ssh-key: Hash impl cleanups

ssh-key/src/mpint.rs

@@ -1,9 +1,8 @@
 //! Multiple precision integer
 
 use crate::{Error, Result};
-use alloc::vec::Vec;
+use alloc::{boxed::Box, vec::Vec};
 use core::fmt;
-use core::hash::{Hash, Hasher};
 use encoding::{CheckedSum, Decode, Encode, Reader, Writer};
 use subtle::{Choice, ConstantTimeEq};
 use zeroize::Zeroize;
@@ -42,7 +41,7 @@ use zeroize::Zeroizing;
 #[derive(Clone, PartialOrd, Ord)]
 pub struct Mpint {
     /// Inner big endian-serialized integer value
-    inner: Vec<u8>,
+    inner: Box<[u8]>,
 }
 
 impl Mpint {
@@ -69,7 +68,7 @@ impl Mpint {
         }
 
         inner.extend_from_slice(bytes);
-        inner.try_into()
+        inner.into_boxed_slice().try_into()
     }
 
     /// Get the big integer data encoded as big endian bytes.
@@ -115,17 +114,11 @@ impl PartialEq for Mpint {
     }
 }
 
-impl Hash for Mpint {
-    fn hash<H: Hasher>(&self, state: &mut H) {
-        self.inner.hash(state)
-    }
-}
-
 impl Decode for Mpint {
     type Error = Error;
 
     fn decode(reader: &mut impl Reader) -> Result<Self> {
-        Vec::decode(reader)?.try_into()
+        Vec::decode(reader)?.into_boxed_slice().try_into()
     }
 }
 
@@ -144,15 +137,15 @@ impl TryFrom<&[u8]> for Mpint {
     type Error = Error;
 
     fn try_from(bytes: &[u8]) -> Result<Self> {
-        Vec::from(bytes).try_into()
+        Vec::from(bytes).into_boxed_slice().try_into()
     }
 }
 
-impl TryFrom<Vec<u8>> for Mpint {
+impl TryFrom<Box<[u8]>> for Mpint {
     type Error = Error;
 
-    fn try_from(bytes: Vec<u8>) -> Result<Self> {
-        match bytes.as_slice() {
+    fn try_from(bytes: Box<[u8]>) -> Result<Self> {
+        match &*bytes {
             // Unnecessary leading 0
             [0x00] => Err(Error::FormatEncoding),
             // Unnecessary leading 0

ssh-key/src/public/dsa.rs

@@ -1,12 +1,13 @@
 //! Digital Signature Algorithm (DSA) public keys.
 
 use crate::{Error, Mpint, Result};
+use core::hash::{Hash, Hasher};
 use encoding::{CheckedSum, Decode, Encode, Reader, Writer};
 
 /// Digital Signature Algorithm (DSA) public key.
 ///
 /// Described in [FIPS 186-4 § 4.1](https://csrc.nist.gov/publications/detail/fips/186/4/final).
-#[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+#[derive(Clone, Debug, Eq, Ord, PartialEq, PartialOrd)]
 pub struct DsaPublicKey {
     /// Prime modulus.
     pub p: Mpint,
@@ -53,6 +54,16 @@ impl Encode for DsaPublicKey {
     }
 }
 
+impl Hash for DsaPublicKey {
+    #[inline]
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.p.as_bytes().hash(state);
+        self.q.as_bytes().hash(state);
+        self.g.as_bytes().hash(state);
+        self.y.as_bytes().hash(state);
+    }
+}
+
 #[cfg(feature = "dsa")]
 impl TryFrom<DsaPublicKey> for dsa::VerifyingKey {
     type Error = Error;

ssh-key/src/public/key_data.rs

@@ -11,7 +11,7 @@ use super::{DsaPublicKey, OpaquePublicKey, RsaPublicKey};
 use super::{EcdsaPublicKey, SkEcdsaSha2NistP256};
 
 /// Public key data.
-#[derive(Clone, Debug, Hash, Ord, Eq, PartialEq, PartialOrd)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
 #[non_exhaustive]
 pub enum KeyData {
     /// Digital Signature Algorithm (DSA) public key data.

ssh-key/src/public/rsa.rs

@@ -1,6 +1,7 @@
 //! Rivest–Shamir–Adleman (RSA) public keys.
 
 use crate::{Error, Mpint, Result};
+use core::hash::{Hash, Hasher};
 use encoding::{CheckedSum, Decode, Encode, Reader, Writer};
 
 #[cfg(feature = "rsa")]
@@ -13,7 +14,7 @@ use {
 /// RSA public key.
 ///
 /// Described in [RFC4253 § 6.6](https://datatracker.ietf.org/doc/html/rfc4253#section-6.6).
-#[derive(Clone, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+#[derive(Clone, Debug, Eq, Ord, PartialEq, PartialOrd)]
 pub struct RsaPublicKey {
     /// RSA public exponent.
     pub e: Mpint,
@@ -49,6 +50,14 @@ impl Encode for RsaPublicKey {
     }
 }
 
+impl Hash for RsaPublicKey {
+    #[inline]
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.e.as_bytes().hash(state);
+        self.n.as_bytes().hash(state);
+    }
+}
+
 #[cfg(feature = "rsa")]
 impl TryFrom<RsaPublicKey> for rsa::RsaPublicKey {
     type Error = Error;