Penautan Akun Google dengan OAuth

Akun ditautkan menggunakan alur implisit dan kode otorisasi OAuth 2.0 standar industri. Layanan Anda harus mendukung endpoint otorisasi dan pertukaran token yang mematuhi OAuth 2.0.

In the implicit flow, Google opens your authorization endpoint in the user's browser. After successful sign in, you return a long-lived access token to Google. This access token is now included in every request sent from Google.

In the authorization code flow, you need two endpoints:

• The authorization endpoint, which presents the sign-in UI to your users that aren't already signed in. The authorization endpoint also creates a short-lived authorization code to record users' consent to the requested access.

• The token exchange endpoint, which is responsible for two types of exchanges:

  1. Exchanges an authorization code for a long-lived refresh token and a short-lived access token. This exchange happens when the user goes through the account linking flow.
  2. Exchanges a long-lived refresh token for a short-lived access token. This exchange happens when Google needs a new access token because the one it had expired.

Choose an OAuth 2.0 flow

Although the implicit flow is simpler to implement, Google recommends that access tokens issued by the implicit flow never expire. This is because the user is forced to link their account again after a token expires with the implicit flow. If you need token expiration for security reasons, we strongly recommend that you use the authorization code flow instead.

Note: Use the following buttons to choose which OAuth 2.0 flow you want to implement. If needed, the content of this guide will reload to match your choice.

Implicit flow Authorization code

Design guidelines

This section describes the design requirements and recommendations for the user screen that you host for OAuth linking flows. After it's called by Google's app, your platform displays a sign in to Google page and account linking consent screen to the user. The user is directed back to Google's app after giving their consent to link accounts.

Figure 1. Account linking user sign in to Google and consent screens.

Requirements

1. You must communicate that the user’s account will be linked to Google, not a specific Google product like Google Home or Google Assistant.

Recommendations

We recommend that you do the following:

1. Display Google's Privacy Policy. Include a link to Google’s Privacy Policy on the consent screen.

2. Data to be shared. Use clear and concise language to tell the user what data of theirs Google requires and why.

3. Clear call-to-action. State a clear call-to-action on your consent screen, such as “Agree and link.” This is because users need to understand what data they're required to share with Google to link their accounts.

4. Ability to cancel. Provide a way for users to go back or cancel, if they choose not to link.

5. Clear sign-in process. Ensure that users have clear method for signing in to their Google account, such as fields for their username and password or Sign in with Google.

6. Ability to unlink. Offer a mechanism for users to unlink, such as a URL to their account settings on your platform. Alternatively, you can include a link to Google Account where users can manage their linked account.

7. Ability to change user account. Suggest a method for users to switch their account(s). This is especially beneficial if users tend to have multiple accounts.

   • If a user must close the consent screen to switch accounts, send a recoverable error to Google so the user can sign in to the desired account with OAuth linking and the implicit flow.

8. Include your logo. Display your company logo on the consent screen. Use your style guidelines to place your logo. If you wish to also display Google's logo, see Logos and trademarks.

Figure 2. Design guidelines for user sign in to Google and consent screens.

Membuat project

Catatan: Anda dapat menggunakan kembali project yang sudah ada dan tidak perlu membuat project baru terutama untuk penautan akun.

Untuk membuat project Anda agar dapat menggunakan penautan akun:

1. Go to the Google API Console.
2. Klik Buat proyek .
3. Masukkan nama atau terima saran yang dihasilkan.
4. Konfirmasikan atau edit bidang yang tersisa.
5. Klik Buat .

Untuk melihat ID proyek Anda:

1. Go to the Google API Console.
2. Temukan proyek Anda di tabel di halaman arahan. ID proyek muncul di kolom ID .

Mengonfigurasi Layar Izin OAuth

Proses Penautan Akun Google mencakup layar izin yang memberi tahu pengguna aplikasi yang meminta akses ke data mereka, jenis data yang diminta, dan persyaratan yang berlaku. Anda perlu mengonfigurasi layar izin OAuth sebelum membuat ID klien Google API.

1. Buka halaman Layar persetujuan OAuth di konsol Google API.
2. Jika diminta, pilih project yang baru saja dibuat.

3. Di halaman "layar izin OAuth" isi formulir, lalu klik tombol “Simpan”.

   Nama aplikasi: Nama aplikasi yang meminta izin. Nama harus secara akurat mencerminkan aplikasi Anda dan konsisten dengan nama aplikasi yang dilihat pengguna di tempat lain. Nama aplikasi akan ditampilkan di layar izin Penautan Akun.

