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Merge pull request #50 from huitseeker/simplifications

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Simplifications and Normalizations
This commit is contained in:
François Garillot
2020-09-21 14:41:16 -04:00
committed by GitHub
parent 84cc0e9b72 56d38dba2c
commit ae890dbac4
11 changed files with 185 additions and 237 deletions
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src/ciphersuite.rs
+1 -1
View File
@@ -34,7 +34,7 @@ pub trait CipherSuite {
/// A keypair type composed of public and private components
type KeyFormat: KeyPair<Repr = Key> + PartialEq;
/// A key exchange protocol
type KeyExchange: KeyExchange<Self::Hash>;
type KeyExchange: KeyExchange<Self::Hash, Self::KeyFormat>;
/// The main hash function use (for HKDF computations and hashing transcripts)
type Hash: Hash;
/// A slow hashing function, typically used for password hashing
src/elligator/mod.rs
+3 -2
View File
@@ -58,6 +58,7 @@ pub fn hash_to_point(bytes: &[u8]) -> EdwardsPoint {
#[cfg(test)]
mod tests {
use super::*;
use std::convert::TryInto;
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Signal tests from //
@@ -73,8 +74,8 @@ mod tests {
#[test]
fn elligator_correct() {
let bytes: Vec<u8> = (0u8..32u8).collect();
let mut bits_in = [0u8; 32];
bits_in.copy_from_slice(&bytes);
let bits_in: [u8; 32] = (&bytes[..]).try_into().expect("Range invariant broken");
let fe = FieldElement51::from_bytes(&bits_in);
let eg = elligator_signal(&fe);
assert_eq!(eg.to_bytes(), ELLIGATOR_CORRECT_OUTPUT);
src/group.rs
+12 -7
View File
@@ -87,7 +87,7 @@ impl Group for RistrettoPoint {
) -> Result<Self, InternalPakeError> {
CompressedRistretto::from_slice(element_bits)
.decompress()
.ok_or_else(|| InternalPakeError::PointError)
.ok_or(InternalPakeError::PointError)
}
// serialization of a group element
fn to_arr(&self) -> GenericArray<u8, Self::ElemLen> {
@@ -97,9 +97,12 @@ impl Group for RistrettoPoint {
type UniformBytesLen = U64;
fn hash_to_curve(uniform_bytes: &GenericArray<u8, Self::UniformBytesLen>) -> Self {
let mut bits = [0u8; 64];
bits.copy_from_slice(&uniform_bytes);
// https://caniuse.rs/features/array_gt_32_impls
let bits: [u8; 64] = {
let mut bytes = [0u8; 64];
bytes.copy_from_slice(uniform_bytes);
bytes
};
RistrettoPoint::from_uniform_bytes(&bits)
}
}
@@ -132,7 +135,7 @@ impl Group for EdwardsPoint {
) -> Result<Self, InternalPakeError> {
let point = CompressedEdwardsY::from_slice(element_bits)
.decompress()
.ok_or_else(|| InternalPakeError::PointError)?;
.ok_or(InternalPakeError::PointError)?;
if point.is_small_order() {
return Err(InternalPakeError::SubGroupError);
@@ -155,6 +158,7 @@ impl Group for EdwardsPoint {
mod tests {
use super::*;
use anyhow::{anyhow, Result};
use std::convert::TryInto;
const EIGHT_TORSION: [[u8; 32]; 8] = [
[
@@ -192,8 +196,9 @@ mod tests {
];
fn deserialize_point(pt: &[u8]) -> Result<EdwardsPoint> {
let mut bytes = [0u8; 32];
bytes.copy_from_slice(&pt[..32]);
let bytes: [u8; 32] = (&pt[..32])
.try_into()
.expect("Slice pattern invariant broken");
curve25519_dalek::edwards::CompressedEdwardsY(bytes)
.decompress()
src/hash.rs
+2 -11
View File
@@ -4,19 +4,10 @@
// LICENSE file in the root directory of this source tree.
