1use core::{fmt::Debug, marker::PhantomData};
  2
  3use crate::crh::{
  4    injective_map::{InjectiveMap, PedersenCRHCompressor, TECompressor},
  5    pedersen::{
  6        constraints::{PedersenCRHGadget, PedersenCRHGadgetParameters},
  7        PedersenWindow,
  8    },
  9    FixedLengthCRHGadget,
 10};
 11
 12use algebra_core::{
 13    curves::{
 14        models::{ModelParameters, TEModelParameters},
 15        twisted_edwards_extended::{GroupAffine as TEAffine, GroupProjective as TEProjective},
 16    },
 17    fields::{Field, PrimeField, SquareRootField},
 18    groups::Group,
 19};
 20use r1cs_core::{ConstraintSystem, SynthesisError};
 21use r1cs_std::{
 22    fields::fp::FpGadget,
 23    groups::{curves::twisted_edwards::AffineGadget as TwistedEdwardsGadget, GroupGadget},
 24    prelude::*,
 25};
 26
 27pub trait InjectiveMapGadget<
 28    G: Group,
 29    I: InjectiveMap<G>,
 30    ConstraintF: Field,
 31    GG: GroupGadget<G, ConstraintF>,
 32>
 33{
 34    type OutputGadget: EqGadget<ConstraintF>
 35        + ToBytesGadget<ConstraintF>
 36        + CondSelectGadget<ConstraintF>
 37        + AllocGadget<I::Output, ConstraintF>
 38        + Debug
 39        + Clone
 40        + Sized;
 41
 42    fn evaluate_map<CS: ConstraintSystem<ConstraintF>>(
 43        cs: CS,
 44        ge: &GG,
 45    ) -> Result<Self::OutputGadget, SynthesisError>;
 46}
 47
 48pub struct TECompressorGadget;
 49
 50impl<ConstraintF, P>
 51    InjectiveMapGadget<
 52        TEAffine<P>,
 53        TECompressor,
 54        ConstraintF,
 55        TwistedEdwardsGadget<P, ConstraintF, FpGadget<ConstraintF>>,
 56    > for TECompressorGadget
 57where
 58    ConstraintF: PrimeField + SquareRootField,
 59    P: TEModelParameters + ModelParameters<BaseField = ConstraintF>,
 60{
 61    type OutputGadget = FpGadget<ConstraintF>;
 62
 63    fn evaluate_map<CS: ConstraintSystem<ConstraintF>>(
 64        _cs: CS,
 65        ge: &TwistedEdwardsGadget<P, ConstraintF, FpGadget<ConstraintF>>,
 66    ) -> Result<Self::OutputGadget, SynthesisError> {
 67        Ok(ge.x.clone())
 68    }
 69}
 70
 71impl<ConstraintF, P>
 72    InjectiveMapGadget<
 73        TEProjective<P>,
 74        TECompressor,
 75        ConstraintF,
 76        TwistedEdwardsGadget<P, ConstraintF, FpGadget<ConstraintF>>,
 77    > for TECompressorGadget
 78where
 79    ConstraintF: PrimeField + SquareRootField,
 80    P: TEModelParameters + ModelParameters<BaseField = ConstraintF>,
 81{
 82    type OutputGadget = FpGadget<ConstraintF>;
 83
 84    fn evaluate_map<CS: ConstraintSystem<ConstraintF>>(
 85        _cs: CS,
 86        ge: &TwistedEdwardsGadget<P, ConstraintF, FpGadget<ConstraintF>>,
 87    ) -> Result<Self::OutputGadget, SynthesisError> {
 88        Ok(ge.x.clone())
 89    }
 90}
 91
 92pub struct PedersenCRHCompressorGadget<G, I, ConstraintF, GG, IG>
 93where
 94    G: Group,
 95    I: InjectiveMap<G>,
 96    ConstraintF: Field,
 97    GG: GroupGadget<G, ConstraintF>,
 98    IG: InjectiveMapGadget<G, I, ConstraintF, GG>,
 99{
100    _compressor:        PhantomData<I>,
101    _compressor_gadget: PhantomData<IG>,
102    _crh:               PedersenCRHGadget<G, ConstraintF, GG>,
103}
104
105impl<G, I, ConstraintF, GG, IG, W> FixedLengthCRHGadget<PedersenCRHCompressor<G, I, W>, ConstraintF>
106    for PedersenCRHCompressorGadget<G, I, ConstraintF, GG, IG>
107where
108    G: Group,
109    I: InjectiveMap<G>,
110    ConstraintF: Field,
111    GG: GroupGadget<G, ConstraintF>,
112    IG: InjectiveMapGadget<G, I, ConstraintF, GG>,
113    W: PedersenWindow,
114{
115    type OutputGadget = IG::OutputGadget;
116    type ParametersGadget = PedersenCRHGadgetParameters<G, W, ConstraintF, GG>;
117
118    fn check_evaluation_gadget<CS: ConstraintSystem<ConstraintF>>(
119        mut cs: CS,
120        parameters: &Self::ParametersGadget,
121        input: &[UInt8],
122    ) -> Result<Self::OutputGadget, SynthesisError> {
123        let result = PedersenCRHGadget::<G, ConstraintF, GG>::check_evaluation_gadget(
124            cs.ns(|| "PedCRH"),
125            parameters,
126            input,
127        )?;
128        IG::evaluate_map(cs.ns(|| "InjectiveMap"), &result)
129    }
130}