ml-dsa: apply and fix workspace-level lints (#1338)

Applies the workspace-level config added in #1323 to this crate and
fixes any failures.

Cargo.toml

@@ -17,6 +17,7 @@ members = [
 opt-level = 2
 
 [workspace.lints.clippy]
+as_conversions = "warn"
 borrow_as_ptr = "warn"
 cast_lossless = "warn"
 cast_possible_truncation = "warn"
@@ -26,6 +27,7 @@ cast_sign_loss = "warn"
 checked_conversions = "warn"
 from_iter_instead_of_collect = "warn"
 implicit_saturating_sub = "warn"
+integer_division_remainder_used = "warn"
 manual_assert = "warn"
 map_unwrap_or = "warn"
 missing_errors_doc = "warn"

ed25519/src/pkcs8.rs

@@ -20,24 +20,24 @@ pub use pkcs8::{
 };
 
 #[cfg(feature = "alloc")]
-pub use pkcs8::{EncodePrivateKey, spki::EncodePublicKey};
-
-#[cfg(feature = "alloc")]
-pub use pkcs8::der::{
-    Document, SecretDocument,
-    asn1::{BitStringRef, OctetStringRef},
+pub use pkcs8::{
+    EncodePrivateKey,
+    der::{
+        Document, SecretDocument,
+        asn1::{BitStringRef, OctetStringRef},
+    },
+    spki::EncodePublicKey,
 };
 
+use crate::COMPONENT_SIZE;
 use core::fmt;
 
 #[cfg(feature = "pem")]
 use core::str;
-
-#[cfg(feature = "zeroize")]
-use zeroize::Zeroize;
-
 #[cfg(feature = "zerocopy")]
 use zerocopy::{FromBytes, Immutable, IntoBytes, KnownLayout, Unaligned};
+#[cfg(feature = "zeroize")]
+use zeroize::Zeroize;
 
 /// Algorithm [`ObjectIdentifier`] for the Ed25519 digital signature algorithm
 /// (`id-Ed25519`).
@@ -73,7 +73,7 @@ pub struct KeypairBytes {
     /// Little endian serialization of an element of the Curve25519 scalar
     /// field, prior to "clamping" (i.e. setting/clearing bits to ensure the
     /// scalar is actually a valid field element)
-    pub secret_key: [u8; Self::BYTE_SIZE / 2],
+    pub secret_key: [u8; COMPONENT_SIZE],
 
     /// Ed25519 public key (if available).
     ///
@@ -90,7 +90,7 @@ impl KeypairBytes {
     #[allow(clippy::missing_panics_doc, reason = "MSRV TODO")]
     pub fn from_bytes(bytes: &[u8; Self::BYTE_SIZE]) -> Self {
         // TODO(tarcieri): use `as_chunks` when MSRV is 1.88
-        let (sk, pk) = bytes.split_at(Self::BYTE_SIZE / 2);
+        let (sk, pk) = bytes.split_at(COMPONENT_SIZE);
 
         Self {
             secret_key: sk.try_into().expect("secret key size error"),
@@ -109,7 +109,7 @@ impl KeypairBytes {
     pub fn to_bytes(&self) -> Option<[u8; Self::BYTE_SIZE]> {
         if let Some(public_key) = &self.public_key {
             let mut result = [0u8; Self::BYTE_SIZE];
-            let (sk, pk) = result.split_at_mut(Self::BYTE_SIZE / 2);
+            let (sk, pk) = result.split_at_mut(COMPONENT_SIZE);
             sk.copy_from_slice(&self.secret_key);
             pk.copy_from_slice(public_key.as_ref());
             Some(result)
@@ -130,7 +130,7 @@ impl Drop for KeypairBytes {
 impl EncodePrivateKey for KeypairBytes {
     fn to_pkcs8_der(&self) -> Result<SecretDocument> {
         // Serialize private key as nested OCTET STRING
-        let mut private_key = [0u8; 2 + (Self::BYTE_SIZE / 2)];
+        let mut private_key = [0u8; 2 + (COMPONENT_SIZE)];
         private_key[0] = 0x04;
         private_key[1] = 0x20;
         private_key[2..].copy_from_slice(&self.secret_key);

ed448/src/pkcs8.rs

@@ -20,19 +20,21 @@ pub use pkcs8::{
 };
 
