使用 OAuth 和 Google Sign-In 简化链接

概述

基于OAuth的谷歌登录在流线型联增加了谷歌登录在之上OAuth的链接。这为 Google 用户提供了无缝链接体验,并且还为使用非 Google 身份注册到您的服务的用户启用了帐户链接。

要使用 OAuth 和 Google Sign-In 执行帐户关联,请按照以下常规步骤操作:

  1. 首先,请用户同意访问他们的 Google 个人资料。
  2. 使用他们的个人资料中的信息检查用户帐户是否存在。
  3. 对于现有用户,链接帐户。
  4. 如果您在身份验证系统中找不到 Google 用户的匹配项,请验证从 Google 收到的 ID 令牌。然后,您可以根据 ID 令牌中包含的配置文件信息创建用户。

图3。使用简化链接在用户手机上进行帐户链接

帐户使用行业标准的OAuth 2.0隐式授权码流相关。您的服务必须支持2.0标准的OAuth授权令牌交换端点。此外,您的令牌交换终结点应该支持JSON网络令牌(JWT)的断言和实施checkcreateget意图。

获取您的 Google API 客户端 ID 和密钥

您需要使用您在完成创建的项目,让您的API客户端ID和秘密的OAuth链接步骤。为此,请完成以下步骤:

  1. 打开的凭据谷歌API控制台
  2. 创建或选择一个 Google API 项目。

    如果你的项目没有为Web应用程序类型客户端ID,单击创建证书> OAuth用户端ID创建一个。一定要包括你的网站的域名在授权JavaScript源框。当您执行本地测试或开发,你必须同时添加http://localhosthttp://localhost:<port_number>授权JavaScript源领域。

实施您的 OAuth 服务器

检查现有的用户帐户

用户同意访问其Google个人资料后,Google会发送请求,其中包含对Google用户身份的签名声明。断言包含的信息包括用户的Google帐户ID,名称和电子邮件地址。为您的项目配置的令牌交换端点处理该请求。

如果您的身份验证系统中已经存在相应的Google帐户,则令牌交换端点将使用account_found=true响应。如果Google帐户与现有用户不匹配,则令牌交换端点将返回一个HTTP 404 Not Found错误,带有account_found=false

该请求具有以下形式:

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

grant_type=urn:ietf:params:oauth:grant-type:jwt-bearer&intent=check&assertion=JWT&scope=SCOPES

您的令牌交换端点必须能够处理以下参数:

令牌端点参数
intent对于这些请求,此参数的值为check
grant_type交换令牌的类型。对于这些请求,此参数的值为urn:ietf:params:oauth:grant-type:jwt-bearer
assertion JSON Web令牌(JWT),提供对Google用户身份的签名断言。 JWT包含的信息包括用户的Google帐户ID,名称和电子邮件地址。

当您的令牌交换端点接收到check请求时,它需要验证和解码JWT断言。

验证并解码JWT断言

您可以使用针对您的语言JWT解码库来验证和解码JWT断言。使用Google的JWKPEM格式的公钥来验证令牌的签名。

解码后,JWT断言类似于以下示例:

{
  "sub": "1234567890",      // The unique ID of the user's Google Account
  "iss": "https://accounts.google.com",        // The assertion's issuer
  "aud": "123-abc.apps.googleusercontent.com", // Your server's client ID
  "iat": 233366400,         // Unix timestamp of the assertion's creation time
  "exp": 233370000,         // Unix timestamp of the assertion's expiration time
  "name": "Jan Jansen",
  "given_name": "Jan",
  "family_name": "Jansen",
  "email": "jan@gmail.com", // If present, the user's email address
  "email_verified": true,   // true, if Google has verified the email address
  "hd": "example.com",      // If present, the host domain of the user's GSuite email address
                            // If present, a URL to user's profile picture
  "picture": "https://lh3.googleusercontent.com/a-/AOh14GjlTnZKHAeb94A-FmEbwZv7uJD986VOF1mJGb2YYQ",
  "locale": "en_US"         // User's locale, from browser or phone settings
}

