Add support for Ristretto

Replaces P-256 as the curve used for testing FROST.

coins/monero/src/frost.rs

@@ -11,7 +11,7 @@ use curve25519_dalek::{
 
 use transcript::{Transcript as TranscriptTrait, DigestTranscript};
 use frost::Curve;
-pub use frost::curves::ed25519::Ed25519;
+pub use frost::curves::dalek::Ed25519;
 use dalek_ff_group as dfg;
 
 use crate::random_scalar;

crypto/dalek-ff-group/src/lib.rs

@@ -16,88 +16,123 @@ use dalek::{
   traits::Identity,
   scalar::Scalar as DScalar,
   edwards::{
-    EdwardsPoint as DPoint,
+    EdwardsPoint as DEdwardsPoint,
-    EdwardsBasepointTable as DTable,
+    EdwardsBasepointTable as DEdwardsBasepointTable,
-    CompressedEdwardsY as DCompressed
+    CompressedEdwardsY as DCompressedEdwards
+  },
+  ristretto::{
+    RistrettoPoint as DRistrettoPoint,
+    RistrettoBasepointTable as DRistrettoBasepointTable,
+    CompressedRistretto as DCompressedRistretto
   }
 };
 
 use group::{ff::{Field, PrimeField}, Group};
 
-#[derive(Clone, Copy, PartialEq, Eq, Debug, Default)]
+macro_rules! deref_borrow {
-pub struct Scalar(pub DScalar);
+  ($Source: ident, $Target: ident) => {
-
+    impl Deref for $Source {
-impl Deref for Scalar {
+      type Target = $Target;
-  type Target = DScalar;
 
       fn deref(&self) -> &Self::Target {
         &self.0
       }
     }
 
-impl Borrow<DScalar> for Scalar {
+    impl Borrow<$Target> for $Source {
-  fn borrow(&self) -> &DScalar {
+      fn borrow(&self) -> &$Target {
         &self.0
       }
     }
 
-impl Borrow<DScalar> for &Scalar {
+    impl Borrow<$Target> for &$Source {
-  fn borrow(&self) -> &DScalar {
+      fn borrow(&self) -> &$Target {
         &self.0
       }
     }
-
-impl Add<Scalar> for Scalar {
-  type Output = Self;
-  fn add(self, other: Scalar) -> Scalar { Self(self.0 + other.0) }
   }
-impl AddAssign for Scalar {
-  fn add_assign(&mut self, other: Scalar) { self.0 += other.0 }
 }
 
-impl<'a> Add<&'a Scalar> for Scalar {
+macro_rules! math {
+  ($Value: ident, $Factor: ident, $Product: ident) => {
+    impl Add<$Value> for $Value {
       type Output = Self;
-  fn add(self, other: &'a Scalar) -> Scalar { Self(self.0 + other.0) }
+      fn add(self, other: $Value) -> Self::Output { Self(self.0 + other.0) }
     }
-impl<'a> AddAssign<&'a Scalar> for Scalar {
+    impl AddAssign for $Value {
-  fn add_assign(&mut self, other: &'a Scalar) { self.0 += other.0 }
+      fn add_assign(&mut self, other: $Value) { self.0 += other.0 }
     }
 
-impl Sub<Scalar> for Scalar {
+    impl<'a> Add<&'a $Value> for $Value {
       type Output = Self;
-  fn sub(self, other: Scalar) -> Scalar { Self(self.0 - other.0) }
+      fn add(self, other: &'a $Value) -> Self::Output { Self(self.0 + other.0) }
     }
-impl SubAssign for Scalar {
+    impl<'a> AddAssign<&'a $Value> for $Value {
-  fn sub_assign(&mut self, other: Scalar) { self.0 -= other.0 }
+      fn add_assign(&mut self, other: &'a $Value) { self.0 += other.0 }
     }
 
-impl<'a> Sub<&'a Scalar> for Scalar {
+    impl Sub<$Value> for $Value {
       type Output = Self;
-  fn sub(self, other: &'a Scalar) -> Scalar { Self(self.0 - other.0) }
+      fn sub(self, other: $Value) -> Self::Output { Self(self.0 - other.0) }
     }
-impl<'a> SubAssign<&'a Scalar> for Scalar {
+    impl SubAssign for $Value {
-  fn sub_assign(&mut self, other: &'a Scalar) { self.0 -= other.0 }
+      fn sub_assign(&mut self, other: $Value) { self.0 -= other.0 }
     }
 
-impl Neg for Scalar {
+    impl<'a> Sub<&'a $Value> for $Value {
       type Output = Self;
-  fn neg(self) -> Scalar { Self(-self.0) }
+      fn sub(self, other: &'a $Value) -> Self::Output { Self(self.0 - other.0) }
+    }
+    impl<'a> SubAssign<&'a $Value> for $Value {
+      fn sub_assign(&mut self, other: &'a $Value) { self.0 -= other.0 }
     }
 
