透過 OAuth 連結帳戶

OAuth 連結類型支援兩種符合業界標準的 OAuth 2.0 流程，分別是隱含和授權程式碼流程。

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

實作 OAuth 帳戶連結

注意： 如果您要導入帳戶連結以處理財務資訊，請注意，動作可能須遵守其他政策。我們可能需要六週的時間，才能審核含有財務資訊帳戶連結的動作，因此在規劃發布時間表時，請將這段時間納入考量。為了簡化審查程序，請務必遵守金融服務政策，再將動作送審。

設定專案

如要將專案設為使用 OAuth 連結，請按照下列步驟操作：

1. 開啟「Actions Console」，然後選取要使用的專案。
2. 按一下「開發」分頁標籤，然後選擇「帳戶連結」。
3. 啟用「帳戶連結」旁的切換鈕。
4. 在「建立帳戶」部分中，選取「否，我只想允許在我的網站上建立帳戶」。

5. 在「連結類型」中，選取「OAuth」和「隱含」。

   

6. 在「客戶資訊」部分中：

   • 將值指派給「Actions to Google」的用戶端 ID，即可識別來自 Google 的要求。
   • 插入授權和權杖交換端點的網址。

注意： 如果您希望用戶端 ID 以 Base64 編碼字串的形式傳送，請按一下「設定用戶端 (選用)」旁的下拉式箭頭，然後勾選「Google 透過 HTTP 基本驗證標頭傳送用戶端 ID 和密鑰」方塊。

6. 點按「儲存」。

實作 OAuth 伺服器

To support the OAuth 2.0 implicit flow, your service makes an authorization endpoint available by HTTPS. This endpoint is responsible for authenticating 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 your Action 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 by redirecting 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 your Action 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.

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&response_type=token

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

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

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 that Google will 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 will receive the access token and confirm that the state value hasn't changed. After Google has obtained an access token for your service, Google will attach the token to subsequent calls to your Action as part of the AppRequest.

設計驗證流程的語音使用者介面

警告：請勿在對話開始時向使用者傳送必要的帳戶連結提示，請改為向未經驗證的使用者提供訪客流程，以顯示動作的運作方式，然後在必要時才要求連結帳戶，才能繼續操作。如果使用者因為帳戶連結問題而持續退出「動作」，Google 不會主動宣傳該動作，但這可能會減少動作的使用者流量。

注意： 您必須使用動作建構工具來建構會導入帳戶連結的動作。

檢查使用者是否已通過驗證，並啟動帳戶連結流程

1. 在 Actions 主控台中開啟 Actions Builder 專案。
2. 建立新的場景，以便在動作中開始連結帳戶：
   1. 按一下「Scenes」。
   2. 按一下「add」圖示 (+) 即可新增場景。
3. 在新建立的場景中，按一下「Conditions」(條件) 圖示 。
4. 新增條件，檢查與對話相關聯的使用者是否為已驗證的使用者。如果檢查失敗，您的動作就無法在對話期間執行帳戶連結，而是應改回提供不需要帳戶連結的功能。
   1. 在「Condition」(條件) 下方的 Enter new expression 欄位中，輸入下列邏輯：user.verificationStatus != "VERIFIED"
   2. 在「轉換」下方，選取不需要連結帳戶的場景，或不需要訪客專屬功能的進入點。

1. 按一下「條件」的「新增」圖示 。
2. 新增條件，在使用者沒有相關聯的身分時觸發帳戶連結流程。
   1. 在「Condition」(條件) 下方的 Enter new expression 欄位中，輸入下列邏輯：user.verificationStatus == "VERIFIED"
   2. 在「轉換」下方，選取「帳戶連結」系統場景。
   3. 點按「儲存」。

儲存後，名為 <SceneName>_AccountLinking 的帳戶連結系統場景就會新增至專案中。

自訂帳戶連結情境

1. 在「場景」下方，選取帳戶連結系統場景。
2. 按一下「Send 提示」，然後新增簡短句子，說明動作需要存取其身分的原因 (例如「如要儲存偏好設定」)。
3. 點按「儲存」。

1. 在「條件」下方，按一下「如果使用者成功完成帳戶連結」。
2. 設定使用者同意連結帳戶時，流程的後續步驟。 舉例來說，呼叫 Webhook 以處理任何所需的自訂商業邏輯，然後切換回原始場景。
3. 點按「儲存」。

1. 在「條件」下方，按一下「如果使用者取消或關閉帳戶連結」。
2. 如果使用者不同意連結帳戶，請設定流程。例如，傳送已確認的訊息，然後重新導向至提供不需要連結帳戶的功能的場景。
3. 點按「儲存」。

1. 在「條件」下方，按一下「如果發生系統或網路錯誤」。
2. 設定若帳戶連結流程因系統或網路錯誤而無法順利完成時，流程該如何繼續。 例如，傳送已確認的訊息，然後重新導向至提供不需要連結帳戶的功能的場景。
3. 點按「儲存」。

處理資料存取要求

如果 Google 助理要求包含存取權杖，請先檢查存取權杖是否有效 (且未過期)，然後從資料庫中擷取相關聯的使用者帳戶。