除了验证令牌的签名外,还要验证断言的颁发者( iss字段)为https://accounts.google.com ,受众( aud字段)是您分配的客户端ID,并且令牌尚未过期( exp场地)。

使用emailemail_verifiedhd字段,您可以确定Google是否托管电子邮件地址并对其具有权威性。如果Google具有权威性,则当前已知该用户为合法帐户所有者,您可以跳过密码或其他挑战方法。否则,可以使用这些方法在链接之前验证帐户。

Google具有权威性的情况:

  • email后缀为@gmail.com ,这是一个Gmail帐户。
  • email_verified为true并且设置了hd ,这是一个G Suite帐户。

用户可以在不使用Gmail或G Suite的情况下注册Google帐户。如果email不包含@gmail.com后缀,并且没有hd则Google并不具有权威性,建议您使用密码或其他验证方法来验证用户。当Google在创建Google帐户时最初验证了用户时, email_verfied也可能为true,但是此后第三方电子邮件帐户的所有权可能已更改。

检查您的身份验证系统中是否已存在Google帐户

检查以下条件之一是否成立:

  • 在断言的sub字段中找到的Google帐户ID在您的用户数据库中。
  • 断言中的电子邮件地址与您的用户数据库中的用户匹配。

如果任一条件为真,则用户已经注册。在这种情况下,返回如下响应:

HTTP/1.1 200 Success
Content-Type: application/json;charset=UTF-8

{
  "account_found":"true",
}

然后,Google向用户显示一个链接同意对话框,并请求同意所需的范围,以便继续进行链接。 Google征得用户同意后,Google get向您的令牌端点发送一个get请求,以继续进行链接。

如果断言中指定的Google帐户ID或电子邮件地址都不匹配您数据库中的用户,则该用户尚未注册。在这种情况下,令牌交换端点需要使用HTTP 404错误进行响应,该错误指定为"account_found": "false" ,如以下示例所示:

HTTP/1.1 404 Not found
Content-Type: application/json;charset=UTF-8

{
  "account_found":"false",
}
当Google收到带有"account_found": "false"错误的404错误响应时,Google会向用户显示一个对话框,以请求同意创建新帐户并访问所需的范围。 Google征得用户同意后,Google会使用设置为intent参数的值调用您的令牌交换端点,以create该令牌,并包括一个ID令牌,该令牌包含请求中的用户个人资料信息。

Handle automatic linking

After the user gives consent to access their Google profile, Google sends a request that contains a signed assertion of the Google user's identity. The assertion contains information that includes the user's Google Account ID, name, and email address. The token exchange endpoint configured for your project handles that request.

If the corresponding Google Account is already present in your authentication system, your token exchange endpoint returns a token for the user. If the Google Account doesn't match an existing user, your token exchange endpoint returns a linking_error error and optional login_hint.

The request has the following form:

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

grant_type=urn:ietf:params:oauth:grant-type:jwt-bearer&intent=get&assertion=JWT&scope=SCOPES

Your token exchange endpoint must be able to handle the following parameters:

Token endpoint parameters
intent For these requests, the value of this parameter is get.
grant_type The type of token being exchanged. For these requests, this parameter has the value urn:ietf:params:oauth:grant-type:jwt-bearer.
assertion A JSON Web Token (JWT) that provides a signed assertion of the Google user's identity. The JWT contains information that includes the user's Google Account ID, name, and email address.
scope Optional: Any scopes that you've configured Google to request from users.

When your token exchange endpoint receives the linking request, it needs to validate and decode the JWT assertion.

