//! Implements the X-Wing key-encapsulation mechanism (X-Wing KEM).
//!
//! X-Wing creates an encapsulation and decapsulation keypair. Anyone can use the
//! encapsulation key to establish a shared secret with the holder of the decapsulation
//! key. It is a general-purpose hybrid post-quantum KEM that combines X25519 with ML-KEM
//! or Classic McEliece.
use crate::{deserialize_hex_or_bin, error::*, kem::*, serialize_hex_or_bin};
use rand_core::RngCore;
use serde::{Deserialize, Serialize};
use sha3::{
digest::{ExtendableOutput, XofReader},
Digest, Sha3_256, Shake256,
};
use std::{
fmt::{self, Display, Formatter},
str::FromStr,
};
use x25519_dalek::*;
/// An X-Wing shared secret.
pub type SharedSecret = [u8; 32];
const X_WING_LABEL: &[u8; 6] = br"\.//^\";
// Naming convention matching the RFC:
// ss -> shared secret
// ct -> ciphertext
// ek -> ephemeral key
// pk -> public key
// sk -> secret key
// Suffixes:
// _m -> KEM-related key
// _x -> X25519-related key
/// The schemes supported by X-Wing.
///
/// The X-Wing Internet-Draft defines the ML-KEM-768 combination. This implementation also
/// supports the additional combinations listed below.
#[derive(Copy, Clone, Debug, Default, PartialEq, Eq, Ord, PartialOrd, Hash)]
pub enum XwingScheme {
#[cfg(feature = "ml-kem")]
/// X25519 with ML-KEM-768.
#[default]
X25519MlKem768,
#[cfg(feature = "ml-kem")]
/// X25519 with ML-KEM-1024.
X25519MlKem1024,
#[cfg(feature = "mceliece")]
#[cfg_attr(not(feature = "ml-kem"), default)]
/// X25519 with Classic McEliece 348864.
X25519McEliece348864,
}
impl From<XwingScheme> for u8 {
fn from(scheme: XwingScheme) -> Self {
use XwingScheme::*;
match scheme {
#[cfg(feature = "ml-kem")]
X25519MlKem768 => 2,
#[cfg(feature = "ml-kem")]
X25519MlKem1024 => 3,
#[cfg(feature = "mceliece")]
X25519McEliece348864 => 4,
}
}
}
impl From<&XwingScheme> for u8 {
fn from(scheme: &XwingScheme) -> Self {
Self::from(*scheme)
}
}
impl TryFrom<u8> for XwingScheme {
type Error = Error;
fn try_from(v: u8) -> Result<Self> {
match v {
#[cfg(feature = "ml-kem")]
2 => Ok(XwingScheme::X25519MlKem768),
#[cfg(feature = "ml-kem")]
3 => Ok(XwingScheme::X25519MlKem1024),
#[cfg(feature = "mceliece")]
4 => Ok(XwingScheme::X25519McEliece348864),
// Deprecated: X25519-ML-KEM-512 was removed for building on the too-weak
// ML-KEM-512. Discriminant 1 stays reserved for a clear migration error.
