Add ECC test

src/circuit/gadget/ecc/chip.rs

@@ -806,3 +806,139 @@ impl<C: CurveAffine> EccInstructions<C> for EccChip<C> {
         Ok(point)
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::constants;
+    use group::{Curve, Group};
+    use halo2::{
+        arithmetic::{CurveAffine, FieldExt},
+        circuit::layouter::SingleChipLayouter,
+        dev::MockProver,
+        pasta::pallas,
+        plonk::{Assignment, Circuit, ConstraintSystem, Error},
+    };
+
+    use super::super::EccInstructions;
+    use super::{EccChip, EccConfig, OrchardFixedBases};
+
+    struct MyCircuit<C: CurveAffine> {
+        _marker: std::marker::PhantomData<C>,
+    }
+
+    #[allow(non_snake_case)]
+    impl<C: CurveAffine> Circuit<C::Base> for MyCircuit<C> {
+        type Config = EccConfig;
+
+        fn configure(meta: &mut ConstraintSystem<C::Base>) -> Self::Config {
+            let bits = meta.advice_column();
+            let P = (meta.advice_column(), meta.advice_column());
+            let lambda = (meta.advice_column(), meta.advice_column());
+            let extras = [
+                meta.advice_column(),
+                meta.advice_column(),
+                meta.advice_column(),
+                meta.advice_column(),
+                meta.advice_column(),
+            ];
+
+            EccChip::<C>::configure(meta, bits, P, lambda, extras)
+        }
+
+        fn synthesize(
+            &self,
+            cs: &mut impl Assignment<C::Base>,
+            config: Self::Config,
+        ) -> Result<(), Error> {
+            let loaded = EccChip::<C>::load();
+            let chip = EccChip::construct(config, loaded);
+            let mut layouter = SingleChipLayouter::new(cs)?;
+
+            // Generate a random point
+            let point_val = C::CurveExt::random(rand::rngs::OsRng).to_affine(); // P
+            let point = chip.witness_point(&mut layouter, Some(point_val))?;
+
+            // Check doubled point [2]P
+            let real_doubled = point_val * C::Scalar::from_u64(2); // [2]P
+            let doubled = chip.add(&mut layouter, &point, &point)?;
+            if let (Some(x), Some(y)) = (doubled.x.value, doubled.y.value) {
+                assert_eq!(real_doubled.to_affine(), C::from_xy(x, y).unwrap());
+            }
+
+            let real_added = point_val * C::Scalar::from_u64(3); // [3]P
+
+            // Check incomplete addition point [3]P
+            {
+                let added = chip.add(&mut layouter, &point, &doubled)?;
+                if let (Some(x), Some(y)) = (added.x.value, added.y.value) {
+                    assert_eq!(real_added.to_affine(), C::from_xy(x, y).unwrap());
+                }
+            }
+
+            // Check complete addition point [3]P
+            {
+                let added_complete = chip.add_complete(&mut layouter, &point, &doubled)?;
+                if let (Some(x), Some(y)) = (added_complete.x.value, added_complete.y.value) {
+                    if C::from_xy(x, y).is_some().into() {
+                        assert_eq!(real_added.to_affine(), C::from_xy(x, y).unwrap());
+                    }
+                }
+            }
+
+            // Check fixed-base scalar multiplication
+            {
+                let scalar_fixed = C::Scalar::rand();
+                let nullifier_k = constants::nullifier_k::generator();
+                let base = nullifier_k.0.value();
+                let real_mul_fixed = base * scalar_fixed;
+
+                let scalar_fixed = chip.witness_scalar_fixed(&mut layouter, Some(scalar_fixed))?;
+                let nullifier_k = chip.get_fixed(OrchardFixedBases::NullifierK(nullifier_k))?;
+                let mul_fixed = chip.mul_fixed(&mut layouter, &scalar_fixed, &nullifier_k)?;
+                if let (Some(x), Some(y)) = (mul_fixed.x.value, mul_fixed.y.value) {
+                    assert_eq!(real_mul_fixed.to_affine(), C::from_xy(x, y).unwrap());
+                }
+            }
+
+            // Check short signed fixed-base scalar multiplication
+            {
+                let scalar_fixed_short = C::Scalar::from_u64(rand::random::<u64>());
+                let value_commit_v = constants::value_commit_v::generator();
+                let real_mul_fixed_short = value_commit_v.0.value() * scalar_fixed_short;
+
+                let scalar_fixed_short =
+                    chip.witness_scalar_fixed_short(&mut layouter, Some(scalar_fixed_short))?;
+                let value_commit_v =
+                    chip.get_fixed(OrchardFixedBases::ValueCommitV(value_commit_v))?;
+                let mul_fixed_short =
+                    chip.mul_fixed_short(&mut layouter, &scalar_fixed_short, &value_commit_v)?;
+                if let (Some(x), Some(y)) = (mul_fixed_short.x.value, mul_fixed_short.y.value) {
+                    assert_eq!(real_mul_fixed_short.to_affine(), C::from_xy(x, y).unwrap());
+                }
+            }
+
+            // Check variable-base scalar multiplication
+            {
+                let scalar_val = C::Scalar::rand();
+                let real_mul = point_val * scalar_val;
+
+                let mul = chip.mul(&mut layouter, scalar_val, &point)?;
+                if let (Some(x), Some(y)) = (mul.x.value, mul.y.value) {
+                    assert_eq!(real_mul.to_affine(), C::from_xy(x, y).unwrap());
+                }
+            }
+
+            Ok(())
+        }
+    }
+
+    #[test]
+    fn ecc() {
+        let k = 11;
+        let circuit = MyCircuit::<pallas::Affine> {
+            _marker: std::marker::PhantomData,
+        };
+        let prover = MockProver::run(k, &circuit, vec![]).unwrap();
+        assert_eq!(prover.verify(), Ok(()))
+    }
+}