Reconcile the two copies of scalar_vector.rs in monero-serai

coins/monero/src/ringct/bulletproofs/original.rs

@@ -9,7 +9,7 @@ use curve25519_dalek::{scalar::Scalar as DalekScalar, edwards::EdwardsPoint as D
 use group::{ff::Field, Group};
 use dalek_ff_group::{ED25519_BASEPOINT_POINT as G, Scalar, EdwardsPoint};
 
-use multiexp::BatchVerifier;
+use multiexp::{BatchVerifier, multiexp};
 
 use crate::{Commitment, ringct::bulletproofs::core::*};
 
@@ -17,7 +17,20 @@ include!(concat!(env!("OUT_DIR"), "/generators.rs"));
 
 static IP12_CELL: OnceLock<Scalar> = OnceLock::new();
 pub(crate) fn IP12() -> Scalar {
-  *IP12_CELL.get_or_init(|| inner_product(&ScalarVector(vec![Scalar::ONE; N]), TWO_N()))
+  *IP12_CELL.get_or_init(|| ScalarVector(vec![Scalar::ONE; N]).inner_product(TWO_N()))
+}
+
+pub(crate) fn hadamard_fold(
+  l: &[EdwardsPoint],
+  r: &[EdwardsPoint],
+  a: Scalar,
+  b: Scalar,
+) -> Vec<EdwardsPoint> {
+  let mut res = Vec::with_capacity(l.len() / 2);
+  for i in 0 .. l.len() {
+    res.push(multiexp(&[(a, l[i]), (b, r[i])]));
+  }
+  res
 }
 
 #[derive(Clone, PartialEq, Eq, Debug)]
@@ -57,7 +70,7 @@ impl OriginalStruct {
     let mut cache = hash_to_scalar(&y.to_bytes());
     let z = cache;
 
-    let l0 = &aL - z;
+    let l0 = aL - z;
     let l1 = sL;
 
     let mut zero_twos = Vec::with_capacity(MN);
@@ -69,12 +82,12 @@ impl OriginalStruct {
     }
 
     let yMN = ScalarVector::powers(y, MN);
-    let r0 = (&(aR + z) * &yMN) + ScalarVector(zero_twos);
-    let r1 = yMN * sR;
+    let r0 = ((aR + z) * &yMN) + &ScalarVector(zero_twos);
+    let r1 = yMN * &sR;
 
     let (T1, T2, x, mut taux) = {
-      let t1 = inner_product(&l0, &r1) + inner_product(&l1, &r0);
-      let t2 = inner_product(&l1, &r1);
+      let t1 = l0.clone().inner_product(&r1) + r0.clone().inner_product(&l1);
+      let t2 = l1.clone().inner_product(&r1);
 
       let mut tau1 = Scalar::random(&mut *rng);
       let mut tau2 = Scalar::random(&mut *rng);
@@ -100,10 +113,10 @@ impl OriginalStruct {
       taux += zpow[i + 2] * gamma;
     }
 
-    let l = &l0 + &(l1 * x);
-    let r = &r0 + &(r1 * x);
+    let l = l0 + &(l1 * x);
+    let r = r0 + &(r1 * x);
 
-    let t = inner_product(&l, &r);
+    let t = l.clone().inner_product(&r);
 
     let x_ip =
       hash_cache(&mut cache, &[x.to_bytes(), taux.to_bytes(), mu.to_bytes(), t.to_bytes()]);
@@ -126,8 +139,8 @@ impl OriginalStruct {
       let (aL, aR) = a.split();
       let (bL, bR) = b.split();
 
-      let cL = inner_product(&aL, &bR);
-      let cR = inner_product(&aR, &bL);
+      let cL = aL.clone().inner_product(&bR);
+      let cR = aR.clone().inner_product(&bL);
 
       let (G_L, G_R) = G_proof.split_at(aL.len());
       let (H_L, H_R) = H_proof.split_at(aL.len());
@@ -140,8 +153,8 @@ impl OriginalStruct {
       let w = hash_cache(&mut cache, &[L_i.compress().to_bytes(), R_i.compress().to_bytes()]);
       let winv = w.invert().unwrap();
 