use digest::{BlockInput, FixedOutput, Reset, Update};
use generic_array::ArrayLength;
/// Trait inheriting the requirements from digest::Digest for compatibility with HKDF and HMAC
// Associated types could be simplified when they are made as defaults:
// https://github.com/rust-lang/rust/issues/29661
pub trait Hash: Update + BlockInput + FixedOutput + Reset + Default + Clone {
/// The block size for the hash function
type BlockSize: ArrayLength<u8>;
/// The output size of the hash function
type OutputSize: ArrayLength<u8>;
}
pub trait Hash: Update + BlockInput + FixedOutput + Reset + Default + Clone {}
impl<T: Update + BlockInput + FixedOutput + Reset + Default + Clone> Hash for T {
type BlockSize = T::BlockSize;
type OutputSize = T::OutputSize;
}
impl<T: Update + BlockInput + FixedOutput + Reset + Default + Clone> Hash for T {}
src/key_exchange/traits.rs
+4 -4
View File
@@ -12,19 +12,19 @@ use rand_core::{CryptoRng, RngCore};
use std::convert::TryFrom;
pub trait KeyExchange<D: Hash> {
pub trait KeyExchange<D: Hash, KeyFormat: KeyPair<Repr = Key>> {
type KE1State: TryFrom<Vec<u8>, Error = InternalPakeError> + ToBytes;
type KE2State: TryFrom<Vec<u8>, Error = ProtocolError> + ToBytes;
type KE1Message: TryFrom<Vec<u8>, Error = InternalPakeError> + ToBytes;
type KE2Message: TryFrom<Vec<u8>, Error = ProtocolError> + ToBytes;
type KE3Message: TryFrom<Vec<u8>, Error = ProtocolError> + ToBytes;
fn generate_ke1<R: RngCore + CryptoRng, KeyFormat: KeyPair<Repr = Key>>(
fn generate_ke1<R: RngCore + CryptoRng>(
l1_component: Vec<u8>,
rng: &mut R,
) -> Result<(Self::KE1State, Self::KE1Message), ProtocolError>;
fn generate_ke2<R: RngCore + CryptoRng, KeyFormat: KeyPair<Repr = Key>>(
fn generate_ke2<R: RngCore + CryptoRng>(
rng: &mut R,
l1_bytes: Vec<u8>,
l2_bytes: Vec<u8>,
@@ -33,7 +33,7 @@ pub trait KeyExchange<D: Hash> {
server_s_sk: KeyFormat::Repr,
) -> Result<(Self::KE2State, Self::KE2Message), ProtocolError>;
fn generate_ke3<KeyFormat: KeyPair<Repr = Key>>(
fn generate_ke3(
l2_component: Vec<u8>,
ke2_message: Self::KE2Message,
ke1_state: &Self::KE1State,
src/key_exchange/tripledh.rs
+79 -71
View File
@@ -9,12 +9,11 @@ use crate::{
hash::Hash,
key_exchange::traits::{KeyExchange, ToBytes},
keypair::{Key, KeyPair, SizedBytes},
sized_bytes_using_constant_and_try_from,
};
use digest::Digest;
use digest::{Digest, FixedOutput};
use generic_array::{
typenum::{U64, U96},
GenericArray,
typenum::{Unsigned, U32},
ArrayLength, GenericArray,
};
use hkdf::Hkdf;
use hmac::{Hmac, Mac, NewMac};
@@ -24,31 +23,34 @@ use std::convert::TryFrom;
const KEY_LEN: usize = 32;
pub(crate) const NONCE_LEN: usize = 32;
pub(crate) type NonceLen = U32;
const KE1_STATE_LEN: usize = KEY_LEN + KEY_LEN + NONCE_LEN;
const KE2_MESSAGE_LEN: usize = NONCE_LEN + 2 * KEY_LEN;
static STR_3DH: &[u8] = b"3DH keys";
/// The Triple Diffie-Hellman key exchange implementation
pub struct TripleDH;
impl<D: Hash> KeyExchange<D> for TripleDH {
type KE1State = KE1State;
type KE2State = KE2State;
impl<D: Hash, KeyFormat: KeyPair<Repr = Key>> KeyExchange<D, KeyFormat> for TripleDH {
type KE1State = KE1State<<D as FixedOutput>::OutputSize>;
type KE2State = KE2State<<D as FixedOutput>::OutputSize>;
type KE1Message = KE1Message;
type KE2Message = KE2Message;
type KE3Message = KE3Message;
type KE2Message = KE2Message<<D as FixedOutput>::OutputSize>;
type KE3Message = KE3Message<<D as FixedOutput>::OutputSize>;
fn generate_ke1<R: RngCore + CryptoRng, KeyFormat: KeyPair<Repr = Key>>(
fn generate_ke1<R: RngCore + CryptoRng>(
l1_component: Vec<u8>,
rng: &mut R,
) -> Result<(Self::KE1State, Self::KE1Message), ProtocolError> {
let client_e_kp = KeyFormat::generate_random(rng)?;
let mut client_nonce = [0u8; NONCE_LEN];
rng.fill_bytes(&mut client_nonce);
let client_nonce: GenericArray<u8, NonceLen> = {
let mut client_nonce_bytes = [0u8; NONCE_LEN];
rng.fill_bytes(&mut client_nonce_bytes);
client_nonce_bytes.into()
};
let ke1_message = KE1Message {
client_nonce: client_nonce.to_vec(),
client_nonce,
client_e_pk: client_e_kp.public().clone(),
};
@@ -60,14 +62,14 @@ impl<D: Hash> KeyExchange<D> for TripleDH {
Ok((
KE1State {
client_e_sk: client_e_kp.private().clone(),
client_nonce: client_nonce.to_vec(),
hashed_l1: hashed_l1.to_vec(),
client_nonce,
hashed_l1,
},
ke1_message,
))
}
fn generate_ke2<R: RngCore + CryptoRng, KeyFormat: KeyPair<Repr = Key>>(
