1use crate::prelude::*;
  2use algebra::{Field, PairingEngine};
  3use r1cs_core::{ConstraintSystem, SynthesisError};
  4use std::fmt::Debug;
  5
  6pub mod bls12;
  7pub use self::bls12::bls12_377;
  8
  9pub trait PairingGadget<PairingE: PairingEngine, ConstraintF: Field> {
 10    type G1Gadget: GroupGadget<PairingE::G1Projective, ConstraintF>;
 11    type G2Gadget: GroupGadget<PairingE::G2Projective, ConstraintF>;
 12    type G1PreparedGadget: ToBytesGadget<ConstraintF> + Clone + Debug;
 13    type G2PreparedGadget: ToBytesGadget<ConstraintF> + Clone + Debug;
 14    type GTGadget: FieldGadget<PairingE::Fqk, ConstraintF> + Clone;
 15
 16    fn miller_loop<CS: ConstraintSystem<ConstraintF>>(
 17        cs: CS,
 18        p: &[Self::G1PreparedGadget],
 19        q: &[Self::G2PreparedGadget],
 20    ) -> Result<Self::GTGadget, SynthesisError>;
 21
 22    fn final_exponentiation<CS: ConstraintSystem<ConstraintF>>(
 23        cs: CS,
 24        p: &Self::GTGadget,
 25    ) -> Result<Self::GTGadget, SynthesisError>;
 26
 27    fn pairing<CS: ConstraintSystem<ConstraintF>>(
 28        mut cs: CS,
 29        p: Self::G1PreparedGadget,
 30        q: Self::G2PreparedGadget,
 31    ) -> Result<Self::GTGadget, SynthesisError> {
 32        let tmp = Self::miller_loop(cs.ns(|| "miller loop"), &[p], &[q])?;
 33        Self::final_exponentiation(cs.ns(|| "final_exp"), &tmp)
 34    }
 35
 36    /// Computes a product of pairings.
 37    #[must_use]
 38    fn product_of_pairings<CS: ConstraintSystem<ConstraintF>>(
 39        mut cs: CS,
 40        p: &[Self::G1PreparedGadget],
 41        q: &[Self::G2PreparedGadget],
 42    ) -> Result<Self::GTGadget, SynthesisError> {
 43        let miller_result = Self::miller_loop(&mut cs.ns(|| "Miller loop"), p, q)?;
 44        Self::final_exponentiation(&mut cs.ns(|| "Final Exp"), &miller_result)
 45    }
 46
 47    fn prepare_g1<CS: ConstraintSystem<ConstraintF>>(
 48        cs: CS,
 49        q: &Self::G1Gadget,
 50    ) -> Result<Self::G1PreparedGadget, SynthesisError>;
 51
 52    fn prepare_g2<CS: ConstraintSystem<ConstraintF>>(
 53        cs: CS,
 54        q: &Self::G2Gadget,
 55    ) -> Result<Self::G2PreparedGadget, SynthesisError>;
 56}
 57
 58#[cfg(test)]
 59mod test {
 60    // use rand;
 61    use crate::test_constraint_system::TestConstraintSystem;
 62    use algebra::{BitIterator, Field, One};
 63    use r1cs_core::ConstraintSystem;
 64
 65    #[test]
 66    fn bls12_377_gadget_bilinearity_test() {
 67        use algebra::{
 68            fields::{
 69                bls12_377::{fq::Fq, fr::Fr},
 70                PrimeField,
 71            },
 72            PairingEngine, ProjectiveCurve,
 73        };
 74
 75        use super::bls12_377::PairingGadget;
 76        use crate::{
 77            groups::bls12::bls12_377::{G1Gadget, G1PreparedGadget, G2Gadget, G2PreparedGadget},
 78            pairing::PairingGadget as _,
 79            prelude::*,
 80        };
 81        use algebra::curves::bls12_377::{Bls12_377, G1Projective, G2Projective};
 82        use std::ops::Mul;
 83
 84        let mut cs = TestConstraintSystem::<Fq>::new();
 85
 86        // let a: G1Projective = rand::random();
 87        // let b: G2Projective = rand::random();
 88        // let s: Fr = rand::random();
 89
 90        let a: G1Projective = G1Projective::prime_subgroup_generator();
