EIP-7702 Authorization-Tuple Decoder

Recomputes the EIP-7702 authorization-tuple hash (keccak256(0x05 || rlp([chain_id, address, nonce])), the 'Set EOA account code' standard live on Ethereum mainnet since the Pectra upgrade, 2025-05-07), recovers the ECDSA signer from a caller-supplied signature, and reports the address the recovered signer is authorizing as its delegate. The node does not apply EIP-2's low-s rule, which EIP-7702 requires. A tuple with s above secp256k1n/2 is skipped by clients, yet still returns AUTHORIZATION_RECOVERED here. The tuple's own address field IS the delegate: the code the EOA is pointing itself at. A zero delegate address clears the account's delegation rather than naming a delegate. This node stops at that address -- it never inspects, fetches, or judges the delegate contract's bytecode, and makes no safe/unsafe verdict about it. chain_id = 0 is EIP-7702-defined as a valid, deliberate cross-chain authorization (replayable on any chain) and is reported as such, never treated as malformed input. RLP encoding is hand-authored public-spec arithmetic (Ethereum Yellow Paper Appendix B); keccak256 and secp256k1 recovery come from the already-vendored, pinned noble-curves bundle, no new vendoring. Malformed or incomplete input produces a clean INDETERMINATE/RECOVERY_FAILED finding, never a thrown exception. Zero network calls: does not confirm the authorization was ever submitted on-chain, does not confirm the EOA's account nonce matches the declared nonce at any block, and makes no settlement claim.

Tool URL: https://ainumbers.co/chaingraph/art-614-eip7702-authorization-tuple-decoder.html