Add GHA, small clean

.github/workflows/rust.yml

@@ -0,0 +1,13 @@
+name: Test
+on: [push, pull_request]
+env:
+  CARGO_TERM_COLOR: always
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Build
+      run: cargo build --verbose
+    - name: Run tests
+      run: cargo test --verbose

.travis.yml

@@ -1,9 +0,0 @@
-language: rust
-rust:
-- stable
-
-cache:
-- cargo
-
-script:
-- RUST_BACKTRACE=1 cargo test --all

README.md

@@ -1,4 +1,4 @@
-# mimc-rs [![Crates.io](https://img.shields.io/crates/v/mimc-rs.svg)](https://crates.io/crates/mimc-rs) [![Build Status](https://travis-ci.org/arnaucube/mimc-rs.svg?branch=master)](https://travis-ci.org/arnaucube/mimc-rs)
+# mimc-rs [![Crates.io](https://img.shields.io/crates/v/mimc-rs.svg)](https://crates.io/crates/mimc-rs) [![Test](https://github.com/arnaucube/mimc-rs/workflows/Test/badge.svg)](https://github.com/arnaucube/mimc-rs/actions?query=workflow%3ATest)
 MIMC7 hash implementation in Rust, a zkSNARK friendly hash function.
 
 https://eprint.iacr.org/2016/492.pdf

benches/bench_mimc_hash.rs

@@ -20,7 +20,7 @@ fn criterion_benchmark(c: &mut Criterion) {
     big_arr.push(b2.clone());
     let mimc7 = Mimc7::new();
 
-    c.bench_function("hash", |b| b.iter(|| mimc7.hash(big_arr.clone()).unwrap()));
+    c.bench_function("hash", |b| b.iter(|| mimc7.hash(big_arr.clone())));
 }
 
 criterion_group!(benches, criterion_benchmark);

gen_constants/src/main.rs

@@ -90,9 +90,6 @@ fn main() {
         println!("  {:?},", c.cts[i].to_string());
     }
     println!("];");
-    println!("let r: Fr = Fr::from_str(");
-    println!("  {:?},", c.r.to_string());
-    println!(").unwrap();");
     println!("let n_rounds: i64 = {:?};", c.n_rounds);
 }
 

src/lib.rs

@@ -9,7 +9,6 @@ use ff::*;
 pub struct Fr(FrRepr);
 
 pub struct Constants {
-    r: Fr,
     n_rounds: i64,
     cts: Vec<Fr>,
 }
@@ -109,10 +108,6 @@ pub fn load_constants() -> Constants {
         "18979889247746272055963929241596362599320706910852082477600815822482192194401",
         "13602139229813231349386885113156901793661719180900395818909719758150455500533",
     ];
-    let r: Fr = Fr::from_str(
-        "21888242871839275222246405745257275088548364400416034343698204186575808495617",
-    )
-    .unwrap();
     let n_rounds: i64 = 91;
 
     let mut cts: Vec<Fr> = Vec::new();
@@ -121,7 +116,6 @@ pub fn load_constants() -> Constants {
         cts.push(n);
     }
     Constants {
-        r: r,
         n_rounds: n_rounds,
         cts: cts,
     }
@@ -159,14 +153,13 @@ impl Mimc7 {
                 t.add_assign(&k);
                 t.add_assign(&self.constants.cts[i]);
             }
-            let mut t5 = t.clone();
-            t5.mul_assign(&t);
-            t5.mul_assign(&t);
-            t5.mul_assign(&t);
-            t5.mul_assign(&t);
-            t5.mul_assign(&t);
-            t5.mul_assign(&t);
-            h = t5.clone();
+            let mut t2 = t.clone();
+            t2.square();
+            let mut t7 = t2.clone();
+            t7.square();
+            t7.mul_assign(&t2);
+            t7.mul_assign(&t);
+            h = t7.clone();
         }
         h.add_assign(&k);
         h