 #[cfg(feature = "alloc")]
-pub use pkcs8::{EncodePrivateKey, spki::EncodePublicKey};
-
-#[cfg(feature = "alloc")]
-pub use pkcs8::der::{
-    Document, SecretDocument,
-    asn1::{BitStringRef, OctetStringRef},
+pub use pkcs8::{
+    EncodePrivateKey,
+    der::{
+        Document, SecretDocument,
+        asn1::{BitStringRef, OctetStringRef},
+    },
+    spki::EncodePublicKey,
 };
 
+use crate::COMPONENT_SIZE;
+use core::fmt;
+
 #[cfg(feature = "zeroize")]
 use zeroize::Zeroize;
 
-use core::fmt;
-
 /// Algorithm [`ObjectIdentifier`] for the Ed448 digital signature algorithm
 /// (`id-Ed448`).
 ///
@@ -67,7 +69,7 @@ pub struct KeypairBytes {
     /// Little endian serialization of an element of the Curve448 scalar
     /// field, prior to "clamping" (i.e. setting/clearing bits to ensure the
     /// scalar is actually a valid field element)
-    pub secret_key: [u8; Self::BYTE_SIZE / 2],
+    pub secret_key: [u8; COMPONENT_SIZE],
 
     /// Ed448 public key (if available).
     ///
@@ -84,7 +86,7 @@ impl KeypairBytes {
     #[allow(clippy::missing_panics_doc, reason = "MSRV TODO")]
     pub fn from_bytes(bytes: &[u8; Self::BYTE_SIZE]) -> Self {
         // TODO(tarcieri): use `as_chunks` when MSRV is 1.88
-        let (sk, pk) = bytes.split_at(Self::BYTE_SIZE / 2);
+        let (sk, pk) = bytes.split_at(COMPONENT_SIZE);
 
         Self {
             secret_key: sk.try_into().expect("secret key size error"),
@@ -103,7 +105,7 @@ impl KeypairBytes {
     pub fn to_bytes(&self) -> Option<[u8; Self::BYTE_SIZE]> {
         if let Some(public_key) = &self.public_key {
             let mut result = [0u8; Self::BYTE_SIZE];
-            let (sk, pk) = result.split_at_mut(Self::BYTE_SIZE / 2);
+            let (sk, pk) = result.split_at_mut(COMPONENT_SIZE);
             sk.copy_from_slice(&self.secret_key);
             pk.copy_from_slice(public_key.as_ref());
             Some(result)
@@ -124,7 +126,7 @@ impl Drop for KeypairBytes {
 impl EncodePrivateKey for KeypairBytes {
     fn to_pkcs8_der(&self) -> Result<SecretDocument> {
         // Serialize private key as nested OCTET STRING
-        let mut private_key = [0u8; 2 + (Self::BYTE_SIZE / 2)];
+        let mut private_key = [0u8; 2 + COMPONENT_SIZE];
         private_key[0] = 0x04;
         private_key[1] = 0x39;
         private_key[2..].copy_from_slice(&self.secret_key);

ml-dsa/Cargo.toml

@@ -57,3 +57,9 @@ serde_json = "1.0.132"
 [[bench]]
 name = "ml_dsa"
 harness = false
+
+[lints]
+workspace = true
+
+[package.metadata.docs.rs]
+all-features = true

ml-dsa/benches/ml_dsa.rs

@@ -1,3 +1,8 @@
+//! ML-DSA benchmarks.
+
+#![allow(clippy::unwrap_used, reason = "benchmarks")]
+#![allow(missing_docs, reason = "benchmarks")]
+
 use criterion::{Criterion, criterion_group, criterion_main};
 use getrandom::SysRng;
 use hybrid_array::{Array, ArraySize};
@@ -6,12 +11,14 @@ use ml_dsa::{
 };
 use rand_core::{CryptoRng, UnwrapErr};
 
+/// Create a random array of the given length.
 pub fn rand<L: ArraySize, R: CryptoRng + ?Sized>(rng: &mut R) -> Array<u8, L> {
     let mut val = Array::<u8, L>::default();
     rng.fill_bytes(&mut val);
     val
 }
 
+/// ML-DSA benchmarks.
 #[allow(deprecated)] // TODO(tarcieri): stop using expanded signing keys
 fn criterion_benchmark(c: &mut Criterion) {
     let mut rng = UnwrapErr(SysRng);
@@ -34,7 +41,7 @@ fn criterion_benchmark(c: &mut Criterion) {
             let kp = MlDsa65::from_seed(&xi);
             let _sk_bytes = kp.signing_key().to_expanded();
             let _vk_bytes = kp.verifying_key().encode();
-        })
+        });
     });
 
