digest: add implementations of the AssociatedOid trait

.github/workflows/digest.yml

@@ -50,7 +50,7 @@ jobs:
     strategy:
       matrix:
         rust:
-          - 1.41.0 # MSRV
+          # - 1.41.0 # MSRV
           - stable
     steps:
       - uses: actions/checkout@v2
@@ -60,12 +60,33 @@ jobs:
           toolchain: ${{ matrix.rust }}
           override: true
           profile: minimal
-      # Isolate this crate from workspace which is otherwise MSRV 1.56 due to 2021 edition crates
-      - run: rm ../Cargo.toml
       - run: cargo check --all-features
       - run: cargo test --no-default-features
       - run: cargo test
       - run: cargo test --features dev
       - run: cargo test --features alloc
       - run: cargo test --features std
       - run: cargo test --all-features
+
+  # The `oid` feature bumps MSRV to 1.57, so we temporarily split this job.
+  test-msrv:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        rust:
+          - 1.41.0 # MSRV
+    steps:
+      - uses: actions/checkout@v2
+      - uses: RustCrypto/actions/cargo-cache@master
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: ${{ matrix.rust }}
+          override: true
+          profile: minimal
+      # Isolate this crate from workspace which is otherwise MSRV 1.56 due to 2021 edition crates
+      - run: rm ../Cargo.toml
+      - run: cargo test --no-default-features
+      - run: cargo test
+      - run: cargo test --features dev
+      - run: cargo test --features alloc
+      - run: cargo test --features std

digest/CHANGELOG.md

@@ -5,6 +5,13 @@ 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).
 
+## 0.10.4 (2022-09-16)
+### Added
+- Feature-gated implementation of the `const_oid::AssociatedOid` trait
+for the core wrappers. ([#1098])
+
+[#1098]: https://github.com/RustCrypto/traits/pull/1098
+
 ## 0.10.3 (2022-02-16)
 ### Fixed
 - Minimal versions build ([#940])

digest/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "digest"
 description = "Traits for cryptographic hash functions"
-version = "0.10.3" # Also update html_root_url in lib.rs when bumping this
+version = "0.10.4"
 authors = ["RustCrypto Developers"]
 license = "MIT OR Apache-2.0"
 readme = "README.md"
@@ -18,12 +18,14 @@ crypto-common = { version = "0.1.3", path = "../crypto-common" }
 block-buffer = { version = "0.10", optional = true }
 subtle = { version = "=2.4", default-features = false, optional = true }
 blobby = { version = "0.3", optional = true }
+const-oid = { version = "0.9", optional = true }
 
 [features]
 default = ["core-api"]
 core-api = ["block-buffer"] # Enable Core API traits
 mac = ["subtle"] # Enable MAC traits
 rand_core = ["crypto-common/rand_core"] # Enable random key generation methods
+oid = ["const-oid"] # OID support. WARNING: Bumps MSRV to 1.57
 alloc = []
 std = ["alloc", "crypto-common/std"]
 dev = ["blobby"]

digest/src/core_api/ct_variable.rs

@@ -5,17 +5,24 @@ use super::{
 use crate::HashMarker;
 #[cfg(feature = "mac")]
 use crate::MacMarker;
+#[cfg(feature = "oid")]
+use const_oid::{AssociatedOid, ObjectIdentifier};
 use core::{fmt, marker::PhantomData};
 use crypto_common::{
     generic_array::{ArrayLength, GenericArray},
     typenum::{IsLess, IsLessOrEqual, Le, LeEq, NonZero, U256},
     Block, BlockSizeUser, OutputSizeUser,
 };
 
+/// Dummy type used with [`CtVariableCoreWrapper`] in cases when
+/// resulting hash does not have a known OID.
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
+pub struct NoOid;
+
 /// Wrapper around [`VariableOutputCore`] which selects output size
 /// at compile time.
 #[derive(Clone)]
-pub struct CtVariableCoreWrapper<T, OutSize>
+pub struct CtVariableCoreWrapper<T, OutSize, O = NoOid>
 where
     T: VariableOutputCore,
     OutSize: ArrayLength<u8> + IsLessOrEqual<T::OutputSize>,
@@ -24,10 +31,10 @@ where
     Le<T::BlockSize, U256>: NonZero,
 {
     inner: T,
-    _out: PhantomData<OutSize>,
+    _out: PhantomData<(OutSize, O)>,
 }
 
-impl<T, OutSize> HashMarker for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize, O> HashMarker for CtVariableCoreWrapper<T, OutSize, O>
 where
     T: VariableOutputCore + HashMarker,
     OutSize: ArrayLength<u8> + IsLessOrEqual<T::OutputSize>,
@@ -38,7 +45,7 @@ where
 }
 
 #[cfg(feature = "mac")]
-impl<T, OutSize> MacMarker for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize, O> MacMarker for CtVariableCoreWrapper<T, OutSize, O>
 where
     T: VariableOutputCore + MacMarker,
     OutSize: ArrayLength<u8> + IsLessOrEqual<T::OutputSize>,
@@ -48,7 +55,7 @@ where
 {
 }
 
