Rename `IntModP`/`IntModN` to `CurveField`/`ScalarField`

[dnssec-prover] / src / crypto / ec.rs

diff --git a/src/crypto/ec.rs b/src/crypto/ec.rs
index 7562deb111330ba360e0caa86e9bdf30c1417763..0908e33694e1eebd9425f1a3c6e86e0aa75bf81b 100644 (file)
--- a/src/crypto/ec.rs
+++ b/src/crypto/ec.rs
@@ -63,29 +63,29 @@ impl<M: PrimeModulus<U384> + Clone + Eq> IntMod for U384Mod<M> {
 pub(super) trait Curve : Copy {
        type Int: Int;
 
-       // With const generics, both IntModP and IntModN can be replaced with a single IntMod.
-       type IntModP: IntMod<I = Self::Int>;
-       type IntModN: IntMod<I = Self::Int>;
+       // With const generics, both CurveField and ScalarField can be replaced with a single IntMod.
+       type CurveField: IntMod<I = Self::Int>;
+       type ScalarField: IntMod<I = Self::Int>;
 
-       type P: PrimeModulus<Self::Int>;
-       type N: PrimeModulus<Self::Int>;
+       type CurveModulus: PrimeModulus<Self::Int>;
+       type ScalarModulus: PrimeModulus<Self::Int>;
 
        // Curve parameters y^2 = x^3 + ax + b
-       const A: Self::IntModP;
-       const B: Self::IntModP;
+       const A: Self::CurveField;
+       const B: Self::CurveField;
 
        const G: Point<Self>;
 }
 
 #[derive(Clone, PartialEq, Eq)]
 pub(super) struct Point<C: Curve + ?Sized> {
-       x: C::IntModP,
-       y: C::IntModP,
-       z: C::IntModP,
+       x: C::CurveField,
+       y: C::CurveField,
+       z: C::CurveField,
 }
 
 impl<C: Curve + ?Sized> Point<C> {
-       fn on_curve(x: &C::IntModP, y: &C::IntModP) -> Result<(), ()> {
+       fn on_curve(x: &C::CurveField, y: &C::CurveField) -> Result<(), ()> {
                let x_2 = x.square();
                let x_3 = x_2.mul(&x);
                let v = x_3.add(&C::A.mul(&x)).add(&C::B);
@@ -99,8 +99,8 @@ impl<C: Curve + ?Sized> Point<C> {
        }
 
        #[cfg(debug_assertions)]
-       fn on_curve_z(x: &C::IntModP, y: &C::IntModP, z: &C::IntModP) -> Result<(), ()> {
-               let m = C::IntModP::from_modinv_of(z.clone().into_i())?;
+       fn on_curve_z(x: &C::CurveField, y: &C::CurveField, z: &C::CurveField) -> Result<(), ()> {
+               let m = C::CurveField::from_modinv_of(z.clone().into_i())?;
                let m_2 = m.square();
                let m_3 = m_2.mul(&m);
                let x_norm = x.mul(&m_2);
@@ -109,25 +109,25 @@ impl<C: Curve + ?Sized> Point<C> {
        }
 
        #[cfg(test)]
-       fn normalize_x(&self) -> Result<C::IntModP, ()> {
-               let m = C::IntModP::from_modinv_of(self.z.clone().into_i())?;
+       fn normalize_x(&self) -> Result<C::CurveField, ()> {
+               let m = C::CurveField::from_modinv_of(self.z.clone().into_i())?;
                Ok(self.x.mul(&m.square()))
        }
 
        fn from_xy(x: C::Int, y: C::Int) -> Result<Self, ()> {
-               let x = C::IntModP::from_i(x);
-               let y = C::IntModP::from_i(y);
+               let x = C::CurveField::from_i(x);
+               let y = C::CurveField::from_i(y);
                Self::on_curve(&x, &y)?;
-               Ok(Point { x, y, z: C::IntModP::ONE })
+               Ok(Point { x, y, z: C::CurveField::ONE })
        }
 