1 => Err(Error::DeprecatedScheme {
scheme: "X25519-ML-KEM-512",
replacement: "X25519-ML-KEM-768",
}),
_ => Err(Error::InvalidScheme(v)),
}
}
}
impl Display for XwingScheme {
fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
write!(
f,
"{}",
match self {
#[cfg(feature = "ml-kem")]
Self::X25519MlKem768 => "X25519-ML-KEM-768",
#[cfg(feature = "ml-kem")]
Self::X25519MlKem1024 => "X25519-ML-KEM-1024",
#[cfg(feature = "mceliece")]
Self::X25519McEliece348864 => "X25519-ClassicMcEliece348864",
}
)
}
}
impl FromStr for XwingScheme {
type Err = Error;
fn from_str(s: &str) -> Result<Self> {
match s {
#[cfg(feature = "ml-kem")]
"X25519-ML-KEM-768" => Ok(XwingScheme::X25519MlKem768),
#[cfg(feature = "ml-kem")]
"X25519-ML-KEM-1024" => Ok(XwingScheme::X25519MlKem1024),
#[cfg(feature = "mceliece")]
"X25519-ClassicMcEliece348864" => Ok(XwingScheme::X25519McEliece348864),
"X25519-ML-KEM-512" => Err(Error::DeprecatedScheme {
scheme: "X25519-ML-KEM-512",
replacement: "X25519-ML-KEM-768",
}),
_ => Err(Error::InvalidSchemeStr(s.to_string())),
}
}
}
serde_impl!(XwingScheme);
impl From<XwingScheme> for KemScheme {
fn from(scheme: XwingScheme) -> Self {
match scheme {
#[cfg(feature = "ml-kem")]
XwingScheme::X25519MlKem768 => KemScheme::MlKem768,
#[cfg(feature = "ml-kem")]
XwingScheme::X25519MlKem1024 => KemScheme::MlKem1024,
#[cfg(feature = "mceliece")]
XwingScheme::X25519McEliece348864 => KemScheme::ClassicMcEliece348864,
}
}
}
impl From<&XwingScheme> for KemScheme {
fn from(scheme: &XwingScheme) -> Self {
Self::from(*scheme)
}
}
impl XwingScheme {
/// Generates an X-Wing keypair.
pub fn keypair(&self) -> Result<(EncapsulationKey, DecapsulationKey)> {
let seed = match self {
#[cfg(feature = "ml-kem")]
XwingScheme::X25519MlKem768 | XwingScheme::X25519MlKem1024 => {
let mut seed = [0u8; 32];
rand_core::OsRng.fill_bytes(&mut seed);
seed.to_vec()
}
#[cfg(feature = "mceliece")]
XwingScheme::X25519McEliece348864 => {
let mut seed = [0u8; 32];
rand_core::OsRng.fill_bytes(&mut seed);
seed.to_vec()
}
};
self.keypair_from_seed(&seed)
}
/// Generates an X-Wing keypair from a seed.
pub fn keypair_from_seed(&self, seed: &[u8]) -> Result<(EncapsulationKey, DecapsulationKey)> {
let dk = DecapsulationKey {
scheme: *self,
seed: seed.to_vec(),
};
let ExpandedDecapsulationKey {
sk_m: _,
sk_x: _,
pk_m,
pk_x,
} = dk.expand()?;
let ek = EncapsulationKey { pk_m, pk_x };
Ok((ek, dk))
}
}
/// An X-Wing encapsulation key.
#[derive(Clone, Debug, Deserialize, Serialize)]
#[cfg_attr(test, derive(PartialEq, Eq))]
pub struct EncapsulationKey {
pk_m: KemEncapsulationKey,
#[serde(
serialize_with = "serialize_public_key_bin_or_hex",
deserialize_with = "deserialize_public_key_bin_or_hex"
)]
pk_x: PublicKey,
}
impl From<&ExpandedDecapsulationKey> for EncapsulationKey {
fn from(value: &ExpandedDecapsulationKey) -> Self {
Self {
pk_m: value.pk_m.clone(),
pk_x: value.pk_x,
}
}
}
impl From<&DecapsulationKey> for EncapsulationKey {
fn from(value: &DecapsulationKey) -> Self {
let expanded = value.expand().expect("Failed to expand decapsulation key");
Self::from(&expanded)
}
}
impl EncapsulationKey {
/// Creates an X-Wing ciphertext and shared secret.