   Logo aplikasi: Gambar di layar izin yang akan membantu pengguna mengenali aplikasi Anda. Logo ditampilkan di layar izin penautan Akun dan di setelan akun

   Email dukungan: Agar pengguna dapat menghubungi Anda untuk mengajukan pertanyaan tentang izin mereka.

   Cakupan untuk Google API: Cakupan memungkinkan aplikasi Anda mengakses data pribadi Google pengguna. Untuk kasus penggunaan Penautan Akun Google, cakupan default (email, profil, openid) sudah memadai, Anda tidak perlu menambahkan cakupan sensitif apa pun. Secara umum, praktik terbaik adalah meminta cakupan secara bertahap, pada saat akses diperlukan, bukan di awal. Pelajari lebih lanjut.

   Domain yang diotorisasi: Untuk melindungi Anda dan pengguna, Google hanya mengizinkan aplikasi yang melakukan autentikasi menggunakan OAuth untuk menggunakan Domain yang Diotorisasi. Link aplikasi Anda harus dihosting di Domain yang Diotorisasi. Pelajari lebih lanjut.

   Link Halaman Beranda Aplikasi: Halaman beranda untuk aplikasi Anda. Harus dihosting di Domain yang Diotorisasi.

   Application Privacy Policy link: Ditampilkan di layar izin Google Acount Linking. Harus dihosting di Domain yang Diotorisasi.

   Link Persyaratan Layanan Aplikasi (Opsional): Harus dihosting di Domain yang Diotorisasi.

   

   Gambar 1. Layar Izin Penautan Akun Google untuk Aplikasi fiktif, Tuner

4. Periksa "Status Verifikasi", jika aplikasi Anda memerlukan verifikasi, klik tombol "Kirim Untuk Verifikasi" untuk mengirimkan permohonan verifikasi. Lihat persyaratan verifikasi OAuth untuk mengetahui detailnya.

Mengimplementasikan server OAuth

To support the OAuth 2.0 implicit flow, your service makes an authorization endpoint available by HTTPS. This endpoint is responsible for authentication and obtaining consent from users for data access. The authorization endpoint presents a sign-in UI to your users that aren't already signed in and records consent to the requested access.

When a Google application needs to call one of your service's authorized APIs, Google uses this endpoint to get permission from your users to call these APIs on their behalf.

A typical OAuth 2.0 implicit flow session initiated by Google has the following flow:

1. Google opens your authorization endpoint in the user's browser. The user signs in, if not signed in already, and grants Google permission to access their data with your API, if they haven't already granted permission.
2. Your service creates an access token and returns it to Google. To do so, redirect the user's browser back to Google with the access token attached to the request.
3. Google calls your service's APIs and attaches the access token with each request. Your service verifies that the access token grants Google authorization to access the API and then completes the API call.

Handle authorization requests

When a Google application needs to perform account linking via an OAuth 2.0 implicit flow, Google sends the user to your authorization endpoint with a request that includes the following parameters:

Authorization endpoint parameters
client_id	The client ID you assigned to Google.
redirect_uri	The URL to which you send the response to this request.
state	A bookkeeping value that is passed back to Google unchanged in the redirect URI.
response_type	The type of value to return in the response. For the OAuth 2.0 implicit flow, the response type is always token.
user_locale	The Google Account language setting in RFC5646 format used to localize your content in the user's preferred language.

For example, if your authorization endpoint is available at https://myservice.example.com/auth, a request might look like the following:

GET https://myservice.example.com/auth?client_id=GOOGLE_CLIENT_ID&redirect_uri=REDIRECT_URI&state=STATE_STRING&response_type=token&user_locale=LOCALE

For your authorization endpoint to handle sign-in requests, do the following steps:

1. Verify the client_id and redirect_uri values to prevent granting access to unintended or misconfigured client apps:

   • Confirm that the client_id matches the client ID you assigned to Google.
   • Confirm that the URL specified by the redirect_uri parameter has the following form:

     https://oauth-redirect.googleusercontent.com/r/YOUR_PROJECT_ID
     https://oauth-redirect-sandbox.googleusercontent.com/r/YOUR_PROJECT_ID
     

2. Check if the user is signed in to your service. If the user isn't signed in, complete your service's sign-in or sign-up flow.

3. Generate an access token for Google to use to access your API. The access token can be any string value, but it must uniquely represent the user and the client the token is for and must not be guessable.

