Struct KeyCandidateBudget 

pub struct KeyCandidateBudget { /* private fields */ }

Aggregate key-candidate work allowance for one cryptographic operation.

Resolver implementations must consume one unit before each key lookup or unwrap attempt. A single budget is shared across direct and recipient keys.

Implementations

impl KeyCandidateBudget

pub fn for_operation() -> Self

Create the fixed implementation-wide budget for one operation.

pub fn with_limit(maximum: usize) -> Self

Create a budget from a validated operation policy ceiling.

pub const fn remaining(&self) -> usize

Number of candidate attempts still available to this operation.

pub fn derive_key( &mut self, provider: &dyn CryptoProvider, policy: &DecryptionPolicy, parameters: &KdfParameters<'_>, secret: &[u8], ) -> Result<Zeroizing<Vec<u8>>, XmlEncError>

Derive a key against the caller’s operation snapshot, retaining all KDF reservations in this same budget across nested sources and retries. Resolvers must forward the snapshot received by their policy-aware entry point; they must never choose a profile from document content.

pub fn agree_and_derive( &mut self, provider: &dyn CryptoProvider, policy: &DecryptionPolicy, key: &dyn KeyAgreementKey, agreement: &KeyAgreementParameters<'_>, parameters: &KdfParameters<'_>, ) -> Result<Zeroizing<Vec<u8>>, XmlEncError>

Establish a shared secret and derive its consuming key after reserving both outputs and checking both permissions before either provider call. Candidate allowance includes scalar multiplication and derivation.

pub fn consume(&mut self, count: usize) -> Result<(), XmlEncError>

Charge attempted candidate work before performing it.

Trait Implementations

impl Debug for KeyCandidateBudget

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

Formats the value using the given formatter.