При использовании Google Identity Services или кода авторизации OAuth 2.0, Google возвращает токен ID методом POST на конечную точку перенаправления. В качестве альтернативы, неявный поток OIDC использует запрос GET. Следовательно, ваше приложение несет ответственность за безопасную передачу полученных учетных данных на ваш сервер.
Это неявный поток: токен идентификатора возвращается во фрагменте URL, который должен быть обработан клиентским JavaScript. Ваше приложение отвечает за реализацию собственных механизмов проверки для обеспечения подлинности запроса и предотвращения атак, таких как CSRF. Идентификационный токен отправляется обратно в качестве поля HTTP/1.1 302 Found
Location: https://<REDIRECT_URI>#access_token=<ACCESS_TOKEN>&token_type=bearer&expires_in=<TIME_IN_SECONDS>&scope=<SCOPE>&state=<STATE_STRING>
credential . При подготовке к отправке идентификационного токена на сервер библиотека GIS автоматически добавляет g_csrf_token в заголовок cookie и тело запроса. Вот пример POST-запроса:POST /auth/token-verification HTTP/1.1
Host: example.com
Content-Type: application/json;charset=UTF-8
Cookie: g_csrf_token=<CSRF_TOKEN>
Origin: https://example.com
Content-Length: <LENGTH_OF_JSON_BODY>
{
"credential": "<ID_TOKEN>",
"g_csrf_token": "<CSRF_TOKEN>",
"client_id": "<CLIENT_ID>"
}
Проверка токена
g_csrf_tokenдля предотвращения атак типа Cross-Site Request Forgery (CSRF):- Извлеките значение токена CSRF из cookie-файла
g_csrf_token. - Извлеките значение токена CSRF из тела запроса. Библиотека GIS включает этот токен в тело POST-запроса в качестве параметра, также называемого
g_csrf_token. - Сравните значения двух токенов.
- Если оба значения присутствуют и полностью совпадают, запрос считается легитимным и исходит из вашего домена.
- Если значения отсутствуют или не совпадают, запрос должен быть отклонен сервером. Эта проверка гарантирует, что запрос был инициирован JavaScript, работающим на вашем собственном домене, поскольку доступ к cookie-файлу
g_csrf_tokenимеет только ваш домен.
- Извлеките значение токена CSRF из cookie-файла
Проверьте идентификационный токен.
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-Controlheader in the response to determine when you should retrieve them again. - The value of
audin 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
issin the ID token is equal toaccounts.google.comorhttps://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
hdclaim, 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_verifiedandhdfields, 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:
emailhas a@gmail.comsuffix, this is a Gmail account.email_verifiedis true andhdis set, this is a Google Workspace account.
Users may register for Google Accounts without using Gmail or Google Workspace. When
emaildoes not contain a@gmail.comsuffix andhdis absent, Google is not authoritative and password or other challenge methods are recommended to verify the user.email_verifiedcan 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
tokeninfovalidation 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.
Java 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. This ID is unique to each Google Account, making it suitable for // use as a primary key during account lookup. Email is not a good choice because it can be // changed by the user. 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, theaudclaim, theissclaim, and theexpclaim.If you need to validate that the ID token represents a Google Workspace or Cloud organization account, you can verify the
hdclaim by checking the domain name returned by thePayload.getHostedDomain()method. The domain of theemailclaim is insufficient to ensure that the account is managed by a domain or organization.Node.js To validate an ID token in Node.js, use the Google Auth Library for Node.js. Install the library:
Then, call thenpm 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(); // This ID is unique to each Google Account, making it suitable for use as a primary key // during account lookup. Email is not a good choice because it can be changed by the user. const userid = payload['sub']; // If the request specified a Google Workspace domain: // const domain = payload['hd']; } verify().catch(console.error);
The
verifyIdTokenfunction verifies the JWT signature, theaudclaim, theexpclaim, and theissclaim.If you need to validate that the ID token represents a Google Workspace or Cloud organization account, you can check the
hdclaim, 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.PHP To validate an ID token in PHP, use the Google API Client Library for PHP. Install the library (for example, using Composer):
Then, call thecomposer 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) { // This ID is unique to each Google Account, making it suitable for use as a primary key // during account lookup. Email is not a good choice because it can be changed by the user. $userid = $payload['sub']; // If the request specified a Google Workspace domain //$domain = $payload['hd']; } else { // Invalid ID token }
The
verifyIdTokenfunction verifies the JWT signature, theaudclaim, theexpclaim, and theissclaim.If you need to validate that the ID token represents a Google Workspace or Cloud organization account, you can check the
hdclaim, 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.Python 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. # This ID is unique to each Google Account, making it suitable for use as a primary key # during account lookup. Email is not a good choice because it can be changed by the user. userid = idinfo['sub'] except ValueError: # Invalid token pass
The
verify_oauth2_tokenfunction verifies the JWT signature, theaudclaim, and theexpclaim. You must also verify thehdclaim (if applicable) by examining the object thatverify_oauth2_tokenreturns. If multiple clients access the backend server, also manually verify theaudclaim.- 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
После подтверждения действительности токена вы можете использовать информацию из токена Google ID для сопоставления статуса учетной записи вашего сайта:
Для незарегистрированного пользователя: вы можете отобразить интерфейс регистрации, позволяющий пользователю при необходимости предоставить дополнительную информацию о своем профиле. Это также позволяет пользователю автоматически создать новую учетную запись и войти в систему.
Существующая учетная запись на вашем сайте: вы можете показать веб-страницу, которая позволит конечному пользователю ввести свой пароль и связать старую учетную запись со своими учетными данными Google. Это подтвердит, что пользователь имеет доступ к существующей учетной записи.
Для пользователя, повторно вошедшего в систему с использованием федерации: вы можете выполнить вход пользователя в систему в автоматическом режиме.