4. Send an HTTP response that redirects the user's browser to the URL specified by the redirect_uri parameter. Include all of the following parameters in the URL fragment:

   • access_token: The access token you just generated
   • token_type: The string bearer
   • state: The unmodified state value from the original request

   The following is an example of the resulting URL:

   https://oauth-redirect.googleusercontent.com/r/YOUR_PROJECT_ID#access_token=ACCESS_TOKEN&token_type=bearer&state=STATE_STRING

Google's OAuth 2.0 redirect handler receives the access token and confirms that the state value hasn't changed. After Google has obtained an access token for your service, Google attaches the token to subsequent calls to your service APIs.

Menangani permintaan info pengguna

The userinfo endpoint adalah sumber daya yang dilindungi OAuth 2.0 bahwa klaim pengembalian tentang pengguna terkait. Menerapkan dan menghosting endpoint userinfo adalah opsional, kecuali untuk kasus penggunaan berikut:

• Terkait Sign-In dengan Google Satu Tap.
• Berlangganan gesekan pada androidtv.

Setelah token akses berhasil diambil dari titik akhir token Anda, Google mengirimkan permintaan ke titik akhir info pengguna Anda untuk mengambil informasi profil dasar tentang pengguna yang ditautkan.

header permintaan endpoint userinfo
Authorization header	Token akses tipe Bearer.

Misalnya, jika endpoint userinfo Anda tersedia di https://myservice.example.com/userinfo , permintaan akan terlihat seperti berikut ini:

GET /userinfo HTTP/1.1
Host: myservice.example.com
Authorization: Bearer ACCESS_TOKEN

Agar endpoint userinfo Anda menangani permintaan, lakukan langkah-langkah berikut:

1. Ekstrak token akses dari header Otorisasi dan kembalikan informasi untuk pengguna yang terkait dengan token akses.
2. Jika token akses tidak valid, mengembalikan HTTP 401 Unauthorized error dengan menggunakan WWW-Authenticate Respon header. Di bawah ini adalah contoh dari respon kesalahan userinfo:

   HTTP/1.1 401 Unauthorized
   WWW-Authenticate: error="invalid_token",
   error_description="The Access Token expired"
   

   Jika 401 tidak sah, atau respon kesalahan yang gagal lainnya dikembalikan selama proses menghubungkan, kesalahan akan non-dipulihkan, token yang diambil akan dibuang dan pengguna akan memiliki untuk memulai proses penautan lagi.

3. Jika token akses valid, kembali dan HTTP 200 respon dengan objek JSON berikut dalam tubuh respon HTTPS:

   {
   "sub": "USER_UUID",
   "email": "EMAIL_ADDRESS",
   "given_name": "FIRST_NAME",
   "family_name": "LAST_NAME",
   "name": "FULL_NAME",
   "picture": "PROFILE_PICTURE",
   }
   

   Jika Anda userinfo titik akhir pengembalian respon sukses HTTP 200, diambil token dan klaim yang terdaftar terhadap pengguna Google Akun.

   tanggapan titik akhir info pengguna
   sub	ID unik yang mengidentifikasi pengguna di sistem Anda.
   email	Alamat email pengguna.
   given_name	Opsional: Nama depan pengguna.
   family_name	Opsional: Nama belakang pengguna.
   name	Opsional: Nama lengkap dari pengguna.
   picture	Opsional: Gambar riwayat pengguna.

Memvalidasi implementasi

You can validate your implementation by using the OAuth 2.0 Playground tool.

In the tool, do the following steps:

1. Click Configuration to open the OAuth 2.0 Configuration window.
2. In the OAuth flow field, select Client-side.
3. In the OAuth Endpoints field, select Custom.
4. Specify your OAuth 2.0 endpoint and the client ID you assigned to Google in the corresponding fields.
5. In the Step 1 section, don't select any Google scopes. Instead, leave this field blank or type a scope valid for your server (or an arbitrary string if you don't use OAuth scopes). When you're done, click Authorize APIs.
6. In the Step 2 and Step 3 sections, go through the OAuth 2.0 flow and verify that each step works as intended.

You can validate your implementation by using the Google Account Linking Demo tool.

In the tool, do the following steps:

1. Click the Sign-in with Google button.
2. Choose the account you'd like to link.
3. Enter the service ID.
4. Optionally enter one or more scopes that you will request access for.
5. Click Start Demo.
6. When prompted, confirm that you may consent and deny the linking request.
7. Confirm that you are redirected to your platform.