fn generate_ke2<R: RngCore + CryptoRng>(
rng: &mut R,
l1_bytes: Vec<u8>,
l2_bytes: Vec<u8>,
@@ -76,8 +78,11 @@ impl<D: Hash> KeyExchange<D> for TripleDH {
server_s_sk: KeyFormat::Repr,
) -> Result<(Self::KE2State, Self::KE2Message), ProtocolError> {
let server_e_kp = KeyFormat::generate_random(rng)?;
let mut server_nonce = [0u8; NONCE_LEN];
rng.fill_bytes(&mut server_nonce);
let server_nonce: GenericArray<u8, NonceLen> = {
let mut server_nonce_bytes = [0u8; NONCE_LEN];
rng.fill_bytes(&mut server_nonce_bytes);
server_nonce_bytes.into()
};
let (shared_secret, km2, km3) = derive_3dh_keys::<KeyFormat, D>(
TripleDHComponents {
@@ -115,19 +120,19 @@ impl<D: Hash> KeyExchange<D> for TripleDH {
Ok((
KE2State {
km3: km3.to_vec(),
hashed_transcript: hashed_transcript.to_vec(),
shared_secret: shared_secret.to_vec(),
km3,
hashed_transcript,
shared_secret,
},
KE2Message {
server_nonce: server_nonce.to_vec(),
server_nonce,
server_e_pk: server_e_kp.public().clone(),
mac: mac.finalize().into_bytes().to_vec(),
mac: mac.finalize().into_bytes(),
},
))
}
fn generate_ke3<KeyFormat: KeyPair<Repr = Key>>(
fn generate_ke3(
l2_component: Vec<u8>,
ke2_message: Self::KE2Message,
ke1_state: &Self::KE1State,
@@ -165,7 +170,7 @@ impl<D: Hash> KeyExchange<D> for TripleDH {
Hmac::<D>::new_varkey(&km2).map_err(|_| InternalPakeError::HmacError)?;
server_mac.update(&hashed_transcript);
if ke2_message.mac != server_mac.finalize().into_bytes().to_vec() {
if ke2_message.mac != server_mac.finalize().into_bytes() {
return Err(ProtocolError::VerificationError(
PakeError::KeyExchangeMacValidationError,
));
@@ -178,7 +183,7 @@ impl<D: Hash> KeyExchange<D> for TripleDH {
Ok((
shared_secret.to_vec(),
KE3Message {
mac: client_mac.finalize().into_bytes().to_vec(),
mac: client_mac.finalize().into_bytes(),
},
))
}
@@ -191,7 +196,7 @@ impl<D: Hash> KeyExchange<D> for TripleDH {
Hmac::<D>::new_varkey(&ke2_state.km3).map_err(|_| InternalPakeError::HmacError)?;
client_mac.update(&ke2_state.hashed_transcript);
if ke3_message.mac != client_mac.finalize().into_bytes().to_vec() {
if ke3_message.mac != client_mac.finalize().into_bytes() {
return Err(ProtocolError::VerificationError(
PakeError::KeyExchangeMacValidationError,
));
@@ -205,40 +210,46 @@ impl<D: Hash> KeyExchange<D> for TripleDH {
}
fn ke2_message_size() -> usize {
KE2_MESSAGE_LEN
NONCE_LEN + KEY_LEN + <<D as FixedOutput>::OutputSize as Unsigned>::to_usize()
}
}
/// The client state produced after the first key exchange message
#[derive(PartialEq, Eq)]
pub struct KE1State {
pub struct KE1State<HashLen: ArrayLength<u8>> {
client_e_sk: Key,
client_nonce: Vec<u8>,
hashed_l1: Vec<u8>,
client_nonce: GenericArray<u8, NonceLen>,
hashed_l1: GenericArray<u8, HashLen>,
}
/// The first key exchange message
#[derive(PartialEq, Eq)]
pub struct KE1Message {
pub(crate) client_nonce: Vec<u8>,
pub(crate) client_nonce: GenericArray<u8, NonceLen>,
pub(crate) client_e_pk: Key,
}
impl TryFrom<Vec<u8>> for KE1State {
impl<HashLen: ArrayLength<u8>> TryFrom<Vec<u8>> for KE1State<HashLen> {
type Error = InternalPakeError;
fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
let checked_bytes = check_slice_size(&bytes, KE1_STATE_LEN, "ke1_state")?;
let checked_bytes = check_slice_size(
&bytes,
KEY_LEN + NONCE_LEN + HashLen::to_usize(),
"ke1_state",
)?;
Ok(Self {
client_e_sk: Key::from_bytes(&checked_bytes[..KEY_LEN])?,
client_nonce: checked_bytes[KEY_LEN..KEY_LEN + NONCE_LEN].to_vec(),
hashed_l1: checked_bytes[KEY_LEN + NONCE_LEN..].to_vec(),
client_nonce: GenericArray::clone_from_slice(
&checked_bytes[KEY_LEN..KEY_LEN + NONCE_LEN],
),
hashed_l1: GenericArray::clone_from_slice(&checked_bytes[KEY_LEN + NONCE_LEN..]),
})
}
}
impl ToBytes for KE1State {
impl<HashLen: ArrayLength<u8>> ToBytes for KE1State<HashLen> {
fn to_bytes(&self) -> Vec<u8> {
let output: Vec<u8> = [
&self.client_e_sk.to_arr(),
@@ -250,8 +261,6 @@ impl ToBytes for KE1State {
}
}
sized_bytes_using_constant_and_try_from!(KE1State, U96);
impl ToBytes for KE1Message {
fn to_bytes(&self) -> Vec<u8> {
[&self.client_nonce[..], &self.client_e_pk.to_arr()].concat()
@@ -266,29 +275,27 @@ impl TryFrom<Vec<u8>> for KE1Message {
check_slice_size(&ke1_message_bytes, NONCE_LEN + KEY_LEN, "ke1_message")?;
Ok(Self {
client_nonce: checked_bytes[..NONCE_LEN].to_vec(),
