Module chain 

Per-broker audit hash-chain primitives.

The chain binds each record to all prior records: new_head = SHA256(prev_head ‖ seq_be ‖ value). The writer stamps (seq, prev_head) on each record. The verifier recomputes the chain and checks continuity. The writer and the verifier must use these functions. Never reimplement the formula.

Structs

ChainLink

The chain position a record is stamped with.

ChainState

Running per-broker chain state.

Constants

GENESIS_HEAD

Chain head before the writer writes the first record.

Functions

chain_hash

Canonical chain hash. new_head = SHA256(prev ‖ seq.to_be_bytes() ‖ value).

from_hex32

Parse exactly 32 bytes of lowercase or uppercase hex.

to_hex

Encode bytes as lowercase hex.