How to Validate Telegram Login Widget Payloads Using PHP and Yii2

A developer tutorial published on DEV Community outlines how to verify Telegram Login Widget authentication payloads in a PHP and Yii2 backend. When users log in via the Telegram widget, parameters including a hash signature are sent to the application's redirect URL and must be validated server-side. The guide explains constructing the data_check_string, deriving a secret key from the bot token using SHA-256, and comparing HMAC signatures with a timing-safe hash_equals() check. It also covers verifying that the auth_date timestamp falls within an acceptable freshness window, typically 86,400 seconds. Finally, the tutorial demonstrates binding the verified telegram_id to an existing or new user record within a Yii2 controller.