1use core::{fmt::Debug, marker::PhantomData};
 2
 3use crate::crh::{
 4    injective_map::{InjectiveMap, PedersenCRHCompressor, TECompressor},
 5    pedersen::{constraints as ped_constraints, Window},
 6    FixedLengthCRHGadget,
 7};
 8
 9use algebra_core::{
10    curves::{
11        models::{ModelParameters, TEModelParameters},
12        twisted_edwards_extended::GroupProjective as TEProjective,
13    },
14    fields::{Field, PrimeField, SquareRootField},
15    ProjectiveCurve,
16};
17use r1cs_core::SynthesisError;
18use r1cs_std::{
19    fields::fp::FpVar,
20    groups::{curves::twisted_edwards::AffineVar as TEVar, CurveVar},
21    prelude::*,
22};
23
24type ConstraintF<C> = <<C as ProjectiveCurve>::BaseField as Field>::BasePrimeField;
25
26pub trait InjectiveMapGadget<
27    C: ProjectiveCurve,
28    I: InjectiveMap<C>,
29    GG: CurveVar<C, ConstraintF<C>>,
30> where
31    for<'a> &'a GG: GroupOpsBounds<'a, C, GG>,
32{
33    type OutputVar: EqGadget<ConstraintF<C>>
34        + ToBytesGadget<ConstraintF<C>>
35        + CondSelectGadget<ConstraintF<C>>
36        + AllocVar<I::Output, ConstraintF<C>>
37        + R1CSVar<ConstraintF<C>, Value = I::Output>
38        + Debug
39        + Clone
40        + Sized;
41
42    fn evaluate(ge: &GG) -> Result<Self::OutputVar, SynthesisError>;
43}
44
45pub struct TECompressorGadget;
46
47impl<F, P> InjectiveMapGadget<TEProjective<P>, TECompressor, TEVar<P, FpVar<F>>>
48    for TECompressorGadget
49where
50    F: PrimeField + SquareRootField,
51    P: TEModelParameters + ModelParameters<BaseField = F>,
52{
53    type OutputVar = FpVar<F>;
54
55    fn evaluate(ge: &TEVar<P, FpVar<F>>) -> Result<Self::OutputVar, SynthesisError> {
56        Ok(ge.x.clone())
57    }
58}
59
60pub struct PedersenCRHCompressorGadget<C, I, W, GG, IG>
61where
62    C: ProjectiveCurve,
63    I: InjectiveMap<C>,
64    W: Window,
65    GG: CurveVar<C, ConstraintF<C>>,
66    for<'a> &'a GG: GroupOpsBounds<'a, C, GG>,
67    IG: InjectiveMapGadget<C, I, GG>,
68{
69    #[doc(hidden)]
70    _compressor: PhantomData<I>,
71    #[doc(hidden)]
72    _compressor_gadget: PhantomData<IG>,
73    #[doc(hidden)]
74    _crh: ped_constraints::CRHGadget<C, GG, W>,
75}
76
77impl<C, I, GG, IG, W> FixedLengthCRHGadget<PedersenCRHCompressor<C, I, W>, ConstraintF<C>>
78    for PedersenCRHCompressorGadget<C, I, W, GG, IG>
79where
80    C: ProjectiveCurve,
81    I: InjectiveMap<C>,
82    GG: CurveVar<C, ConstraintF<C>>,
83    for<'a> &'a GG: GroupOpsBounds<'a, C, GG>,
84    IG: InjectiveMapGadget<C, I, GG>,
85    W: Window,
86{
87    type OutputVar = IG::OutputVar;
88    type ParametersVar = ped_constraints::CRHParametersVar<C, GG>;
89
90    fn evaluate(
91        parameters: &Self::ParametersVar,
92        input: &[UInt8<ConstraintF<C>>],
93    ) -> Result<Self::OutputVar, SynthesisError> {
94        let result = ped_constraints::CRHGadget::<C, GG, W>::evaluate(parameters, input)?;
95        IG::evaluate(&result)
96    }
97}