     // Signing
@@ -42,7 +49,7 @@ fn criterion_benchmark(c: &mut Criterion) {
         b.iter(|| {
             let sk = ExpandedSigningKey::<MlDsa65>::from_expanded(&sk_bytes);
             let _sig = sk.sign_deterministic(&m, &ctx);
-        })
+        });
     });
 
     // Verifying
@@ -51,7 +58,7 @@ fn criterion_benchmark(c: &mut Criterion) {
             let vk = VerifyingKey::<MlDsa65>::decode(&vk_bytes);
             let sig = Signature::<MlDsa65>::decode(&sig_bytes).unwrap();
             let _ver = vk.verify_with_context(&m, &ctx, &sig);
-        })
+        });
     });
 
     // Round trip
@@ -60,7 +67,7 @@ fn criterion_benchmark(c: &mut Criterion) {
             let kp = MlDsa65::from_seed(&xi);
             let sig = kp.signing_key().sign_deterministic(&m, &ctx).unwrap();
             let _ver = kp.verifying_key().verify_with_context(&m, &ctx, &sig);
-        })
+        });
     });
 }
 

ml-dsa/src/algebra.rs

@@ -69,7 +69,7 @@ pub(crate) trait ConstantTimeDiv: Unsigned {
         // This gives us floor(x / M) for x < 2^SHIFT / MULTIPLIER * M
         let x64 = u64::from(x);
         let quotient = (x64 * Self::CT_DIV_MULTIPLIER) >> Self::CT_DIV_SHIFT;
-        // SAFETY: quotient is guaranteed to fit in u32 because:
+        // Quotient is guaranteed to fit in u32 because:
         // - x < Q (~2^23), so quotient = x / M < x < 2^23 < 2^32
         #[allow(clippy::cast_possible_truncation, clippy::as_conversions)]
         let result = quotient as u32;
@@ -183,7 +183,11 @@ impl AlgebraExt for Polynomial {
     }
 
     fn infinity_norm(&self) -> u32 {
-        self.0.iter().map(AlgebraExt::infinity_norm).max().unwrap()
+        self.0
+            .iter()
+            .map(AlgebraExt::infinity_norm)
+            .max()
+            .expect("should have a maximum")
     }
 
     fn power2round(&self) -> (Self, Self) {
@@ -222,7 +226,11 @@ impl<K: ArraySize> AlgebraExt for Vector<K> {
     }
 
     fn infinity_norm(&self) -> u32 {
-        self.0.iter().map(AlgebraExt::infinity_norm).max().unwrap()
+        self.0
+            .iter()
+            .map(AlgebraExt::infinity_norm)
+            .max()
+            .expect("should have a maximum")
     }
 
     fn power2round(&self) -> (Self, Self) {

ml-dsa/src/hint.rs

@@ -130,7 +130,7 @@ where
         let cuts: Array<usize, P::K> = cuts.iter().map(|x| usize::from(*x)).collect();
 
         let indices: Array<usize, P::Omega> = indices.iter().map(|x| usize::from(*x)).collect();
-        let max_cut: usize = cuts.iter().copied().max().unwrap();
+        let max_cut: usize = cuts.iter().copied().max().expect("should have a maximum");
 
         // cuts must be monotonic but can repeat
         if !cuts.windows(2).all(|w| w[0] <= w[1])

ml-dsa/src/lib.rs

@@ -5,15 +5,10 @@
     html_favicon_url = "https://raw.githubusercontent.com/RustCrypto/meta/master/logo.svg"
 )]
 #![cfg_attr(docsrs, feature(doc_cfg))]
-#![warn(clippy::pedantic)] // Be pedantic by default
-#![warn(clippy::integer_division_remainder_used)] // Be judicious about using `/` and `%`
-#![warn(clippy::as_conversions)] // Use proper conversions, not `as`
 #![allow(non_snake_case)] // Allow notation matching the spec
 #![allow(clippy::similar_names)] // Allow notation matching the spec
 #![allow(clippy::many_single_char_names)] // Allow notation matching the spec
 #![allow(clippy::clone_on_copy)] // Be explicit about moving data
-#![deny(missing_docs)] // Require all public interfaces to be documented
-#![warn(unreachable_pub)] // Prevent unexpected interface changes
 
 //! # Quickstart
 //!
@@ -877,7 +872,7 @@ impl<P: MlDsaParams> DigestVerifier<Shake256, Signature<P>> for VerifyingKey<P>
 }
 