-      a = (aL * w) + (aR * winv);
-      b = (bL * winv) + (bR * w);
+      a = (aL * w) + &(aR * winv);
+      b = (bL * winv) + &(bR * w);
 
       if a.len() != 1 {
         G_proof = hadamard_fold(G_L, G_R, winv, w);

coins/monero/src/ringct/bulletproofs/plus/aggregate_range_proof.rs

@@ -112,7 +112,7 @@ impl AggregateRangeStatement {
     let mut d = ScalarVector::new(mn);
     for j in 1 ..= V.len() {
       z_pow.push(z.pow(Scalar::from(2 * u64::try_from(j).unwrap()))); // TODO: Optimize this
-      d = d.add_vec(&Self::d_j(j, V.len()).mul(z_pow[j - 1]));
+      d = d + &(Self::d_j(j, V.len()) * (z_pow[j - 1]));
     }
 
     let mut ascending_y = ScalarVector(vec![y]);
@@ -124,7 +124,8 @@ impl AggregateRangeStatement {
     let mut descending_y = ascending_y.clone();
     descending_y.0.reverse();
 
-    let d_descending_y = d.mul_vec(&descending_y);
+    let d_descending_y = d.clone() * &descending_y;
+    let d_descending_y_plus_z = d_descending_y + z;
 
     let y_mn_plus_one = descending_y[0] * y;
 
@@ -135,9 +136,9 @@ impl AggregateRangeStatement {
 
     let neg_z = -z;
     let mut A_terms = Vec::with_capacity((generators.len() * 2) + 2);
-    for (i, d_y_z) in d_descending_y.add(z).0.drain(..).enumerate() {
+    for (i, d_y_z) in d_descending_y_plus_z.0.iter().enumerate() {
       A_terms.push((neg_z, generators.generator(GeneratorsList::GBold1, i)));
-      A_terms.push((d_y_z, generators.generator(GeneratorsList::HBold1, i)));
+      A_terms.push((*d_y_z, generators.generator(GeneratorsList::HBold1, i)));
     }
     A_terms.push((y_mn_plus_one, commitment_accum));
     A_terms.push((
@@ -145,7 +146,14 @@ impl AggregateRangeStatement {
       Generators::g(),
     ));
 
-    (y, d_descending_y, y_mn_plus_one, z, ScalarVector(z_pow), A + multiexp_vartime(&A_terms))
+    (
+      y,
+      d_descending_y_plus_z,
+      y_mn_plus_one,
+      z,
+      ScalarVector(z_pow),
+      A + multiexp_vartime(&A_terms),
+    )
   }
 
   pub(crate) fn prove<R: RngCore + CryptoRng>(
@@ -191,7 +199,7 @@ impl AggregateRangeStatement {
       a_l.0.append(&mut u64_decompose(*witness.values.get(j - 1).unwrap_or(&0)).0);
     }
 
-    let a_r = a_l.sub(Scalar::ONE);
+    let a_r = a_l.clone() - Scalar::ONE;
 
     let alpha = Scalar::random(&mut *rng);
 
@@ -209,11 +217,11 @@ impl AggregateRangeStatement {
     // Multiply by INV_EIGHT per earlier commentary
     A.0 *= crate::INV_EIGHT();
 
-    let (y, d_descending_y, y_mn_plus_one, z, z_pow, A_hat) =
+    let (y, d_descending_y_plus_z, y_mn_plus_one, z, z_pow, A_hat) =
       Self::compute_A_hat(PointVector(V), &generators, &mut transcript, A);
 
-    let a_l = a_l.sub(z);
-    let a_r = a_r.add_vec(&d_descending_y).add(z);
+    let a_l = a_l - z;
+    let a_r = a_r + &d_descending_y_plus_z;
     let mut alpha = alpha;
     for j in 1 ..= witness.gammas.len() {
       alpha += z_pow[j - 1] * witness.gammas[j - 1] * y_mn_plus_one;

coins/monero/src/ringct/bulletproofs/plus/mod.rs

@@ -3,8 +3,7 @@
 use group::Group;
 use dalek_ff_group::{Scalar, EdwardsPoint};
 
