Jika Anda menggunakan Login dengan Google dengan aplikasi atau situs yang berkomunikasi dengan backend server web, Anda mungkin perlu mengidentifikasi pengguna yang sedang masuk di server tersebut. Untuk melakukannya dengan aman, setelah pengguna berhasil login, kirim informasi ke server Anda menggunakan HTTPS. Kemudian, pada server, verifikasi integritas token ID dan menggunakan informasi pengguna yang terdapat dalam token untuk menetapkan sesi atau membuat akun baru.
Kirim token ID ke server Anda
Setelah pengguna berhasil login, dapatkan token ID pengguna:
function onSignIn(googleUser) { var id_token = googleUser.getAuthResponse().id_token; ... }
Kemudian, kirim token ID ke server Anda dengan permintaan HTTPS POST:
var xhr = new XMLHttpRequest(); xhr.open('POST', 'https://yourbackend.example.com/tokensignin'); xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded'); xhr.onload = function() { console.log('Signed in as: ' + xhr.responseText); }; xhr.send('idtoken=' + id_token);
Memverifikasi integritas token ID
Setelah menerima token ID melalui HTTPS POST, Anda harus memverifikasi integritas token kata.
To verify that the token is valid, ensure that the following criteria are satisfied:
- The ID token is properly signed by Google. Use Google's public keys
(available in
JWK or
PEM format)
to verify the token's signature. These keys are regularly rotated; examine
the
Cache-Control
header in the response to determine when you should retrieve them again. - The value of
aud
in the ID token is equal to one of your app's client IDs. This check is necessary to prevent ID tokens issued to a malicious app being used to access data about the same user on your app's backend server. - The value of
iss
in the ID token is equal toaccounts.google.com
orhttps://accounts.google.com
. - The expiry time (
exp
) of the ID token has not passed. - If you need to validate that the ID token represents a Google Workspace or Cloud
organization account, you can check the
hd
claim, which indicates the hosted domain of the user. This must be used when restricting access to a resource to only members of certain domains. The absence of this claim indicates that the account does not belong to a Google hosted domain.
Using the email
, email_verified
and hd
fields, you can determine if
Google hosts and is authoritative for an email address. In the cases where Google is authoritative,
the user is known to be the legitimate account owner, and you may skip password or other
challenge methods.
Cases where Google is authoritative:
email
has a@gmail.com
suffix, this is a Gmail account.email_verified
is true andhd
is set, this is a G Suite account.
Users may register for Google Accounts without using Gmail or G Suite. When
email
does not contain a @gmail.com
suffix and hd
is absent, Google is not
authoritative and password or other challenge methods are recommended to verify
the user. email_verified
can also be true as Google initially verified the
user when the Google account was created, however ownership of the third party
email account may have since changed.
Rather than writing your own code to perform these verification steps, we strongly
recommend using a Google API client library for your platform, or a general-purpose
JWT library. For development and debugging, you can call our tokeninfo
validation endpoint.
Using a Google API Client Library
Using one of the Google API Client Libraries (e.g. Java, Node.js, PHP, Python) is the recommended way to validate Google ID tokens in a production environment.
To validate an ID token in Java, use the GoogleIdTokenVerifier object. For example:
import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken; import com.google.api.client.googleapis.auth.oauth2.GoogleIdToken.Payload; import com.google.api.client.googleapis.auth.oauth2.GoogleIdTokenVerifier; ... GoogleIdTokenVerifier verifier = new GoogleIdTokenVerifier.Builder(transport, jsonFactory) // Specify the WEB_CLIENT_ID of the app that accesses the backend: .setAudience(Collections.singletonList(WEB_CLIENT_ID)) // Or, if multiple clients access the backend: //.setAudience(Arrays.asList(WEB_CLIENT_ID_1, WEB_CLIENT_ID_2, WEB_CLIENT_ID_3)) .build(); // (Receive idTokenString by HTTPS POST) GoogleIdToken idToken = verifier.verify(idTokenString); if (idToken != null) { Payload payload = idToken.getPayload(); // Print user identifier String userId = payload.getSubject(); System.out.println("User ID: " + userId); // Get profile information from payload String email = payload.getEmail(); boolean emailVerified = Boolean.valueOf(payload.getEmailVerified()); String name = (String) payload.get("name"); String pictureUrl = (String) payload.get("picture"); String locale = (String) payload.get("locale"); String familyName = (String) payload.get("family_name"); String givenName = (String) payload.get("given_name"); // Use or store profile information // ... } else { System.out.println("Invalid ID token."); }
The GoogleIdTokenVerifier.verify()
method verifies the JWT
signature, the aud
claim, the iss
claim, and the
exp
claim.
