HMAC webhook verification
Your task
Implement HMAC verification for a webhook receiver. Given a shared secret key, the received message, and the signature_hex the sender claims is the HMAC-SHA256 of the message, return True only if the signature is valid. Compute the HMAC using the secret as the key and verify it matches the provided hex digest. You must compare in a way that does not leak timing information about how many leading bytes matched.
Examples
verify_hmac(key: str, message: str, signature_hex: str) -> boolExample 1
Input
verify_hmac("secret", "hello", "88aab3ede8d3adf94d26ab90d3bafd4a2083070c3bcce9c014ee04a443847c0b")Output
True