 91        let b: G2Projective = G2Projective::prime_subgroup_generator();
 92        let s: Fr = Fr::one() + &Fr::one();
 93
 94        let sa = a.mul(&s);
 95        let sb = b.mul(&s);
 96
 97        let a_g = G1Gadget::alloc(&mut cs.ns(|| "a"), || Ok(a)).unwrap();
 98        let b_g = G2Gadget::alloc(&mut cs.ns(|| "b"), || Ok(b)).unwrap();
 99        let sa_g = G1Gadget::alloc(&mut cs.ns(|| "sa"), || Ok(sa)).unwrap();
100        let sb_g = G2Gadget::alloc(&mut cs.ns(|| "sb"), || Ok(sb)).unwrap();
101
102        let a_prep_g = G1PreparedGadget::from_affine(&mut cs.ns(|| "a_prep"), &a_g).unwrap();
103        let b_prep_g = G2PreparedGadget::from_affine(&mut cs.ns(|| "b_prep"), &b_g).unwrap();
104
105        let sa_prep_g = G1PreparedGadget::from_affine(&mut cs.ns(|| "sa_prep"), &sa_g).unwrap();
106        let sb_prep_g = G2PreparedGadget::from_affine(&mut cs.ns(|| "sb_prep"), &sb_g).unwrap();
107
108        let (ans1_g, ans1_n) = {
109            let ans_g =
110                PairingGadget::pairing(cs.ns(|| "pair(sa, b)"), sa_prep_g, b_prep_g.clone())
111                    .unwrap();
112            let ans_n = Bls12_377::pairing(sa, b);
113            (ans_g, ans_n)
114        };
115
116        let (ans2_g, ans2_n) = {
117            let ans_g =
118                PairingGadget::pairing(cs.ns(|| "pair(a, sb)"), a_prep_g.clone(), sb_prep_g)
119                    .unwrap();
120            let ans_n = Bls12_377::pairing(a, sb);
121            (ans_g, ans_n)
122        };
123
124        let (ans3_g, ans3_n) = {
125            let s_iter = BitIterator::new(s.into_repr())
126                .map(Boolean::constant)
127                .collect::<Vec<_>>();
128
129            let mut ans_g =
130                PairingGadget::pairing(cs.ns(|| "pair(a, b)"), a_prep_g, b_prep_g).unwrap();
131            let mut ans_n = Bls12_377::pairing(a, b);
132            ans_n = ans_n.pow(s.into_repr());
133            ans_g = ans_g.pow(cs.ns(|| "pow"), &s_iter).unwrap();
134
135            (ans_g, ans_n)
136        };
137
138        assert_eq!(ans1_n, ans2_n, "Failed ans1_native == ans2_native");
139        assert_eq!(ans2_n, ans3_n, "Failed ans2_native == ans3_native");
140        assert_eq!(
141            ans1_g.get_value(),
142            ans3_g.get_value(),
143            "Failed ans1 == ans3"
144        );
145        assert_eq!(
146            ans1_g.get_value(),
147            ans2_g.get_value(),
148            "Failed ans1 == ans2"
149        );
150        assert_eq!(
151            ans2_g.get_value(),
152            ans3_g.get_value(),
153            "Failed ans2 == ans3"
154        );
155
156        ans1_g
157            .enforce_equal(&mut cs.ns(|| "ans1 == ans2?"), &ans2_g)
158            .unwrap();
159        ans2_g
160            .enforce_equal(&mut cs.ns(|| "ans2 == ans3?"), &ans3_g)
161            .unwrap();
162
163        assert_eq!(ans1_g.get_value().unwrap(), ans1_n, "Failed native test 1");
164        assert_eq!(ans2_g.get_value().unwrap(), ans2_n, "Failed native test 2");
165        assert_eq!(ans3_g.get_value().unwrap(), ans3_n, "Failed native test 3");
166
167        if !cs.is_satisfied() {
168            println!("Unsatisfied: {:?}", cs.which_is_unsatisfied());
169        }
170
171        assert!(cs.is_satisfied(), "cs is not satisfied");
172    }
173}