Files
librustzcash/src/tests/key_agreement.rs
2018-06-12 15:32:20 -06:00

75 lines
2.2 KiB
Rust

use pairing::bls12_381::Bls12;
use pairing::{PrimeField, PrimeFieldRepr};
use rand::{OsRng, Rng};
use sapling_crypto::jubjub::{edwards, JubjubBls12};
use sapling_crypto::primitives::{Diversifier, ViewingKey};
use {
librustzcash_sapling_generate_r, librustzcash_sapling_ka_agree,
librustzcash_sapling_ka_derivepublic,
};
#[test]
fn test_key_agreement() {
let params = JubjubBls12::new();
let mut rng = OsRng::new().unwrap();
// Create random viewing key
let vk = ViewingKey::<Bls12> {
ak: edwards::Point::rand(&mut rng, &params).mul_by_cofactor(&params),
nk: edwards::Point::rand(&mut rng, &params).mul_by_cofactor(&params),
};
// Create a random address with the viewing key
let addr = loop {
match vk.into_payment_address(Diversifier(rng.gen()), &params) {
Some(a) => break a,
None => {}
}
};
// Grab ivk from our viewing key in serialized form
let ivk = vk.ivk();
let mut ivk_serialized = [0u8; 32];
ivk.into_repr().write_le(&mut ivk_serialized[..]).unwrap();
// Create random esk
let mut esk = [0u8; 32];
librustzcash_sapling_generate_r(&mut esk);
// The sender will create a shared secret with the recipient
// by multiplying the pk_d from their address with the esk
// we randomly generated
let mut shared_secret_sender = [0u8; 32];
// Serialize pk_d for the call to librustzcash_sapling_ka_agree
let mut addr_pk_d = [0u8; 32];
addr.pk_d.write(&mut addr_pk_d[..]).unwrap();
assert!(librustzcash_sapling_ka_agree(
&addr_pk_d,
&esk,
&mut shared_secret_sender
));
// Create epk for the recipient, placed in the transaction. Computed
// using the diversifier and esk.
let mut epk = [0u8; 32];
assert!(librustzcash_sapling_ka_derivepublic(
&addr.diversifier.0,
&esk,
&mut epk
));
// Create sharedSecret with ephemeral key
let mut shared_secret_recipient = [0u8; 32];
assert!(librustzcash_sapling_ka_agree(
&epk,
&ivk_serialized,
&mut shared_secret_recipient
));
assert!(!shared_secret_sender.iter().all(|&v| v == 0));
assert_eq!(shared_secret_sender, shared_secret_recipient);
}