Update deps

Cargo.toml

@@ -11,7 +11,7 @@ repository = "https://github.com/penumbra-zone/decaf377-rdsa"
 [dependencies]
 blake2b_simd = "0.5"
 byteorder = "1.3"
-decaf377 = {default-features = false, git = "https://github.com/penumbra-zone/decaf377", rev = "c8f6a6c5e83736813e95277e82f546bff55ae90a"}
+decaf377 = {git = "https://github.com/penumbra-zone/decaf377", rev = "c8f6a6c5e83736813e95277e82f546bff55ae90a", features = ["arkworks", "r1cs"]}
 digest = "0.9"
 rand_core = "0.6"
 serde = { version = "1", optional = true, features = ["derive"] }

src/batch.rs

@@ -11,7 +11,7 @@
 use std::convert::TryFrom;
 
 use ark_ff::Zero;
-use decaf377::{Element, FieldExt, Fr};
+use decaf377::{Element, Fr};
 use rand_core::{CryptoRng, RngCore};
 
 use crate::{
@@ -190,7 +190,7 @@ impl Verifier {
                 Inner::Binding { sig, c, .. } => (sig.s_bytes(), sig.r_bytes(), c),
             };
 
-            let s = Fr::from_bytes(s_bytes).map_err(|_| Error::InvalidSignature)?;
+            let s = Fr::from_bytes_checked(&s_bytes).map_err(|_| Error::InvalidSignature)?;
             let R = decaf377::Encoding(r_bytes)
                 .vartime_decompress()
                 .map_err(|_| Error::InvalidSignature)?;

src/signing_key.rs

@@ -1,7 +1,6 @@
 use std::convert::{TryFrom, TryInto};
 
-use ark_ff::PrimeField;
-use decaf377::{FieldExt, Fr};
+use decaf377::Fr;
 use rand_core::{CryptoRng, RngCore};
 
 use crate::{Binding, Domain, Error, Signature, SpendAuth, VerificationKey};

src/verification_key.rs

@@ -5,7 +5,7 @@ use std::{
     marker::PhantomData,
 };
 
-use decaf377::{FieldExt, Fr};
+use decaf377::Fr;
 
 use crate::{domain::Sealed, Binding, Domain, Error, Signature, SpendAuth};
 
@@ -222,7 +222,8 @@ impl<D: Domain> VerificationKey<D> {
             .vartime_decompress()
             .map_err(|_| Error::InvalidSignature)?;
 
-        let s = Fr::from_bytes(signature.s_bytes()).map_err(|_| Error::InvalidSignature)?;
+        let s =
+            Fr::from_bytes_checked(&signature.s_bytes()).map_err(|_| Error::InvalidSignature)?;
 
         // XXX rewrite as normal double scalar mul
         // Verify check is h * ( - s * B + R  + c * A) == 0