קישור יעיל יותר עם OAuth וכניסה באמצעות חשבון Google

סקירה כללית

קישור פשוט יותר של כניסה באמצעות חשבון Google שמבוסס על OAuth מוסיף את כניסה באמצעות חשבון Google לקישור OAuth. כך המשתמשים ב-Google יכולים לקשר את החשבון שלהם בצורה חלקה, וגם ליצור חשבון חדש בשירות שלכם באמצעות חשבון Google שלהם.

כדי לבצע קישור חשבון באמצעות OAuth ו-Google Sign-In, צריך לבצע את השלבים הכלליים הבאים:

  1. קודם צריך לבקש מהמשתמש לתת הסכמה לגישה לפרופיל שלו ב-Google.
  2. משתמשים במידע בפרופיל כדי לבדוק אם חשבון המשתמש קיים.
  3. למשתמשים קיימים, מקשרים את החשבונות.
  4. אם לא מצאתם התאמה למשתמש ב-Google במערכת האימות, צריך לאמת את אסימון המזהה שקיבלתם מ-Google. לאחר מכן תוכלו ליצור משתמש על סמך פרטי הפרופיל שמכיל אסימון המזהה.
באיור הזה מוצגים השלבים שמשתמש צריך לבצע כדי לקשר את חשבון Google שלו באמצעות תהליך הקישור המהיר. בצילום המסך הראשון מוצג איך משתמש יכול לבחור את האפליקציה שלכם לצורך קישור. צילום המסך השני מאפשר למשתמש לאשר אם יש לו חשבון קיים בשירות שלכם או לא. בצילום המסך השלישי, המשתמש יכול לבחור את חשבון Google שרוצים לקשר. בצילום המסך הרביעי מוצג אישור הקישור של חשבון Google לאפליקציה. בצילום המסך החמישי מוצג חשבון משתמש שמקושר בהצלחה לאפליקציית Google.

איור 1. קישור חשבון בטלפון של המשתמש באמצעות קישור פשוט

הדרישות לקישור פשוט

הטמעת שרת OAuth

נקודת הקצה של המרת האסימון חייבת לתמוך בכוונות check,‏ create ו-get. בהמשך מפורטים השלבים שבוצעו בתהליך הקישור של החשבון, ומופיע ציון של הזמנים שבהם מתבצעות הקריאות לכוונות השונות:

  1. האם למשתמש יש חשבון במערכת האימות שלכם? (המשתמש מחליט על ידי בחירה באפשרות 'כן' או 'לא')
    1. כן : האם המשתמש משתמש בכתובת האימייל שמשויכת לחשבון Google שלו כדי להיכנס לפלטפורמה? (המשתמש מחליט על ידי בחירה באפשרות 'כן' או 'לא')
      1. כן : האם למשתמש יש חשבון תואם במערכת האימות? (check intent מתקשר לווידוא)
        1. כן : get intent נקרא והחשבון מקושר אם הפונקציה get intent מחזירה נתונים.
        2. לא : יצירת חשבון חדש? (המשתמש מחליט על ידי בחירה באפשרות 'כן' או 'לא')
          1. כן : create intent נקרא והחשבון מקושר אם הפונקציה create intent מחזירה נתונים.
          2. לא : תהליך OAuth באינטרנט מופעל, המשתמש מופנה לדפדפן שלו והוא מקבל אפשרות לקשר עם כתובת אימייל אחרת.
      2. לא : תהליך OAuth לאינטרנט מופעל, המשתמש מופנה לדפדפן שלו וניתנת לו אפשרות לקשר עם כתובת אימייל אחרת.
    2. לא : האם למשתמש יש חשבון תואם במערכת האימות? (check intent מתקשר כדי לאשר)
      1. כן : get intent נקרא והחשבון מקושר אם הפונקציה get intent מחזירה נתונים.
      2. לא : create intent נקרא והחשבון מקושר אם הפונקציה create intent מחזירה נתונים.

Check for an existing user account (check intent)

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 responds with account_found=true. If the Google account doesn't match an existing user, your token exchange endpoint returns an HTTP 404 Not Found error with account_found=false.

