AWS cognito authenticate user with number

Question

Is it possible to authenticate a user with just their mobile phone like whatsapp does on mobile?

The mobile hub asks for a password, along with phone number.

So should i randomly generate it on the users mobile. Then store it in keychain for future logins?

Answer 1

Cognito provides a custom authentication flow where you can add your own custom challenge to authenticate the user by using lambda functions. Basically you generate a code in your lambda that you send to the mobile phone number and the user enters the code to authenticate.

An example is given in the following AWS presentation (towards the end)

https://www.youtube.com/watch?v=8DDIxqIW1sM