Struct ExpandedKeypair

pub struct ExpandedKeypair {
    pub(crate) secret: ExpandedSecretKey,
    pub(crate) public: PublicKey,
}

A variant of Keypair containing an [ExpandedSecretKey].

In the Tor protocol, we use this type for blinded onion service identity keys (KS_hs_blind_id). Since their scalar values are computed, rather than taken directly from a SHA-512 transformation of a SecretKey, we cannot use the regular Keypair type.

Fields

secret: ExpandedSecretKey

The secret part of the key.

public: PublicKey

The public part of this key.

NOTE: As with [ed25519_dalek::SigningKey], this public key must be the public key matching secret. Putting a different public key in here would enable a class of attacks against ed25519 and enable secret key recovery.

Implementations

impl ExpandedKeypair

pub fn public(&self) -> &PublicKey

Return the public part of this expanded keypair.

pub fn sign(&self, message: &[u8]) -> Signature

Compute a signature over a message using this keypair.

pub fn to_secret_key_bytes(&self) -> [u8; 64]

Return a representation of the secret key in this keypair.

(Since it is an expanded secret key, we represent it as its scalar part followed by its hash_prefix.)

pub fn from_secret_key_bytes(bytes: [u8; 64]) -> Option<Self>

Reconstruct a key from its byte representation as returned by to_secret_key_bytes().

Return None if the input cannot be the output of to_secret_key_bytes().

Trait Implementations

impl Ed25519SigningKey for ExpandedKeypair

fn sign(&self, message: &[u8]) -> Signature

Sign a message with this key.

impl<'a> From<&'a Keypair> for ExpandedKeypair

fn from(kp: &'a Keypair) -> ExpandedKeypair

Converts to this type from the input type.

impl From<ExpandedKeypair> for PublicKey

fn from(ekp: ExpandedKeypair) -> PublicKey

Converts to this type from the input type.