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=check&assertion=JWT&scope=SCOPES&client_id=GOOGLE_CLIENT_ID&client_secret=GOOGLE_CLIENT_SECRET

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 check.
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.
client_id The client ID you assigned to Google.
client_secret The client secret you assigned to Google.

To respond to the check intent requests, your token exchange endpoint must perform the following steps:

  • Validate and decode the JWT assertion.
  • Check if the Google account is already present in your authentication system.
Validate and decode the JWT assertion

You can validate and decode the JWT assertion by using a JWT-decoding library for your language. Use Google's public keys, available in JWK or PEM formats, to verify the token's signature.

When decoded, the JWT assertion looks like the following example:

{
  "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
}

In addition to verifying the token's signature, verify that the assertion's issuer (iss field) is https://accounts.google.com, that the audience (aud field) is your assigned client ID, and that the token has not expired (exp field).

Using the email, email_verified and hd fields you can determine if Google hosts and is authoritative for an email address. In cases where Google is authoritative the user is currently known to be the legitimate account owner and you may skip password or other challenges methods. Otherwise, these methods can be used to verify the account prior to linking.

Cases where Google is authoritative:

  • email has a @gmail.com suffix, this is a Gmail account.
  • email_verified is true and hd is set, this is a G Suite account.

Users may register for Google Accounts without using Gmail or G Suite. When email does not contain a @gmail.com suffix and hd is absent Google is not authoritative and password or other challenge methods are recommended to verify the user. email_verified can also be true as Google initially verified the user when the Google account was created, however ownership of the third party email account may have since changed.

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.

If either condition is true, the user has already signed up. In that case, return a response like the following:

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

{
  "account_found":"true",
}

If neither the Google Account ID nor the email address specified in the assertion matches a user in your database, the user hasn't signed up yet. In this case, your token exchange endpoint needs to reply with a HTTP 404 error that specifies "account_found": "false", as in the following example:

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

{
  "account_found":"false",
}

Handle automatic linking (get intent)

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&client_id=GOOGLE_CLIENT_ID&client_secret=GOOGLE_CLIENT_SECRET

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.
client_id The client ID you assigned to Google.
client_secret The client secret you assigned to Google.

To respond to the get intent requests, your token exchange endpoint must perform the following steps:

  • Validate and decode the JWT assertion.
  • Check if the Google account is already present in your authentication system.
Validate and decode the JWT assertion

You can validate and decode the JWT assertion by using a JWT-decoding library for your language. Use Google's public keys, available in JWK or PEM formats, to verify the token's signature.

When decoded, the JWT assertion looks like the following example:

{
  "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
}

In addition to verifying the token's signature, verify that the assertion's issuer (iss field) is https://accounts.google.com, that the audience (aud field) is your assigned client ID, and that the token has not expired (exp field).

Using the email, email_verified and hd fields you can determine if Google hosts and is authoritative for an email address. In cases where Google is authoritative the user is currently known to be the legitimate account owner and you may skip password or other challenges methods. Otherwise, these methods can be used to verify the account prior to linking.

Cases where Google is authoritative:

  • email has a @gmail.com suffix, this is a Gmail account.
  • email_verified is true and hd is set, this is a G Suite account.

Users may register for Google Accounts without using Gmail or G Suite. When email does not contain a @gmail.com suffix and hd is absent Google is not authoritative and password or other challenge methods are recommended to verify the user. email_verified can also be true as Google initially verified the user when the Google account was created, however ownership of the third party email account may have since changed.

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.

If an account is found for the user, 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",
  "refresh_token": "REFRESH_TOKEN",
  "expires_in": SECONDS_TO_EXPIRATION
}

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 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.

Handle account creation via Google Sign-In (create intent)

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&client_id=GOOGLE_CLIENT_ID&client_secret=GOOGLE_CLIENT_SECRET

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.
client_id The client ID you assigned to Google.
client_secret The client secret you assigned to Google.

