "https://Enter_the_Tenant_Subdomain_Here.ciamlogin.com/Enter_the_Tenant_Subdomain_Here.onmicrosoft.com/" 
    } 
  ], 
  "challenge_types": ["oob"], 
  "logging": { 
    "pii_enabled": false, 
    "log_level": "INFO", 
    "logcat_enabled": true 
  } 
} 
 //...

Replace the following placeholders with your tenant values that you obtained from the Microsoft Entra admin center:
- Replace the Enter_the_Application_Id_Here placeholder with the application (client) ID of the app you registered earlier.
- Replace the Enter_the_Tenant_Subdomain_Here with the directory (tenant) subdomain. For example, if your tenant primary domain is contoso.onmicrosoft.com, use contoso. If you don't have your tenant name, learn how to read your tenant details.
The challenge types are a list of values, which the app uses to notify Microsoft Entra about the authentication method that it supports.
- For sign-up and sign-in flows with email one-time passcode, use ["oob"].
- For sign-up and sign-in flows with email and password, use ["oob","password"].
- For self-service password reset (SSPR), use ["oob"].
Learn more challenge types.

Optional: Logging configuration

Turn on logging at app creation by creating a logging callback, so the SDK can output logs.

import com.microsoft.identity.client.Logger

fun initialize(context: Context) {
        Logger.getInstance().setExternalLogger { tag, logLevel, message, containsPII ->
            Logs.append("$tag $logLevel $message")
        }
    }

To configure the logger, you need to add a section in the configuration file, auth_config_native_auth.json:

    //...
   { 
     "logging": { 
       "pii_enabled": false, 
       "log_level": "INFO", 
       "logcat_enabled": true 
     } 
   } 
    //...

logcat_enabled: Enables the logging functionality of the library.
pii_enabled: Specifies whether messages containing personal data, or organizational data are logged. When set to false, logs won't contain personal data. When set to true, the logs might contain personal data.
log_level: Use it to decide which level of logging to enable. Android supports the following log levels:
1. ERROR
2. WARNING
3. INFO
4. VERBOSE

For more information on MSAL logging, see Logging in MSAL for Android.

Create native authentication MSAL SDK instance

In the onCreate() method, create an MSAL instance so the app can perform authentication with your tenant through native authentication. The createNativeAuthPublicClientApplication() method returns an instance called authClient. Pass the JSON configuration file that you created earlier as a parameter.

    //...
    authClient = PublicClientApplication.createNativeAuthPublicClientApplication( 
        this, 
        R.raw.auth_config_native_auth 
    )
    //...

Your code should look something similar to the following snippet:

    class MainActivity : AppCompatActivity() { 
        private lateinit var authClient: INativeAuthPublicClientApplication 
 
        override fun onCreate(savedInstanceState: Bundle?) { 
            super.onCreate(savedInstanceState) 
            setContentView(R.layout.activity_main) 
 
            authClient = PublicClientApplication.createNativeAuthPublicClientApplication( 
                this, 
                R.raw.auth_config_native_auth 
            ) 
            getAccountState() 
        } 
 
        private fun getAccountState() {
            CoroutineScope(Dispatchers.Main).launch {
                val accountResult = authClient.getCurrentAccount()
                when (accountResult) {
                    is GetAccountResult.AccountFound -> {
                        displaySignedInState(accountResult.resultValue)
                    }
                    is GetAccountResult.NoAccountFound -> {
                        displaySignedOutState()
                    }
                }
            }
        } 
 
        private fun displaySignedInState(accountResult: AccountState) { 
            val accountName = accountResult.getAccount().username 
            val textView: TextView = findViewById(R.id.accountText) 
            textView.text = "Cached account found: $accountName" 
        } 
 
        private fun displaySignedOutState() { 
            val textView: TextView = findViewById(R.id.accountText) 
            textView.text = "No cached account found" 
        } 
    }

Retrieve the cached account by using the getCurrentAccount(), which returns an object, accountResult.
If an account is found in persistence, use GetAccountResult.AccountFound to display a signed-in state.
Otherwise, use GetAccountResult.NoAccountFound to display a signed-out state.

Make sure you include the import statements. Android Studio should include the import statements for you automatically.

Next step

Tutorial: Add sign-up in an Android mobile app using native authentication

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