Enum AeadAlg 

#[repr(u8)]
pub enum AeadAlg {
    XChaCha20Poly1305 = 1,
    Aes256Gcm = 2,
    Aes256GcmSiv = 3,
}

Algorithm identifiers covered by the header signature.

Agility uses explicit numbers rather than “the current best choice” because the KEM will change during the product’s lifetime: X25519 will give way to an ML-KEM hybrid, and slots using different KEMs must coexist in one file.

Variants

XChaCha20Poly1305 = 1

Primary profile. A 192-bit nonce allows storing a random nonce.

Aes256Gcm = 2

Profile for FIPS requirements. A 96-bit nonce requires a counter and makes the container effectively write-once.

Aes256GcmSiv = 3

Nonce-reuse-resistant variant.

This used to say “for editable files”, which was a promise, not a description: editable files use aead_id = 1, like all others. The property SIV was meant to provide comes from plaintext-hedged nonces (aead::seal_chunk_hedged), introduced after the promise itself and making the second profile unnecessary. See docs/format.md §6.1.

The member remains to prevent assigning number 3 to another cipher.

Implementations

impl AeadAlg

pub fn from_u8(v: u8) -> Result<Self, CryptoError>

Parse an identifier from a file. Unknown values cause rejection, not substitution of a default.

Parsing immediately passes the second boundary, aead::ensure_supported, just as TreeHashAlg::from_u8 already does. The asymmetry was substantive: a header with aead_id = 2 passed signature verification, slot parsing, key agreement, and CEK unwrapping before failing on the first chunk. All that work was done on a file already known, at parsing time, to be impossible to open.

Trait Implementations

impl Clone for AeadAlg

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for AeadAlg

impl Debug for AeadAlg

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

Formats the value using the given formatter.

impl Eq for AeadAlg

impl PartialEq for AeadAlg

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for AeadAlg