If you need to validate that the ID token represents a Google Workspace or Cloud
organization account, you can verify the hd
claim by checking the domain name
returned by the Payload.getHostedDomain()
method. The domain of the
email
claim is insufficient to ensure that the account is managed by a domain
or organization.
To validate an ID token in Node.js, use the Google Auth Library for Node.js. Install the library:
npm install google-auth-library --save
verifyIdToken()
function. For example:
const {OAuth2Client} = require('google-auth-library'); const client = new OAuth2Client(); async function verify() { const ticket = await client.verifyIdToken({ idToken: token, audience: WEB_CLIENT_ID, // Specify the WEB_CLIENT_ID of the app that accesses the backend // Or, if multiple clients access the backend: //[WEB_CLIENT_ID_1, WEB_CLIENT_ID_2, WEB_CLIENT_ID_3] }); const payload = ticket.getPayload(); const userid = payload['sub']; // If the request specified a Google Workspace domain: // const domain = payload['hd']; } verify().catch(console.error);
The verifyIdToken
function verifies
the JWT signature, the aud
claim, the exp
claim,
and the iss
claim.
If you need to validate that the ID token represents a Google Workspace or Cloud
organization account, you can check the hd
claim, which indicates the hosted
domain of the user. This must be used when restricting access to a resource to only members
of certain domains. The absence of this claim indicates that the account does not belong to
a Google hosted domain.
To validate an ID token in PHP, use the Google API Client Library for PHP. Install the library (for example, using Composer):
composer require google/apiclient
verifyIdToken()
function. For example:
require_once 'vendor/autoload.php'; // Get $id_token via HTTPS POST. $client = new Google_Client(['client_id' => $WEB_CLIENT_ID]); // Specify the WEB_CLIENT_ID of the app that accesses the backend $payload = $client->verifyIdToken($id_token); if ($payload) { $userid = $payload['sub']; // If the request specified a Google Workspace domain //$domain = $payload['hd']; } else { // Invalid ID token }
The verifyIdToken
function verifies
the JWT signature, the aud
claim, the exp
claim,
and the iss
claim.
If you need to validate that the ID token represents a Google Workspace or Cloud
organization account, you can check the hd
claim, which indicates the hosted
domain of the user. This must be used when restricting access to a resource to only members
of certain domains. The absence of this claim indicates that the account does not belong to
a Google hosted domain.
To validate an ID token in Python, use the verify_oauth2_token function. For example:
from google.oauth2 import id_token from google.auth.transport import requests # (Receive token by HTTPS POST) # ... try: # Specify the WEB_CLIENT_ID of the app that accesses the backend: idinfo = id_token.verify_oauth2_token(token, requests.Request(), WEB_CLIENT_ID) # Or, if multiple clients access the backend server: # idinfo = id_token.verify_oauth2_token(token, requests.Request()) # if idinfo['aud'] not in [WEB_CLIENT_ID_1, WEB_CLIENT_ID_2, WEB_CLIENT_ID_3]: # raise ValueError('Could not verify audience.') # If the request specified a Google Workspace domain # if idinfo['hd'] != DOMAIN_NAME: # raise ValueError('Wrong domain name.') # ID token is valid. Get the user's Google Account ID from the decoded token. userid = idinfo['sub'] except ValueError: # Invalid token pass
The verify_oauth2_token
function verifies the JWT
signature, the aud
claim, and the exp
claim.
