Struct Ed25519Signer 

pub struct Ed25519Signer { /* private fields */ }

In-process Ed25519 signer.

Implementations

impl Ed25519Signer

pub fn generate() -> Self

Generate a fresh keypair. The key id is derived from the public key (first 32 hex chars of its SHA-256) so ids are collision-resistant and never chosen by an attacker.

Defense-in-depth against a compromised getrandom (VM without entropy, cloud image with a broken /dev/urandom) — regenerate rather than accept an all-zero or all-0xFF seed. Reader-side already refuses these known-weak seeds; this closes the gap for generator-side. Astronomically unlikely from a healthy OsRng, but the failure mode is silent installation of a globally-predictable keypair — cheap to guard.

pub fn from_seed(seed: &[u8; 32]) -> Self

Load from a 32-byte secret seed.

Takes &[u8; 32] (borrow), not by value. Passing the seed by value materializes a caller-owned temp slot on the stack that Rust does not guarantee to zeroize on drop — a Zeroizing<[u8; 32]> wrapper only zeroizes the slot IT owns, not the copy the callee received. By taking a reference we let the caller keep the seed inside a Zeroizing and never lose control of the memory.

Caveat: caller must reject known-weak seeds

This constructor does NOT reject the all-zero or all-0xFF seeds (both produce globally-predictable keypairs). The production seed-loading path in av-harness::main::read_signer refuses both before reaching this function (see the [0u8; 32] / [0xFFu8; 32] guard in av-harness/src/main.rs); every OTHER caller (tests, avctl keygen) must apply the same policy or use Ed25519Signer::generate which loops until a non-weak seed is drawn. This contract is documented in-signature so a future refactor cannot silently drop the pre-validation.

pub fn seed(&self) -> Zeroizing<[u8; 32]>

Export the 32-byte secret seed (for avctl keygen persistence).

Returns Zeroizing<[u8; 32]> so the caller’s receiving slot zeroes on drop — historically the bare [u8; 32] return let a copy linger in freed stack/heap.

Trait Implementations

impl Debug for Ed25519Signer

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

Formats the value using the given formatter.

impl Signer for Ed25519Signer

fn key_id(&self) -> &str

Stable identifier for the signing key (embedded in receipts).

fn sign(&self, msg: &[u8]) -> [u8; 64]

Sign msg, returning the 64-byte Ed25519 signature.

fn public_key_bytes(&self) -> [u8; 32]

The corresponding public key (32 bytes).