-impl Mul<Scalar> for Scalar {
+    impl Neg for $Value {
       type Output = Self;
-  fn mul(self, other: Scalar) -> Scalar { Self(self.0 * other.0) }
+      fn neg(self) -> Self::Output { Self(-self.0) }
-}
-impl MulAssign for Scalar {
-  fn mul_assign(&mut self, other: Scalar) { self.0 *= other.0 }
     }
 
-impl<'a> Mul<&'a Scalar> for Scalar {
+    impl Mul<$Factor> for $Value {
-  type Output = Self;
+      type Output = $Product;
-  fn mul(self, other: &'a Scalar) -> Scalar { Self(self.0 * other.0) }
+      fn mul(self, other: $Factor) -> Self::Output { Self(self.0 * other.0) }
+    }
+    impl MulAssign<$Factor> for $Value {
+      fn mul_assign(&mut self, other: $Factor) { self.0 *= other.0 }
+    }
+
+    impl<'a> Mul<&'a $Factor> for $Value {
+      type Output = Self;
+      fn mul(self, b: &'a $Factor) -> $Product { Self(b.0 * self.0) }
+    }
+    impl<'a> MulAssign<&'a $Factor> for $Value {
+      fn mul_assign(&mut self, other: &'a $Factor) { self.0 *= other.0 }
+    }
+  }
+}
+
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Default)]
+pub struct Scalar(pub DScalar);
+deref_borrow!(Scalar, DScalar);
+math!(Scalar, Scalar, Scalar);
+
+impl Scalar {
+  pub fn from_canonical_bytes(bytes: [u8; 32]) -> Option<Scalar> {
+    DScalar::from_canonical_bytes(bytes).map(|x| Self(x))
+  }
+
+  pub fn from_bytes_mod_order(bytes: [u8; 32]) -> Scalar {
+    Self(DScalar::from_bytes_mod_order(bytes))
+  }
+
+  pub fn from_bytes_mod_order_wide(bytes: &[u8; 64]) -> Scalar {
+    Self(DScalar::from_bytes_mod_order_wide(bytes))
+  }
+
+  pub fn from_hash<D: Digest<OutputSize = U64>>(hash: D) -> Scalar {
+    let mut output = [0u8; 64];
+    output.copy_from_slice(&hash.finalize());
+    Scalar(DScalar::from_bytes_mod_order_wide(&output))
   }
-impl<'a> MulAssign<&'a Scalar> for Scalar {
-  fn mul_assign(&mut self, other: &'a Scalar) { self.0 *= other.0 }
 }
 
 impl ConstantTimeEq for Scalar {
@@ -153,126 +188,52 @@ impl PrimeField for Scalar {
   fn root_of_unity() -> Self { unimplemented!() }
 }
 
-impl Scalar {
+macro_rules! dalek_group {
-  pub fn from_hash<D: Digest<OutputSize = U64>>(hash: D) -> Scalar {
+  (
-    let mut output = [0u8; 64];
+    $Point: ident,
-    output.copy_from_slice(&hash.finalize());
+    $DPoint: ident,
-    Scalar(DScalar::from_bytes_mod_order_wide(&output))
-  }
-}
 
+    $Table: ident,
+    $DTable: ident,
+
+    $Compressed: ident,
+    $DCompressed: ident,
+
+    $BASEPOINT_POINT: ident,
+    $BASEPOINT_TABLE: ident
+  ) => {
     #[derive(Clone, Copy, PartialEq, Eq, Debug)]
-pub struct EdwardsPoint(pub DPoint);
+    pub struct $Point(pub $DPoint);
-pub const ED25519_BASEPOINT_POINT: EdwardsPoint = EdwardsPoint(constants::ED25519_BASEPOINT_POINT);
+    deref_borrow!($Point, $DPoint);
+    math!($Point, Scalar, $Point);
 
-impl Deref for EdwardsPoint {
+    pub const $BASEPOINT_POINT: $Point = $Point(constants::$BASEPOINT_POINT);
-    type Target = DPoint;
 
-    fn deref(&self) -> &Self::Target {
+    impl Sum<$Point> for $Point {
-        &self.0
+      fn sum<I: Iterator<Item = $Point>>(iter: I) -> $Point { Self($DPoint::sum(iter)) }
     }
+    impl<'a> Sum<&'a $Point> for $Point {
+      fn sum<I: Iterator<Item = &'a $Point>>(iter: I) -> $Point { Self($DPoint::sum(iter)) }
     }
 