You must also verify the hd
claim (if applicable) by examining the object that
verify_oauth2_token
returns. If multiple clients access the
backend server, also manually verify the aud
claim.
Memanggil endpoint tokeninfo
Cara mudah untuk memvalidasi tanda tangan token ID untuk proses debug adalah dengan
gunakan endpoint tokeninfo
. Memanggil endpoint ini melibatkan
permintaan jaringan tambahan yang melakukan sebagian besar
validasi untuk Anda saat menguji
validasi dan ekstraksi payload dalam kode Anda sendiri. Tidak cocok untuk digunakan dalam produksi
kode karena permintaan dapat terhambat atau mengalami error intermiten.
Untuk memvalidasi token ID menggunakan endpoint tokeninfo
, buat HTTPS
POST atau GET ke endpoint, dan teruskan token ID di
Parameter id_token
.
Misalnya, untuk memvalidasi token "XYZ123", buat permintaan GET berikut:
https://oauth2.googleapis.com/tokeninfo?id_token=XYZ123
Jika token ditandatangani dengan benar dan iss
serta exp
klaim memiliki nilai yang diharapkan, Anda akan
mendapatkan respons HTTP 200, dengan bagian
berisi klaim token ID berformat JSON.
Berikut adalah contoh respons:
{ // These six fields are included in all Google ID Tokens. "iss": "https://accounts.google.com", "sub": "110169484474386276334", "azp": "1008719970978-hb24n2dstb40o45d4feuo2ukqmcc6381.apps.googleusercontent.com", "aud": "1008719970978-hb24n2dstb40o45d4feuo2ukqmcc6381.apps.googleusercontent.com", "iat": "1433978353", "exp": "1433981953", // These seven fields are only included when the user has granted the "profile" and // "email" OAuth scopes to the application. "email": "testuser@gmail.com", "email_verified": "true", "name" : "Test User", "picture": "https://lh4.googleusercontent.com/-kYgzyAWpZzJ/ABCDEFGHI/AAAJKLMNOP/tIXL9Ir44LE/s99-c/photo.jpg", "given_name": "Test", "family_name": "User", "locale": "en" }
Jika perlu memvalidasi bahwa token ID mewakili akun Google Workspace, Anda dapat memeriksanya
klaim hd
, yang menunjukkan domain pengguna yang dihosting. Ini harus digunakan saat
membatasi akses ke sumber daya hanya
untuk anggota domain tertentu. Tidak adanya klaim ini
menunjukkan bahwa akun tersebut tidak termasuk dalam domain yang dihosting Google Workspace.
Buat akun atau sesi
Setelah Anda memverifikasi token, periksa apakah pengguna sudah berada di akun pengguna Anda di skrip untuk menyiapkan database. Jika demikian, buat sesi terautentikasi untuk pengguna. Jika pengguna belum ada dalam {i>database<i} pengguna, buat catatan pengguna baru dari informasi dalam payload token ID, dan membuat sesi untuk pengguna. Anda dapat meminta pengguna untuk informasi profil tambahan yang Anda butuhkan saat Anda mendeteksi yang baru dibuat di aplikasi Anda.
Mengamankan pengguna Anda akun dengan Perlindungan Lintas Akun
Jika Anda mengandalkan Google untuk memproses login pengguna, Anda akan otomatis mendapatkan manfaat dari semua fitur dan infrastruktur keamanan yang dibuat Google untuk melindungi data pengguna. Namun, jika Akun Google pengguna disusupi atau ada beberapa masalah peristiwa keamanan yang signifikan, aplikasi Anda juga bisa menjadi rentan terhadap serangan. Untuk melindungi dari peristiwa keamanan besar, gunakan Cross Account Perlindungan untuk menerima notifikasi keamanan dari Google. Saat menerima peristiwa ini, Anda mendapatkan visibilitas terhadap perubahan penting pada keamanan akun Google pengguna dan Anda dapat mengambil tindakan terhadap layanan Anda untuk mengamankan akun Anda.