spki: implement Hash for AlgorithmIdentifier

der/src/asn1/any.rs

@@ -23,7 +23,7 @@ use crate::SliceWriter;
 /// and useful concept which is still extensively used in things like
 /// PKI-related RFCs.
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
-#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Copy, Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
 pub struct AnyRef<'a> {
     /// Tag representing the type of the encoded value.
     tag: Tag,
@@ -169,7 +169,7 @@ mod allocating {
     /// This type provides the same functionality as [`AnyRef`] but owns the
     /// backing data.
     #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
-    #[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+    #[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
     pub struct Any {
         /// Tag representing the type of the encoded value.
         tag: Tag,

der/src/bytes_owned.rs

@@ -9,7 +9,7 @@ use alloc::{boxed::Box, vec::Vec};
 use core::cmp::Ordering;
 
 /// Byte slice newtype which respects the `Length::max()` limit.
-#[derive(Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
 pub(crate) struct BytesOwned {
     /// Precomputed `Length` (avoids possible panicking conversions)
     length: Length,

der/src/bytes_ref.rs

@@ -10,7 +10,7 @@ use core::cmp::Ordering;
 use crate::StrOwned;
 
 /// Byte slice newtype which respects the `Length::max()` limit.
-#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Copy, Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
 pub(crate) struct BytesRef<'a> {
     /// Precomputed `Length` (avoids possible panicking conversions)
     pub length: Length,

der/src/length.rs

@@ -24,7 +24,7 @@ const INDEFINITE_LENGTH_OCTET: u8 = 0b10000000; // 0x80
 /// ASN.1-encoded length.
 ///
 /// Maximum length is defined by the [`Length::MAX`] constant (256 MiB).
-#[derive(Copy, Clone, Debug, Default, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Copy, Clone, Debug, Default, Eq, Hash, PartialEq, PartialOrd, Ord)]
 pub struct Length(u32);
 
 impl Length {

der/src/tag.rs

@@ -48,7 +48,7 @@ impl<T: FixedTag> Tagged for T {
 /// - Bit 6: primitive (0) or constructed (1)
 /// - Bits 5-1: tag number
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
-#[derive(Copy, Clone, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Copy, Clone, Eq, Hash, PartialEq, PartialOrd, Ord)]
 #[non_exhaustive]
 pub enum Tag {
     /// `BOOLEAN` tag: `1`.

der/src/tag/number.rs

@@ -18,7 +18,7 @@ use core::fmt;
 /// encoded by using a leading tag number of 31 (`0b11111`). This library
 /// deliberately does not support this: tag numbers greater than 30 are
 /// disallowed.
-#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Copy, Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
 pub struct TagNumber(pub(super) u8);
 
 impl TagNumber {

spki/src/algorithm.rs

@@ -21,7 +21,7 @@ use der::asn1::Any;
 ///
 /// [RFC 5280 Section 4.1.1.2]: https://tools.ietf.org/html/rfc5280#section-4.1.1.2
 #[cfg_attr(feature = "arbitrary", derive(arbitrary::Arbitrary))]
-#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Copy, Clone, Debug, Eq, Hash, PartialEq, PartialOrd, Ord)]
 pub struct AlgorithmIdentifier<Params> {
     /// Algorithm OID, i.e. the `algorithm` field in the `AlgorithmIdentifier`
     /// ASN.1 schema.

spki/tests/spki.rs

@@ -5,7 +5,10 @@ use hex_literal::hex;
 use spki::SubjectPublicKeyInfoRef;
 
 #[cfg(feature = "alloc")]
-use der::Encode;
+use {
+    der::Encode,
+    spki::{AlgorithmIdentifier, AlgorithmIdentifierOwned},
+};
 
 #[cfg(feature = "pem")]
 use der::{pem::LineEnding, EncodePem};
@@ -159,3 +162,20 @@ fn encode_rsa_2048_pem() {
     let pk_encoded = pk.to_pem(LineEnding::LF).unwrap();
     assert_eq!(RSA_2048_PEM_EXAMPLE, pk_encoded);
 }
+
+#[test]
+#[cfg(feature = "alloc")]
+fn build_hashset_of_digests() {
+    const SHA1: AlgorithmIdentifierOwned = AlgorithmIdentifier {
+        oid: ObjectIdentifier::new_unwrap("1.3.14.3.2.26"),
+        parameters: None,
+    };
+    const SHA256: AlgorithmIdentifierOwned = AlgorithmIdentifier {
+        oid: ObjectIdentifier::new_unwrap("2.16.840.1.101.3.4.2.1"),
+        parameters: None,
+    };
+
+    let mut hashes = std::collections::HashSet::new();
+    hashes.insert(SHA1);
+    hashes.insert(SHA256);
+}