pub fn encapsulate(&self) -> Result<(Ciphertext, SharedSecret)> {
let (ct_m, ss_m) = self.pk_m.scheme().encapsulate(&self.pk_m)?;
let ek_x = EphemeralSecret::random();
let ct_x = PublicKey::from(&ek_x);
let ss_x = ek_x.diffie_hellman(&self.pk_x);
let ss = combine(&ss_m, &ss_x, &ct_x, &self.pk_x);
let ct = Ciphertext { ct_m, ct_x };
Ok((ct, ss))
}
/// Converts the encapsulation key to raw bytes.
pub fn to_raw_bytes(&self) -> Vec<u8> {
let mut bytes = self.pk_m.to_raw_bytes();
bytes.extend_from_slice(self.pk_x.as_bytes());
bytes
}
/// Constructs an encapsulation key from raw bytes.
pub fn from_raw_bytes(scheme: XwingScheme, raw_bytes: &[u8]) -> Result<Self> {
let scheme: KemScheme = scheme.into();
let pk_m = KemEncapsulationKey::from_raw_bytes(scheme, &raw_bytes[..raw_bytes.len() - 32])?;
let pk_x_bytes: [u8; 32] = (&raw_bytes[raw_bytes.len() - 32..])
.try_into()
.map_err(|_| Error::InvalidLength(raw_bytes.len() - 32))?;
let pk_x = PublicKey::from(pk_x_bytes);
Ok(Self { pk_m, pk_x })
}
}
/// An X-Wing ciphertext.
#[derive(Clone, Debug, Deserialize, Serialize)]
#[cfg_attr(test, derive(PartialEq, Eq))]
pub struct Ciphertext {
ct_m: KemCiphertext,
#[serde(
serialize_with = "serialize_public_key_bin_or_hex",
deserialize_with = "deserialize_public_key_bin_or_hex"
)]
ct_x: PublicKey,
}
impl Ciphertext {
/// Converts the ciphertext to raw bytes.
pub fn to_raw_bytes(&self) -> Vec<u8> {
let mut bytes = self.ct_m.to_raw_bytes();
bytes.extend_from_slice(self.ct_x.as_bytes());
bytes
}
/// Constructs a ciphertext from raw bytes.
pub fn from_raw_bytes(scheme: XwingScheme, raw_bytes: &[u8]) -> Result<Self> {
let scheme: KemScheme = scheme.into();
let ct_m = KemCiphertext::from_raw_bytes(scheme, &raw_bytes[..raw_bytes.len() - 32])?;
let ct_x_bytes: [u8; 32] = (&raw_bytes[raw_bytes.len() - 32..])
.try_into()
.map_err(|_| Error::InvalidLength(raw_bytes.len() - 32))?;
let ct_x = PublicKey::from(ct_x_bytes);
Ok(Self { ct_m, ct_x })
}
}
/// An X-Wing decapsulation key.
#[derive(Clone, Deserialize, Serialize)]
#[cfg_attr(test, derive(PartialEq, Eq))]
pub struct DecapsulationKey {
scheme: XwingScheme,
#[serde(
serialize_with = "serialize_hex_or_bin",
deserialize_with = "deserialize_hex_or_bin"
)]
seed: Vec<u8>,
}
impl std::fmt::Debug for DecapsulationKey {
fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
f.debug_struct("DecapsulationKey")
.field("scheme", &self.scheme)
.field("seed", &"<redacted>")
.finish()
}
}
#[cfg(feature = "zeroize")]
impl zeroize::Zeroize for DecapsulationKey {
fn zeroize(&mut self) {
self.seed.zeroize();
}
}
#[cfg(feature = "zeroize")]
impl zeroize::ZeroizeOnDrop for DecapsulationKey {}
impl DecapsulationKey {
/// Decapsulates the ciphertext to produce the shared secret.
pub fn decapsulate(&self, ct: &Ciphertext) -> Result<SharedSecret> {
let ExpandedDecapsulationKey {
sk_m,
sk_x,
pk_m: _,
pk_x,
} = self.expand()?;
let ss_m = sk_m.scheme().decapsulate(&ct.ct_m, &sk_m)?;
let ss_x = sk_x.diffie_hellman(&ct.ct_x);
let ss = combine(&ss_m, &ss_x, &ct.ct_x, &pk_x);
Ok(ss)
}
/// Returns the decapsulation key's seed bytes.
