x

Signed-off-by: Eric Lagergren <[email protected]>

crates/acvp/src/vectors/sha2.rs

@@ -8,6 +8,7 @@
 #![cfg_attr(docsrs, doc(cfg(feature = "sha2")))]
 
 use alloc::{string::String, vec::Vec};
+use core::fmt;
 
 use serde::{Deserialize, Serialize};
 
@@ -46,6 +47,27 @@ pub enum MctVersion {
     Alternate,
 }
 
+impl MctVersion {
+    /// Shorthand for `self == MctVersion::Standard`.
+    pub const fn is_std(self) -> bool {
+        matches!(self, Self::Standard)
+    }
+
+    /// Shorthand for `self == MctVersion::Alternate`.
+    pub const fn is_alt(self) -> bool {
+        matches!(self, Self::Alternate)
+    }
+}
+
+impl fmt::Display for MctVersion {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Standard => write!(f, "standard"),
+            Self::Alternate => write!(f, "alternate"),
+        }
+    }
+}
+
 /// SHA-2 tests.
 #[derive(Clone, Debug, Serialize, Deserialize)]
 #[serde(rename_all = "UPPERCASE")]

crates/acvp/src/vectors/sha3.rs

@@ -8,6 +8,7 @@
 #![cfg_attr(docsrs, doc(cfg(feature = "sha3")))]
 
 use alloc::vec::Vec;
+use core::fmt;
 
 use serde::{Deserialize, Serialize};
 
@@ -40,6 +41,27 @@ pub enum MctVersion {
     Alternate,
 }
 
+impl MctVersion {
+    /// Shorthand for `self == MctVersion::Standard`.
+    pub const fn is_std(self) -> bool {
+        matches!(self, Self::Standard)
+    }
+
+    /// Shorthand for `self == MctVersion::Alternate`.
+    pub const fn is_alt(self) -> bool {
+        matches!(self, Self::Alternate)
+    }
+}
+
+impl fmt::Display for MctVersion {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Standard => write!(f, "standard"),
+            Self::Alternate => write!(f, "alternate"),
+        }
+    }
+}
+
 /// SHA-3 tests.
 #[derive(Clone, Debug, Serialize, Deserialize)]
 #[serde(rename_all = "UPPERCASE")]

crates/crypto/src/hash.rs

@@ -1,14 +1,13 @@
 //! Cryptographic hash functions.
 
-#![forbid(unsafe_code)]
-
 use core::{
     fmt::{self, Debug},
     num::NonZeroU16,
     ops::{Deref, DerefMut},
+    ptr,
 };
 
-use generic_array::{ArrayLength, GenericArray, IntoArrayLength};
+use generic_array::{ArrayLength, GenericArray, IntoArrayLength, LengthError};
 use sha3_utils::{encode_string, right_encode_bytes};
 use subtle::{Choice, ConstantTimeEq};
 use typenum::{
@@ -119,6 +118,21 @@ impl<N: ArrayLength> Digest<N> {
         Self::new(GenericArray::from_array(digest))
     }
 
+    /// Creates a hash digest from a slice.
+    #[inline]
+    pub const fn try_from_slice(digest: &[u8]) -> Result<&Self, LengthError> {
+        match GenericArray::<u8, N>::try_from_slice(digest) {
+            Ok(array) => {
+                // SAFETY: `Self` is a `#[repr(transparent)]` wrapper
+                // around `GenericArray<u8, N>`, so they both have the
+                // same layout in memory.
+                let digest = unsafe { &*(ptr::from_ref(array).cast::<Self>()) };
+                Ok(digest)
+            }
+            Err(err) => Err(err),
+        }
+    }
+
     /// Returns the length of the hash digest.
     #[inline]
     #[allow(clippy::len_without_is_empty)]
@@ -201,6 +215,15 @@ impl<N: ArrayLength> ConstantTimeEq for Digest<N> {
     }
 }
 
+impl<'a, N: ArrayLength> TryFrom<&'a [u8]> for &'a Digest<N> {
+    type Error = LengthError;
+
+    #[inline]
+    fn try_from(digest: &'a [u8]) -> Result<Self, Self::Error> {
+        Digest::try_from_slice(digest)
+    }
+}
+
 /// A cryptographic hash over a set of strings such that each
 /// element is unambiguously encoded per [NIST SP 800-185].
 ///