-mod scalar_vector;
-pub(crate) use scalar_vector::{ScalarVector, weighted_inner_product};
+pub(crate) use crate::ringct::bulletproofs::scalar_vector::ScalarVector;
 mod point_vector;
 pub(crate) use point_vector::PointVector;
 

coins/monero/src/ringct/bulletproofs/plus/scalar_vector.rs

@@ -1,114 +0,0 @@
-use core::{
-  borrow::Borrow,
-  ops::{Index, IndexMut},
-};
-use std_shims::vec::Vec;
-
-use zeroize::Zeroize;
-
-use group::ff::Field;
-use dalek_ff_group::Scalar;
-
-#[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
-pub(crate) struct ScalarVector(pub(crate) Vec<Scalar>);
-
-impl Index<usize> for ScalarVector {
-  type Output = Scalar;
-  fn index(&self, index: usize) -> &Scalar {
-    &self.0[index]
-  }
-}
-
-impl IndexMut<usize> for ScalarVector {
-  fn index_mut(&mut self, index: usize) -> &mut Scalar {
-    &mut self.0[index]
-  }
-}
-
-impl ScalarVector {
-  pub(crate) fn new(len: usize) -> Self {
-    ScalarVector(vec![Scalar::ZERO; len])
-  }
-
-  pub(crate) fn add(&self, scalar: impl Borrow<Scalar>) -> Self {
-    let mut res = self.clone();
-    for val in &mut res.0 {
-      *val += scalar.borrow();
-    }
-    res
-  }
-
-  pub(crate) fn sub(&self, scalar: impl Borrow<Scalar>) -> Self {
-    let mut res = self.clone();
-    for val in &mut res.0 {
-      *val -= scalar.borrow();
-    }
-    res
-  }
-
-  pub(crate) fn mul(&self, scalar: impl Borrow<Scalar>) -> Self {
-    let mut res = self.clone();
-    for val in &mut res.0 {
-      *val *= scalar.borrow();
-    }
-    res
-  }
-
-  pub(crate) fn add_vec(&self, vector: &Self) -> Self {
-    debug_assert_eq!(self.len(), vector.len());
-    let mut res = self.clone();
-    for (i, val) in res.0.iter_mut().enumerate() {
-      *val += vector.0[i];
-    }
-    res
-  }
-
-  pub(crate) fn mul_vec(&self, vector: &Self) -> Self {
-    debug_assert_eq!(self.len(), vector.len());
-    let mut res = self.clone();
-    for (i, val) in res.0.iter_mut().enumerate() {
-      *val *= vector.0[i];
-    }
-    res
-  }
-
-  pub(crate) fn inner_product(&self, vector: &Self) -> Scalar {
-    self.mul_vec(vector).sum()
-  }
-
-  pub(crate) fn powers(x: Scalar, len: usize) -> Self {
-    debug_assert!(len != 0);
-
-    let mut res = Vec::with_capacity(len);
-    res.push(Scalar::ONE);
-    res.push(x);
-    for i in 2 .. len {
-      res.push(res[i - 1] * x);
-    }
-    res.truncate(len);
-    ScalarVector(res)
-  }
-
-  pub(crate) fn sum(mut self) -> Scalar {
-    self.0.drain(..).sum()
-  }
-
-  pub(crate) fn len(&self) -> usize {
-    self.0.len()
-  }
-
-  pub(crate) fn split(mut self) -> (Self, Self) {
-    debug_assert!(self.len() > 1);
-    let r = self.0.split_off(self.0.len() / 2);
-    debug_assert_eq!(self.len(), r.len());
-    (self, ScalarVector(r))
-  }
-}
-
-pub(crate) fn weighted_inner_product(
-  a: &ScalarVector,
-  b: &ScalarVector,
-  y: &ScalarVector,
-) -> Scalar {
-  a.inner_product(&b.mul_vec(y))
-}

coins/monero/src/ringct/bulletproofs/plus/weighted_inner_product.rs

@@ -4,7 +4,7 @@ use rand_core::{RngCore, CryptoRng};
 
 use zeroize::{Zeroize, ZeroizeOnDrop};
 
