[📚] Does this module support MFA with Firebase?

[thertzelle]

Documentation Feedback

Firebase support MFA with any login type, I was wondering if this module supports it, its not in the documentation?

[mikehardy]

MFA is a strategy, not an API. So, sure?

You can do email/password (or social auth) and then also an SMS verification. That would be MFA, yes?

[andersonaddo]

Just a couple months ago an update was made to Firebase to support MFA via Google Cloud Identity.

https://cloud.google.com/identity-platform/docs/web/mfa

I doubt we support that though, so you'll have to improvise

[mikehardy]

That is - I think - basically the SMS verification, which the native SDKs and react-native-firebase handle fine

[thertzelle]

Is there a way to access the multifactor object within the native SDK from react-native-firebase module ? According to the documentation it's on the user object, without it, it's not possible to enroll an device as MFA

[mikehardy]

You will have to instrument the code to inspect that object and log out contents to see, it likely does if you are on up to date SDKs

I just read the doc more carefully and it looks like this is an API extension that needs wrapping here in order to expose it:

https://cloud.google.com/identity-platform/docs/web/mfa#enrolling_a_second_factor

Steps 9

Initialize a MultiFactorAssertion object with the PhoneAuthCredential:

var multiFactorAssertion = firebase.auth.PhoneMultiFactorGenerator.assertion(cred);

and 10

Complete the enrollment. Optionally, you can specify a display name for the second factor. This is useful for users with multiple second factors, since the phone number is masked during the authentication flow (for example, +1******1234).

// Complete enrollment. This will update the underlying tokens
// and trigger ID token change listener.
user.multiFactor.enroll(multiFactorAssertion, 'My personal phone number');

It exists at least on android: https://firebase.google.com/docs/reference/android/com/google/firebase/auth/MultiFactor

iOS it appears to be there as of pod version 6.20.0 https://firebase.google.com/support/release-notes/ios#version_6200_-_march_12_2020

PRs welcome!

[thertzelle]

I'll see what I can do about doing a PR, thank you for your guidance!

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[mikehardy]

Worth reopening I think - there is MFA information to expose on the user object I believe, an easy for PR for someone, similar to the #5019 PR

[mikehardy]

Released in v11.3.0 here!

[chenop]

Thanks @mikehardy, but if thats ok I need a clarification. I would like to do MFA and Im not holding my users data in Firebase (currently not using "@react-native-firebase/auth").
Is there a way to access the MultiFactor object via react-native-firebase and send sms to a user not signed in with Firebase?

[Nantris]

I'm not clear on whether React Native Firebase supports TOTP for second factor. Can anyone clarify?

[mikehardy]

@Slapbox with apologies this isn't a use case of mine so I haven't explored it. I think this may be a "try it and see" 😬 - if it doesn't work, it can't be far off from working with all the multi-factor stuff in place now

[Nantris]

At least one of the necessary methods, TotpMultiFactorGenerator doesn't appear to be included in React Native Firebase, not even as a dummy function that logs a "Not implemented" warning.

The other required method, getMultiFactorResolver does appear to be implemented.

I wonder about the potential feasibility of adding that required method.

• JS SDK: https://firebase.google.com/docs/auth/web/totp-mfa#sign_in_users_with_a_second_factor
• Android SDK: https://firebase.google.com/docs/auth/android/totp-mfa#sign_in_users_with_a_second_factor

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Edit: Added to list in #7483