通过 OAuth 进行账号关联

OAuth 关联类型支持两种业界标准 OAuth 2.0 流程，即隐式和授权代码流程。

In the implicit code 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 the Assistant to your Action.

In the authorization code flow, you need two endpoints:

• The authorization endpoint, which is responsible for presenting the sign-in UI to your users that aren't already signed in and recording consent to the requested access in the form of a short-lived authorization code.
• 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.

Although the implicit code flow is simpler to implement, Google recommends that access tokens issued using the implicit flow never expire, because using token expiration with the implicit flow forces the user to link their account again. If you need token expiration for security reasons, you should strongly consider using the auth code flow instead.

Note: Please choose which OAuth 2.0 flow you want to implement. If needed, the content of this guide reloads to adapt to your choice.

Auth code Implicit flow

实现 OAuth 账号关联

注意 ：如果您要实现帐号关联来处理财务信息，请注意，您的 Action 可能还需要遵循其他政策。我们最多可能需要 6 周时间来审核包含帐号关联帐号的 Action，以获取财务信息，因此在规划发布时间表时请将这段时间考虑在内。为简化审核流程，请确保在提交 Action 以供审核之前遵守金融服务政策。

配置项目

如需将项目配置为使用 OAuth 关联，请按以下步骤操作：

1. 打开 Actions 控制台，然后选择您要使用的项目。
2. 点击开发标签页，然后选择帐号关联。
3. 启用帐号关联旁边的开关。
4. 在帐号创建部分，选择不，我只允许在我的网站上创建帐号。

5. 在关联类型中，选择 OAuth 和授权代码。

   

6. 在客户信息中：

   • 为您的 Actions 向 Google 发出的客户端 ID 分配一个值，以标识来自 Google 的请求。
   • 记下 Google 向您的 Action 发放的 Client ID 的值；
   • 插入授权端点和令牌交换端点的网址。

注意 ：如果您希望以 base64 编码的字符串形式发送客户端 ID 和密钥，请点击配置客户端（可选）旁边的下拉箭头，然后选中 Google 通过 HTTP 基本身份验证标头传输 ClientID 和密钥复选框。

6. 点击保存。

实现 OAuth 服务器

An OAuth 2.0 server implementation of the authorization code flow consists of two endpoints, which your service makes available by HTTPS. The first endpoint is the authorization endpoint, which is responsible for finding or 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. The second endpoint is the token exchange endpoint, which is used to obtain encrypted strings called tokens that authorize the Action user to access your service.

When your Action needs to call one of your service's APIs, Google uses these endpoints together to get permission from your users to call these APIs on their behalf.

OAuth 2.0 auth code flow session initiated by Google has the following flow:

1. Google opens your authorization endpoint in the user's browser. If the flow started on a voice-only device for an Action, Google would transfer the execution to a phone.

2. 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.

   Note: You must communicate that the user’s account is being linked to Google, not to a specific Google product, such as Google Home or Google Assistant.

3. Your service creates an authorization code and returns it to Google by redirecting the user's browser back to Google with the authorization code attached to the request.

4. Google sends the authorization code to your token exchange endpoint, which verifies the authenticity of the code and returns an access token and a refresh token. The access token is a short-lived token that your service accepts as credentials to access APIs. The refresh token is a long-lived token that Google can store and use to acquire new access tokens when they expire.

5. After the user has completed the account linking flow, every subsequent request sent from the Assistant to your fulfillment webhook contains an access token.

Handle authorization requests

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

Authorization endpoint parameters
client_id	The Google client ID you registered with 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.
scope	Optional: A space-delimited set of scope strings that specify the data Google is requesting authorization for.
response_type	The string code.

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

GET https://myservice.example.com/auth?client_id=GOOGLE_CLIENT_ID&redirect_uri=REDIRECT_URI&state=STATE_STRING&scope=REQUESTED_SCOPES&response_type=code

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

1. Verify that the client_id matches the Google client ID you registered with Google, and that the redirect_uri matches the redirect URL provided by Google for your service. These checks are important to prevent granting access to unintended or misconfigured client apps.

   If you support multiple OAuth 2.0 flows, also confirm that the response_type is code.

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 authorization code that Google will use to access your API. The authorization code can be any string value, but it must uniquely represent the user, the client the token is for, and the code's expiration time, and it must not be guessable. You typically issue authorization codes that expire after approximately 10 minutes.

4. Confirm that the URL specified by the redirect_uri parameter has the following form:

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

   YOUR_PROJECT_ID is the ID found on the Project settings page of the Actions Console.

5. Redirect the user's browser to the URL specified by the redirect_uri parameter. Include the authorization code you just generated and the original, unmodified state value when you redirect by appending the code and state parameters. The following is an example of the resulting URL:

   https://oauth-redirect.googleusercontent.com/r/YOUR_PROJECT_ID?code=AUTHORIZATION_CODE&state=STATE_STRING

Handle token exchange requests

Your service's token exchange endpoint is responsible for two kinds of token exchanges:

• Exchange authorization codes for access tokens and refresh tokens
• Exchange refresh tokens for access tokens

Token exchange requests include the following parameters:

Token exchange endpoint parameters
client_id	A string that identifies the request origin as Google. This string must be registered within your system as Google's unique identifier.
client_secret	A secret string that you registered with Google for your service.
grant_type	The type of token being exchanged. Either authorization_code or refresh_token.
code	When grant_type=authorization_code, the code Google received from either your sign-in or token exchange endpoint.
redirect_uri	When grant_type=authorization_code, this parameter is the URL used in the initial authorization request.
refresh_token	When grant_type=refresh_token, the refresh token Google received from your token exchange endpoint.

Exchange authorization codes for access tokens and refresh tokens

After the user signs in and your authorization endpoint returns a short-lived authorization code to Google, Google sends a request to your token exchange endpoint to exchange the authorization code for an access token and a refresh token.

For these requests, the value of grant_type is authorization_code, and the value of code is the value of the authorization code you previously granted to Google. The following is an example of a request to exchange an authorization code for an access token and a refresh token:

POST /token HTTP/1.1
Host: oauth2.example.com
Content-Type: application/x-www-form-urlencoded

client_id=GOOGLE_CLIENT_ID&client_secret=GOOGLE_CLIENT_SECRET&grant_type=authorization_code&code=AUTHORIZATION_CODE&redirect_uri=REDIRECT_URI

To exchange authorization codes for an access token and a refresh token, your token exchange endpoint responds to POST requests executing the following steps:

1. Verify that the client_id identifies the request origin as an authorized origin, and that the client_secret matches the expected value.
2. Verify the following:
   • The authorization code is valid and not expired, and the client ID specified in the request matches the client ID associated with the authorization code.
   • The URL specified by the redirect_uri parameter is identical to the value used in the initial authorization request.
3. If you cannot verify all of the above criteria, return an HTTP 400 Bad Request error with {"error": "invalid_grant"} as the body.
4. Otherwise, using the user ID from the authorization code, generate a refresh token and an access token. These tokens can be any string value, but they must uniquely represent the user and the client the token is for, and they must not be guessable. For access tokens, also record the expiration time of the token (typically an hour after you issue the token). Refresh tokens do not expire.
5. Return the following JSON object in the body of the HTTPS response:

   {
   "token_type": "Bearer",
   "access_token": "ACCESS_TOKEN",
   "refresh_token": "REFRESH_TOKEN",
   "expires_in": SECONDS_TO_EXPIRATION
   }

Google stores the access token and the refresh token for the user and records the expiration of the access token. When the access token expires, Google uses the refresh token to get a new access token from your token exchange endpoint.

Exchange refresh tokens for access tokens

When an access token expires, Google sends a request to your token exchange endpoint to exchange a refresh token for a new access token.

