Jędrzej Stuczyński
2d3b4f4b91
* Added github actions templates * removed travis .yml file * initial clippy cleanup pass * fixed the rest of clippy warnings * Made github badges more fancy and consistent with the ones in sphinx * Updated local rustc version and removed compilation warningns * ... and fresh clippy warnings * formatting * beta clippy specific warnings fixed * Fixed all nightly clippy warnings * Fixed trying to unwrap a () * Actually running all tests * Correctly passing the --all flag * Hopefullly third time's a charm in fixing argument passing
69 lines
2.7 KiB
Rust
69 lines
2.7 KiB
Rust
// Copyright 2020 Nym Technologies SA
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
use crate::asymmetric::encryption;
|
|
use crate::hkdf;
|
|
use digest::{BlockInput, FixedOutput, Reset, Update};
|
|
use generic_array::{typenum::Unsigned, ArrayLength};
|
|
use rand::{CryptoRng, RngCore};
|
|
use stream_cipher::{Key, NewStreamCipher, SyncStreamCipher};
|
|
|
|
/// Generate an ephemeral encryption keypair and perform diffie-hellman to establish
|
|
/// shared key with the remote.
|
|
pub fn new_ephemeral_shared_key<C, D, R>(
|
|
rng: &mut R,
|
|
remote_key: &encryption::PublicKey,
|
|
) -> (encryption::KeyPair, Key<C>)
|
|
where
|
|
C: SyncStreamCipher + NewStreamCipher,
|
|
D: Update + BlockInput + FixedOutput + Reset + Default + Clone,
|
|
D::BlockSize: ArrayLength<u8>,
|
|
D::OutputSize: ArrayLength<u8>,
|
|
R: RngCore + CryptoRng,
|
|
{
|
|
let ephemeral_keypair = encryption::KeyPair::new(rng);
|
|
|
|
// after performing diffie-hellman we don't care about the private component anymore
|
|
let dh_result = ephemeral_keypair.private_key().diffie_hellman(remote_key);
|
|
|
|
// there is no reason for this to fail as our okm is expected to be only C::KeySize bytes
|
|
let okm = hkdf::extract_then_expand::<D>(None, &dh_result, None, C::KeySize::to_usize())
|
|
.expect("somehow too long okm was provided");
|
|
|
|
let derived_shared_key =
|
|
Key::<C>::from_exact_iter(okm).expect("okm was expanded to incorrect length!");
|
|
|
|
(ephemeral_keypair, derived_shared_key)
|
|
}
|
|
|
|
/// Recompute shared key using remote public key and local private key.
|
|
pub fn recompute_shared_key<C, D>(
|
|
remote_key: &encryption::PublicKey,
|
|
local_key: &encryption::PrivateKey,
|
|
) -> Key<C>
|
|
where
|
|
C: SyncStreamCipher + NewStreamCipher,
|
|
D: Update + BlockInput + FixedOutput + Reset + Default + Clone,
|
|
D::BlockSize: ArrayLength<u8>,
|
|
D::OutputSize: ArrayLength<u8>,
|
|
{
|
|
let dh_result = local_key.diffie_hellman(remote_key);
|
|
|
|
// there is no reason for this to fail as our okm is expected to be only C::KeySize bytes
|
|
let okm = hkdf::extract_then_expand::<D>(None, &dh_result, None, C::KeySize::to_usize())
|
|
.expect("somehow too long okm was provided");
|
|
|
|
Key::<C>::from_exact_iter(okm).expect("okm was expanded to incorrect length!")
|
|
}
|