Implement ZeroizeOnDrop for buffer_ct_variable wrappers

blake2/CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+### Fixed
+- Implement `ZeroizeOnDrop` for `Blake2b`/`Blake2s` wrappers ([#912])
+
 ## 0.11.0 (2026-08-26)
 ### Added
 - `zeroize` support ([#545])

blake2/src/lib.rs

@@ -73,6 +73,13 @@ where
     }
 }
 
+// TODO: impl in the `buffer_ct_variable!` macro (as `buffer_fixed!` already does)
+#[cfg(feature = "zeroize")]
+impl<OutSize> ZeroizeOnDrop for Blake2b<OutSize> where
+    OutSize: ArraySize + IsLessOrEqual<U64, Output = True>
+{
+}
+
 /// BLAKE2b-128 hasher state.
 pub type Blake2b128 = Blake2b<U16>;
 /// BLAKE2b-256 hasher state.
@@ -121,6 +128,13 @@ where
     }
 }
 
+// TODO: impl in the `buffer_ct_variable!` macro (as `buffer_fixed!` already does)
+#[cfg(feature = "zeroize")]
+impl<OutSize> ZeroizeOnDrop for Blake2s<OutSize> where
+    OutSize: ArraySize + IsLessOrEqual<U32, Output = True>
+{
+}
+
 /// BLAKE2s-128 hasher state.
 pub type Blake2s128 = Blake2s<U16>;
 /// BLAKE2s-256 hasher state.
@@ -130,3 +144,21 @@ blake2_mac_impl!(Blake2sMac, Blake2sVarCore, U32, "Blake2s MAC function");
 
 /// BLAKE2s-256 MAC state.
 pub type Blake2sMac256 = Blake2sMac<U32>;
+
+#[cfg(all(test, feature = "zeroize"))]
+mod zeroize_on_drop {
+    use super::*;
+
+    fn assert_zeroize_on_drop<T: ZeroizeOnDrop>() {}
+
+    #[test]
+    fn wrappers_impl_zeroize_on_drop() {
+        assert_zeroize_on_drop::<Blake2b128>();
+        assert_zeroize_on_drop::<Blake2b256>();
+        assert_zeroize_on_drop::<Blake2b512>();
+        assert_zeroize_on_drop::<Blake2s128>();
+        assert_zeroize_on_drop::<Blake2s256>();
+        assert_zeroize_on_drop::<Blake2bMac512>();
+        assert_zeroize_on_drop::<Blake2sMac256>();
+    }
+}

groestl/CHANGELOG.md

@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+### Fixed
+- Implement `ZeroizeOnDrop` for `GroestlShort`/`GroestlLong` wrappers
+
 ## 0.11.0 (2026-03-27)
 ### Added
 - `alloc` crate feature ([#678])

groestl/src/lib.rs

@@ -18,6 +18,12 @@ mod compress_short;
 mod table;
 
 use digest::consts::{U28, U32, U48, U64};
+#[cfg(feature = "zeroize")]
+use digest::{
+    array::ArraySize,
+    typenum::{IsLessOrEqual, True},
+    zeroize::ZeroizeOnDrop,
+};
 
 digest::buffer_ct_variable!(
     /// Short Groestl variant generic over output size.
@@ -30,6 +36,20 @@ digest::buffer_ct_variable!(
     max_size: U64;
 );
 
+// TODO: impl in the `buffer_ct_variable!` macro (as `buffer_fixed!` already does)
+#[cfg(feature = "zeroize")]
+impl<OutSize> ZeroizeOnDrop for GroestlShort<OutSize> where
+    OutSize: ArraySize + IsLessOrEqual<U32, Output = True>
+{
+}
+
+// TODO: impl in the `buffer_ct_variable!` macro (as `buffer_fixed!` already does)
+#[cfg(feature = "zeroize")]
+impl<OutSize> ZeroizeOnDrop for GroestlLong<OutSize> where
+    OutSize: ArraySize + IsLessOrEqual<U64, Output = True>
+{
+}
+
 /// Groestl-224 hasher.
 pub type Groestl224 = GroestlShort<U28>;
 /// Groestl-256 hasher.
@@ -39,3 +59,18 @@ pub type Groestl256 = GroestlShort<U32>;
 pub type Groestl384 = GroestlLong<U48>;
 /// Groestl-512 hasher.
 pub type Groestl512 = GroestlLong<U64>;
+
+#[cfg(all(test, feature = "zeroize"))]
+mod zeroize_on_drop {
+    use super::*;
+
+    fn assert_zeroize_on_drop<T: ZeroizeOnDrop>() {}
+
+    #[test]
+    fn wrappers_impl_zeroize_on_drop() {
+        assert_zeroize_on_drop::<Groestl224>();
+        assert_zeroize_on_drop::<Groestl256>();
+        assert_zeroize_on_drop::<Groestl384>();
+        assert_zeroize_on_drop::<Groestl512>();
+    }
+}

kupyna/CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+### Fixed
+- Implement `ZeroizeOnDrop` for `KupynaShort`/`KupynaLong` wrappers
+
 ## 0.1.0 (2026-03-27)
 - Initial release ([#621])
 

kupyna/src/lib.rs

@@ -19,6 +19,12 @@ mod table;
 pub(crate) mod utils;
 
 use digest::consts::{U28, U32, U48, U64};
+#[cfg(feature = "zeroize")]
+use digest::{
+    array::ArraySize,
+    typenum::{IsLessOrEqual, True},
+    zeroize::ZeroizeOnDrop,
+};
 
 digest::buffer_ct_variable!(
     /// Short Kupyna variant generic over output size.
@@ -31,6 +37,20 @@ digest::buffer_ct_variable!(
     max_size: U64;
 );
 
+// TODO: impl in the `buffer_ct_variable!` macro (as `buffer_fixed!` already does)
+#[cfg(feature = "zeroize")]
+impl<OutSize> ZeroizeOnDrop for KupynaShort<OutSize> where
+    OutSize: ArraySize + IsLessOrEqual<U32, Output = True>
+{
+}
+
+// TODO: impl in the `buffer_ct_variable!` macro (as `buffer_fixed!` already does)
+#[cfg(feature = "zeroize")]
+impl<OutSize> ZeroizeOnDrop for KupynaLong<OutSize> where
+    OutSize: ArraySize + IsLessOrEqual<U64, Output = True>
+{
+}
+
 /// Kupyna-224 hasher.
 pub type Kupyna224 = KupynaShort<U28>;
 /// Kupyna-256 hasher.
@@ -39,3 +59,18 @@ pub type Kupyna256 = KupynaShort<U32>;
 pub type Kupyna384 = KupynaLong<U48>;
 /// Kupyna-512 hasher.
 pub type Kupyna512 = KupynaLong<U64>;
+
+#[cfg(all(test, feature = "zeroize"))]
+mod zeroize_on_drop {
+    use super::*;
+
+    fn assert_zeroize_on_drop<T: ZeroizeOnDrop>() {}
+
+    #[test]
+    fn wrappers_impl_zeroize_on_drop() {
+        assert_zeroize_on_drop::<Kupyna224>();
+        assert_zeroize_on_drop::<Kupyna256>();
+        assert_zeroize_on_drop::<Kupyna384>();
+        assert_zeroize_on_drop::<Kupyna512>();
+    }
+}