How can I setup passwordless email signin in Firebase? - firebase

I'm trying to setup passwordless authentification in Firebase. I already enabled "email without password" auth in my Project settings.
Using this documentation : https://firebase.google.com/docs/auth/admin/email-action-links#generate_email_link_for_sign-in I managed to implement a way to create auth links.
My goal is to open https://dev.test.com/signup/ with the email of the user so he will be instantly signed in.
This is my code so far:
import firebase_admin
from firebase_admin import auth
def main():
default_app = firebase_admin.initialize_app()
email = 'name.chris#gmail.com'
action_code_settings = auth.ActionCodeSettings(
url=f'https://dev.test.com/signup/?email={email}',
handle_code_in_app=True,
ios_bundle_id='com.example.ios',
android_package_name='com.example.android',
android_install_app=True,
android_minimum_version='12',
dynamic_link_domain='magic42.page.link',
)
link = auth.generate_sign_in_with_email_link(email, action_code_settings)
print(f"LINK = {link}")
When I click on the link, I don't get automatically signed in. I guess I should also modify my front end. I'm using Angular. My signup looks like this :
signUp(email: string, password: string): Observable<UserCredential> {
const credential = firebase.auth.EmailAuthProvider.credential(email, password);
return from(firebase.auth().currentUser.linkWithCredential(credential));
}

I'm confused why you have email and password on frontend. To complete sign in using the email link, you should be using firebase.auth().signInWithEmailLink() method and not linkWithCredential on your /signup page.
You can get sample code (which should be executed on your /signup page) of completing sign in with email link in the documentation:
https://firebase.google.com/docs/auth/web/email-link-auth

Related

Setup programmatically the language code to send translated email verification - ns+angular app

I'm using this plugin: https://docs.nativescript.org/plugins/firebase-auth.html
to integrate my nativescript+angular mobile app with firebase authentication system.
Is there any way to setup the language code to send a translated email verification (template provided already by firebase) ?
I tried to setup by doing that
import { firebase } from '#nativescript/firebase-core'
import '#nativescript/firebase-auth'
...
let authFirebase = firebase().auth()
authFirebase.languageCode = 'fr'
authFirebase
.createUserWithEmailAndPassword(useremail, userpassword)
.then((cred) => {
if (cred && !cred.user.emailVerified) {
// send the account activation email
cred.user.sendEmailVerification()
}
})
but I got immediately a compilation error:
Cannot assign to 'languageCode' because it is a read-only property.ts(2540)
Any suggestion?
Many thanks in advance

How can I solve create account problem with different providers?

I have a sign in with Google:example#gmail.com
then create an account with the same email:example#gmail.com
There is a problem with two different providers
Sign in with Google (same Gmail)
Sign in with Email (same Gmail)
How Can I handle these two (When I delete the google sign-in account from Firebase Console. I can create an account with that email) Otherwise I can't create an account with that email and also can't sign in.
I learning Firebase Auth with https://github.com/gladly-team/next-firebase-auth
If you first sign in with Google using "example#gmail.com", it means a user will be created using this particular email address. If you try to sign in with any other provider or with an email and password using the same email address, you'll get an error message that says that the user already exists. And it makes sense since you have already used that email for a user before.
There are two ways in which you can solve this problem. When you get such an error, you can check the provider used to create the account, and notify the user to use it. For example, if the user signs in with Google and tries to authenticate with email and password right after that, display a message to the user in which you should say that the user already exists, and should use the authentication provider which was selected to create the account in the first place, in this case, Google.
The second option would be to allow the user to have multiple accounts using the same email address with different authentication providers. This option can be enabled directly in the Firebase Console, in the Authentication section.
So it's up to you to decide which option works better for your project.
The simple Solution is to enable multiple account an email.
Or ----------------
You Link the account.
This is an example when there is a facebook account with a certain email
and you want to use that same email to sign in with Email and password or gmail, if those two emails are not linked different provider error will be thrown. check here for more
export function linkFaceBookAccount(authContext?: AuthContextType, notificationContext?: NotificationContextType, history?: History.History) {
const provider = new FacebookAuthProvider(); // create a provider
linkWithPopup(auth.currentUser as User, provider).then((result) => {
// This gives you a Google Access Token. You can use it to access the Google API.
// const credential = FacebookAuthProvider.credentialFromResult(result);
// const token = credential?.accessToken;
// The signed-in user info.
const user = result.user;
saveUserToLocalStorage(user);
authContext?.loadUserToState(user);
notificationContext?.addNotification({
message: `This email's (${auth.currentUser?.email}) account has been successful linked with your facebook account`,
title: "Link successful",
notificationType: "SUCCESS",
positiveActionText: "continue",
positiveAction: () => {
history?.push("/")
}
})
}).catch((error) => {
const email = error.customData?.email;
const errorCode = error.code;
const duplicateAccount = errorCode === "auth/account-exists-with-different-credential";
notificationContext?.addNotification({
message: errorFirebase(error, email),
title: "Linking Error",
notificationType: "WARNING",
positiveActionText: duplicateAccount ? "Link" : "ok",
negativeActionText: duplicateAccount ? "cancel" : undefined,
code: errorCode,
positiveAction: () => {
if (duplicateAccount) {
duplicateAccountLinking(email, "FACEBOOK", history);
}
}
})
});}

