Credential Manager

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

Furthermore, for users, Credential Manager unifies the sign-in interface across authentication methods, making it clearer and easier for users to sign into apps, regardless of the method they choose

Note this package is only supported for android

Getting Started

• Add the dependency to your pubspec.yaml file

  dependencies:
     credential_manager: <latest_version>
  

  --------------------------------------------OR------------------------------------------------

  flutter pub get credential_manager
  

Setup android

• Add proguard rules if proguard-rules.pro is not exist in android/app then create new file with same name

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

• Update android\app\build.gradle

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

Setup Google Sign In (optional)

• Google Cloud Console Set Up
• Go to Google Could Console
• Create a project if you haven’t yet.
• Find the search bar (top center) and type “Credentials” and select Credentials under “Product & Pages”.
• Find the “Create Credentials” button and click it!
• Click on “OAuth client ID” from the pop-up window.
• We have to select an “Application Type”.
• Add package ID and Get debug SHA-1 and release SHA-1
  • cd android
  • ./gradlew signInReport
• Copy WebClient(auto created by google)

Usage in flutter

• import the package

  import 'package:credential_manager/credential_manager dart';
  

• Create object for CredentialManager()

  CredentialManager credentialManager = CredentialManager();
  

• Check if target platform is supported or not

if(credentialManager.isSupportedPlatform){
    // if supported
}

• Initialize credential manager

if(credentialManager.isSupportedPlatform){
    // if supported
    await credentialManager.init(preferImmediatelyAvailableCredentials: true
    //optional perameter for integrate google signing
        googleClientId: googleClientId 
    );

}

Note: If the call to Credential Manager was triggered by an explicit user action, credential will be available immediately after saving if true(by default) or user will not able to get credential as soon as possible(May throw error if fetched just after saving credentials)

If you want to encrypted credential manager encrypted_credential_manager

• Save credentials in credential manager

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

• Save Google credentials in credential manager

final GoogleIdTokenCredential? gCredential= await credentialManager.saveGoogleCredential();

Note: It is not necessary to be username and password,you can send any string you want to store but you will get credentials as PasswordCredential which has username and password properties.

• Get the saved credentials

 Credentials credential =await credentialManager.getPasswordCredentials();

Encrypt Your credentials

To ensure the security of credentials, we will encrypt the password field using the encrypt library and store the encrypted information in a credential manager. This approach reduces the risk of exposing sensitive information, such as passwords.

To encrypt value and decrypt the encrypted data, you need 128 bit-key of secret_key and 128 bit-key of iv_key.

you need to provide a 16 character string as a key.

  final secretKey = "<Secret-key>"; // Use a secure key here for example "1234567812345678"
  final ivKey = "<16-bit-iv-key>" //for e.g: "xfpkDQJXIfb3mcnb"; 

• Save encrypted credentials

await credentialManager.saveEncryptedCredentials(
        credential: PasswordCredential(username: username, password: password),
        secretKey: secretKey,
        ivKey: ivKey,
      );

• Get encrypted credentials and decrypted the sensitive data

 Credentials credential = await credentialManager
          .getEncryptedCredentials(secretKey: secretKey, ivKey: ivKey);

Properties and Methods

Method	Type	Description
isSupportedPlatform	boolean	Check if targeted platform supported or not(Only Android supported)
init(bool preferImmediatelyAvailableCredentials,googleClientId)	Future(void)	To initialize credential Manager,preferImmediatelyAvailableCredentials,If the call to Credential Manager was triggered by an explicit user action, credential will be available immediately after saving if true(by default) or user will not able to get credential as soon as possible(May throw error if fetched just after saving credentials) googleClientId(optional) required when google sign-in is enabled
savePasswordCredentials(PasswordCredential credential)	Future(void)	To save credentials in credential Manager
saveEncryptedCredentials(PasswordCredential credential,String secretKey,String ivKey)	Future(void)	To save credentials in credential Manager with encryption
getPasswordCredentials()	Future(Credential)	return Credential object which has either GoogleIdTokenCredential or PasswordCredential at time, other would have null value.
getEncryptedCredentials(String secretKey,String ivKey)	Future(Credential )	which has either GoogleIdTokenCredential or PasswordCredential at time, other would have null value. if PasswordCredential is not null then password will be return as decrypted values.

About PasswordCredential()

Field	Type	Description
username	String?	User's username for authentication.
password	String?	User's password for authentication.
Constructor:
PasswordCredential({String? username, String? password})	Creates a new instance of PasswordCredential.
Properties:
String? get username => _username;	Retrieves the username.
set username(String? username) => _username = username;	Sets the username.
String? get password => _password;	Retrieves the password.
set password(String? password) => _password = password;	Sets the password.
JSON Serialization/Deserialization:
PasswordCredential.fromJson(Map<String, dynamic> json)	Creates an instance from a JSON map.
Map<String, dynamic> toJson()	Converts the instance to a JSON map.

About GoogleIdTokenCredential()

Field	Type	Description
id	String	Identifier for the Google account.
idToken	String	Google ID token for authentication.
displayName	String?	Display name of the user.
familyName	String?	Family name of the user.
givenName	String?	Given name of the user.
phoneNumber	String?	Phone number of the user.
profilePictureUri	Uri?	URI for the user's profile picture.

About Credentials()

Field	Type	Description
passwordCredential	PasswordCredential?	Password credentials for authentication. Null if not available.
googleIdTokenCredential	GoogleIdTokenCredential?	Google ID token credentials. Null if not available.

NOTE: at a time only one of them will be not null.

Error Handling

if any exception occurs it throws CredentialException which has field int code and String message.

Code	Message	Description
101	Initialization failure	The initialization process encountered an error.
102	Plugin exception	An exception occurred within the plugin.
103	Not implemented	The functionality is not implemented.
201	Login cancelled	The login process was cancelled by the user.
202	No credentials found	No valid credentials were found for authentication.
203	Mismatched credentials	The provided credentials do not match the expected format.
204	Login failed	The login attempt was unsuccessful.
301	Save Credentials cancelled	The process of saving credentials was cancelled by the user.
302	Create Credentials failed	Failed to create new credentials.
401	Encryption failed	Failed to encrypt value.
402	Decryption failed	Failed to decrypt value.
501	Received an invalid google id token response	Bad response received from Custom Credentials
502	Invalid request	Invalid request has been made while saving google credentials
503	Google client is not initialized yet	Google Web token Id is invalid or not missing
504	Credentials operation failed	Operation failed,something went wrong

Upcoming

• iOS Support
• Passkey extension for flawless integration with web

Contributing

• Fork it
• Create your feature branch (git checkout -b my-new-feature)
• Commit your changes (git commit -am 'Add some feature')
• Push to the branch (git push origin my-new-feature)
• Create new Pull Request
• If you have any questions, please open an issue.
• If you found a bug, please open an issue.
• If you have a feature request, please open an issue.
• If you want to contribute, please submit a pull request.
• If you use this package, please add a star on GitHub.
• If you use this package, please tweet about it.
• If you use this package, please mention it in a blog post.