Function verify_watchtower_challenges

pub fn verify_watchtower_challenges(
    circuit_input: &BridgeCircuitInput,
) -> WatchtowerChallengeSet

Verifies watchtower challenge transactions and collects their outputs.

This function performs validation on a set of watchtower challenge transactions and their associated inputs, witnesses, and public keys. It checks that:

• Each challenge input corresponds to the correct kickoff_tx output (P2TR),

• The signature is valid under the Taproot sighash rules,

• The public key matches the one registered for the watchtower,

• And, if all checks pass, it marks the corresponding bit in a 20-byte bitmap (challenge_sending_watchtowers) and collects the first 3 outputs of the watchtower transaction into watchtower_challenges_outputs.

  Note: This function only verifies keypath spends.

Parameters

• circuit_input: Data structure holding serialized watchtower transactions, UTXOs, input indices, and pubkeys.
• kickoff_txid: The transaction ID of the kickoff_tx.

Returns

A tuple containing:

• A 20-byte bitmap indicating which watchtower challenges were valid,
• A vector of the first 3 outputs from each valid watchtower transaction.

Notes

Invalid or malformed challenge data (e.g., decoding errors, invalid signatures) will be skipped gracefully without causing the function to panic.