Google Auth Library

Open source authentication client library for Java.

• API Documentation

This project consists of 3 artifacts:

• google-auth-library-credentials: contains base classes and
  interfaces for Google credentials
• google-auth-library-appengine: contains App Engine
  credentials. This artifacts depends on the App Engine SDK
• google-auth-library-oauth2-http: contains a wide variety of
  credentials as well as utility methods to create them and to get Application Default Credentials

Note: This client is a work-in-progress, and may occasionally
make backwards-incompatible changes.

Quickstart

If you are using Maven, add this to your pom.xml file (notice that you can replace
google-auth-library-oauth2-http with any of google-auth-library-credentials and
google-auth-library-appengine, depending on your application needs):

<dependency>
  <groupId>com.google.auth</groupId>
  <artifactId>google-auth-library-oauth2-http</artifactId>
  <version>0.10.0</version>
</dependency>

If you are using Gradle, add this to your dependencies

compile 'com.google.auth:google-auth-library-oauth2-http:0.10.0'

If you are using SBT, add this to your dependencies

libraryDependencies += "com.google.auth" % "google-auth-library-oauth2-http" % "0.10.0"

google-auth-library-credentials

This artifact contains base classes and interfaces for Google credentials:

• Credentials: base class for an authorized identity. Implementations of this class can be used to
  authorize your application
• RequestMetadataCallback: interface for the callback that receives the result of the asynchronous
  Credentials.getRequestMetadata(URI, Executor, RequestMetadataCallback)
• ServiceAccountSigner: interface for a service account signer. Implementations of this class are
  capable of signing byte arrays using the credentials associated to a Google Service Account

google-auth-library-appengine

This artifact depends on the App Engine SDK (appengine-api-1.0-sdk) and should be used only by
applications running on App Engine. The AppEngineCredentials class allows to authorize your App
Engine application given an instance of AppIdentityService.

google-auth-library-oauth2-http

Application Default Credentials

This artifact contains a wide variety of credentials as well as utility methods to create them and
to get Application Default Credentials.
Credentials classes contained in this artifact are:

• CloudShellCredentials: credentials for Google Cloud Shell built-in service account
• CloudShellCredentials: credentials for Google Compute Engine built-in service account
• OAuth2Credentials: base class for OAuth2-based credentials
• ServiceAccountCredentials: credentials for a Service Account - use a JSON Web Token (JWT) to get
  access tokens
• ServiceAccountJwtAccessCredentials: credentials for a Service Account - use JSON Web Token (JWT)
  directly in the request metadata to provide authorization
• UserCredentials: credentials for a user identity and consent

To get Application Default Credentials use GoogleCredentials.getApplicationDefault() or
GoogleCredentials.getApplicationDefault(HttpTransportFactory). These methods return the
Application Default Credentials which are used to identify and authorize the whole application. The
following are searched (in order) to find the Application Default Credentials:

1. Credentials file pointed to by the GOOGLE_APPLICATION_CREDENTIALS environment variable
2. Credentials provided by the Google Cloud SDK gcloud auth application-default login command
3. Google App Engine built-in credentials
4. Google Cloud Shell built-in credentials
5. Google Compute Engine built-in credentials
   • Skip this check by setting the environment variable NO_GCE_CHECK=true
   • Customize the GCE metadata server address by setting the environment variable GCE_METADATA_HOST=<hostname>

Explicit Credential Loading

To get Credentials from a Service Account JSON key use GoogleCredentials.fromStream(InputStream)
or GoogleCredentials.fromStream(InputStream, HttpTransportFactory). Note that the credentials must
be refreshed before the access token is available.

GoogleCredentials credentials = GoogleCredentials.fromStream(new FileInputStream("/path/to/credentials.json"));
credentials.refreshIfExpired();
AccessToken token = credentials.getAccessToken();
// OR
AccessToken token = credentials.refreshAccessToken();

Contributing

Contributions to this library are always welcome and highly encouraged.

See CONTRIBUTING documentation for more information on how to get started.

Please note that this project is released with a Contributor Code of Conduct. By participating in
this project you agree to abide by its terms. See Code of Conduct for more
information.

License

BSD 3-Clause - See LICENSE for more information.