Google 返回 ID 令牌后,系统会通过 HTTP POST
方法请求(参数名称为 credential
)将该令牌提交到您的登录端点。
以下是一个 Python 语言示例,显示了验证和使用 ID 令牌的常规步骤:
验证跨站请求伪造 (CSRF) 令牌。当您将凭据提交到登录端点时,我们会使用双重提交 Cookie 模式来防止 CSRF 攻击。每次提交前,我们都会生成令牌。然后,将令牌同时放入 Cookie 和 post 正文,如以下代码示例所示:
csrf_token_cookie = self.request.cookies.get('g_csrf_token') if not csrf_token_cookie: webapp2.abort(400, 'No CSRF token in Cookie.') csrf_token_body = self.request.get('g_csrf_token') if not csrf_token_body: webapp2.abort(400, 'No CSRF token in post body.') if csrf_token_cookie != csrf_token_body: webapp2.abort(400, 'Failed to verify double submit cookie.')
验证 ID 令牌。
如需验证令牌是否有效,请确保满足以下条件:
- ID 令牌由 Google 正确签名。使用 Google 的公钥(以 JWK 或 PEM 格式提供)来验证令牌的签名。这些密钥会定期轮替;请检查响应中的
Cache-Control
标头,以确定何时应再次检索它们。 - ID 令牌中
aud
的值等于应用的某个客户端 ID。通过进行这项检查,可以防止向恶意应用颁发的 ID 令牌用于访问应用后端服务器上同一用户的数据。 - ID 令牌中
iss
的值等于accounts.google.com
或https://accounts.google.com
。 - ID 令牌的过期时间 (
exp
) 尚未过去。 - 如果您需要验证该 ID 令牌代表的是 Google Workspace 或 Cloud 组织帐号,则可以检查
hd
声明,该声明指示用户的托管网域。仅允许特定网域的成员访问资源时,必须使用此方法。缺少此声明表示帐号不属于 Google 托管的网域。
我们强烈建议您使用适合您的平台的 Google API 客户端库或通用 JWT 库,而不是自行编写代码来执行这些验证步骤。对于开发和调试,您可以调用我们的
tokeninfo
验证端点。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 CLIENT_ID of the app that accesses the backend: .setAudience(Collections.singletonList(CLIENT_ID)) // Or, if multiple clients access the backend: //.setAudience(Arrays.asList(CLIENT_ID_1, CLIENT_ID_2, 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, theaud
claim, theiss
claim, and theexp
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 thePayload.getHostedDomain()
method. The domain of theemail
claim 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:
npm install google-auth-library --save
Then, call theverifyIdToken()
function. For example:const {OAuth2Client} = require('google-auth-library'); const client = new OAuth2Client(); async function verify() { const ticket = await client.verifyIdToken({ idToken: token, audience: CLIENT_ID, // Specify the CLIENT_ID of the app that accesses the backend // Or, if multiple clients access the backend: //[CLIENT_ID_1, CLIENT_ID_2, CLIENT_ID_3] }); const payload = ticket.getPayload(); const userid = payload['sub']; // If request specified a G Suite domain: // const domain = payload['hd']; } verify().catch(console.error);
The
verifyIdToken
function verifies the JWT signature, theaud
claim, theexp
claim, and theiss
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.PHP 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
Then, call theverifyIdToken()
function. For example:require_once 'vendor/autoload.php'; // Get $id_token via HTTPS POST. $client = new Google_Client(['client_id' => $CLIENT_ID]); // Specify the CLIENT_ID of the app that accesses the backend $payload = $client->verifyIdToken($id_token); if ($payload) { $userid = $payload['sub']; // If request specified a G Suite domain: //$domain = $payload['hd']; } else { // Invalid ID token }
The
verifyIdToken
function verifies the JWT signature, theaud
claim, theexp
claim, and theiss
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.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 CLIENT_ID of the app that accesses the backend: idinfo = id_token.verify_oauth2_token(token, requests.Request(), CLIENT_ID) # Or, if multiple clients access the backend server: # idinfo = id_token.verify_oauth2_token(token, requests.Request()) # if idinfo['aud'] not in [CLIENT_ID_1, CLIENT_ID_2, CLIENT_ID_3]: # raise ValueError('Could not verify audience.') # If auth request is from a G Suite domain: # if idinfo['hd'] != GSUITE_DOMAIN_NAME: # raise ValueError('Wrong hosted domain.') # 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, theaud
claim, and theexp
claim. You must also verify thehd
claim (if applicable) by examining the object thatverify_oauth2_token
returns. If multiple clients access the backend server, also manually verify theaud
claim.- ID 令牌由 Google 正确签名。使用 Google 的公钥(以 JWK 或 PEM 格式提供)来验证令牌的签名。这些密钥会定期轮替;请检查响应中的
确认令牌的有效性后,您可以使用 Google ID 令牌中的信息将您网站的帐号状态关联起来:
未注册用户:您可以显示一个注册界面,以便用户根据需要提供额外的个人资料信息。它还允许用户以静默方式创建新帐号和已登录的用户会话。
网站中已存在的现有帐号:您可以显示一个网页,供最终用户输入密码并将旧版帐号与其 Google 凭据相关联。这将确认用户有权访问现有帐号。
回访联合用户:您可以让用户以静默方式登录。