验证并解码JWT断言

您可以使用针对您的语言JWT解码库来验证和解码JWT断言。使用Google的JWKPEM格式的公钥来验证令牌的签名。

解码后,JWT断言类似于以下示例:

{
  "sub": "1234567890",      // The unique ID of the user's Google Account
  "iss": "https://accounts.google.com",        // The assertion's issuer
  "aud": "123-abc.apps.googleusercontent.com", // Your server's client ID
  "iat": 233366400,         // Unix timestamp of the assertion's creation time
  "exp": 233370000,         // Unix timestamp of the assertion's expiration time
  "name": "Jan Jansen",
  "given_name": "Jan",
  "family_name": "Jansen",
  "email": "jan@gmail.com", // If present, the user's email address
  "email_verified": true,   // true, if Google has verified the email address
  "hd": "example.com",      // If present, the host domain of the user's GSuite email address
                            // If present, a URL to user's profile picture
  "picture": "https://lh3.googleusercontent.com/a-/AOh14GjlTnZKHAeb94A-FmEbwZv7uJD986VOF1mJGb2YYQ",
  "locale": "en_US"         // User's locale, from browser or phone settings
}

除了验证令牌的签名外,还要验证断言的颁发者( iss字段)为https://accounts.google.com ,受众( aud字段)是您分配的客户端ID,并且令牌尚未过期( exp场地)。

使用emailemail_verifiedhd字段,您可以确定Google是否托管电子邮件地址并对其具有权威性。如果Google具有权威性,则当前已知该用户为合法帐户所有者,您可以跳过密码或其他挑战方法。否则,可以使用这些方法在链接之前验证帐户。

Google具有权威性的情况:

  • email后缀为@gmail.com ,这是一个Gmail帐户。
  • email_verified为true并且设置了hd ,这是一个G Suite帐户。

用户可以在不使用Gmail或G Suite的情况下注册Google帐户。如果email不包含@gmail.com后缀,并且没有hd则Google并不具有权威性,建议您使用密码或其他验证方法来验证用户。当Google在创建Google帐户时最初验证了用户时, email_verfied也可能为true,但是此后第三方电子邮件帐户的所有权可能已更改。

Check if the Google account is already present in your authentication system

Check whether either of the following conditions are true:

  • The Google Account ID, found in the assertion's sub field, is in your user database.
  • The email address in the assertion matches a user in your user database.

In some cases, account linking based on ID token might fail for the user. If it does so for any reason, your token exchange endpoint needs to reply with a HTTP 401 error that specifies error=linking_error, as the following example shows:

HTTP/1.1 401 Unauthorized
Content-Type: application/json;charset=UTF-8

{
  "error":"linking_error",
  "login_hint":"foo@bar.com"
}
When Google receives a 401 error response with linking_error, Google calls your token exchange endpoint with the following in the request:

  • The intent parameter set to create
  • A JWT with the ID token and user's profile information

Handle account creation via Google Sign-In

When a user needs to create an account on your service, Google makes a request to your token exchange endpoint that specifies intent=create.

The request has the following form:

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

response_type=token&grant_type=urn:ietf:params:oauth:grant-type:jwt-bearer&scope=SCOPES&intent=create&assertion=JWT

Your token exchange endpoint must able to handle the following parameters:

Token endpoint parameters
intent For these requests, the value of this parameter is create.
grant_type The type of token being exchanged. For these requests, this parameter has the value urn:ietf:params:oauth:grant-type:jwt-bearer.
assertion A JSON Web Token (JWT) that provides a signed assertion of the Google user's identity. The JWT contains information that includes the user's Google Account ID, name, and email address.

The JWT within the assertion parameter contains the user's Google Account ID, name, and email address, which you can use to create a new account on your service.

To respond to account creation requests, your token exchange endpoint must perform the steps in the following two sections.