-impl Borrow<DPoint> for EdwardsPoint {
+    impl Group for $Point {
-  fn borrow(&self) -> &DPoint {
-    &self.0
-  }
-}
-
-impl Borrow<DPoint> for &EdwardsPoint {
-  fn borrow(&self) -> &DPoint {
-    &self.0
-  }
-}
-
-impl Add<EdwardsPoint> for EdwardsPoint {
-  type Output = Self;
-  fn add(self, b: EdwardsPoint) -> EdwardsPoint { Self(self.0 + b.0) }
-}
-impl AddAssign<EdwardsPoint> for EdwardsPoint {
-  fn add_assign(&mut self, other: EdwardsPoint) { self.0 += other.0 }
-}
-impl Sum<EdwardsPoint> for EdwardsPoint {
-  fn sum<I: Iterator<Item = EdwardsPoint>>(iter: I) -> EdwardsPoint { Self(DPoint::sum(iter)) }
-}
-
-impl<'a> Add<&'a EdwardsPoint> for EdwardsPoint {
-  type Output = Self;
-  fn add(self, b: &'a EdwardsPoint) -> EdwardsPoint { Self(self.0 + b.0) }
-}
-impl<'a> AddAssign<&'a EdwardsPoint> for EdwardsPoint {
-  fn add_assign(&mut self, other: &'a EdwardsPoint) { self.0 += other.0 }
-}
-impl<'a> Sum<&'a EdwardsPoint> for EdwardsPoint {
-  fn sum<I: Iterator<Item = &'a EdwardsPoint>>(iter: I) -> EdwardsPoint { Self(DPoint::sum(iter)) }
-}
-
-impl Sub<EdwardsPoint> for EdwardsPoint {
-  type Output = Self;
-  fn sub(self, b: EdwardsPoint) -> EdwardsPoint { Self(self.0 - b.0) }
-}
-impl SubAssign<EdwardsPoint> for EdwardsPoint {
-  fn sub_assign(&mut self, other: EdwardsPoint) { self.0 -= other.0 }
-}
-
-impl<'a> Sub<&'a EdwardsPoint> for EdwardsPoint {
-  type Output = Self;
-  fn sub(self, b: &'a EdwardsPoint) -> EdwardsPoint { Self(self.0 - b.0) }
-}
-impl<'a> SubAssign<&'a EdwardsPoint> for EdwardsPoint {
-  fn sub_assign(&mut self, other: &'a EdwardsPoint) { self.0 -= other.0 }
-}
-
-impl Neg for EdwardsPoint {
-  type Output = Self;
-  fn neg(self) -> EdwardsPoint { Self(-self.0) }
-}
-
-impl Mul<Scalar> for EdwardsPoint {
-  type Output = Self;
-  fn mul(self, b: Scalar) -> EdwardsPoint { Self(b.0 * self.0) }
-}
-impl MulAssign<Scalar> for EdwardsPoint {
-  fn mul_assign(&mut self, other: Scalar) { self.0 *= other.0 }
-}
-
-impl<'a> Mul<&'a Scalar> for EdwardsPoint {
-  type Output = Self;
-  fn mul(self, b: &'a Scalar) -> EdwardsPoint { Self(b.0 * self.0) }
-}
-impl<'a> MulAssign<&'a Scalar> for EdwardsPoint {
-  fn mul_assign(&mut self, other: &'a Scalar) { self.0 *= other.0 }
-}
-
-impl Group for EdwardsPoint {
       type Scalar = Scalar;
-  fn random(rng: impl RngCore) -> Self { &ED25519_BASEPOINT_TABLE * Scalar::random(rng) }
+      fn random(rng: impl RngCore) -> Self { &$BASEPOINT_TABLE * Scalar::random(rng) }
-  fn identity() -> Self { Self(DPoint::identity()) }
+      fn identity() -> Self { Self($DPoint::identity()) }
-  fn generator() -> Self { ED25519_BASEPOINT_POINT }
+      fn generator() -> Self { $BASEPOINT_POINT }
-  fn is_identity(&self) -> Choice { self.0.ct_eq(&DPoint::identity()) }
+      fn is_identity(&self) -> Choice { self.0.ct_eq(&$DPoint::identity()) }
       fn double(&self) -> Self { *self + self }
     }
 
-impl Scalar {
+    pub struct $Compressed(pub $DCompressed);
-  pub fn from_canonical_bytes(bytes: [u8; 32]) -> Option<Scalar> {
+    deref_borrow!($Compressed, $DCompressed);
-    DScalar::from_canonical_bytes(bytes).map(|x| Self(x))
+    impl $Compressed {
-  }
+      pub fn new(y: [u8; 32]) -> $Compressed {
-  pub fn from_bytes_mod_order(bytes: [u8; 32]) -> Scalar {
+        Self($DCompressed(y))
-    Self(DScalar::from_bytes_mod_order(bytes))
-  }
-  pub fn from_bytes_mod_order_wide(bytes: &[u8; 64]) -> Scalar {
-    Self(DScalar::from_bytes_mod_order_wide(bytes))
-  }
       }
 
-pub struct CompressedEdwardsY(pub DCompressed);
+      pub fn decompress(&self) -> Option<$Point> {
-impl CompressedEdwardsY {
+        self.0.decompress().map(|x| $Point(x))
-  pub fn new(y: [u8; 32]) -> CompressedEdwardsY {
-    Self(DCompressed(y))
-  }
-
-  pub fn decompress(&self) -> Option<EdwardsPoint> {
-    self.0.decompress().map(|x| EdwardsPoint(x))
       }
 
       pub fn to_bytes(&self) -> [u8; 32] {
@@ -280,36 +241,53 @@ impl CompressedEdwardsY {
       }
     }
 