-       pub(super) const fn from_xy_assuming_on_curve(x: C::IntModP, y: C::IntModP) -> Self {
-               Point { x, y, z: C::IntModP::ONE }
+       pub(super) const fn from_xy_assuming_on_curve(x: C::CurveField, y: C::CurveField) -> Self {
+               Point { x, y, z: C::CurveField::ONE }
        }
 
        /// Checks that `expected_x` is equal to our X affine coordinate (without modular inversion).
-       fn eq_x(&self, expected_x: &C::IntModN) -> Result<(), ()> {
-               debug_assert!(expected_x.clone().into_i() < C::P::PRIME, "N is < P");
+       fn eq_x(&self, expected_x: &C::ScalarField) -> Result<(), ()> {
+               debug_assert!(expected_x.clone().into_i() < C::CurveModulus::PRIME, "N is < P");
 
                // If x is between N and P the below calculations will fail and we'll spuriously reject a
                // signature and the wycheproof tests will fail. We should in theory accept such
@@ -136,18 +136,18 @@ impl<C: Curve + ?Sized> Point<C> {
                #[allow(unused_mut, unused_assignments)]
                let mut slow_check = None;
                #[cfg(test)] {
-                       slow_check = Some(C::IntModN::from_i(self.normalize_x()?.into_i()) == *expected_x);
+                       slow_check = Some(C::ScalarField::from_i(self.normalize_x()?.into_i()) == *expected_x);
                }
 
-               let e: C::IntModP = C::IntModP::from_i(expected_x.clone().into_i());
-               if self.z == C::IntModP::ZERO { return Err(()); }
+               let e: C::CurveField = C::CurveField::from_i(expected_x.clone().into_i());
+               if self.z == C::CurveField::ZERO { return Err(()); }
                let ezz = e.mul(&self.z).mul(&self.z);
                if self.x == ezz || slow_check == Some(true) { Ok(()) } else { Err(()) }
        }
 
        fn double(&self) -> Result<Self, ()> {
-               if self.y == C::IntModP::ZERO { return Err(()); }
-               if self.z == C::IntModP::ZERO { return Err(()); }
+               if self.y == C::CurveField::ZERO { return Err(()); }
+               if self.z == C::CurveField::ZERO { return Err(()); }
 
                let s = self.x.times_four().mul(&self.y.square());
                let z_2 = self.z.square();
@@ -191,7 +191,7 @@ impl<C: Curve + ?Sized> Point<C> {
 
 /// Calculates i * I + j * J
 #[allow(non_snake_case)]
-fn add_two_mul<C: Curve>(i: C::IntModN, I: &Point<C>, j: C::IntModN, J: &Point<C>) -> Result<Point<C>, ()> {
+fn add_two_mul<C: Curve>(i: C::ScalarField, I: &Point<C>, j: C::ScalarField, J: &Point<C>) -> Result<Point<C>, ()> {
        let i = i.into_i();
        let j = j.into_i();
 
@@ -273,14 +273,14 @@ pub(super) fn validate_ecdsa<C: Curve>(pk: &[u8], sig: &[u8], hash_input: &[u8])
        // perfectly safe to do so, the wycheproof tests expect such signatures to be rejected, so we
        // do so here.
        let r_u256 = C::Int::from_be_bytes(r_bytes)?;
-       if r_u256 > C::N::PRIME { return Err(()); }
+       if r_u256 > C::ScalarModulus::PRIME { return Err(()); }
        let s_u256 = C::Int::from_be_bytes(s_bytes)?;
-       if s_u256 > C::N::PRIME { return Err(()); }
+       if s_u256 > C::ScalarModulus::PRIME { return Err(()); }
 
-       let r = C::IntModN::from_i(r_u256);
-       let s_inv = C::IntModN::from_modinv_of(s_u256)?;
+       let r = C::ScalarField::from_i(r_u256);
+       let s_inv = C::ScalarField::from_modinv_of(s_u256)?;
 
-       let z = C::IntModN::from_i(C::Int::from_be_bytes(hash_input)?);
+       let z = C::ScalarField::from_i(C::Int::from_be_bytes(hash_input)?);
 
        let u_a = z.mul(&s_inv);
        let u_b = r.mul(&s_inv);