Credential Manager Documentation

Credential Manager Overview

Credential Manager is a Jetpack API that supports multiple sign-in methods, such as username and password, passkeys, and federated sign-in solutions (like Sign-in with Google) in a single API, simplifying integration for developers.

For users, Credential Manager unifies the sign-in interface across authentication methods, making it clearer and easier to sign into apps, regardless of the chosen method.

Note: This package is currently only supported for Android.

Getting Started

Add the dependency to your pubspec.yaml file:

dependencies:
            credential_manager: <latest_version>

Or run:

flutter pub add credential_manager

Setup Android

1. Add proguard rules:

   Create or update android/app/proguard-rules.pro:

   -if class androidx.credentials.CredentialManager
                   -keep class androidx.credentials.playservices. {
                   ;
                   }

2. Update android/app/build.gradle:

   android {
                   buildTypes {
                   release {
                   minifyEnabled true
                   proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
                   }
                   }
                   }

Usage in Flutter

1. Import the package:

   import 'package:credential_manager/credential_manager.dart';

2. Create a CredentialManager instance:

   CredentialManager credentialManager = CredentialManager();

3. Check if the platform is supported:

   if (credentialManager.isSupportedPlatform) {
               // Supported
               }

4. Initialize the Credential Manager:

   await credentialManager.init(
               preferImmediatelyAvailableCredentials: true,
               googleClientId: googleClientId // Optional for Google Sign-In
               );

5. Save credentials:

   await credentialManager.savePasswordCredentials(
               PasswordCredential(username: username, password: password)
               );

6. Get saved credentials:

   Credentials credential = await credentialManager.getPasswordCredentials();

7. Logout:

   await credentialManager.logout();

Google Sign-In Setup (Optional)

1. Access Google Cloud Console
2. Create or select a project
3. Configure OAuth Consent Screen
4. Create Credentials (OAuth client ID)
5. Set Application Type to Android
6. Configure Android App (package name and SHA-1)
7. Create Web Application Credentials
8. Obtain Client ID for use in Flutter app

Implementation in Flutter:

await credentialManager.init(
            preferImmediatelyAvailableCredentials: true,
            googleClientId: 'YOUR_WEB_CLIENT_ID_HERE'
            );

Passkey Integration

Prerequisites

• An Android app with a unique package name
• A website (sign-in domain) for authentication

Steps

1. Create and host a Digital Asset Links JSON file
2. Configure your host to allow Google to retrieve the file

Create Passkey

final res = await credentialManager.savePasskeyCredentials(
            request: CredentialCreationOptions.fromJson({
            // Passkey creation options
            })
            );

Fetch Generated Passkey

CredentialLoginOptions? passKeyLoginOption = CredentialLoginOptions(
            challenge: "<challenge>",
            rpId: "<domain.com>",
            userVerification: "required",
            );
            Credentials credential = await credentialManager.getEncryptedCredentials(
            secretKey: secretKey,
            ivKey: ivKey,
            passKeyOption: passKeyLoginOption
            );
            bool isPublicKeyBasedCredentials = credential.publicKeyCredential != null;

Error Handling

When an exception occurs, a CredentialException is thrown with the following fields:

• int code: A numeric identifier for the error
• String message: A descriptive message about the error

Error Codes and Descriptions

Handling Exceptions

try {
            // Credential Manager operation
            await credentialManager.someOperation();
            } on CredentialException catch (e) {
            print('Error Code: ${e.code}');
            print('Error Message: ${e.message}');
            // Handle the error appropriately
            } catch (e) {
            // Handle other unexpected errors
            print('Unexpected error: $e');
            }

Contributors

Djsmk123

jlafazia-figure

wildsylvan

Granfalloner