pub fn to_seed(&self) -> Vec<u8> {
self.seed.clone()
}
/// Constructs a [`DecapsulationKey`] from a seed.
pub fn from_seed(scheme: XwingScheme, raw_bytes: &[u8]) -> Self {
Self {
scheme,
seed: raw_bytes.to_vec(),
}
}
/// Converts the decapsulation key to expanded form.
pub fn expand(&self) -> Result<ExpandedDecapsulationKey> {
use sha3::digest::Update;
let mut hasher = Shake256::default();
hasher.update(&self.seed);
let mut reader = hasher.finalize_xof();
let (seed_length, scheme) = match self.scheme {
#[cfg(feature = "ml-kem")]
XwingScheme::X25519MlKem768 => (64, KemScheme::MlKem768),
#[cfg(feature = "ml-kem")]
XwingScheme::X25519MlKem1024 => (64, KemScheme::MlKem1024),
#[cfg(feature = "mceliece")]
XwingScheme::X25519McEliece348864 => (32, KemScheme::ClassicMcEliece348864),
};
let mut seed = vec![0u8; seed_length];
reader.read(&mut seed);
let (pk_m, sk_m) = scheme.keypair_from_seed(&seed)?;
#[cfg(feature = "zeroize")]
{
use zeroize::Zeroize;
seed.zeroize();
}
let mut x25519_seed = [0u8; 32];
reader.read(&mut x25519_seed);
let sk_x = StaticSecret::from(x25519_seed);
#[cfg(feature = "zeroize")]
{
use zeroize::Zeroize;
x25519_seed.zeroize();
}
let pk_x = PublicKey::from(&sk_x);
Ok(ExpandedDecapsulationKey {
sk_m,
sk_x,
pk_m,
pk_x,
})
}
}
/// An expanded X-Wing decapsulation key.
#[derive(Clone)]
#[allow(missing_debug_implementations)]
pub struct ExpandedDecapsulationKey {
sk_m: KemDecapsulationKey,
sk_x: StaticSecret,
pk_m: KemEncapsulationKey,
pk_x: PublicKey,
}
impl ExpandedDecapsulationKey {
/// Decapsulates the ciphertext to produce the shared secret.
pub fn decapsulate(&self, ct: &Ciphertext) -> Result<SharedSecret> {
let ss_m = self.sk_m.scheme().decapsulate(&ct.ct_m, &self.sk_m)?;
let ss_x = self.sk_x.diffie_hellman(&ct.ct_x);
let ss = combine(&ss_m, &ss_x, &ct.ct_x, &self.pk_x);
Ok(ss)
}
/// Returns the associated encapsulation key.