client_nonce: GenericArray::clone_from_slice(&checked_bytes[..NONCE_LEN]),
client_e_pk: Key::from_bytes(&checked_bytes[NONCE_LEN..])?,
})
}
}
sized_bytes_using_constant_and_try_from!(KE1Message, U64);
/// The server state produced after the second key exchange message
pub struct KE2State {
km3: Vec<u8>,
hashed_transcript: Vec<u8>,
shared_secret: Vec<u8>,
pub struct KE2State<HashLen: ArrayLength<u8>> {
km3: GenericArray<u8, HashLen>,
hashed_transcript: GenericArray<u8, HashLen>,
shared_secret: GenericArray<u8, HashLen>,
}
/// The second key exchange message
pub struct KE2Message {
server_nonce: Vec<u8>,
pub struct KE2Message<HashLen: ArrayLength<u8>> {
server_nonce: GenericArray<u8, NonceLen>,
server_e_pk: Key,
mac: Vec<u8>,
mac: GenericArray<u8, HashLen>,
}
impl ToBytes for KE2State {
impl<HashLen: ArrayLength<u8>> ToBytes for KE2State<HashLen> {
fn to_bytes(&self) -> Vec<u8> {
let output: Vec<u8> = [
&self.km3[..],
@@ -300,21 +307,21 @@ impl ToBytes for KE2State {
}
}
impl TryFrom<Vec<u8>> for KE2State {
impl<HashLen: ArrayLength<u8>> TryFrom<Vec<u8>> for KE2State<HashLen> {
type Error = ProtocolError;
fn try_from(ke1_message_bytes: Vec<u8>) -> Result<Self, Self::Error> {
let checked_bytes = check_slice_size(&ke1_message_bytes, 3 * KEY_LEN, "ke2_state")?;
Ok(Self {
km3: checked_bytes[..KEY_LEN].to_vec(),
hashed_transcript: checked_bytes[KEY_LEN..2 * KEY_LEN].to_vec(),
shared_secret: checked_bytes[2 * KEY_LEN..].to_vec(),
km3: GenericArray::clone_from_slice(&checked_bytes[..KEY_LEN]),
hashed_transcript: GenericArray::clone_from_slice(&checked_bytes[KEY_LEN..2 * KEY_LEN]),
shared_secret: GenericArray::clone_from_slice(&checked_bytes[2 * KEY_LEN..]),
})
}
}
impl ToBytes for KE2Message {
impl<HashLen: ArrayLength<u8>> ToBytes for KE2Message<HashLen> {
fn to_bytes(&self) -> Vec<u8> {
let output: Vec<u8> = [
&self.server_nonce[..],
@@ -326,16 +333,17 @@ impl ToBytes for KE2Message {
}
}
impl TryFrom<Vec<u8>> for KE2Message {
impl<HashLen: ArrayLength<u8>> TryFrom<Vec<u8>> for KE2Message<HashLen> {
type Error = ProtocolError;
fn try_from(ke2_message_bytes: Vec<u8>) -> Result<Self, Self::Error> {
let checked_bytes = check_slice_size(&ke2_message_bytes, KE2_MESSAGE_LEN, "ke2_message")?;
let ke2_message_len = NONCE_LEN + KEY_LEN + HashLen::to_usize();
let checked_bytes = check_slice_size(&ke2_message_bytes, ke2_message_len, "ke2_message")?;
Ok(Self {
server_nonce: checked_bytes[..NONCE_LEN].to_vec(),
server_nonce: GenericArray::clone_from_slice(&checked_bytes[..NONCE_LEN]),
server_e_pk: Key::from_bytes(&checked_bytes[NONCE_LEN..NONCE_LEN + KEY_LEN])?,
mac: checked_bytes[NONCE_LEN + KEY_LEN..].to_vec(),
mac: GenericArray::clone_from_slice(&checked_bytes[NONCE_LEN + KEY_LEN..]),
})
}
}
@@ -352,17 +360,17 @@ struct TripleDHComponents {
// Consists of a shared secret, followed by two mac keys
type TripleDHDerivationResult<D> = (
GenericArray<u8, <D as Hash>::OutputSize>,
GenericArray<u8, <D as Hash>::OutputSize>,
GenericArray<u8, <D as Hash>::OutputSize>,
GenericArray<u8, <D as FixedOutput>::OutputSize>,
GenericArray<u8, <D as FixedOutput>::OutputSize>,
GenericArray<u8, <D as FixedOutput>::OutputSize>,
);
// Internal function which takes the public and private components of the client and server keypairs, along
// with some auxiliary metadata, to produce the shared secret and two MAC keys
fn derive_3dh_keys<KeyFormat: KeyPair<Repr = Key>, D: Hash>(
dh: TripleDHComponents,
client_nonce: &[u8],
server_nonce: &[u8],
client_nonce: &GenericArray<u8, NonceLen>,
server_nonce: &GenericArray<u8, NonceLen>,
client_s_pk: KeyFormat::Repr,
server_s_pk: KeyFormat::Repr,
) -> Result<TripleDHDerivationResult<D>, ProtocolError> {
@@ -395,24 +403,24 @@ fn derive_3dh_keys<KeyFormat: KeyPair<Repr = Key>, D: Hash>(
}
/// The third key exchange message
pub struct KE3Message {
mac: Vec<u8>,
pub struct KE3Message<HashLen: ArrayLength<u8>> {
mac: GenericArray<u8, HashLen>,
}
impl ToBytes for KE3Message {
impl<HashLen: ArrayLength<u8>> ToBytes for KE3Message<HashLen> {
fn to_bytes(&self) -> Vec<u8> {
self.mac.clone()
self.mac.to_vec()
}
}
impl TryFrom<Vec<u8>> for KE3Message {
impl<HashLen: ArrayLength<u8>> TryFrom<Vec<u8>> for KE3Message<HashLen> {
type Error = ProtocolError;
fn try_from(bytes: Vec<u8>) -> Result<Self, Self::Error> {
let checked_bytes = check_slice_size(&bytes, KEY_LEN, "ke3_message")?;
Ok(Self {