+    impl $Point {
+      pub fn compress(&self) -> $Compressed {
+        $Compressed(self.0.compress())
+      }
+    }
+
+    pub struct $Table(pub $DTable);
+    deref_borrow!($Table, $DTable);
+    pub const $BASEPOINT_TABLE: $Table = $Table(constants::$BASEPOINT_TABLE);
+
+    impl Mul<Scalar> for &$Table {
+      type Output = $Point;
+      fn mul(self, b: Scalar) -> $Point { $Point(&b.0 * &self.0) }
+    }
+  };
+}
+
+dalek_group!(
+  EdwardsPoint,
+  DEdwardsPoint,
+
+  EdwardsBasepointTable,
+  DEdwardsBasepointTable,
+
+  CompressedEdwardsY,
+  DCompressedEdwards,
+
+  ED25519_BASEPOINT_POINT,
+  ED25519_BASEPOINT_TABLE
+);
+
 impl EdwardsPoint {
   pub fn is_torsion_free(&self) -> bool {
     self.0.is_torsion_free()
   }
-
-  pub fn compress(&self) -> CompressedEdwardsY {
-    CompressedEdwardsY(self.0.compress())
-  }
 }
 
-pub struct EdwardsBasepointTable(pub DTable);
+dalek_group!(
-pub const ED25519_BASEPOINT_TABLE: EdwardsBasepointTable = EdwardsBasepointTable(
+  RistrettoPoint,
-  constants::ED25519_BASEPOINT_TABLE
+  DRistrettoPoint,
+
+  RistrettoBasepointTable,
+  DRistrettoBasepointTable,
+
+  CompressedRistretto,
+  DCompressedRistretto,
+
+  RISTRETTO_BASEPOINT_POINT,
+  RISTRETTO_BASEPOINT_TABLE
 );
-
-impl Deref for EdwardsBasepointTable {
-    type Target = DTable;
-
-    fn deref(&self) -> &Self::Target {
-        &self.0
-    }
-}
-
-impl Borrow<DTable> for &EdwardsBasepointTable {
-  fn borrow(&self) -> &DTable {
-    &self.0
-  }
-}
-
-impl Mul<Scalar> for &EdwardsBasepointTable {
-  type Output = EdwardsPoint;
-  fn mul(self, b: Scalar) -> EdwardsPoint { EdwardsPoint(&b.0 * &self.0) }
-}

crypto/frost/Cargo.toml

@@ -30,12 +30,13 @@ multiexp = { path = "../multiexp", features = ["batch"] }
 rand = "0.8"
 
 sha2 = "0.10"
-elliptic-curve = { version = "0.12", features = ["hash2curve"] }
+dalek-ff-group = { path = "../dalek-ff-group" }
-p256 = { version = "0.11", features = ["arithmetic", "hash2curve"] }
 
 [features]
-curves = []
+curves = ["sha2"] # All officially denoted curves use the SHA2 family of hashes
-kp256 = ["elliptic-curve"]
+kp256 = ["elliptic-curve", "curves"]
-p256 = ["curves", "kp256", "sha2", "dep:p256"]
+p256 = ["dep:p256", "kp256"]
-k256 = ["curves", "kp256", "sha2", "dep:k256"]
+k256 = ["dep:k256", "kp256"]
-ed25519 = ["curves", "sha2", "dalek-ff-group"]
+dalek = ["curves", "dalek-ff-group"]
+ed25519 = ["dalek"]
+ristretto = ["dalek"]

