[firebase_auth]: internal-error increases with phone number authentication on iOS since 3/14

[FujiKinaga]

Is there an existing issue for this?

• I have searched the existing issues.

Which plugins are affected?

Auth

Which platforms are affected?

iOS

Description

FirebaseAuthException: [firebase_auth/internal-error] An internal error has occurred, print and inspect the error details for more information.
  File "verify_phone_number.dart", line 58, in VerifyPhoneNumberUseCase.call.handleVerificationFailed
  File "method_channel_firebase_auth.dart", line 620, in MethodChannelFirebaseAuth.verifyPhoneNumber.<fn>
  File "zone.dart", line 1594, in _RootZone.runUnaryGuarded
  File "stream_impl.dart", line 339, in _BufferingStreamSubscription._sendData
  File "stream_impl.dart", line 271, in _BufferingStreamSubscription._add
  File "stream_pipe.dart", line 123, in _ForwardingStreamSubscription._add
  File "stream_pipe.dart", line 253, in _HandleErrorStream._handleData
  File "stream_pipe.dart", line 153, in _ForwardingStreamSubscription._handleData
  File "zone.dart", line 1594, in _RootZone.runUnaryGuarded
  File "stream_impl.dart", line 339, in _BufferingStreamSubscription._sendData
  File "stream_impl.dart", line 515, in _DelayedData.perform
  File "stream_impl.dart", line 620, in _PendingEvents.handleNext
  File "stream_impl.dart", line 591, in _PendingEvents.schedule.<fn>
  File "schedule_microtask.dart", line 40, in _microtaskLoop
  File "schedule_microtask.dart", line 49, in _startMicrotaskLoop

• Our service has seen a significant increase in the frequency of errors since 3/13~3/14.
• These errors occur when a reCaptcha is displayed during phone number authentication.
• Cannot be reproduced on Web or Android, only occurs on iOS

Sentry Errors

Reproducing the issue

1. call FirebaseAuth#verifyPhoneNumber by iOS devices.
2. encountering the reCaptcha.
3. complete the reCaptcha.
4. The reCaptcha will either loop or retry and start again.

---

supplements

• Silent APNs notifications setting is inactive
  • https://firebase.google.com/docs/auth/ios/phone-auth#enable-app-verification
• reCaptcha verification is inactive
  • https://firebase.google.com/docs/auth/ios/phone-auth#set-up-recaptcha-verification

Firebase Core version

2.19.0

Flutter Version

3.13.9

Flutter dependencies

Expand Flutter dependencies snippet

  firebase_core: 2.19.0
  firebase_auth: 4.11.1
  firebase_messaging: 14.7.1

Additional context and comments

firebase/firebase-js-sdk#8056 was made at the same time on the day the problem occurred🧐

Movie

sms_bug_demo.mp4

[Lyokone]

Hello @FujiKinaga, I'm unable to reproduce the issue on my end 🤔 Have you tried to add App Check to your iOS app to see if the verification works?

[FujiKinaga]

@Lyokone
Thanks for your response.

Have you tried to add App Check to your iOS app to see if the verification works?

Is 'App Check' from Firebase? or App Attest?
in any event, We haven't tried it yet...

I am struggling to investigate because it does not reproduce all the time, but only when the ReCaptcha is passed, and once it happens, I have to wait for several hours until the restriction is removed.😭

[FujiKinaga]

@Lyokone
Is it unlikely that this bug is caused by firebase/firebase-js-sdk#8056 ? Because they appear to be occurring at the same time.

[Lyokone]

It's unlikely, since it's for the JS SDK, I don't see any recent changes in Auth in the iOS release note: https://firebase.google.com/support/release-notes/ios

[FujiKinaga]

@Lyokone
The new findings indicate that the root cause seems to be 503 or 400 status code in the following APIs🧐

POST https://www.googleapis.com/identitytoolkit/v3/relyingparty/sendVerificationCode?key=[key]

other Error messages

• [firebase_auth/internal-error] An internal error has occurred, print and inspect the error details for more information.