mac: checked_bytes.to_vec(),
mac: GenericArray::clone_from_slice(&checked_bytes),
})
}
}
src/keypair.rs
+5 -33
View File
@@ -16,6 +16,7 @@ use proptest::prelude::*;
#[cfg(test)]
use rand::{rngs::StdRng, SeedableRng};
use rand_core::{CryptoRng, RngCore};
use std::convert::TryInto;
use std::fmt::Debug;
use x25519_dalek::{PublicKey, StaticSecret};
@@ -91,35 +92,6 @@ trait KeyPairExt: KeyPair + Debug {
#[cfg(test)]
impl<KP> KeyPairExt for KP where KP: KeyPair + Debug {}
/// This assumes you have defined:
/// - an `impl TryFrom<&[u8b], Error = InternalPakeError>` for a non-generic `T`
/// - an `fn to_bytes(&self) -> Vec<u8>` in an `impl T` block
/// and it both of the above to produce a sensible SizedBytes implementation
///
/// Because SizedBytes has a strong notion of size, and TryFrom/to_bytes does
/// not, it's better to use the macro below rather than this one, where possible.
#[macro_export]
macro_rules! sized_bytes_using_constant_and_try_from {
($sized_type: ident, $len: ident) => {
impl SizedBytes for $sized_type {
type Len = $len;
fn to_arr(&self) -> generic_array::GenericArray<u8, Self::Len> {
generic_array::GenericArray::clone_from_slice(&self.to_bytes())
}
fn from_bytes(bytes: &[u8]) -> Result<Self, InternalPakeError> {
let checked_bytes = check_slice_size(
bytes,
<Self::Len as generic_array::typenum::Unsigned>::to_usize(),
"bytes",
)?;
std::convert::TryFrom::try_from(checked_bytes.to_vec())
}
}
};
}
/// This assumes you have defined a SizedBytes instance for a `T`, and defines:
/// - an `impl TryFrom<&[u8b], Error = InternalPakeError>` for a non-generic `T`
/// - an `fn to_bytes(&self) -> Vec<u8>` in an `impl T` block
@@ -245,15 +217,15 @@ impl KeyPair for X25519KeyPair {
}
fn public_from_private(secret: &Self::Repr) -> Self::Repr {
let mut secret_data = [0u8; 32];
secret_data.copy_from_slice(&secret.0[..]);
let secret_data: [u8; 32] = (&secret.0[..])
.try_into()
.expect("Keypair::Repr invariant broken");
let base_data = ::x25519_dalek::X25519_BASEPOINT_BYTES;
Key(::x25519_dalek::x25519(secret_data, base_data).to_vec())
}
fn check_public_key(key: Self::Repr) -> Result<Self::Repr, InternalPakeError> {
let mut key_bytes = [0u8; 32];
key_bytes.copy_from_slice(&key);
let key_bytes: [u8; 32] = (&key[..]).try_into().expect("Key invariant broken");
let point = ::curve25519_dalek::montgomery::MontgomeryPoint(key_bytes)
.to_edwards(1)
.ok_or(InternalPakeError::PointError)?;
src/map_to_curve.rs
+2 -3
View File
@@ -9,7 +9,6 @@
use crate::group::Group;
use curve25519_dalek::{edwards::EdwardsPoint, ristretto::RistrettoPoint};
use generic_array::GenericArray;
use hkdf::Hkdf;
use sha2::{Sha256, Sha512};
@@ -22,13 +21,13 @@ pub trait GroupWithMapToCurve: Group {
impl GroupWithMapToCurve for RistrettoPoint {
fn map_to_curve(password: &[u8], pepper: Option<&[u8]>) -> Self {
let (hashed_input, _) = Hkdf::<Sha512>::extract(pepper, password);
<Self as Group>::hash_to_curve(GenericArray::from_slice(&hashed_input))
<Self as Group>::hash_to_curve(&hashed_input)
}
}
impl GroupWithMapToCurve for EdwardsPoint {
fn map_to_curve(password: &[u8], pepper: Option<&[u8]>) -> Self {
let (hashed_input, _) = Hkdf::<Sha256>::extract(pepper, password);
<Self as Group>::hash_to_curve(GenericArray::from_slice(&hashed_input))
<Self as Group>::hash_to_curve(&hashed_input)
}
}
src/opaque.rs
+57 -85
View File
@@ -141,7 +141,7 @@ where
pub struct LoginFirstMessage<CS: CipherSuite> {
/// blinded password information
alpha: CS::Group,
ke1_message: <CS::KeyExchange as KeyExchange<CS::Hash>>::KE1Message,
ke1_message: <CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE1Message,
}
impl<CS: CipherSuite> TryFrom<&[u8]> for LoginFirstMessage<CS> {
@@ -163,9 +163,10 @@ impl<CS: CipherSuite> TryFrom<&[u8]> for LoginFirstMessage<CS> {
let arr = GenericArray::from_slice(&checked_slice[..elem_len]);
let alpha = CS::Group::from_element_slice(arr)?;
let ke1_message = <CS::KeyExchange as KeyExchange<CS::Hash>>::KE1Message::try_from(
checked_slice[elem_len..].to_vec(),
)?;
let ke1_message =
<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE1Message::try_from(
checked_slice[elem_len..].to_vec(),
)?;
Ok(Self { alpha, ke1_message })
}
}
@@ -179,28 +180,15 @@ impl<CS: CipherSuite> LoginFirstMessage<CS> {
/// The answer sent by the server to the user, upon reception of the
/// login attempt.