crypto/frost/src/curves/dalek.rs

@@ -0,0 +1,163 @@
+use core::convert::TryInto;
+
+use rand_core::{RngCore, CryptoRng};
+
+use sha2::{Digest, Sha512};
+
+use ff::PrimeField;
+use group::Group;
+
+use dalek_ff_group::Scalar;
+
+use crate::{CurveError, Curve, algorithm::Hram};
+
+macro_rules! dalek_curve {
+  (
+    $Curve:      ident,
+    $Hram:       ident,
+    $Point:      ident,
+    $Compressed: ident,
+    $Table:      ident,
+
+    $POINT: ident,
+    $TABLE: ident,
+
+    $torsioned: expr,
+
+    $ID:      literal,
+    $CONTEXT: literal,
+    $chal:    literal,
+    $digest:  literal,
+  ) => {
+    use dalek_ff_group::{$Point, $Compressed, $Table, $POINT, $TABLE};
+
+    #[derive(Clone, Copy, PartialEq, Eq, Debug)]
+    pub struct $Curve;
+    impl Curve for $Curve {
+      type F = Scalar;
+      type G = $Point;
+      type T = &'static $Table;
+
+      const ID: &'static [u8] = $ID;
+
+      const GENERATOR: Self::G = $POINT;
+      const GENERATOR_TABLE: Self::T = &$TABLE;
+
+      const LITTLE_ENDIAN: bool = true;
+
+      fn random_nonce<R: RngCore + CryptoRng>(secret: Self::F, rng: &mut R) -> Self::F {
+        let mut seed = vec![0; 32];
+        rng.fill_bytes(&mut seed);
+        seed.extend(&secret.to_bytes());
+        Self::hash_to_F(b"nonce", &seed)
+      }
+
+      fn hash_msg(msg: &[u8]) -> Vec<u8> {
+        Sha512::new()
+          .chain_update($CONTEXT)
+          .chain_update($digest)
+          .chain_update(msg)
+          .finalize()
+          .to_vec()
+      }
+
+      fn hash_binding_factor(binding: &[u8]) -> Self::F {
+        Self::hash_to_F(b"rho", binding)
+      }
+
+      fn hash_to_F(dst: &[u8], msg: &[u8]) -> Self::F {
+        Scalar::from_hash(Sha512::new().chain_update($CONTEXT).chain_update(dst).chain_update(msg))
+      }
+
+      fn F_len() -> usize {
+        32
+      }
+
+      fn G_len() -> usize {
+        32
+      }
+
+      fn F_from_slice(slice: &[u8]) -> Result<Self::F, CurveError> {
+        let scalar = Self::F::from_repr(
+          slice.try_into().map_err(|_| CurveError::InvalidLength(32, slice.len()))?
+        );
+        if scalar.is_some().unwrap_u8() == 0 {
+          Err(CurveError::InvalidScalar)?;
+        }
+        Ok(scalar.unwrap())
+      }
+
+      fn G_from_slice(slice: &[u8]) -> Result<Self::G, CurveError> {
+        let bytes = slice.try_into().map_err(|_| CurveError::InvalidLength(32, slice.len()))?;
+        let point = $Compressed::new(bytes).decompress();
+
+        if let Some(point) = point {
+          // Ban identity
+          if point.is_identity().into() {
+            Err(CurveError::InvalidPoint)?;
+          }
+          // Ban torsioned points to meet the prime order group requirement
+          if $torsioned(point) {
+            Err(CurveError::InvalidPoint)?;
+          }
+          // Ban points which weren't canonically encoded
+          if point.compress().to_bytes() != bytes {
+            Err(CurveError::InvalidPoint)?;
+          }
+          Ok(point)
+        } else {
+          Err(CurveError::InvalidPoint)
+        }
+      }
+
+      fn F_to_bytes(f: &Self::F) -> Vec<u8> {
+        f.to_repr().to_vec()
+      }
+
+      fn G_to_bytes(g: &Self::G) -> Vec<u8> {
+        g.compress().to_bytes().to_vec()
+      }
+    }
+
+    #[derive(Copy, Clone)]
+    pub struct $Hram;
+    impl Hram<$Curve> for $Hram {
+      #[allow(non_snake_case)]
+      fn hram(R: &$Point, A: &$Point, m: &[u8]) -> Scalar {
+        $Curve::hash_to_F($chal, &[&R.compress().to_bytes(), &A.compress().to_bytes(), m].concat())
+      }
+    }
+  }
+}
+
+#[cfg(feature = "ed25519")]
+dalek_curve!(
+  Ed25519,
+  IetfEd25519Hram,
+  EdwardsPoint,
+  CompressedEdwardsY,
+  EdwardsBasepointTable,
+  ED25519_BASEPOINT_POINT,
+  ED25519_BASEPOINT_TABLE,
+  |point: EdwardsPoint| !bool::from(point.is_torsion_free()),
+  b"edwards25519",
+  b"",
+  b"",
+  b"",
+);
+
+#[cfg(any(test, feature = "ristretto"))]
+dalek_curve!(
+  Ristretto,
+  IetfRistrettoHram,
+  RistrettoPoint,
+  CompressedRistretto,
+  RistrettoBasepointTable,
+  RISTRETTO_BASEPOINT_POINT,
+  RISTRETTO_BASEPOINT_TABLE,
+  |_| false,
+  b"ristretto",
+  b"FROST-RISTRETTO255-SHA512-v5",
+  b"chal",
+  b"digest",
+);