-impl<T, OutSize> BlockSizeUser for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize, O> BlockSizeUser for CtVariableCoreWrapper<T, OutSize, O>
 where
     T: VariableOutputCore,
     OutSize: ArrayLength<u8> + IsLessOrEqual<T::OutputSize>,
@@ -59,7 +66,7 @@ where
     type BlockSize = T::BlockSize;
 }
 
-impl<T, OutSize> UpdateCore for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize, O> UpdateCore for CtVariableCoreWrapper<T, OutSize, O>
 where
     T: VariableOutputCore,
     OutSize: ArrayLength<u8> + IsLessOrEqual<T::OutputSize>,
@@ -73,7 +80,7 @@ where
     }
 }
 
-impl<T, OutSize> OutputSizeUser for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize, O> OutputSizeUser for CtVariableCoreWrapper<T, OutSize, O>
 where
     T: VariableOutputCore,
     OutSize: ArrayLength<u8> + IsLessOrEqual<T::OutputSize> + 'static,
@@ -84,7 +91,7 @@ where
     type OutputSize = OutSize;
 }
 
-impl<T, OutSize> BufferKindUser for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize, O> BufferKindUser for CtVariableCoreWrapper<T, OutSize, O>
 where
     T: VariableOutputCore,
     OutSize: ArrayLength<u8> + IsLessOrEqual<T::OutputSize>,
@@ -95,7 +102,7 @@ where
     type BufferKind = T::BufferKind;
 }
 
-impl<T, OutSize> FixedOutputCore for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize, O> FixedOutputCore for CtVariableCoreWrapper<T, OutSize, O>
 where
     T: VariableOutputCore,
     OutSize: ArrayLength<u8> + IsLessOrEqual<T::OutputSize> + 'static,
@@ -120,7 +127,7 @@ where
     }
 }
 
-impl<T, OutSize> Default for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize, O> Default for CtVariableCoreWrapper<T, OutSize, O>
 where
     T: VariableOutputCore,
     OutSize: ArrayLength<u8> + IsLessOrEqual<T::OutputSize>,
@@ -137,7 +144,7 @@ where
     }
 }
 
-impl<T, OutSize> Reset for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize, O> Reset for CtVariableCoreWrapper<T, OutSize, O>
 where
     T: VariableOutputCore,
     OutSize: ArrayLength<u8> + IsLessOrEqual<T::OutputSize>,
@@ -151,7 +158,7 @@ where
     }
 }
 
-impl<T, OutSize> AlgorithmName for CtVariableCoreWrapper<T, OutSize>
+impl<T, OutSize, O> AlgorithmName for CtVariableCoreWrapper<T, OutSize, O>
 where
     T: VariableOutputCore + AlgorithmName,
     OutSize: ArrayLength<u8> + IsLessOrEqual<T::OutputSize>,
@@ -165,3 +172,33 @@ where
         write!(f, "{}", OutSize::USIZE)
     }
 }
+
+#[cfg(feature = "oid")]
+#[cfg_attr(docsrs, doc(cfg(feature = "oid")))]
+impl<T, OutSize, O> AssociatedOid for CtVariableCoreWrapper<T, OutSize, O>
+where
+    T: VariableOutputCore,
+    O: AssociatedOid,
+    OutSize: ArrayLength<u8> + IsLessOrEqual<T::OutputSize>,
+    LeEq<OutSize, T::OutputSize>: NonZero,
+    T::BlockSize: IsLess<U256>,
+    Le<T::BlockSize, U256>: NonZero,
+{
+    const OID: ObjectIdentifier = O::OID;
+}
+
+/// Implement dummy type with hidden docs which is used to "carry" hasher
+/// OID for [`CtVariableCoreWrapper`].
+#[macro_export]
+macro_rules! impl_oid_carrier {
+    ($name:ident, $oid:literal) => {
+        #[doc(hidden)]
+        #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
+        pub struct $name;
+
+        #[cfg(feature = "oid")]
+        impl AssociatedOid for $name {
+            const OID: ObjectIdentifier = ObjectIdentifier::new_unwrap($oid);
+        }
+    };
+}

digest/src/core_api/wrapper.rs

@@ -14,6 +14,8 @@ use crypto_common::{
 
 #[cfg(feature = "mac")]
 use crate::MacMarker;
+#[cfg(feature = "oid")]
+use const_oid::{AssociatedOid, ObjectIdentifier};
 
 /// Wrapper around [`BufferKindUser`].
 ///
@@ -227,6 +229,17 @@ where
     }
 }
 
+#[cfg(feature = "oid")]
+#[cfg_attr(docsrs, doc(cfg(feature = "oid")))]
+impl<T> AssociatedOid for CoreWrapper<T>
+where
+    T: BufferKindUser + AssociatedOid,
+    T::BlockSize: IsLess<U256>,
+    Le<T::BlockSize, U256>: NonZero,
+{
+    const OID: ObjectIdentifier = T::OID;
+}
+
 #[cfg(feature = "std")]
 #[cfg_attr(docsrs, doc(cfg(feature = "std")))]
 impl<T> std::io::Write for CoreWrapper<T>