Cada acción smart home debe incluir un mecanismo para autenticar usuarios.
La autenticación te permite vincular las Cuentas de Google de tus usuarios a las cuentas de usuario en tu sistema de autenticación. Esto te permite identificar a los usuarios cuando la entrega recibe un intent de casa inteligente. La casa inteligente de Google solo admite OAuth con un flujo de código de autorización.
En esta página, se describe cómo configurar el servidor de OAuth 2.0 para que funcione con la acción smart home.
Flujo de código de autorización
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 a user to access your service.
When a Google application 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.
An OAuth 2.0 authorization code flow session initiated by Google has the following flow:
- Google opens your authorization endpoint in the user's browser. If the flow started on a voice-only device for an Action, Google transfers the execution to a phone.
- 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.
- Your service creates an authorization code and returns it to Google. To do so, redirect the user's browser back to Google with the authorization code attached to the request.
- 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.
- After the user has completed the account linking flow, every subsequent request sent from Google contains an access token.
Handle authorization requests
When you need to perform account linking using the 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 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. |
scope |
Optional: A space-delimited set of scope strings that specify the data Google is requesting authorization for. |
response_type |
The type of value to return in the response. For the OAuth 2.0
authorization code flow, the response type is always code .
|
user_locale |
The Google Account language setting in RFC5646 format, used to localize your content in the user's preferred language. |
For example, if your authorization endpoint is available at
https://myservice.example.com/auth
, a request might look like the following:
GET https://myservice.example.com/auth?client_id=GOOGLE_CLIENT_ID&redirect_uri=REDIRECT_URI&state=STATE_STRING&scope=REQUESTED_SCOPES&response_type=code&user_locale=LOCALE
For your authorization endpoint to handle sign-in requests, do the following steps:
- Verify that the
client_id
matches the Client ID you assigned to Google, and that theredirect_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 theresponse_type
iscode
. - 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.
- Generate an authorization code for Google to 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.
- Confirm that the URL specified by the
redirect_uri
parameter has the following form:https://oauth-redirect.googleusercontent.com/r/YOUR_PROJECT_ID https://oauth-redirect-sandbox.googleusercontent.com/r/YOUR_PROJECT_ID
- 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 thecode
andstate
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. It's either
authorization_code or refresh_token . |
code |
When grant_type=authorization_code , this parameter is 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 , this parameter is 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 by executing the following
steps:
- Verify that the
client_id
identifies the request origin as an authorized origin, and that theclient_secret
matches the expected value. - Verify that the authorization code is valid and not expired, and that the client ID specified in the request matches the client ID associated with the authorization code.
- Confirm that the URL specified by the
redirect_uri
parameter is identical to the value used in the initial authorization request. - If you can't verify all of the above criteria, return an HTTP
400 Bad Request error with
{"error": "invalid_grant"}
as the body. - Otherwise, use the user ID from the authorization code to 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, which is typically an hour after you issue the token. Refresh tokens don't expire.
- 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 by executing the following steps:
- Verify that the
client_id
identifies the request origin as Google, and that theclient_secret
matches the expected value. - 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.
- If you can't verify all of the above criteria, return an HTTP 400
Bad Request error with
{"error": "invalid_grant"}
as the body. - 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.
- Return the following JSON object in the body of the HTTPS
response:
{ "token_type": "Bearer", "access_token": "ACCESS_TOKEN", "expires_in": SECONDS_TO_EXPIRATION }
Cómo controlar solicitudes de información del usuario
El extremo userinfo es un recurso protegido con OAuth 2.0 que muestra reclamos sobre el usuario vinculado. Implementar y alojar el extremo userinfo es opcional, excepto en los siguientes casos prácticos:
- Acceso con una cuenta vinculada con Google One Tap.
- Suscripción sin inconvenientes en Android TV.
Una vez que el token de acceso se recupera correctamente del extremo del token, Google envía una solicitud al extremo userinfo para recuperar la información básica de perfil del usuario vinculado.
Encabezados de solicitud del extremo userinfo | |
---|---|
Authorization header |
El token de acceso del tipo Bearer. |
Por ejemplo, si tu extremo userinfo está disponible en https://myservice.example.com/userinfo
, una solicitud podría verse de la siguiente manera:
GET /userinfo HTTP/1.1 Host: myservice.example.com Authorization: Bearer ACCESS_TOKEN
Para que el extremo userinfo maneje las solicitudes, sigue estos pasos:
- Extrae el token de acceso del encabezado de autorización y muestra información para el usuario asociado con el token de acceso.
- Si el token de acceso no es válido, muestra un error HTTP 401 No autorizado con el encabezado de respuesta
WWW-Authenticate
. A continuación, se muestra un ejemplo de una respuesta de error de información del usuario:HTTP/1.1 401 Unauthorized WWW-Authenticate: error="invalid_token", error_description="The Access Token expired"
Si se muestra una respuesta de error 401 No autorizado o cualquier error en el proceso de vinculación, el error será irrecuperable, el token recuperado se descartará y el usuario deberá volver a iniciar el proceso de vinculación. Si el token de acceso es válido, se muestra una respuesta HTTP 200 con el siguiente objeto JSON en el cuerpo de la respuesta HTTPS:
{ "sub": "USER_UUID", "email": "EMAIL_ADDRESS", "given_name": "FIRST_NAME", "family_name": "LAST_NAME", "name": "FULL_NAME", "picture": "PROFILE_PICTURE", }
Si el extremo userinfo muestra una respuesta HTTP 200 exitosa, el token recuperado y las reclamaciones se registran en la Cuenta de Google del usuario.respuesta de extremo userinfo sub
Un ID único que identifica al usuario en tu sistema. email
Dirección de correo electrónico del usuario. given_name
Opcional: El nombre del usuario. family_name
Opcional: Apellido del usuario. name
Opcional: El nombre completo del usuario. picture
Opcional: La foto de perfil del usuario.