pub fn encapsulation_key(&self) -> EncapsulationKey {
EncapsulationKey {
pk_m: self.pk_m.clone(),
pk_x: self.pk_x,
}
}
}
fn combine(
ss_m: &KemSharedSecret,
ss_x: &x25519_dalek::SharedSecret,
ct_x: &PublicKey,
pk_x: &PublicKey,
) -> SharedSecret {
let mut hasher = Sha3_256::new();
hasher.update(ss_m.to_raw_bytes());
hasher.update(ss_x);
hasher.update(ct_x);
hasher.update(pk_x.as_bytes());
hasher.update(X_WING_LABEL);
hasher.finalize().into()
}
fn serialize_public_key_bin_or_hex<S>(pk: &PublicKey, s: S) -> std::result::Result<S::Ok, S::Error>
where
S: serde::Serializer,
{
serdect::array::serialize_hex_lower_or_bin(pk.as_bytes(), s)
}
fn deserialize_public_key_bin_or_hex<'de, D>(d: D) -> std::result::Result<PublicKey, D::Error>
where
D: serde::Deserializer<'de>,
{
let mut a = [0u8; 32];
serdect::array::deserialize_hex_or_bin(&mut a, d)?;
Ok(PublicKey::from(a))
}
#[cfg(test)]
mod tests {
use super::*;
use rstest::*;
#[rstest]
#[cfg_attr(feature = "ml-kem", case::mlkem768(XwingScheme::X25519MlKem768))]
#[cfg_attr(feature = "ml-kem", case::mlkem1024(XwingScheme::X25519MlKem1024))]
#[cfg_attr(
feature = "mceliece",
case::mceliece348864(XwingScheme::X25519McEliece348864)
)]
fn round_trip(#[case] scheme: XwingScheme) {
let (ek, dk) = scheme.keypair().unwrap();
let (ct, ss_e) = ek.encapsulate().unwrap();
let ss_d = dk.decapsulate(&ct).unwrap();
assert_eq!(ss_d, ss_e);
}
#[rstest]
#[cfg_attr(feature = "ml-kem", case::mlkem768(XwingScheme::X25519MlKem768))]
#[cfg_attr(feature = "ml-kem", case::mlkem1024(XwingScheme::X25519MlKem1024))]
#[cfg_attr(
feature = "mceliece",
case::mceliece348864(XwingScheme::X25519McEliece348864)
)]
fn serialize_bytes(#[case] scheme: XwingScheme) {
let (ek, dk) = scheme.keypair().unwrap();
let (ct, _ss_e) = ek.encapsulate().unwrap();
let bytes = postcard::to_stdvec(&ek).unwrap();
let ek2 = postcard::from_bytes::<EncapsulationKey>(&bytes).unwrap();
assert_eq!(ek, ek2);
let bytes = postcard::to_stdvec(&dk).unwrap();
let dk2 = postcard::from_bytes::<DecapsulationKey>(&bytes).unwrap();
assert_eq!(dk, dk2);
let bytes = postcard::to_stdvec(&ct).unwrap();
let ct2 = postcard::from_bytes::<Ciphertext>(&bytes).unwrap();
assert_eq!(ct, ct2);
}
#[rstest]
#[cfg_attr(feature = "ml-kem", case::mlkem768(XwingScheme::X25519MlKem768))]
#[cfg_attr(feature = "ml-kem", case::mlkem1024(XwingScheme::X25519MlKem1024))]
#[cfg_attr(
feature = "mceliece",
case::mceliece348864(XwingScheme::X25519McEliece348864)
)]
fn serialize_text(#[case] scheme: XwingScheme) {
let (ek, dk) = scheme.keypair().unwrap();
let (ct, _ss_e) = ek.encapsulate().unwrap();
let s = serde_json::to_string(&ek).unwrap();
let ek2 = serde_json::from_str::<EncapsulationKey>(&s).unwrap();
assert_eq!(ek, ek2);
let s = serde_json::to_string(&dk).unwrap();
let dk2 = serde_json::from_str::<DecapsulationKey>(&s).unwrap();
assert_eq!(dk, dk2);
let s = serde_json::to_string(&ct).unwrap();
let ct2 = serde_json::from_str::<Ciphertext>(&s).unwrap();
assert_eq!(ct, ct2);
}
#[cfg(feature = "ml-kem")]
#[test]
fn rfc_vectors() {
let vectors = r#"[
{
"seed": "7f9c2ba4e88f827d616045507605853ed73b8093f6efbc88eb1a6eacfa66ef26",
