Implement Zeroize for scalars and points

.github/workflows/dusk_ci.yml

@@ -18,6 +18,8 @@ jobs:
   test_nightly_std:
     name: Nightly tests std
     uses: dusk-network/.github/.github/workflows/run-tests.yml@main
+    with:
+      test_flags: --features=zeroize
 
   test_nightly_no_std:
     name: Nightly tests no_std

CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Added
+
+- Add `Zeroize` trait for `JubJubScalar`, `JubJubAffine` and `JubJubExtended` [#135]
+- Add `zeroize` optional dependency [#135]
+
 ## [0.14.0] - 2023-12-13
 
 ### Removed
@@ -214,6 +219,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Initial fork from [`zkcrypto/jubjub`]
 
 <!-- ISSUES -->
+[#135]: https://github.com/dusk-network/jubjub/issues/135
 [#129]: https://github.com/dusk-network/jubjub/issues/129
 [#127]: https://github.com/dusk-network/jubjub/issues/127
 [#126]: https://github.com/dusk-network/jubjub/issues/126

Cargo.toml

@@ -61,6 +61,11 @@ version = "0.1"
 version = "0.7"
 optional = true
 default-features = false
+
+[dependencies.zeroize]
+version = "1"
+optional = true
+default-features = false
 # End Dusk dependendencies
 
 [dev-dependencies]

src/dusk.rs

@@ -16,6 +16,12 @@ use dusk_bytes::{Error as BytesError, Serializable};
 
 use crate::{Fr, JubJubAffine, JubJubExtended, EDWARDS_D};
 
+#[cfg(feature = "zeroize")]
+impl zeroize::DefaultIsZeroes for JubJubAffine {}
+
+#[cfg(feature = "zeroize")]
+impl zeroize::DefaultIsZeroes for JubJubExtended {}
+
 /// Compute a shared secret `secret · public` using DHKE protocol
 pub fn dhke(secret: &Fr, public: &JubJubExtended) -> JubJubAffine {
     public.mul(secret).into()
@@ -341,3 +347,17 @@ mod fuzz {
         }
     }
 }
+
+#[cfg(feature = "zeroize")]
+#[test]
+fn test_zeroize() {
+    use zeroize::Zeroize;
+
+    let mut point: JubJubAffine = GENERATOR;
+    point.zeroize();
+    assert!(bool::from(point.is_identity()));
+
+    let mut point: JubJubExtended = GENERATOR_EXTENDED;
+    point.zeroize();
+    assert!(bool::from(point.is_identity()));
+}

src/fr/dusk.rs

@@ -14,6 +14,9 @@ use dusk_bytes::{Error as BytesError, Serializable};
 use super::{Fr, MODULUS, R2};
 use crate::util::sbb;
 
+#[cfg(feature = "zeroize")]
+impl zeroize::DefaultIsZeroes for Fr {}
+
 impl Fr {
     /// Creates a `Fr` from arbitrary bytes by hashing the input with BLAKE2b
     /// into a 512-bits number, and then converting the number into its scalar
@@ -353,3 +356,13 @@ mod fuzz {
         }
     }
 }
+
+#[cfg(feature = "zeroize")]
+#[test]
+fn test_zeroize() {
+    use zeroize::Zeroize;
+
+    let mut scalar = Fr::one();
+    scalar.zeroize();
+    assert_eq!(scalar, Fr::zero());
+}