digest: remove Clone from MacTraits (#2341)

tarcieri · web-flow · commit 84476d3c0d00 · 2026-03-13T14:51:37.000+03:00
NOTE: this is a breaking change! We are doing it in spite of `digest`
having a stable release as the downstream crates that depend on this
functionality have not yet had stable releases, so it should only impact
people who are currently relying on prereleases
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/Cargo.toml b/Cargo.toml
@@ -57,3 +57,4 @@ unused_qualifications = "warn"
 crypto-common = { path = "crypto-common" }
 digest = { path = "digest" }
 signature = { path = "signature" }
+hmac = { git = "https://github.com/RustCrypto/MACs" }
diff --git a/digest/CHANGELOG.md b/digest/CHANGELOG.md
@@ -5,7 +5,17 @@ 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).
 
-## 0.11.1 (2026-02-25)
+## 0.11.2 (UNRELEASED)
+### Changed
+- Do not implement `Clone` as part of `(Reset)MacTraits` in the `buffer_fixed!` macro ([#2341])
+- `EagerHash` trait to be a sub-trait of `Clone` ([#2341])
+
+[#2341]: https://github.com/RustCrypto/traits/pull/2341
+
+## 0.11.1 (2026-02-25) [YANKED]
+Note: this version was yanked because v0.11.2 introduces minor breaking changes
+affecting only pre-release versions of downstream crates.
+
 ### Added
 - `SmallBlockSizeUser` helper trait. The trait is a sub-trait of `BlockSizeUser`
   with `BlockSize` bounded by `block_buffer::BlockSizes`. ([#2309])
diff --git a/digest/src/block_api.rs b/digest/src/block_api.rs
@@ -52,7 +52,7 @@ pub trait BufferKindUser: SmallBlockSizeUser {
 }
 
 /// Trait implemented by eager hashes which expose their block-level core.
-pub trait EagerHash: SmallBlockSizeUser + Digest {
+pub trait EagerHash: SmallBlockSizeUser + Digest + Clone {
     /// Block-level core type of the hash.
     type Core: HashMarker
         + UpdateCore
@@ -65,7 +65,7 @@ pub trait EagerHash: SmallBlockSizeUser + Digest {
 
 impl<T> EagerHash for T
 where
-    T: CoreProxy + SmallBlockSizeUser + Digest,
+    T: CoreProxy + SmallBlockSizeUser + Digest + Clone,
     <T as CoreProxy>::Core: HashMarker
         + UpdateCore
         + FixedOutputCore
diff --git a/digest/src/buffer_macros/fixed.rs b/digest/src/buffer_macros/fixed.rs
@@ -65,8 +65,7 @@ macro_rules! buffer_fixed {
     };
 
     // Implements the set of traits common for MAC functions:
-    // `Debug`, `BlockSizeUser`, `OutputSizeUser`, `CoreProxy`, `Update`, `FixedOutput`,
-    // `Clone`, `MacMarker`.
+    // `Debug`, `BlockSizeUser`, `OutputSizeUser`, `CoreProxy`, `Update`, `FixedOutput`, `MacMarker`
     (
         impl_inner: $name:ident
         $(< $( $lt:tt $( : $clt:tt $(+ $dlt:tt )* )? ),+ >)?
@@ -75,13 +74,13 @@ macro_rules! buffer_fixed {
     ) => {
         $crate::buffer_fixed!(
             impl_inner: $name$(< $( $lt $( : $clt $(+ $dlt )* )? ),+ >)?($core_ty);
-            BaseFixedTraits Clone MacMarker $($trait_name)*;
+            BaseFixedTraits MacMarker $($trait_name)*;
         );
     };
 
     // Implements the set of traits common for resettable MAC functions:
     // `Debug`, `BlockSizeUser`, `OutputSizeUser`, `CoreProxy`, `Update`, `FixedOutput`,
-    // `Clone`, `MacMarker`, `Reset`, `FixedOutputReset`.
+    // `MacMarker`, `Reset`, `FixedOutputReset`.
     (
         impl_inner: $name:ident
         $(< $( $lt:tt $( : $clt:tt $(+ $dlt:tt )* )? ),+ >)?
