Struct KeyEstablishmentBudget 

pub struct KeyEstablishmentBudget<'a> { /* private fields */ }

Cumulative KDF allowance borrowed from one immutable operation policy.

Share this instance across every recipient, derived key and retry. Reservations are monotonic, including failed provider calls. Input slices remain borrowed; only the provider’s returned key buffer is owned and zeroized by this API.

Implementations

impl<'a> KeyEstablishmentBudget<'a>

pub fn new(policy: &'a KeyEstablishmentPolicy) -> Result<Self, PolicyViolation>

Validate the snapshot before compiling or executing key-establishment work.

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

Derive through the selected provider only after syntax, permission, capability and aggregate allocation/CPU reservations have succeeded.

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

Agree and derive using the same monotonic operation allowance. Permission and both workspace/output reservations precede either provider callback.

pub const fn hash_blocks(&self) -> usize

Cumulative compression work reserved, including failed attempts.

pub const fn owned_bytes(&self) -> usize

Cumulative output allocations reserved, including failed attempts.

pub const fn modular_work(&self) -> usize

Cumulative finite-field validation and exponentiation work reserved.