验证并解码JWT断言

您可以使用针对您的语言JWT解码库来验证和解码JWT断言。使用Google的JWKPEM格式的公钥来验证令牌的签名。

解码后,JWT断言类似于以下示例:

{
  "sub": "1234567890",      // The unique ID of the user's Google Account
  "iss": "https://accounts.google.com",        // The assertion's issuer
  "aud": "123-abc.apps.googleusercontent.com", // Your server's client ID
  "iat": 233366400,         // Unix timestamp of the assertion's creation time
  "exp": 233370000,         // Unix timestamp of the assertion's expiration time
  "name": "Jan Jansen",
  "given_name": "Jan",
  "family_name": "Jansen",
  "email": "jan@gmail.com", // If present, the user's email address
  "email_verified": true,   // true, if Google has verified the email address
  "hd": "example.com",      // If present, the host domain of the user's GSuite email address
                            // If present, a URL to user's profile picture
  "picture": "https://lh3.googleusercontent.com/a-/AOh14GjlTnZKHAeb94A-FmEbwZv7uJD986VOF1mJGb2YYQ",
  "locale": "en_US"         // User's locale, from browser or phone settings
}

除了验证令牌的签名外,还要验证断言的颁发者( iss字段)为https://accounts.google.com ,受众( aud字段)是您分配的客户端ID,并且令牌尚未过期( exp场地)。

使用emailemail_verifiedhd字段,您可以确定Google是否托管电子邮件地址并对其具有权威性。如果Google具有权威性,则当前已知该用户为合法帐户所有者,您可以跳过密码或其他挑战方法。否则,可以使用这些方法在链接之前验证帐户。

Google具有权威性的情况:

  • email后缀为@gmail.com ,这是一个Gmail帐户。
  • email_verified为true并且设置了hd ,这是一个G Suite帐户。

用户可以在不使用Gmail或G Suite的情况下注册Google帐户。如果email不包含@gmail.com后缀,并且没有hd则Google并不具有权威性,建议您使用密码或其他验证方法来验证用户。当Google在创建Google帐户时最初验证了用户时, email_verfied也可能为true,但是此后第三方电子邮件帐户的所有权可能已更改。

Validate user information and create new account

Check whether either of the following conditions are true:

  • The Google Account ID, found in the assertion's sub field, is in your user database.
  • The email address in the assertion matches a user in your user database.

If either condition is true, prompt the user to link their existing account with their Google Account. To do so, respond to the request with an HTTP 401 error that specifies error=linking_error and gives the user's email address as the login_hint. The following is a sample response:

HTTP/1.1 401 Unauthorized
Content-Type: application/json;charset=UTF-8

{
  "error":"linking_error",
  "login_hint":"foo@bar.com"
}

When Google receives a 401 error response with linking_error, Google sends the user to your authorization endpoint with login_hint as a parameter. The user completes account linking using the OAuth linking flow in their browser.

If neither condition is true, create a new user account with the information provided in the JWT. New accounts don't typically have a password set. It's recommended that you add Google Sign-In to other platforms to enable users to log in with Google across the surfaces of your application. Alternatively, you can email the user a link that starts your password recovery flow to allow the user to set a password to sign in on other platforms.

When the creation is completed, issue an access token and return the values in a JSON object in the body of your HTTPS response, like in the following example:

{
  "token_type": "Bearer",
  "access_token": "ACCESS_TOKEN",

  "expires_in": SECONDS_TO_EXPIRATION
}

验证您的实施

您可以通过使用验证实现的OAuth 2.0游乐场工具。

在工具中,执行以下步骤:

  1. 单击配置打开的OAuth 2.0配置窗口。
  2. OAuth流场中,选择客户端
  3. OAuth端点字段中,选择自定义
  4. 在相应字段中指定您的 OAuth 2.0 端点和您分配给 Google 的客户端 ID。
  5. 步骤1部分,不要选择任何谷歌范围。相反,将此字段留空或键入对您的服务器有效的范围(如果不使用 OAuth 范围,则输入任意字符串)。当您完成后,单击授权的API。
  6. 步骤2步骤3段,完成OAuth 2.0流程和验证每个步骤按预期工作。

您可以通过验证您的实现谷歌帐户链接演示工具。

在工具中,执行以下步骤:

  1. 点击登录在与谷歌按钮。
  2. 选择您要关联的帐户。
  3. 输入服务标识。
  4. (可选)输入您将请求访问的一个或多个范围。
  5. 单击开始演示
  6. 出现提示时,确认您可以同意并拒绝链接请求。
  7. 确认您被重定向到您的平台。