Module dryoc::classic::crypto_kx

Key exchange

This module implements libsodium’s key exchange functions, which uses a combination of Curve25519, Diffie-Hellman, and Blake2b to generate shared session keys.

Classic API example

use dryoc::classic::crypto_kx::*;

// Generate random client & server keypairs
let (client_pk, client_sk) = crypto_kx_keypair();
let (server_pk, server_sk) = crypto_kx_keypair();

// Variables for client & server rx/tx session keys
let (mut crx, mut ctx, mut srx, mut stx) = (
    SessionKey::default(),
    SessionKey::default(),
    SessionKey::default(),
    SessionKey::default(),
);

// Calculate the client Rx & Tx keys
crypto_kx_client_session_keys(&mut crx, &mut ctx, &client_pk, &client_sk, &server_pk)
    .expect("client kx failed");

// Calculate the server Rx & Tx keys
crypto_kx_server_session_keys(&mut srx, &mut stx, &server_pk, &server_sk, &client_pk)
    .expect("server kx failed");

assert_eq!(crx, stx);
assert_eq!(ctx, srx);

Functions

crypto_kx_client_session_keys

Computes client session keys for rx and tx, using client_pk, client_sk, and server_pk. Returns unit () upon success.

crypto_kx_keypair

Returns a randomly generated keypair, suitable for use with key exchange.

crypto_kx_seed_keypair

Computes and returns a keypair of (PublicKey, SecretKey) based on seed upon success. Uses the Blake2b function to derive a secret from seed.

crypto_kx_server_session_keys

Computes server session keys for rx and tx, using client_pk, client_sk, and server_pk. Returns unit () upon success.

Type Definitions

PublicKey

Public key type for key exchange

SecretKey

Secret key type for key exchange

SessionKey

Session data type for key exchange