I need to integrate web application into Telegram using telegram bot. I need to do an authentication for client, and the web application authenticating user with his phone number + password. I've found interesting method of obtaining user's phone number through special button
This method seems to be quite sufficient to do authentication without user's password, since user cannot send nobody's except his phone number, and all the authentication already done by Telegram. But it's a little embarrassing for me, since I don't know how the phone sharing feature works, and how hard is it, to bypass or cheat on it.
*As the precaution, I think to do only authentication (may be even identification) through Telegram bot. And for sensitive actions will require additional authorization (but I don't know how, for now))