Struct AuditKey 

pub struct AuditKey { /* private fields */ }

Loaded Ed25519 signing key + its identifier. Construct via AuditKey::load_or_generate.

Clone is intentional: the audit-verify CLI needs to load the key once and share it between the SQLite read-only path and the Postgres pool.

Debug is implemented manually to redact the signing key. A derived Debug would dump the private key via any tracing::debug!("{key:?}") or dbg!(key) site, which would leak the audit secret into journald. We keep key_id visible because operators need to identify which key generation a record belongs to when triaging chain breaks.

Implementations

impl AuditKey

pub fn load_or_generate(path: &Path) -> Result<Self, AuditKeyError>

Load the audit key from path. If the file does not exist, generate a 32-byte cryptographically random key and write it with mode 0o600.

On every load (including freshly generated), the file’s permissions are checked: any bit beyond 0o600 for owner-only access is rejected — a world-readable audit key is a self-defeating audit chain.

pub fn key_id(&self) -> &str

Stable identifier for this key generation.

pub fn chain_hash( &self, content: &ChainContent<'_>, prev_chain_hash: &str, ) -> String

Compute the chain signature for content linked to prev_chain_hash.

Hex-encoded Ed25519 signature over canonical(content) || prev_chain_hash. Deterministic (RFC 8032): identical inputs always yield the same value.

pub fn verifying_key(&self) -> VerifyingKey

The public verifying key for this audit key.

pub fn verifying_key_hex(&self) -> String

Hex-encoded 32-byte Ed25519 public key. Safe to publish; auditors use it to verify the chain without the ability to forge entries.

pub fn approval_receipt( &self, transaction_id: &str, request_hash: &str, ) -> String

Derive the bearer receipt for one immutable preview. The signature is deterministic, so a failed response delivery can be retried without storing plaintext bearer credentials in the database.

pub fn approval_commitment( &self, transaction_id: &str, request_hash: &str, ) -> String

Chain-stored SHA-256 commitment to the deterministic approval receipt.

impl AuditKey

pub fn event_hash( &self, content: &EventContent<'_>, prev_chain_hash: &str, ) -> String

Compute the event-chain signature for content linked to prev_chain_hash. Separate domain tag from rows and checkpoints, so an event signature can never be replayed as a transaction row.

impl AuditKey

pub fn sign_checkpoint( &self, seq: u64, chain_tip: &str, created_at: &str, ) -> Checkpoint

Sign a checkpoint committing to (seq, chain_tip) at created_at.

Trait Implementations

impl Clone for AuditKey

fn clone(&self) -> AuditKey

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AuditKey

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.