pub struct LoginSecondMessage<Grp, KeyFormat, KE, D>
where
KeyFormat: KeyPair,
KE: KeyExchange<D>,
D: Hash,
{
_key_format: PhantomData<KeyFormat>,
_key_exchange: PhantomData<KE>,
pub struct LoginSecondMessage<CS: CipherSuite> {
/// the server's oprf output
beta: Grp,
beta: CS::Group,
/// the user's sealed information,
envelope: Envelope<D>,
ke2_message: KE::KE2Message,
envelope: Envelope<CS::Hash>,
ke2_message: <CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE2Message,
}
impl<Grp, KeyFormat, KE, D> LoginSecondMessage<Grp, KeyFormat, KE, D>
where
Grp: Group,
KeyFormat: KeyPair,
KE: KeyExchange<D>,
D: Hash,
{
impl<CS: CipherSuite> LoginSecondMessage<CS> {
/// byte representation for the login response
pub fn to_bytes(&self) -> Vec<u8> {
[
@@ -212,19 +200,13 @@ where
}
}
impl<Grp, KeyFormat, KE, D> TryFrom<&[u8]> for LoginSecondMessage<Grp, KeyFormat, KE, D>
where
Grp: Group,
KeyFormat: KeyPair,
KE: KeyExchange<D>,
D: Hash,
{
impl<CS: CipherSuite> TryFrom<&[u8]> for LoginSecondMessage<CS> {
type Error = ProtocolError;
fn try_from(second_message_bytes: &[u8]) -> Result<Self, Self::Error> {
let key_len = <KeyFormat::Repr as SizedBytes>::Len::to_usize();
let envelope_size = key_len + Envelope::<D>::additional_size();
let elem_len = Grp::ElemLen::to_usize();
let ke2_message_size = KE::ke2_message_size();
let key_len = <<CS::KeyFormat as KeyPair>::Repr as SizedBytes>::Len::to_usize();
let envelope_size = key_len + Envelope::<CS::Hash>::additional_size();
let elem_len = <CS::Group as Group>::ElemLen::to_usize();
let ke2_message_size = CS::KeyExchange::ke2_message_size();
let checked_slice = check_slice_size(
second_message_bytes,
elem_len + envelope_size + ke2_message_size,
@@ -235,17 +217,17 @@ where
// correct subgroup
let beta_bytes = &checked_slice[..elem_len];
let arr = GenericArray::from_slice(beta_bytes);
let beta = Grp::from_element_slice(arr)?;
let beta = CS::Group::from_element_slice(arr)?;
let envelope =
Envelope::<D>::from_bytes(&checked_slice[elem_len..elem_len + envelope_size])?;
Envelope::<CS::Hash>::from_bytes(&checked_slice[elem_len..elem_len + envelope_size])?;
let ke2_message =
KE::KE2Message::try_from(checked_slice[elem_len + envelope_size..].to_vec())?;
<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE2Message::try_from(
checked_slice[elem_len + envelope_size..].to_vec(),
)?;
Ok(Self {
_key_format: PhantomData,
_key_exchange: PhantomData,
beta,
envelope,
ke2_message,
@@ -256,7 +238,7 @@ where
/// The answer sent by the client to the server, upon reception of the
/// sealed envelope
pub struct LoginThirdMessage<CS: CipherSuite> {
ke3_message: <CS::KeyExchange as KeyExchange<CS::Hash>>::KE3Message,
ke3_message: <CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE3Message,
}
impl<CS: CipherSuite> TryFrom<&[u8]> for LoginThirdMessage<CS> {
@@ -264,7 +246,9 @@ impl<CS: CipherSuite> TryFrom<&[u8]> for LoginThirdMessage<CS> {
fn try_from(bytes: &[u8]) -> Result<Self, Self::Error> {
let ke3_message =
<CS::KeyExchange as KeyExchange<CS::Hash>>::KE3Message::try_from(bytes.to_vec())?;
<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE3Message::try_from(
bytes.to_vec(),
)?;
Ok(Self { ke3_message })
}
}
@@ -533,14 +517,12 @@ where
/// byte representation for the server's registration state
pub fn to_bytes(&self) -> Vec<u8> {
let mut output: Vec<u8> = CS::Group::scalar_as_bytes(&self.oprf_key).to_vec();
match &self.client_s_pk {
Some(v) => output.extend_from_slice(&v.to_arr()),
None => {}
};
match &self.envelope {
Some(v) => output.extend_from_slice(&v.to_bytes()),
None => {}
};
self.client_s_pk
.iter()
.for_each(|v| output.extend_from_slice(&v));
self.envelope
.iter()
.for_each(|v| output.extend_from_slice(&v.to_bytes()));
output
}
