Add ToConstraintField impls for some primitives

crypto-primitives/src/commitment/injective_map/constraints.rs

@@ -16,13 +16,15 @@ use r1cs_std::{groups::GroupGadget, uint8::UInt8};
 
 use std::marker::PhantomData;
 
-pub struct PedersenCommitmentCompressorGadget<
+pub struct PedersenCommitmentCompressorGadget<G, I, ConstraintF, GG, IG>
+where
     G: Group,
     I: InjectiveMap<G>,
     ConstraintF: Field,
     GG: GroupGadget<G, ConstraintF>,
     IG: InjectiveMapGadget<G, I, ConstraintF, GG>,
-> {
+
+{
     _compressor:        PhantomData<I>,
     _compressor_gadget: PhantomData<IG>,
     _crh:               PedersenCommitmentGadget<G, ConstraintF, GG>,

crypto-primitives/src/commitment/pedersen/mod.rs

@@ -1,10 +1,12 @@
 use crate::Error;
 use algebra::UniformRand;
+use algebra::{Field, ToConstraintField};
+use algebra::{bytes::ToBytes, groups::Group, BitIterator, FpParameters, PrimeField};
+
 use rand::Rng;
 use std::marker::PhantomData;
 
 use super::CommitmentScheme;
-use algebra::{bytes::ToBytes, groups::Group, BitIterator, FpParameters, PrimeField};
 use std::io::{Result as IoResult, Write};
 
 pub use crate::crh::pedersen::PedersenWindow;
@@ -121,3 +123,11 @@ impl<G: Group, W: PedersenWindow> CommitmentScheme for PedersenCommitment<G, W>
         Ok(result)
     }
 }
+
+
+impl<ConstraintF: Field, G: Group + ToConstraintField<ConstraintF>> ToConstraintField<ConstraintF> for PedersenParameters<G> {
+    #[inline]
+    fn to_field_elements(&self) -> Result<Vec<ConstraintF>, Error> {
+        Ok(Vec::new())
+    }
+}

crypto-primitives/src/crh/injective_map/constraints.rs

@@ -24,8 +24,7 @@ use r1cs_std::{
     prelude::*,
 };
 
-pub trait InjectiveMapGadget<G: Group, I: InjectiveMap<G>, ConstraintF: Field, GG: GroupGadget<G, ConstraintF>>
-{
+pub trait InjectiveMapGadget<G: Group, I: InjectiveMap<G>, ConstraintF: Field, GG: GroupGadget<G, ConstraintF>> {
     type OutputGadget: EqGadget<ConstraintF>
         + ToBytesGadget<ConstraintF>
         + CondSelectGadget<ConstraintF>
@@ -75,13 +74,14 @@ where
     }
 }
 
-pub struct PedersenCRHCompressorGadget<
+pub struct PedersenCRHCompressorGadget<G, I, ConstraintF, GG, IG>
+where
     G: Group,
     I: InjectiveMap<G>,
     ConstraintF: Field,
     GG: GroupGadget<G, ConstraintF>,
     IG: InjectiveMapGadget<G, I, ConstraintF, GG>,
-> {
+{
     _compressor:        PhantomData<I>,
     _compressor_gadget: PhantomData<IG>,
     _crh:               PedersenCRHGadget<G, ConstraintF, GG>,

crypto-primitives/src/crh/pedersen/constraints.rs

@@ -1,10 +1,9 @@
-use algebra::Field;
 
 use crate::crh::{
     FixedLengthCRHGadget,
     pedersen::{PedersenCRH, PedersenParameters, PedersenWindow},
 };
-use algebra::groups::Group;
+use algebra::{Field, Group};
 use r1cs_core::{ConstraintSystem, SynthesisError};
 use r1cs_std::prelude::*;
 

crypto-primitives/src/crh/pedersen/mod.rs

@@ -7,6 +7,7 @@ use std::{
 };
 
 use crate::crh::FixedLengthCRH;
+use algebra::{Field, ToConstraintField};
 use algebra::groups::Group;
 
 
@@ -139,3 +140,11 @@ impl<G: Group> Debug for PedersenParameters<G> {
         write!(f, "}}\n")
     }
 }
+
+
+impl<ConstraintF: Field, G: Group + ToConstraintField<ConstraintF>> ToConstraintField<ConstraintF> for PedersenParameters<G> {
+    #[inline]
+    fn to_field_elements(&self) -> Result<Vec<ConstraintF>, Error> {
+        Ok(Vec::new())
+    }
+}

crypto-primitives/src/mht/constraints.rs

@@ -28,13 +28,12 @@ where
     _f: PhantomData<ConstraintF>,
 }
 
-impl<P, CRHGadget, ConstraintF>  MerklePathVerifierGadget<P, CRHGadget, ConstraintF>
+impl<P, CRHGadget, ConstraintF> MerklePathVerifierGadget<P, CRHGadget, ConstraintF>
 where
     P: MHTParameters,
     ConstraintF: Field,
     CRHGadget: FixedLengthCRHGadget<P::H, ConstraintF>,
 {
-
     pub fn check_membership<CS: ConstraintSystem<ConstraintF>>(
         cs: CS,
         parameters: &CRHGadget::ParametersGadget,

crypto-primitives/src/signature/schnorr/mod.rs

@@ -1,5 +1,6 @@
 use crate::SignatureScheme;
 use algebra::{
+    ToConstraintField,
     bytes::ToBytes,
     fields::{Field, PrimeField},
     groups::Group,
@@ -221,3 +222,12 @@ pub fn bytes_to_bits(bytes: &[u8]) -> Vec<bool> {
     }
     bits
 }
+
+impl<ConstraintF: Field, G: Group + ToConstraintField<ConstraintF>, D: Digest> ToConstraintField<ConstraintF>
+    for SchnorrSigParameters<G, D>
+{
+    #[inline]
+    fn to_field_elements(&self) -> Result<Vec<ConstraintF>, Error> {
+        self.generator.to_field_elements()
+    }
+}