"eseed": "3cb1eea988004b93103cfb0aeefd2a686e01fa4a58e8a3639ca8a1e3f9ae57e235b8cc873c23dc62b8d260169afa2f75ab916a58d974918835d25e6a435085b2",
"ss": "d2df0522128f09dd8e2c92b1e905c793d8f57a54c3da25861f10bf4ca613e384",
"sk": "7f9c2ba4e88f827d616045507605853ed73b8093f6efbc88eb1a6eacfa66ef26",
"pk": "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",
"ct": "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"
},
{
"seed": "badfd6dfaac359a5efbb7bcc4b59d538df9a04302e10c8bc1cbf1a0b3a5120ea",
"eseed": "17cda7cfad765f5623474d368ccca8af0007cd9f5e4c849f167a580b14aabdefaee7eef47cb0fca9767be1fda69419dfb927e9df07348b196691abaeb580b32d",
"ss": "f2e86241c64d60f6649fbc6c5b7d17180b780a3f34355e64a85749949c45f150",
"sk": "badfd6dfaac359a5efbb7bcc4b59d538df9a04302e10c8bc1cbf1a0b3a5120ea",
"pk": "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",
"ct": "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"
},
{
"seed": "ef58538b8d23f87732ea63b02b4fa0f4873360e2841928cd60dd4cee8cc0d4c9",
"eseed": "22a96188d032675c8ac850933c7aff1533b94c834adbb69c6115bad4692d8619f90b0cdf8a7b9c264029ac185b70b83f2801f2f4b3f70c593ea3aeeb613a7f1b",
"ss": "953f7f4e8c5b5049bdc771d1dffada0dd961477d1a2ae0988baa7ea6898d893f",
"sk": "ef58538b8d23f87732ea63b02b4fa0f4873360e2841928cd60dd4cee8cc0d4c9",
"pk": "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",
"ct": "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"
}
]"#;
#[allow(unused)]
#[derive(serde::Deserialize)]
struct TestVector {
#[serde(deserialize_with = "hex::serde::deserialize")]
seed: Vec<u8>,
#[serde(deserialize_with = "hex::serde::deserialize")]
eseed: Vec<u8>,
#[serde(deserialize_with = "hex::serde::deserialize")]
ss: [u8; 32],
#[serde(deserialize_with = "hex::serde::deserialize")]
sk: [u8; 32],
#[serde(deserialize_with = "hex::serde::deserialize")]
pk: Vec<u8>,
#[serde(deserialize_with = "hex::serde::deserialize")]
ct: Vec<u8>,
}
let test_vectors = serde_json::from_str::<Vec<TestVector>>(vectors).unwrap();
for test in &test_vectors {
let (pk, sk) = XwingScheme::X25519MlKem768
.keypair_from_seed(&test.seed)
.unwrap();
let mut out_pk_bytes = pk.pk_m.to_raw_bytes();
out_pk_bytes.extend_from_slice(pk.pk_x.as_bytes());
assert_eq!(test.pk, out_pk_bytes);
assert_eq!(test.sk, sk.seed.as_slice());
let ct_m =
KemCiphertext::from_raw_bytes(KemScheme::MlKem768, &test.ct[..test.ct.len() - 32])
.unwrap();
let ct_x_bytes: [u8; 32] = (&test.ct[test.ct.len() - 32..]).try_into().unwrap();
let ct_x = PublicKey::from(ct_x_bytes);
let ct = Ciphertext { ct_m, ct_x };
let ss = sk.decapsulate(&ct).unwrap();
assert_eq!(ss, test.ss);
}
}
/// The removed X25519-ML-KEM-512 hybrid reports a deprecation error (not a generic
/// `InvalidScheme`) via its old wire discriminant and display string.
#[test]
fn x25519_ml_kem_512_is_deprecated() {
assert!(matches!(
XwingScheme::try_from(1),
Err(Error::DeprecatedScheme {
scheme: "X25519-ML-KEM-512",
replacement: "X25519-ML-KEM-768",
})
));
assert!(matches!(
"X25519-ML-KEM-512".parse::<XwingScheme>(),
Err(Error::DeprecatedScheme {
scheme: "X25519-ML-KEM-512",
..
})
));
}
}