@@ -641,21 +623,20 @@ where
/// The state elements the client holds to perform a login
pub struct ClientLogin<CS: CipherSuite> {
/// A choice of the keypair type
_key_format: PhantomData<CS::KeyFormat>,
/// A blinding factor, which is used to mask (and unmask) secret
/// information before transmission
blinding_factor: <CS::Group as Group>::Scalar,
/// The user's password
password: Vec<u8>,
ke1_state: <CS::KeyExchange as KeyExchange<CS::Hash>>::KE1State,
ke1_state: <CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE1State,
}
impl<CS: CipherSuite> TryFrom<&[u8]> for ClientLogin<CS> {
type Error = ProtocolError;
fn try_from(bytes: &[u8]) -> Result<Self, Self::Error> {
let scalar_len = <CS::Group as Group>::ScalarLen::to_usize();
let ke1_state_size = <CS::KeyExchange as KeyExchange<CS::Hash>>::ke1_state_size();
let ke1_state_size =
<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::ke1_state_size();
let min_expected_len = scalar_len + ke1_state_size;
let checked_slice = (if bytes.len() <= min_expected_len {
@@ -670,12 +651,12 @@ impl<CS: CipherSuite> TryFrom<&[u8]> for ClientLogin<CS> {
let blinding_factor_bytes = GenericArray::from_slice(&checked_slice[..scalar_len]);
let blinding_factor = CS::Group::from_scalar_slice(blinding_factor_bytes)?;
let ke1_state = <CS::KeyExchange as KeyExchange<CS::Hash>>::KE1State::try_from(
checked_slice[scalar_len..scalar_len + ke1_state_size].to_vec(),
)?;
let ke1_state =
<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE1State::try_from(
checked_slice[scalar_len..scalar_len + ke1_state_size].to_vec(),
)?;
let password = bytes[scalar_len + ke1_state_size..].to_vec();
Ok(Self {
_key_format: PhantomData,
blinding_factor,
password,
ke1_state,
@@ -737,15 +718,13 @@ impl<CS: CipherSuite> ClientLogin<CS> {
blinding_factor,
} = oprf::generate_oprf1::<R, CS::Group>(&password, pepper, rng)?;
let (ke1_state, ke1_message) =
CS::KeyExchange::generate_ke1::<_, CS::KeyFormat>(alpha.to_arr().to_vec(), rng)?;
let (ke1_state, ke1_message) = CS::KeyExchange::generate_ke1(alpha.to_arr().to_vec(), rng)?;
let l1 = LoginFirstMessage { alpha, ke1_message };
Ok((
l1,
Self {
_key_format: PhantomData,
blinding_factor,
password: password.to_vec(),
ke1_state,
@@ -790,7 +769,7 @@ impl<CS: CipherSuite> ClientLogin<CS> {
/// ```
pub fn finish<R: RngCore + CryptoRng>(
self,
l2: LoginSecondMessage<CS::Group, CS::KeyFormat, CS::KeyExchange, CS::Hash>,
l2: LoginSecondMessage<CS>,
server_s_pk: &<<CS as CipherSuite>::KeyFormat as KeyPair>::Repr,
_client_e_sk_rng: &mut R,
) -> Result<ClientLoginFinishResult<CS>, ProtocolError> {
@@ -810,7 +789,7 @@ impl<CS: CipherSuite> ClientLogin<CS> {
err => PakeError::from(err),
})?;
let (shared_secret, ke3_message) = CS::KeyExchange::generate_ke3::<CS::KeyFormat>(
let (shared_secret, ke3_message) = CS::KeyExchange::generate_ke3(
l2_bytes,
l2.ke2_message,
&self.ke1_state,
@@ -828,7 +807,7 @@ impl<CS: CipherSuite> ClientLogin<CS> {
/// The state elements the server holds to record a login
pub struct ServerLogin<CS: CipherSuite> {
ke2_state: <CS::KeyExchange as KeyExchange<CS::Hash>>::KE2State,
ke2_state: <CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE2State,
_cs: PhantomData<CS>,
}
@@ -837,22 +816,15 @@ impl<CS: CipherSuite> TryFrom<&[u8]> for ServerLogin<CS> {
fn try_from(bytes: &[u8]) -> Result<Self, Self::Error> {
Ok(Self {
_cs: PhantomData,
ke2_state: <CS::KeyExchange as KeyExchange<CS::Hash>>::KE2State::try_from(
bytes.to_vec(),
)?,
ke2_state:
<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::KE2State::try_from(
bytes.to_vec(),
)?,
})
}
}
type ServerLoginStartResult<CS> = (
LoginSecondMessage<
<CS as CipherSuite>::Group,
<CS as CipherSuite>::KeyFormat,
<CS as CipherSuite>::KeyExchange,
<CS as CipherSuite>::Hash,
>,
