Module chain

HMAC-SHA256 hash chain for tamper-evident audit records.

Each record’s hash is HMAC(root_key, prev_hash || canonical_json(record)). Genesis records use prev_hash = [0; 32].

Structs

ChainId

A unique identifier for one chain (helps when multiple chains coexist).

HashChain

A live hash chain: holds the root key and current head hash.

Enums

ChainLoadError

Errors returned by HashChain::load_head_from_file.

Constants

HASH_LEN

Length of a chain hash in bytes (32 = SHA-256 output).