crypto/frost/src/curves/ed25519.rs

@@ -1,104 +0,0 @@
-use core::convert::TryInto;
-
-use rand_core::{RngCore, CryptoRng};
-
-use sha2::{Digest, Sha512};
-
-use ff::PrimeField;
-use group::Group;
-
-use dalek_ff_group::{
-  EdwardsBasepointTable,
-  ED25519_BASEPOINT_POINT, ED25519_BASEPOINT_TABLE,
-  Scalar, EdwardsPoint, CompressedEdwardsY
-};
-
-use crate::{CurveError, Curve, algorithm::Hram};
-
-#[derive(Clone, Copy, PartialEq, Eq, Debug)]
-pub struct Ed25519;
-impl Curve for Ed25519 {
-  type F = Scalar;
-  type G = EdwardsPoint;
-  type T = &'static EdwardsBasepointTable;
-
-  const ID: &'static [u8] = b"edwards25519";
-
-  const GENERATOR: Self::G = ED25519_BASEPOINT_POINT;
-  const GENERATOR_TABLE: Self::T = &ED25519_BASEPOINT_TABLE;
-
-  const LITTLE_ENDIAN: bool = true;
-
-  fn random_nonce<R: RngCore + CryptoRng>(secret: Self::F, rng: &mut R) -> Self::F {
-    let mut seed = vec![0; 32];
-    rng.fill_bytes(&mut seed);
-    seed.extend(&secret.to_bytes());
-    Self::hash_to_F(b"nonce", &seed)
-  }
-
-  fn hash_msg(msg: &[u8]) -> Vec<u8> {
-    Sha512::digest(msg).to_vec()
-  }
-
-  fn hash_binding_factor(binding: &[u8]) -> Self::F {
-    Self::hash_to_F(b"rho", binding)
-  }
-
-  fn hash_to_F(dst: &[u8], msg: &[u8]) -> Self::F {
-    Scalar::from_hash(Sha512::new().chain_update(dst).chain_update(msg))
-  }
-
-  fn F_len() -> usize {
-    32
-  }
-
-  fn G_len() -> usize {
-    32
-  }
-
-  fn F_from_slice(slice: &[u8]) -> Result<Self::F, CurveError> {
-    let scalar = Self::F::from_repr(
-      slice.try_into().map_err(|_| CurveError::InvalidLength(32, slice.len()))?
-    );
-    if scalar.is_some().unwrap_u8() == 0 {
-      Err(CurveError::InvalidScalar)?;
-    }
-    Ok(scalar.unwrap())
-  }
-
-  fn G_from_slice(slice: &[u8]) -> Result<Self::G, CurveError> {
-    let bytes = slice.try_into().map_err(|_| CurveError::InvalidLength(32, slice.len()))?;
-    let point = CompressedEdwardsY::new(bytes).decompress();
-
-    if let Some(point) = point {
-      // Ban identity and torsioned points
-      if point.is_identity().into() || (!bool::from(point.is_torsion_free())) {
-        Err(CurveError::InvalidPoint)?;
-      }
-      // Ban points which weren't canonically encoded
-      if point.compress().to_bytes() != bytes {
-        Err(CurveError::InvalidPoint)?;
-      }
-      Ok(point)
-    } else {
-      Err(CurveError::InvalidPoint)
-    }
-  }
-
-  fn F_to_bytes(f: &Self::F) -> Vec<u8> {
-    f.to_repr().to_vec()
-  }
-
-  fn G_to_bytes(g: &Self::G) -> Vec<u8> {
-    g.compress().to_bytes().to_vec()
-  }
-}
-
-#[derive(Copy, Clone)]
-pub struct IetfEd25519Hram;
-impl Hram<Ed25519> for IetfEd25519Hram {
-  #[allow(non_snake_case)]
-  fn hram(R: &EdwardsPoint, A: &EdwardsPoint, m: &[u8]) -> Scalar {
-    Ed25519::hash_to_F(b"", &[&R.compress().to_bytes(), &A.compress().to_bytes(), m].concat())
-  }
-}

crypto/frost/src/curves/kp256.rs

@@ -10,7 +10,7 @@ use group::{Group, GroupEncoding};
 use elliptic_curve::{bigint::{Encoding, U384}, hash2curve::{Expander, ExpandMsg, ExpandMsgXmd}};
 
 use crate::{CurveError, Curve};
-#[cfg(any(test, feature = "p256"))]
+#[cfg(feature = "p256")]
 use crate::algorithm::Hram;
 
 #[allow(non_snake_case)]
@@ -25,9 +25,9 @@ pub(crate) trait KP256Instance<G> {
   const GENERATOR: G;
 }
 
-#[cfg(any(test, feature = "p256"))]
+#[cfg(feature = "p256")]
 pub type P256 = KP256<p256::ProjectivePoint>;
-#[cfg(any(test, feature = "p256"))]
+#[cfg(feature = "p256")]
 impl KP256Instance<p256::ProjectivePoint> for P256 {
   const CONTEXT: &'static [u8] = b"FROST-P256-SHA256-v5";
   const ID: &'static [u8] = b"P-256";
@@ -139,10 +139,10 @@ impl<G: Group + GroupEncoding> Curve for KP256<G> where
   }
 }
 
-#[cfg(any(test, feature = "p256"))]
+#[cfg(feature = "p256")]
 #[derive(Clone)]
 pub struct IetfP256Hram;
-#[cfg(any(test, feature = "p256"))]
+#[cfg(feature = "p256")]
 impl Hram<P256> for IetfP256Hram {
   #[allow(non_snake_case)]
   fn hram(R: &p256::ProjectivePoint, A: &p256::ProjectivePoint, m: &[u8]) -> p256::Scalar {

crypto/frost/src/curves/mod.rs

@@ -1,5 +1,5 @@
-#[cfg(any(test, feature = "kp256"))]
+#[cfg(any(test, feature = "dalek"))]
-pub mod kp256;
+pub mod dalek;
 