-use multiexp::{multiexp, multiexp_vartime, BatchVerifier};
+use multiexp::{BatchVerifier, multiexp, multiexp_vartime};
 use group::{
   ff::{Field, PrimeField},
   GroupEncoding,
@@ -12,8 +12,7 @@ use group::{
 use dalek_ff_group::{Scalar, EdwardsPoint};
 
 use crate::ringct::bulletproofs::plus::{
-  ScalarVector, PointVector, GeneratorsList, Generators, padded_pow_of_2, weighted_inner_product,
-  transcript::*,
+  ScalarVector, PointVector, GeneratorsList, Generators, padded_pow_of_2, transcript::*,
 };
 
 // Figure 1
@@ -219,7 +218,7 @@ impl WipStatement {
         .zip(g_bold.0.iter().copied())
         .chain(witness.b.0.iter().copied().zip(h_bold.0.iter().copied()))
         .collect::<Vec<_>>();
-      P_terms.push((weighted_inner_product(&witness.a, &witness.b, &y), g));
+      P_terms.push((witness.a.clone().weighted_inner_product(&witness.b, &y), g));
       P_terms.push((witness.alpha, h));
       debug_assert_eq!(multiexp(&P_terms), P);
       P_terms.zeroize();
@@ -258,14 +257,13 @@ impl WipStatement {
       let d_l = Scalar::random(&mut *rng);
       let d_r = Scalar::random(&mut *rng);
 
-      let c_l = weighted_inner_product(&a1, &b2, &y);
-      let c_r = weighted_inner_product(&(a2.mul(y_n_hat)), &b1, &y);
+      let c_l = a1.clone().weighted_inner_product(&b2, &y);
+      let c_r = (a2.clone() * y_n_hat).weighted_inner_product(&b1, &y);
 
       // TODO: Calculate these with a batch inversion
       let y_inv_n_hat = y_n_hat.invert().unwrap();
 
-      let mut L_terms = a1
-        .mul(y_inv_n_hat)
+      let mut L_terms = (a1.clone() * y_inv_n_hat)
         .0
         .drain(..)
         .zip(g_bold2.0.iter().copied())
@@ -277,8 +275,7 @@ impl WipStatement {
       L_vec.push(L);
       L_terms.zeroize();
 
-      let mut R_terms = a2
-        .mul(y_n_hat)
+      let mut R_terms = (a2.clone() * y_n_hat)
         .0
         .drain(..)
         .zip(g_bold1.0.iter().copied())
@@ -294,8 +291,8 @@ impl WipStatement {
       (e, inv_e, e_square, inv_e_square, g_bold, h_bold) =
         Self::next_G_H(&mut transcript, g_bold1, g_bold2, h_bold1, h_bold2, L, R, y_inv_n_hat);
 
-      a = a1.mul(e).add_vec(&a2.mul(y_n_hat * inv_e));
-      b = b1.mul(inv_e).add_vec(&b2.mul(e));
+      a = (a1 * e) + &(a2 * (y_n_hat * inv_e));
+      b = (b1 * inv_e) + &(b2 * e);
       alpha += (d_l * e_square) + (d_r * inv_e_square);
 
       debug_assert_eq!(g_bold.len(), a.len());

coins/monero/src/ringct/bulletproofs/scalar_vector.rs

@@ -1,85 +1,17 @@
-use core::ops::{Add, Sub, Mul, Index};
+use core::{
+  borrow::Borrow,
+  ops::{Index, IndexMut, Add, Sub, Mul},
+};
 use std_shims::vec::Vec;
 
 use zeroize::{Zeroize, ZeroizeOnDrop};
 
 use group::ff::Field;
 use dalek_ff_group::{Scalar, EdwardsPoint};
-
 use multiexp::multiexp;
 