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 the create intent requests, your token exchange endpoint must perform the following steps:

  • Validate and decode the JWT assertion.
  • Validate user information and create new account.
Validate and decode the JWT assertion

You can validate and decode the JWT assertion by using a JWT-decoding library for your language. Use Google's public keys, available in JWK or PEM formats, to verify the token's signature.

When decoded, the JWT assertion looks like the following example:

{
  "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
}

In addition to verifying the token's signature, verify that the assertion's issuer (iss field) is https://accounts.google.com, that the audience (aud field) is your assigned client ID, and that the token has not expired (exp field).

Using the email, email_verified and hd fields you can determine if Google hosts and is authoritative for an email address. In cases where Google is authoritative the user is currently known to be the legitimate account owner and you may skip password or other challenges methods. Otherwise, these methods can be used to verify the account prior to linking.

Cases where Google is authoritative:

  • email has a @gmail.com suffix, this is a Gmail account.
  • email_verified is true and hd is set, this is a G Suite account.

Users may register for Google Accounts without using Gmail or G Suite. When email does not contain a @gmail.com suffix and hd is absent Google is not authoritative and password or other challenge methods are recommended to verify the user. email_verified can also be true as Google initially verified the user when the Google account was created, however ownership of the third party email account may have since changed.

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 refresh 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",
  "refresh_token": "REFRESH_TOKEN",
  "expires_in": SECONDS_TO_EXPIRATION
}

קבלת מזהה הלקוח ב-Google API

תצטרכו לספק את מזהה הלקוח של Google API במהלך תהליך הרישום לקישור החשבון.

כדי לקבל את מזהה הלקוח של ה-API באמצעות הפרויקט שיצרתם במהלך ביצוע השלבים לקישור OAuth. כדי לעשות זאת, מבצעים את השלבים הבאים:

  1. יוצרים או בוחרים פרויקט ב-Google APIs.

    אם לפרויקט אין מזהה לקוח לסוג אפליקציית האינטרנט, לוחצים על Create Client (יצירת לקוח) כדי ליצור מזהה לקוח. חשוב לכלול את הדומיין של האתר בתיבה Authorized JavaScript origins. כשמבצעים פיתוח או בדיקות מקומיות, צריך להוסיף את http://localhost ואת http://localhost:<port_number> לשדה Authorized JavaScript origins.

אימות ההטמעה

אפשר לאמת את ההטמעה באמצעות הכלי OAuth 2.0 Playground.

בכלי, מבצעים את הפעולות הבאות:

  1. לוחצים על Configuration (הגדרה) כדי לפתוח את חלון ההגדרה של OAuth 2.0.
  2. בשדה תהליך OAuth, בוחרים באפשרות צד הלקוח.
  3. בשדה נקודות קצה של OAuth, בוחרים באפשרות בהתאמה אישית.
  4. מציינים את נקודת הקצה (endpoint) של OAuth 2.0 ואת מזהה הלקוח שהקציתם ל-Google בשדות המתאימים.
  5. בקטע שלב 1, לא בוחרים היקפי גישה של Google. במקום זאת, צריך להשאיר את השדה הזה ריק או להקליד היקף תקין לשרת (או מחרוזת שרירותית אם לא משתמשים בהיקפים של OAuth). בסיום, לוחצים על Authorize API.
  6. בקטעים שלב 2 ושלב 3, מבצעים את התהליך OAuth 2.0 ומוודאים שכל שלב פועל כמו שצריך.

אפשר לאמת את ההטמעה באמצעות הכלי הדגמה של קישור לחשבון Google.

בכלי, מבצעים את השלבים הבאים:

  1. לוחצים על הלחצן כניסה באמצעות חשבון Google.
  2. בוחרים את החשבון שרוצים לקשר.
  3. מזינים את מזהה השירות.
  4. אפשר להזין היקף אחד או יותר שלגביו רוצים לבקש גישה.
  5. לוחצים על התחלת הדגמה.
  6. כשמופיעה הבקשה, מאשרים את האפשרות להביע הסכמה לדחיית בקשת הקישור.
  7. מוודאים שאתם מופנים מחדש לפלטפורמה שלכם.