Generate undo email change link in firebase cloud functions

How can I generate a link to undo the email change in firebase cloud functions?
So when a user changes their email address, I want to generate a link to include in an automated email for them to click to undo this email change. Firebase sends an email when an email changes, but I want to be able to do that myself with my own code.
Currently, I can find that there are ways you can generate a link to change the user password, verify email, etc. However, I cannot find a method that I can use to generate a link to undo email change when the user changes their email.
When a user changes the email, you can store a document in Firestore containing their old email, a token and some metadata if you need to. That being said, you should update user's email from a Cloud function or your server using the Admin SDK only as there are no triggers on E-Mail change.
import jwt from "jsonwebtoken"
import {v4} from "uuid"
exports.changeEmail = functions.https.onCall(async (data, context) => {
const {newEmail} = data;
const {uid} = context.auth;
// change user's email
// send an email to verify new email is required
// generate a JWT
const token = jwt.sign({ uid, eventId: v4() }, 'jwt_signing_secret', { expiresIn: '24h' });
// add a document in Firestore containing details about this event
await admin.firestore().collection("emailChanges").doc(eventId).set({
uid, changedAt: Date.now()
})
const undoURL = `https://[YOUR_DOMAIN]/revert-email-change?token=${token}`
// E-Mail this URL to user
// Terminate this function
})
Replace [YOUR_DOMAIN] will the URL of your website. Once the user visits /revert-change-email email page of your website, call another function that verifies this token.
exports.revertEmailChange = functions.https.onCall((data, context) => {
// pass the token from frontend by checking URL params
const {token} = data
// Verify the token
const decoded = jwt.verify(token, 'jwt_signing_secret');
console.log(decoded)
const {uid, eventId} = decoded
// token is valid
// read the Firestore document using stateId and check old email
const snap = await admin.firestore().collection("emailChanges").doc(eventId).get()
if (!snap.exists) return {error: "Invalid Token"}
const {email} = snap.data()
// use updateUser() method to change email back
// delete that document from Firestore
return {data: "Email changed back successfully"}
});
You can change the lifespan of JWT token i.e. how long the URL should be valid. You can read more about JWT at jwt.io. The additional eventId token is just to prevent that JWT token so it cannot be reused.
When writing Cloud Functions for Firebase, one uses the Admin Node.js SDK.
AFAIK it is not possible, with this Admin SDK, to generate an email action link to undo an email change, as we can we can do, for example, for email verification with the generateEmailVerificationLink() method.
You will need to build your own mechanism yourself. You'll probably have to save somewhere (e.g. in Firestore) the previous email and expose an HTTP endpoint to trigger the action (HTTPS Cloud Function? Call to the Firestore REST API?). In any case you'll have to check the identity of the calling user (by either checking the Firebase ID token as a Bearer token in the Authorization header of the HTTP request or via a dedicated Firestore Security Rule).
There isn't enough details in your question to understand the exact flow of your complete use case (i.e. from the request to change email up to the action of undoing an effective change) and propose a sensible approach.

Can I skip the first step in the passwordless signin method in Firebase?