 #[derive(Clone, PartialEq, Eq, Debug, Zeroize, ZeroizeOnDrop)]
 pub(crate) struct ScalarVector(pub(crate) Vec<Scalar>);
-macro_rules! math_op {
-  ($Op: ident, $op: ident, $f: expr) => {
-    #[allow(clippy::redundant_closure_call)]
-    impl $Op<Scalar> for ScalarVector {
-      type Output = ScalarVector;
-      fn $op(self, b: Scalar) -> ScalarVector {
-        ScalarVector(self.0.iter().map(|a| $f((a, &b))).collect())
-      }
-    }
-
-    #[allow(clippy::redundant_closure_call)]
-    impl $Op<Scalar> for &ScalarVector {
-      type Output = ScalarVector;
-      fn $op(self, b: Scalar) -> ScalarVector {
-        ScalarVector(self.0.iter().map(|a| $f((a, &b))).collect())
-      }
-    }
-
-    #[allow(clippy::redundant_closure_call)]
-    impl $Op<ScalarVector> for ScalarVector {
-      type Output = ScalarVector;
-      fn $op(self, b: ScalarVector) -> ScalarVector {
-        debug_assert_eq!(self.len(), b.len());
-        ScalarVector(self.0.iter().zip(b.0.iter()).map($f).collect())
-      }
-    }
-
-    #[allow(clippy::redundant_closure_call)]
-    impl $Op<&ScalarVector> for &ScalarVector {
-      type Output = ScalarVector;
-      fn $op(self, b: &ScalarVector) -> ScalarVector {
-        debug_assert_eq!(self.len(), b.len());
-        ScalarVector(self.0.iter().zip(b.0.iter()).map($f).collect())
-      }
-    }
-  };
-}
-math_op!(Add, add, |(a, b): (&Scalar, &Scalar)| *a + *b);
-math_op!(Sub, sub, |(a, b): (&Scalar, &Scalar)| *a - *b);
-math_op!(Mul, mul, |(a, b): (&Scalar, &Scalar)| *a * *b);
-
-impl ScalarVector {
-  pub(crate) fn new(len: usize) -> ScalarVector {
-    ScalarVector(vec![Scalar::ZERO; len])
-  }
-
-  pub(crate) fn powers(x: Scalar, len: usize) -> ScalarVector {
-    debug_assert!(len != 0);
-
-    let mut res = Vec::with_capacity(len);
-    res.push(Scalar::ONE);
-    for i in 1 .. len {
-      res.push(res[i - 1] * x);
-    }
-    ScalarVector(res)
-  }
-
-  pub(crate) fn sum(mut self) -> Scalar {
-    self.0.drain(..).sum()
-  }
-
-  pub(crate) fn len(&self) -> usize {
-    self.0.len()
-  }
-
-  pub(crate) fn split(self) -> (ScalarVector, ScalarVector) {
-    let (l, r) = self.0.split_at(self.0.len() / 2);
-    (ScalarVector(l.to_vec()), ScalarVector(r.to_vec()))
-  }
-}
 
 impl Index<usize> for ScalarVector {
   type Output = Scalar;
@@ -87,28 +19,120 @@ impl Index<usize> for ScalarVector {
     &self.0[index]
   }
 }
+impl IndexMut<usize> for ScalarVector {
+  fn index_mut(&mut self, index: usize) -> &mut Scalar {
+    &mut self.0[index]
+  }
+}
 
-pub(crate) fn inner_product(a: &ScalarVector, b: &ScalarVector) -> Scalar {
-  (a * b).sum()
+impl<S: Borrow<Scalar>> Add<S> for ScalarVector {
+  type Output = ScalarVector;
+  fn add(mut self, scalar: S) -> ScalarVector {
+    for s in &mut self.0 {
+      *s += scalar.borrow();
+    }
+    self
+  }
+}
+impl<S: Borrow<Scalar>> Sub<S> for ScalarVector {
+  type Output = ScalarVector;
+  fn sub(mut self, scalar: S) -> ScalarVector {
+    for s in &mut self.0 {
+      *s -= scalar.borrow();
+    }
+    self
+  }
+}
+impl<S: Borrow<Scalar>> Mul<S> for ScalarVector {
+  type Output = ScalarVector;
+  fn mul(mut self, scalar: S) -> ScalarVector {
+    for s in &mut self.0 {
+      *s *= scalar.borrow();
+    }
+    self
+  }
+}
+
+impl Add<&ScalarVector> for ScalarVector {
+  type Output = ScalarVector;
+  fn add(mut self, other: &ScalarVector) -> ScalarVector {
+    debug_assert_eq!(self.len(), other.len());
+    for (s, o) in self.0.iter_mut().zip(other.0.iter()) {
+      *s += o;
+    }
+    self
+  }
+}
+impl Sub<&ScalarVector> for ScalarVector {
+  type Output = ScalarVector;
+  fn sub(mut self, other: &ScalarVector) -> ScalarVector {
+    debug_assert_eq!(self.len(), other.len());
+    for (s, o) in self.0.iter_mut().zip(other.0.iter()) {
+      *s -= o;
+    }
+    self
+  }
+}
+impl Mul<&ScalarVector> for ScalarVector {
+  type Output = ScalarVector;
+  fn mul(mut self, other: &ScalarVector) -> ScalarVector {
+    debug_assert_eq!(self.len(), other.len());
+    for (s, o) in self.0.iter_mut().zip(other.0.iter()) {
+      *s *= o;
+    }
+    self
+  }
 }
 
 impl Mul<&[EdwardsPoint]> for &ScalarVector {
   type Output = EdwardsPoint;
   fn mul(self, b: &[EdwardsPoint]) -> EdwardsPoint {
     debug_assert_eq!(self.len(), b.len());
-    multiexp(&self.0.iter().copied().zip(b.iter().copied()).collect::<Vec<_>>())
+    let mut multiexp_args = self.0.iter().copied().zip(b.iter().copied()).collect::<Vec<_>>();
+    let res = multiexp(&multiexp_args);
+    multiexp_args.zeroize();
+    res
   }
 }
 
-pub(crate) fn hadamard_fold(
-  l: &[EdwardsPoint],
-  r: &[EdwardsPoint],
-  a: Scalar,
-  b: Scalar,
-) -> Vec<EdwardsPoint> {
-  let mut res = Vec::with_capacity(l.len() / 2);
-  for i in 0 .. l.len() {
-    res.push(multiexp(&[(a, l[i]), (b, r[i])]));
+impl ScalarVector {
+  pub(crate) fn new(len: usize) -> Self {
+    ScalarVector(vec![Scalar::ZERO; len])
+  }
+
+  pub(crate) fn powers(x: Scalar, len: usize) -> Self {
+    debug_assert!(len != 0);
+
+    let mut res = Vec::with_capacity(len);
+    res.push(Scalar::ONE);
+    res.push(x);
+    for i in 2 .. len {
+      res.push(res[i - 1] * x);
+    }
+    res.truncate(len);
+    ScalarVector(res)
+  }
+
+  pub(crate) fn len(&self) -> usize {
+    self.0.len()
+  }
+
+  pub(crate) fn sum(mut self) -> Scalar {
+    self.0.drain(..).sum()
+  }
+
+  pub(crate) fn inner_product(self, vector: &Self) -> Scalar {
+    (self * vector).sum()
+  }
+
+  pub(crate) fn weighted_inner_product(self, vector: &Self, y: &Self) -> Scalar {
+    (self * vector * y).sum()
+  }
+
+  pub(crate) fn split(mut self) -> (Self, Self) {
+    debug_assert!(self.len() > 1);
+    let r = self.0.split_off(self.0.len() / 2);
+    debug_assert_eq!(self.len(), r.len());
+    (self, ScalarVector(r))
   }
-  res
 }

coins/monero/src/tests/bulletproofs/plus/weighted_inner_product.rs

@@ -9,7 +9,6 @@ use dalek_ff_group::{Scalar, EdwardsPoint};
 use crate::ringct::bulletproofs::plus::{
   ScalarVector, PointVector, GeneratorsList, Generators,
   weighted_inner_product::{WipStatement, WipWitness},
-  weighted_inner_product,
 };
 
 #[test]
@@ -68,7 +67,7 @@ fn test_weighted_inner_product() {
     #[allow(non_snake_case)]
     let P = g_bold.multiexp(&a) +
       h_bold.multiexp(&b) +
-      (g * weighted_inner_product(&a, &b, &y_vec)) +
+      (g * a.clone().weighted_inner_product(&b, &y_vec)) +
       (h * alpha);
 
     let statement = WipStatement::new(generators, P, y);