ServerLogin<CS>,
);
type ServerLoginStartResult<CS> = (LoginSecondMessage<CS>, ServerLogin<CS>);
impl<CS: CipherSuite> ServerLogin<CS> {
/// byte representation for the server's login state
@@ -911,7 +883,7 @@ impl<CS: CipherSuite> ServerLogin<CS> {
let l2_component: Vec<u8> = [&beta.to_arr()[..], &envelope.to_bytes()].concat();
let (ke2_state, ke2_message) = CS::KeyExchange::generate_ke2::<_, CS::KeyFormat>(
let (ke2_state, ke2_message) = CS::KeyExchange::generate_ke2(
rng,
l1_bytes.to_vec(),
l2_component,
@@ -921,8 +893,6 @@ impl<CS: CipherSuite> ServerLogin<CS> {
)?;
let l2 = LoginSecondMessage {
_key_format: PhantomData,
_key_exchange: PhantomData,
beta,
envelope,
ke2_message,
@@ -975,18 +945,20 @@ impl<CS: CipherSuite> ServerLogin<CS> {
/// # Ok::<(), ProtocolError>(())
/// ```
pub fn finish(&self, message: LoginThirdMessage<CS>) -> Result<Vec<u8>, ProtocolError> {
<CS::KeyExchange as KeyExchange<CS::Hash>>::finish_ke(message.ke3_message, &self.ke2_state)
.map_err(|e| match e {
ProtocolError::VerificationError(PakeError::KeyExchangeMacValidationError) => {
ProtocolError::VerificationError(PakeError::InvalidLoginError)
}
err => err,
})
<CS::KeyExchange as KeyExchange<CS::Hash, CS::KeyFormat>>::finish_ke(
message.ke3_message,
&self.ke2_state,
)
.map_err(|e| match e {
ProtocolError::VerificationError(PakeError::KeyExchangeMacValidationError) => {
ProtocolError::VerificationError(PakeError::InvalidLoginError)
}
err => err,
})
}
}
// Helper functions
fn get_password_derived_key<G: Group, SH: SlowHash<D>, D: Hash>(
password: Vec<u8>,
beta: G,
src/tests/opaque_ke_test.rs
+15 -17
View File
@@ -471,19 +471,15 @@ fn test_l3() -> Result<(), PakeError> {
let parameters = populate_test_vectors(&serde_json::from_str(TEST_VECTOR).unwrap());
let mut client_e_sk_rng = CycleRng::new(parameters.client_e_sk.to_vec());
let (l3, shared_secret, export_key_login) = ClientLogin::<X255193dhNoSlowHash>::try_from(
&parameters.client_login_state[..],
)
.unwrap()
.finish(
LoginSecondMessage::<EdwardsPoint, X25519KeyPair, TripleDH, sha2::Sha256>::try_from(
&parameters.l2[..],
)
.unwrap(),
&Key::try_from(&parameters.server_s_pk[..])?,
&mut client_e_sk_rng,
)
.unwrap();
let (l3, shared_secret, export_key_login) =
ClientLogin::<X255193dhNoSlowHash>::try_from(&parameters.client_login_state[..])
.unwrap()
.finish(
LoginSecondMessage::<X255193dhNoSlowHash>::try_from(&parameters.l2[..]).unwrap(),
&Key::try_from(&parameters.server_s_pk[..])?,
&mut client_e_sk_rng,
)
.unwrap();
assert_eq!(
hex::encode(&parameters.shared_secret),
@@ -558,10 +554,12 @@ fn test_complete_flow(
hex::encode(login_export_key)
);
} else {
let res = match client_login_result {
Err(ProtocolError::VerificationError(PakeError::InvalidLoginError)) => true,
_ => false,
};
let res = matches!(
client_login_result,
Err(ProtocolError::VerificationError(
PakeError::InvalidLoginError
))
);
assert!(res);
}
src/tests/serialization.rs
+5 -3
View File
@@ -167,8 +167,10 @@ fn login_first_message_roundtrip() {
rng.fill_bytes(&mut client_nonce);
let ke1m: Vec<u8> = [&client_nonce[..], &client_e_kp.public()].concat();
let reg =
<TripleDH as KeyExchange<sha2::Sha256>>::KE1Message::try_from(ke1m[..].to_vec()).unwrap();
let reg = <TripleDH as KeyExchange<sha2::Sha256, crate::keypair::X25519KeyPair>>::KE1Message::try_from(
ke1m[..].to_vec(),
)
.unwrap();
let reg_bytes = reg.to_bytes();
assert_eq!(reg_bytes, ke1m);
}
@@ -197,7 +199,7 @@ proptest! {
#[test]
fn test_nocrash_login_second_message(bytes in vec(any::<u8>(), 0..500)) {
LoginSecondMessage::<RistrettoPoint, crate::keypair::X25519KeyPair, TripleDH, sha2::Sha512>::try_from(&bytes[..]).map_or(true, |_| true);
LoginSecondMessage::<Default>::try_from(&bytes[..]).map_or(true, |_| true);
}
#[test]