-#[cfg(feature = "ed25519")]
+#[cfg(feature = "kp256")]
-pub mod ed25519;
+pub mod kp256;

crypto/frost/src/tests/literal/dalek.rs

@@ -0,0 +1,77 @@
+use rand::rngs::OsRng;
+
+use crate::{curves::dalek, tests::vectors::{Vectors, test_with_vectors}};
+
+#[cfg(any(test, feature = "ristretto"))]
+#[test]
+fn ristretto_vectors() {
+  test_with_vectors::<_, dalek::Ristretto, dalek::IetfRistrettoHram>(
+    &mut OsRng,
+    Vectors {
+      threshold: 2,
+      shares: &[
+        "5c3430d391552f6e60ecdc093ff9f6f4488756aa6cebdbad75a768010b8f830e",
+        "b06fc5eac20b4f6e1b271d9df2343d843e1e1fb03c4cbb673f2872d459ce6f01",
+        "f17e505f0e2581c6acfe54d3846a622834b5e7b50cad9a2109a97ba7a80d5c04"
+      ],
+      group_secret: "1b25a55e463cfd15cf14a5d3acc3d15053f08da49c8afcf3ab265f2ebc4f970b",
+      group_key: "e2a62f39eede11269e3bd5a7d97554f5ca384f9f6d3dd9c3c0d05083c7254f57",
+
+      msg: "74657374",
+      included: &[1, 3],
+      nonces: &[
+        [
+          "b358743151e33d84bf00c12f71808f4103957c3e2cabab7b895c436b5e70f90c",
+          "7bd112153b9ae1ab9b31f5e78f61f5c4ca9ee67b7ea6d1181799c409d14c350c"
+        ],
+        [
+          "22acad88478e0d0373a991092a322ebd1b9a2dad90451a976d0db3215426af0e",
+          "9155e3d7bcf7cd468b980c7e20b2c77cbdfbe33a1dcae031fd8bc6b1403f4b04"
+        ]
+      ],
+      sig_shares: &[
+        "ff801b4e0839faa67f16dee4127b9f7fbcf5fd007900257b0e2bbc02cbe5e709",
+        "afdf5481023c855bf3411a5c8a5fafa92357296a078c3b80dc168f294cb4f504"
+      ],
+      sig: "deae61af10e8ee48ba492573592fba547f5debeff6bd6e2024e8673584746f5e".to_owned() +
+           "ae6070cf0a757f027358f8409dda4e29e04c276b808c60fbea414b2c179add0e"
+    }
+  );
+}
+
+#[cfg(feature = "ed25519")]
+#[test]
+fn ed25519_vectors() {
+  test_with_vectors::<_, dalek::Ed25519, dalek::IetfEd25519Hram>(
+    &mut OsRng,
+    Vectors {
+      threshold: 2,
+      shares: &[
+        "929dcc590407aae7d388761cddb0c0db6f5627aea8e217f4a033f2ec83d93509",
+        "a91e66e012e4364ac9aaa405fcafd370402d9859f7b6685c07eed76bf409e80d",
+        "d3cb090a075eb154e82fdb4b3cb507f110040905468bb9c46da8bdea643a9a02"
+      ],
+      group_secret: "7b1c33d3f5291d85de664833beb1ad469f7fb6025a0ec78b3a790c6e13a98304",
+      group_key: "15d21ccd7ee42959562fc8aa63224c8851fb3ec85a3faf66040d380fb9738673",
+
+      msg: "74657374",
+      included: &[1, 3],
+      nonces: &[
+        [
+          "8c76af04340e83bb5fc427c117d38347fc8ef86d5397feea9aa6412d96c05b0a",
+          "14a37ddbeae8d9e9687369e5eb3c6d54f03dc19d76bb54fb5425131bc37a600b"
+        ],
+        [
+          "5ca39ebab6874f5e7b5089f3521819a2aa1e2cf738bae6974ee80555de2ef70e",
+          "0afe3650c4815ff37becd3c6948066e906e929ea9b8f546c74e10002dbcc150c"
+        ]
+      ],
+      sig_shares: &[
+        "4369474a398aa10357b60d683da91ea6a767dcf53fd541a8ed6b4d780827ea0a",
+        "32fcc690d926075e45d2dfb746bab71447943cddbefe80d122c39174aa2e1004"
+      ],
+      sig: "2b8d9c6995333c5990e3a3dd6568785539d3322f7f0376452487ea35cfda587b".to_owned() +
+           "75650edb12b1a8619c88ed1f8463d6baeefb18d3fed3c279102fdfecb255fa0e"
+    }
+  );
+}