I have a list of people with all their personal information (name, first name, date of birth, email, etc.).I want to send to each of these people an email with a link allowing them, once clicked, to be directly connected on our website. Without having to type a password.
I followed the Firebase procedure for passwordless authentication:
from the back back in Python. Generate email link for connexion
for the front in Angular Js. Completing signin in a web page
Fireship.io tutorial
But most of the examples don't quite fit my use case.
Most of the examples:
User comes to your website, asks for passwordless authentication, types in his email, (the email is stored in window.location.href)
User receives an email with a link to log in, he clicks on it
User is on your website, logged in (thanks to his email stored in window.location.href).
My use case:
None. I already have the email of my user, so I send him directly the link to connect.
User receives an email with a link to log in, he clicks on it
User is on my website, but has to type his e-mail again in the prompt (because it is obviously not stored in window.location.href).
In my case the window.location.href variable will never be used. And I don't want my user to have to retype his email once the link is clicked. Since I already have his email, why ask him again?
So how can I skip this step? Is there any security risk in doing so?
This is my code so far:
Back:
import firebase_admin
from firebase_admin import auth
from google.cloud import firestore
def create_new_auth(dictionary):
user = auth.create_user(
email=dictionary['email'],
email_verified=True,
phone_number=dictionary['phone'],
password='super_secure_password_007',
display_name=f"{dictionary['firstName']} {dictionary['lastName']}",
disabled=False)
print('Sucessfully created new user: {0}'.format(user.uid))
return user.uid
def create_new_pre_user(db, dictionary, uid):
dictionary = {
'uid': uid,
'email': dictionary['email'],
'lastName': dictionary['lastName'],
'gender': dictionary['gender'],
'birthday': dictionary['birthday'],
'phone': dictionary['phone'],
'firstName': dictionary['firstName']
}
db.collection(u'users').document(uid).set(dictionary)
def main(dictionary):
firebase_admin.initialize_app()
db = firestore.Client()
uid = create_new_auth(dictionary)
create_new_pre_user(db, dictionary, uid)
action_code_settings = auth.ActionCodeSettings(
url=f'http://localhost:4200/login',
handle_code_in_app=True,
ios_bundle_id='com.example.ios',
android_package_name='com.example.android',
android_install_app=True,
android_minimum_version='12',
dynamic_link_domain='magic42.page.link',
)
link = auth.generate_sign_in_with_email_link(dictionary['email'], action_code_settings)
if __name__ == '__main__':
dictionary = {
"firstName": "Jone",
"lastName": "Doe",
"birthday": 12345678,
"gender": "male",
"email": "john.doe#gmail.com",
"phone": "+33611223344"
}
main(dictionary)
Front:
private signInWithEmail() {
if (this.authService.isSignInWithEmailLink(window.location.href)) {
// Additional state parameters can also be passed via URL.
// This can be used to continue the user's intended action before triggering
// the sign-in operation.
// Get the email if available. This should be available if the user completes
// the flow on the same device where they started it.
let email = window.localStorage.getItem('emailForSignIn');
if (!email) {
// User opened the link on a different device. To prevent session fixation
// attacks, ask the user to provide the associated email again. For example:
email = window.prompt('Please provide your email for confirmation');
}
// The client SDK will parse the code from the link for you.
this.authService.signInWithEmailLink(email, window.location.href)
.then((result) => {
// Clear email from storage.
window.localStorage.removeItem('emailForSignIn');
// You can access the new user via result.user
// Additional user info profile not available via:
// result.additionalUserInfo.profile == null
// You can check if the user is new or existing:
// result.additionalUserInfo.isNewUser
this.router.navigate(['/patient', 'quiz'])
})
.catch((error) => {
// Some error occurred, you can inspect the code: error.code
// Common errors could be invalid email and invalid or expired OTPs.
});
}
}
isSignInWithEmailLink(href) {
return this.afAuth.auth.isSignInWithEmailLink(href);
}
signInWithEmailLink(email: string, href: string) {
return this.afAuth.auth.signInWithEmailLink(email, href)
}
EDITS
The problem is that the front has no knowledge of the user email when he first come the our website using the link. There is a way to pass the email information from our server-side to the front but it's in clear in the URL : that's risky and not a good practice according to Firebase itself (link)
Like this:
def main(dictionary):
firebase_admin.initialize_app()
db = firestore.Client()
uid = create_new_auth(dictionary)
create_new_pre_user(db, dictionary, uid)
action_code_settings = auth.ActionCodeSettings(
url=f'http://localhost:4200/login/?email=john.doe#gmail.com',
handle_code_in_app=True,
ios_bundle_id='com.example.ios',
android_package_name='com.example.android',
android_install_app=True,
android_minimum_version='12',
dynamic_link_domain='magic42.page.link',
)
link = auth.generate_sign_in_with_email_link(dictionary['email'], action_code_settings)
So how can I pass the email information from the back to the front so that the user doesn't have to type it again when redirected to my website after clicking to my "magic link" ?
One thing you could do is to create a single-use token on the backend that links to your user's email (or that links to a document in firestore) and have that be in the url. When the user enters the page, make a call to your backend with the token (could be just a simple uuid) and have your backend sign the user in and then expire/remove that token from use.
E.G.
https://yoursite.com/44ed3716-2b8f-4068-a445-b05a8fee17c3
Frontend sends 44ed3716-2b8f-4068-a445-b05a8fee17c3 to backend...backend sees the token, logs them in, then makes that token no longer valid.
Update
To answer your question in the comments below about not needing email link auth anymore through firebase: not necessarily. At that point, you're kind of creating your own email sign-in system (which actually isn't too hard) and somewhat re-inventing the wheel. Adding a token to the url was just a way for you to associate the user with an email without having to actually put the email in the url so that your frontend can know who the user is once your link is clicked. Once the backend sends you the email, you can store it local storage and complete the sign in with firebase normally.
There's no security risk asking the user to type his/her email versus storing it in the window storage, and one could argue that it's actually more secure to do so. That said, how you can go about doing this:
Make sure you have enabled email passwordless authentication.
Using the admin SDK, add each email address to your auth table (though I wouldn't set emailVerified: true - that will happen when they click the magic link and verify themselves on login.
Again using the admin SDK, generate a magic link for each user and send it to them.
On your login page (where the magic link takes them), prompt them for their email address and then use that along with the magic link to authenticate. The sample code provided from Firebase shows you how to do this in the if(!email){ ... } part of the code where it uses a window prompt to collect the user's email in case the user clicked the link on a separate device or the browser didn't/couldn't store the email address.
If you already have the user's email, you can call firebase.auth().sendSignInLinkToEmail with that email in the client-side JavaScript SDK (docs), or generateSignInWithEmailLink in the server-side Node.js SDK (docs). Both calls take the user's email as an argument.
Once the user lands on your site after clicking the link, you can access their profile with an auth state listener like this:
firebase.auth().onAuthStateChanged((user) => {
if (user) {
var uid = user.uid;
var email = user.email;
}
});

