I am developing Android app using Firebase. Because of that, I want to use Firebase Auth. I have following requirements:
I had a similar problem - I combined firebase auth(email + password) with (phone+otp) to get phone+password auth -
https://medium.com/@shivampesitbng/firebase-phone-password-auth-in-vue-b94f15b8fb3d
Firebase phone authentication is using OTP(one time password). This way there is no hassle for the user to remember the password. Once authenticated, you will be registered. The sms code acts as a password. But that is for one time. Usually , users prefer such behaviour in which you dont have to remember the passwords. If you are still looking for the way you want, see this link and create a custom authentication method. https://firebase.google.com/docs/auth/android/custom-auth
If you have both email and phone of your user and you can use Admin SDK, then perhaps you could exchange users phone number to his email and login with email and password in the background.
Something like this (node.js)
admin.auth().getUserByPhoneNumber(phoneNumber)
.then(user => {
firebase.auth().signInWithEmailAndPassword(user.email, password);
});
Use Fake Email:
Well, Firebase doesn't support sign in with mobile number and password but it supports email and password. So you can create a fake email with your mobile number.
Ie: 78******69@yourdomain.com
Also, you can create a complete Authentication system using it.
Registration:
Input user mobile and password and proceed to the next page.
Now use Firebase Phone Auth (OTP) to createUser. If process success, link fake email, password credentials in background.
AuthCredential credential = EmailAuthProvider.getCredentialWithLink(email, emailLink);
auth.getCurrentUser().linkWithCredential(credential);
Login:
signInWithEmailAndPassword()
.Forget Password: