Zsa functionalities

.github/workflows/ci.yml

@@ -125,33 +125,33 @@ jobs:
  - name: Test halo2 book
  run: mdbook test -L target/debug/deps book/
 
- codecov:
- name: Code coverage
- runs-on: ubuntu-latest
-
- steps:
- - uses: actions/checkout@v3
- # Use stable for this to ensure that cargo-tarpaulin can be built.
- - id: prepare
- uses: ./.github/actions/prepare
- with:
- toolchain: stable
- nightly-features: true
- - name: Install cargo-tarpaulin
- uses: actions-rs/cargo@v1
- with:
- command: install
- args: cargo-tarpaulin
- - name: Generate coverage report
- uses: actions-rs/cargo@v1
- with:
- command: tarpaulin
- args: >
- ${{ steps.prepare.outputs.feature-flags }}
- --timeout 600
- --out Xml
- - name: Upload coverage to Codecov
- uses: codecov/[email protected]
+#  codecov:
+#  name: Code coverage
+#  runs-on: ubuntu-latest
+# 
+#  steps:
+#  - uses: actions/checkout@v3
+#  # Use stable for this to ensure that cargo-tarpaulin can be built.
+#  - id: prepare
+#  uses: ./.github/actions/prepare
+#  with:
+#  toolchain: stable
+#  nightly-features: true
+#  - name: Install cargo-tarpaulin
+#  uses: actions-rs/cargo@v1
+#  with:
+#  command: install
+#  args: cargo-tarpaulin
+#  - name: Generate coverage report
+#  uses: actions-rs/cargo@v1
+#  with:
+#  command: tarpaulin
+#  args: >
+#  ${{ steps.prepare.outputs.feature-flags }}
+#  --timeout 600
+#  --out Xml
+#  - name: Upload coverage to Codecov
+#  uses: codecov/[email protected]
 
  doc-links:
  name: Intra-doc links

halo2_gadgets/src/ecc.rs

@@ -4,7 +4,7 @@ use std::fmt::Debug;
 
 use halo2_proofs::{
  arithmetic::CurveAffine,
- circuit::{Chip, Layouter, Value},
+ circuit::{AssignedCell, Chip, Layouter, Value},
  plonk::Error,
 };
 
@@ -60,6 +60,15 @@ pub trait EccInstructions<C: CurveAffine>:
  value: Value<C>,
  ) -> Result<Self::Point, Error>;
 
+ /// Witnesses the given constant point as a private input to the circuit.
+ /// This allows the point to be the identity, mapped to (0, 0) in
+ /// affine coordinates.
+ fn witness_point_from_constant(
+ &self,
+ layouter: &mut impl Layouter<C::Base>,
+ value: C,
+ ) -> Result<Self::Point, Error>;
+
  /// Witnesses the given point as a private input to the circuit.
  /// This returns an error if the point is the identity.
  fn witness_point_non_id(
@@ -111,6 +120,15 @@ pub trait EccInstructions<C: CurveAffine>:
  b: &B,
  ) -> Result<Self::Point, Error>;
 
+ /// Performs variable-base sign-scalar multiplication, returning `[sign] point`
+ /// `sign` must be in {-1, 1}.
+ fn mul_sign(
+ &self,
+ layouter: &mut impl Layouter<C::Base>,
+ sign: &AssignedCell<C::Base, C::Base>,
+ point: &Self::Point,
+ ) -> Result<Self::Point, Error>;
+
  /// Performs variable-base scalar multiplication, returning `[scalar] base`.
  fn mul(
  &self,
@@ -390,6 +408,16 @@ impl<C: CurveAffine, EccChip: EccInstructions<C> + Clone + Debug + Eq> Point<C,
  point.map(|inner| Point { chip, inner })
  }
 
+ /// Constructs a new point with the given fixed value.
+ pub fn new_from_constant(
+ chip: EccChip,
+ mut layouter: impl Layouter<C::Base>,
+ value: C,
+ ) -> Result<Self, Error> {
+ let point = chip.witness_point_from_constant(&mut layouter, value);
+ point.map(|inner| Point { chip, inner })
+ }
+
  /// Constrains this point to be equal in value to another point.
  pub fn constrain_equal<Other: Into<Point<C, EccChip>> + Clone>(
  &self,
@@ -432,6 +460,21 @@ impl<C: CurveAffine, EccChip: EccInstructions<C> + Clone + Debug + Eq> Point<C,
  inner,
  })
  }
+
+ /// Returns `[sign] self`.
+ /// `sign` must be in {-1, 1}.
+ pub fn mul_sign(
+ &self,
+ mut layouter: impl Layouter<C::Base>,
+ sign: &AssignedCell<C::Base, C::Base>,
+ ) -> Result<Point<C, EccChip>, Error> {
+ self.chip
+ .mul_sign(&mut layouter, sign, &self.inner)
+ .map(|point| Point {
+ chip: self.chip.clone(),
+ inner: point,
+ })
+ }
 }
 
 /// The affine short Weierstrass x-coordinate of a point on a specific elliptic curve.
@@ -750,6 +793,7 @@ pub(crate) mod tests {
  meta.advice_column(),
  ];
  let lookup_table = meta.lookup_table_column();
+ let table_range_check_tag = meta.lookup_table_column();
  let lagrange_coeffs = [
  meta.fixed_column(),
  meta.fixed_column(),
@@ -764,7 +808,12 @@ pub(crate) mod tests {
  let constants = meta.fixed_column();
  meta.enable_constant(constants);
 
- let range_check = LookupRangeCheckConfig::configure(meta, advices[9], lookup_table);
+ let range_check = LookupRangeCheckConfig::configure(
+ meta,
+ advices[9],
+ lookup_table,
+ table_range_check_tag,
+ );
  EccChip::<TestFixedBases>::configure(meta, advices, lagrange_coeffs, range_check)
  }
 
@@ -865,6 +914,14 @@ pub(crate) mod tests {
  )?;
  }
 
+ // Test variable-base sign-scalar multiplication
+ {
+ super::chip::mul_fixed::short::tests::test_mul_sign(
+ chip.clone(),
+ layouter.namespace(|| "variable-base sign-scalar mul"),
+ )?;
+ }
+
  // Test full-width fixed-base scalar multiplication
  {
  super::chip::mul_fixed::full_width::tests::test_mul_fixed(

halo2_gadgets/src/ecc/chip.rs

@@ -453,6 +453,18 @@ where
  )
  }
 
+ fn witness_point_from_constant(
+ &self,
+ layouter: &mut impl Layouter<pallas::Base>,
+ value: pallas::Affine,
+ ) -> Result<Self::Point, Error> {
+ let config = self.config().witness_point;
+ layouter.assign_region(
+ || "witness point (constant)",
+ |mut region| config.constant_point(value, 0, &mut region),
+ )
+ }
+
  fn witness_point_non_id(
  &self,
  layouter: &mut impl Layouter<pallas::Base>,
@@ -532,6 +544,24 @@ where
  )
  }
 
+ /// Performs variable-base sign-scalar multiplication, returning `[sign] point`
+ /// `sign` must be in {-1, 1}.
+ fn mul_sign(
+ &self,
+ layouter: &mut impl Layouter<pallas::Base>,
+ sign: &AssignedCell<pallas::Base, pallas::Base>,
+ point: &Self::Point,
+ ) -> Result<Self::Point, Error> {
+ // Multiply point by sign, using the same gate as mul_fixed::short.
+ // This also constrains sign to be in {-1, 1}.
+ let config_short = self.config().mul_fixed_short.clone();
+ config_short.assign_scalar_sign(
+ layouter.namespace(|| "variable-base sign-scalar mul"),
+ sign,
+ point,
+ )
+ }
+
  fn mul(
  &self,
  layouter: &mut impl Layouter<pallas::Base>,