How to firebase.login() & createNewUser() with react-redux-firebase and email link firebase passwordless auth?

I’m working on a react native application that uses [Firebase Email Link (passwordless) Auth]((https://firebase.google.com/docs/auth/web/email-link-auth)
I have created a ‘users’ collection on the Firestore database.
In order to easily sync users profile data to the redux store,I decided to use react-redux-firebase
I have already configured the rrfConfig and followed every single steps as stated in the getting started documentation, but still remain some parts that unclear and not documented. It’ll be great to get someone’s help on any ideas on how to tackle this part:
1) How to log in users with firebase.login({params}) that are signed up with email link (passwordless) using the methods outlined in the auth section?
This the email/password example:
firebase.login({
email: 'test#test.com',
password: 'testest1'
})
Since the user does not have a password, or credential or accessToken after he signed up using email link firebase.auth().signInWithEmailLink(email, window.location.href) all we have is a uid and email:
firebase.login({
email: 'test#test.com',
// any ideas to add here?
})
2) Similarly, how to create users with createUser(credentials, profile) using [email link (passwordless)](https://firebase.google.com/docs/auth/web/email-link-auth
) auth?
const createNewUser = ({ email, password, username }) => {
firebase.createUser( // should password be replaced by url?
{ email, password },
{ username, email }
)
}
Thank you in advance for helping out with any ideas on how to tackle this

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