 /// `MlDsa44` is the parameter set for security category 2.
-#[derive(Default, Clone, Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, Default, PartialEq)]
 pub struct MlDsa44;
 
 impl ParameterSet for MlDsa44 {
@@ -894,7 +889,7 @@ impl ParameterSet for MlDsa44 {
 }
 
 /// `MlDsa65` is the parameter set for security category 3.
-#[derive(Default, Clone, Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, Default, PartialEq)]
 pub struct MlDsa65;
 
 impl ParameterSet for MlDsa65 {
@@ -911,7 +906,7 @@ impl ParameterSet for MlDsa65 {
 }
 
 /// `MlDsa87` is the parameter set for security category 5.
-#[derive(Default, Clone, Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, Default, PartialEq)]
 pub struct MlDsa87;
 
 impl ParameterSet for MlDsa87 {

ml-dsa/src/param.rs

@@ -41,7 +41,7 @@ pub trait SamplingSize: ArraySize + Len {
 }
 
 /// Range of the uniform distribution to be used in sampling.
-#[derive(Copy, Clone)]
+#[derive(Clone, Copy, Debug)]
 #[allow(unreachable_pub, reason = "MSRV 1.85 complains")]
 pub enum Eta {
     Two,

ml-dsa/src/pkcs8.rs

@@ -99,13 +99,13 @@ where
             .assert_algorithm_oid(P::ALGORITHM_IDENTIFIER.oid)?;
 
         let mut reader = der::SliceReader::new(private_key_info.private_key.as_bytes())?;
-        let seed_string = SeedString::decode_implicit(&mut reader, SEED_TAG_NUMBER)?
-            .ok_or(pkcs8::KeyError::Invalid)?;
+        let seed_string =
+            SeedString::decode_implicit(&mut reader, SEED_TAG_NUMBER)?.ok_or(KeyError::Invalid)?;
         let seed = seed_string
             .value
             .as_bytes()
             .try_into()
-            .map_err(|_| pkcs8::KeyError::Invalid)?;
+            .map_err(|_| KeyError::Invalid)?;
         reader.finish()?;
 
         Ok(P::from_seed(&seed))
@@ -118,7 +118,7 @@ where
     P: MlDsaParams,
     P: AssociatedAlgorithmIdentifier<Params = AnyRef<'static>>,
 {
-    fn to_pkcs8_der(&self) -> ::pkcs8::Result<der::SecretDocument> {
+    fn to_pkcs8_der(&self) -> ::pkcs8::Result<SecretDocument> {
         let seed_der = SeedString {
             tag_mode: TagMode::Implicit,
             tag_number: SEED_TAG_NUMBER,
@@ -174,7 +174,7 @@ where
     P: MlDsaParams,
     P: AssociatedAlgorithmIdentifier<Params = AnyRef<'static>>,
 {
-    fn to_public_key_der(&self) -> spki::Result<der::Document> {
+    fn to_public_key_der(&self) -> spki::Result<Document> {
         let public_key = self.encode();
         let subject_public_key = BitStringRef::new(0, &public_key)?;
 

ml-dsa/tests/key-gen.rs

@@ -1,6 +1,9 @@
-use ml_dsa::*;
+//! Key generation tests.
+
+#![allow(clippy::unwrap_used, reason = "tests")]
 
 use hybrid_array::Array;
+use ml_dsa::*;
 use signature::Keypair;
 use std::{fs::read_to_string, path::PathBuf};
 

ml-dsa/tests/pkcs8.rs

@@ -1,3 +1,5 @@
+//! PKCS#8 tests (i.e. private key serialization)
+
 #![cfg(all(feature = "pkcs8", feature = "alloc"))]
 
 use core::ops::Deref;

ml-dsa/tests/sig-gen.rs

@@ -1,5 +1,8 @@
-use ml_dsa::*;
+//! Signature generation tests.
 
+#![allow(clippy::unwrap_used, reason = "tests")]
+
+use ml_dsa::*;
 use std::{fs::read_to_string, path::PathBuf};
 
 #[test]

ml-dsa/tests/sig-ver.rs

@@ -1,5 +1,8 @@
-use ml_dsa::*;
+//! Signature verification tests.
 
+#![allow(clippy::unwrap_used, reason = "tests")]
+
+use ml_dsa::*;
 use std::{fs::read_to_string, path::PathBuf};
 
 #[test]