Validating MSISDN with vector.im does not work right now

[kittykat]

Steps to reproduce

1. Go to settings
2. Under Phone numbers, enter a valid phone number and press "Add"
   -> SMS message is not received but UI implies that it succeeded

Expected result

Verification SMS is received.

Critical because it fails silently and there is no workaround, and occasional because it fails for everyone but it doesn't feel like we have many users trying to use it.

Proposed solution

• We don't seem to be checking the response status from the OpenMarket API matrix-org/sydent#410
• Sending text messages (SMS) is silently failing on vector.im matrix-org/sydent#411
• Confirm that sending verification codes through Sydent/OpenMarket API works

[t3chguy]

It doesn't work for users using that IS, it could work for users of different ISes, hardcoding is vector.im wouldn't be great

[kittykat]

@t3chguy is there a way to check what IS is being used?

[t3chguy]

The URL yes, but we can't ask it if its using the OpenMarket API or not

[kittykat]

Can the check only be done when the phone number is submitted or when the settings panel is loaded? As far as we know, it only doesn't work with Sydent as far as we know right now.

[t3chguy]

We know the URL of the IS at any point.

[babolivier]

Hide phone number setting for vector.im users or give a warning that it's not possible to add a phone number right now (allow users to remove existing phone numbers?)

This wouldn't cover the case of a user signed up to a homeserver which delegates its msisdn verification to an identity server (which afaik clients can't know about), however it looks like Element automatically configures new users with vector.im as their IS (@t3chguy feel free to correct me if I'm wrong), which means the number of users in this case would probably be fairly minimal.

[novocaine]

upstream issue matrix-org/sydent#411

[novocaine]

@kittykat can you re-test this please

[kittykat]

I can add a phone number now.

I don't get any useful error messages for invalid (wrong number of digits) or numbers which don't exist (e.g. +441234567890) and the error message for an invalid verification code isn't passed on correctly (matrix-org/synapse/issues/11016)

I'm going to close this issue as it is now possible to add a phone number.