Storage seam for server-issued OID4VCI c_nonces.
A server issues an opaque, time-limited c_nonce from the nonce endpoint and
requires the wallet to echo it in the proof sent to the credential endpoint.
This behaviour is where those nonces live: issue/1 mints one, and
valid?/1 reports whether a presented nonce is still live.
Attesto.CNonceStore.ETS is a ready single-node implementation. A
multi-node deployment implements this over a shared store so a nonce issued
by one node is honoured by another.
Summary
Callbacks
Mint and store a fresh nonce valid for ttl_seconds.
Returns true iff nonce was issued by this store and has not expired.
Callbacks
@callback issue(ttl_seconds :: pos_integer()) :: String.t()
Mint and store a fresh nonce valid for ttl_seconds.
Returns true iff nonce was issued by this store and has not expired.