crypto/frost/src/tests/literal/ed25519.rs

@@ -1,51 +0,0 @@
-use rand::rngs::OsRng;
-
-use crate::{
-  curves::ed25519::{Ed25519, IetfEd25519Hram},
-  tests::{curve::test_curve, schnorr::test_schnorr, vectors::{Vectors, vectors}}
-};
-
-#[test]
-fn ed25519_curve() {
-  test_curve::<_, Ed25519>(&mut OsRng);
-}
-
-#[test]
-fn ed25519_schnorr() {
-  test_schnorr::<_, Ed25519>(&mut OsRng);
-}
-
-#[test]
-fn ed25519_vectors() {
-  vectors::<Ed25519, IetfEd25519Hram>(
-    Vectors {
-      threshold: 2,
-      shares: &[
-        "929dcc590407aae7d388761cddb0c0db6f5627aea8e217f4a033f2ec83d93509",
-        "a91e66e012e4364ac9aaa405fcafd370402d9859f7b6685c07eed76bf409e80d",
-        "d3cb090a075eb154e82fdb4b3cb507f110040905468bb9c46da8bdea643a9a02"
-      ],
-      group_secret: "7b1c33d3f5291d85de664833beb1ad469f7fb6025a0ec78b3a790c6e13a98304",
-      group_key: "15d21ccd7ee42959562fc8aa63224c8851fb3ec85a3faf66040d380fb9738673",
-
-      msg: "74657374",
-      included: &[1, 3],
-      nonces: &[
-        [
-          "8c76af04340e83bb5fc427c117d38347fc8ef86d5397feea9aa6412d96c05b0a",
-          "14a37ddbeae8d9e9687369e5eb3c6d54f03dc19d76bb54fb5425131bc37a600b"
-        ],
-        [
-          "5ca39ebab6874f5e7b5089f3521819a2aa1e2cf738bae6974ee80555de2ef70e",
-          "0afe3650c4815ff37becd3c6948066e906e929ea9b8f546c74e10002dbcc150c"
-        ]
-      ],
-      sig_shares: &[
-        "4369474a398aa10357b60d683da91ea6a767dcf53fd541a8ed6b4d780827ea0a",
-        "32fcc690d926075e45d2dfb746bab71447943cddbefe80d122c39174aa2e1004"
-      ],
-      sig: "2b8d9c6995333c5990e3a3dd6568785539d3322f7f0376452487ea35cfda587b".to_owned() +
-           "75650edb12b1a8619c88ed1f8463d6baeefb18d3fed3c279102fdfecb255fa0e"
-    }
-  );
-}

crypto/frost/src/tests/literal/kp256.rs

@@ -1,26 +1,27 @@
 use rand::rngs::OsRng;
 
-use crate::{
+#[cfg(feature = "k256")]
-  curves::kp256::{P256, IetfP256Hram},
+use crate::tests::{curve::test_curve, schnorr::test_schnorr};
-  tests::{curve::test_curve, schnorr::test_schnorr, vectors::{Vectors, vectors}}
-};
-
 #[cfg(feature = "k256")]
 use crate::curves::kp256::K256;
 
+#[cfg(feature = "p256")]
+use crate::tests::vectors::{Vectors, test_with_vectors};
+#[cfg(feature = "p256")]
+use crate::curves::kp256::{P256, IetfP256Hram};
+
+#[cfg(feature = "k256")]
 #[test]
-fn p256_curve() {
+fn k256_not_ietf() {
-  test_curve::<_, P256>(&mut OsRng);
+  test_curve::<_, K256>(&mut OsRng);
-}
+  test_schnorr::<_, K256>(&mut OsRng);
-
-#[test]
-fn p256_schnorr() {
-  test_schnorr::<_, P256>(&mut OsRng);
 }
 
+#[cfg(feature = "p256")]
 #[test]
 fn p256_vectors() {
-  vectors::<P256, IetfP256Hram>(
+  test_with_vectors::<_, P256, IetfP256Hram>(
+    &mut OsRng,
     Vectors {
       threshold: 2,
       shares: &[
@@ -52,15 +53,3 @@ fn p256_vectors() {
     }
   );
 }
-
-#[cfg(feature = "k256")]
-#[test]
-fn k256_curve() {
-  test_curve::<_, K256>(&mut OsRng);
-}
-
-#[cfg(feature = "k256")]
-#[test]
-fn k256_schnorr() {
-  test_schnorr::<_, K256>(&mut OsRng);
-}

crypto/frost/src/tests/literal/mod.rs

@@ -1,3 +1,4 @@
+#[cfg(any(test, feature = "dalek"))]
+mod dalek;
+#[cfg(feature = "kp256")]
 mod kp256;
-#[cfg(feature = "ed25519")]
-mod ed25519;

crypto/frost/src/tests/vectors.rs

@@ -1,10 +1,12 @@
 use std::{sync::Arc, collections::HashMap};
 
+use rand_core::{RngCore, CryptoRng};
+
 use crate::{
   Curve, MultisigKeys,
   algorithm::{Schnorr, Hram},
   sign::{PreprocessPackage, StateMachine, AlgorithmMachine},
-  tests::recover
+  tests::{curve::test_curve, schnorr::test_schnorr, recover}
 };
 
 pub struct Vectors {
@@ -55,7 +57,16 @@ fn vectors_to_multisig_keys<C: Curve>(vectors: &Vectors) -> HashMap<u16, Multisi
   keys
 }
 
-pub fn vectors<C: Curve, H: Hram<C>>(vectors: Vectors) {
+pub fn test_with_vectors<
+  R: RngCore + CryptoRng,
+  C: Curve,
+  H: Hram<C>
+>(rng: &mut R, vectors: Vectors) {
+  // Do basic tests before trying the vectors
+  test_curve::<_, C>(&mut *rng);
+  test_schnorr::<_, C>(rng);
+
+  // Test against the vectors
   let keys = vectors_to_multisig_keys::<C>(&vectors);
   let group_key = C::G_from_slice(&hex::decode(vectors.group_key).unwrap()).unwrap();
   assert_eq!(