For these requests, the value of grant_type is refresh_token, and the value of refresh_token is the value of the refresh token you previously granted to Google. The following is an example of a request to exchange a refresh token for an access token:

POST /token HTTP/1.1
Host: oauth2.example.com
Content-Type: application/x-www-form-urlencoded

client_id=GOOGLE_CLIENT_ID&client_secret=GOOGLE_CLIENT_SECRET&grant_type=refresh_token&refresh_token=REFRESH_TOKEN

To exchange a refresh token for an access token, your token exchange endpoint responds to POST requests executing the following steps:

1. Verify that the client_id identifies the request origin as Google, and that the client_secret matches the expected value.
2. Verify that the refresh token is valid, and that the client ID specified in the request matches the client ID associated with the refresh token.
3. If you cannot verify all of the above criteria, return an HTTP 400 Bad Request error with {"error": "invalid_grant"} as the body.
4. Otherwise, use the user ID from the refresh token to generate an access token. These tokens can be any string value, but they must uniquely represent the user and the client the token is for, and they must not be guessable. For access tokens, also record the expiration time of the token (typically an hour after you issue the token).
5. Return the following JSON object in the body of the HTTPS response:

   {
   "token_type": "Bearer",
   "access_token": "ACCESS_TOKEN",
   "expires_in": SECONDS_TO_EXPIRATION
   }

Note: You can optionally return a new refresh_token in your response. For more information about when returning a new refresh_token is preferred, see Working with tokens.

为身份验证流程设计语音界面

警告：请勿在开始与您的 Action 对话时向用户提供必要的帐号关联提示。而应为未通过身份验证的用户提供访客流程来展示您的 Action 的运作方式，然后仅在必要的情况下才要求进行帐号关联。如果用户由于帐号关联问题总是离开相应 Action，Google 将不会主动推广相应 Action，这可能会减少该 Action 的用户流量。

注意 ：您必须使用 Actions Builder 构建可实现账号关联的 Action。

检查用户是否已通过验证，并启动账号关联流程

1. 在 Actions 控制台中打开您的 Actions Builder 项目。
2. 创建一个新场景，以开始在您的 Action 中关联帐号：
   1. 点击 Scenes。
   2. 点击添加 (+) 图标以添加新场景。
3. 在新创建的场景中，点击条件对应的添加 图标。
4. 添加一个条件，用于检查与对话关联的用户是否为经过验证的用户。如果检查失败，您的 Action 无法在对话期间执行帐号关联，而应回退以提供对不需要帐号关联的功能的访问权限。
   1. 在条件下的 Enter new expression 字段中，输入以下逻辑：user.verificationStatus != "VERIFIED"
   2. 在 Transition 下，选择不需要帐号关联的场景，或选择访客专享功能的入口点。

1. 点击条件对应的添加 图标。
2. 添加一个条件，以便在用户没有关联的身份时触发帐号关联流程。
   1. 在条件下的 Enter new expression 字段中，输入以下逻辑：user.verificationStatus == "VERIFIED"
   2. 在转换下，选择帐号关联系统场景。
   3. 点击保存。

保存后，系统会将一个名为 <SceneName>_AccountLinking 的新帐号关联系统场景添加到您的项目中。

自定义账号关联场景

1. 在 Scenes 下，选择帐号关联系统场景。
2. 点击发送提示并添加一小句话，向用户说明该 Action 为何需要访问其身份（例如“保存您的偏好设置”）。
3. 点击保存。

1. 在条件下，点击如果用户成功完成帐号关联。
2. 配置当用户同意关联其账号时该流程应如何处理。 例如，调用网络钩子以处理所需的任何自定义业务逻辑，并转换回原始场景。
3. 点击保存。

1. 在条件下方，点击如果用户取消或忽略帐号关联。
2. 配置如果用户不同意关联其帐号，相应流程应如何处理。例如，发送确认消息并重定向到提供无需进行帐号关联的功能的场景。
3. 点击保存。

1. 在条件下方，点击如果出现系统或网络错误。
2. 配置帐号关联流程因系统或网络错误而无法完成时应采取的流程。例如，发送确认消息并重定向到提供无需进行帐号关联的功能的场景。
3. 点击保存。

处理数据访问请求

如果 Google 助理请求包含访问令牌，请先检查访问令牌是否有效（且未过期），然后从数据库中检索关联的用户帐号。