mixnet/core/
kx_pair.rs

1// Copyright 2022 Parity Technologies (UK) Ltd.
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20
21//! Mixnet key-exchange key pair.
22
23use super::sphinx::{
24	derive_kx_public, derive_kx_shared_secret, gen_kx_secret, KxPublic, KxSecret, SharedSecret,
25};
26use rand::{CryptoRng, Rng};
27use zeroize::Zeroizing;
28
29pub struct KxPair {
30	/// Unclamped secret key. Boxed to avoid leaving copies around in memory if `KxPair` is moved.
31	secret: Box<Zeroizing<KxSecret>>,
32	public: KxPublic,
33}
34
35impl KxPair {
36	pub fn gen(rng: &mut (impl Rng + CryptoRng)) -> Self {
37		gen_kx_secret(rng).into()
38	}
39
40	pub fn public(&self) -> &KxPublic {
41		&self.public
42	}
43
44	pub fn exchange(&self, their_public: &KxPublic) -> SharedSecret {
45		derive_kx_shared_secret(their_public, self.secret.as_ref())
46	}
47}
48
49impl From<KxSecret> for KxPair {
50	fn from(secret: KxSecret) -> Self {
51		// We box the secret to avoid leaving copies of it in memory when the KxPair is moved. Note
52		// that we will likely leave some copies on the stack here; I'm not aware of any good way
53		// of avoiding this.
54		let secret = Box::new(Zeroizing::new(secret));
55		let public = derive_kx_public(secret.as_ref());
56		Self { secret, public }
57	}
58}
mixnet/core/kx_pair.rs

mixnet/core/
kx_pair.rs
