Publicize necessary functionality for reading diversifiers and notes from data

CHANGELOG.md

@@ -6,6 +6,11 @@ and this project adheres to Rust's notion of
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Changed
+- `note`:
+  - `RandomSeed` and its functions `from_bytes` and `as_bytes` now public
+  -  `Note::from_parts` now public
+- `keys::Diversifier::from_bytes` now public
 
 ## [0.2.0] - 2022-06-24
 ### Added

src/keys.rs

@@ -552,7 +552,8 @@ impl DiversifierKey {
 pub struct Diversifier([u8; 11]);
 
 impl Diversifier {
-    pub(crate) fn from_bytes(d: [u8; 11]) -> Self {
+    ///Read a diversifier from a byte array.
+    pub fn from_bytes(d: [u8; 11]) -> Self {
         Diversifier(d)
     }
 

src/note.rs

@@ -21,7 +21,7 @@ pub use self::nullifier::Nullifier;
 
 /// The ZIP 212 seed randomness for a note.
 #[derive(Copy, Clone, Debug)]
-pub(crate) struct RandomSeed([u8; 32]);
+pub struct RandomSeed([u8; 32]);
 
 impl RandomSeed {
     pub(crate) fn random(rng: &mut impl RngCore, rho: &Nullifier) -> Self {
@@ -35,13 +35,16 @@ impl RandomSeed {
         }
     }
 
-    pub(crate) fn from_bytes(rseed: [u8; 32], rho: &Nullifier) -> CtOption<Self> {
+    ///Read a note's random seed from bytes, given the note's nullifier.
+    ///Returns None if the nullifier is not for the same note as the seed.
+    pub fn from_bytes(rseed: [u8; 32], rho: &Nullifier) -> CtOption<Self> {
         let rseed = RandomSeed(rseed);
         let esk = rseed.esk_inner(rho);
         CtOption::new(rseed, esk.is_some())
     }
 
-    pub(crate) fn as_bytes(&self) -> &[u8; 32] {
+    /// Returns the byte array corresponding to this seed.
+    pub fn as_bytes(&self) -> &[u8; 32] {
         &self.0
     }
 
@@ -108,7 +111,8 @@ impl PartialEq for Note {
 impl Eq for Note {}
 
 impl Note {
-    pub(crate) fn from_parts(
+    ///Create a Note from its component parts.
+    pub fn from_parts(
         recipient: Address,
         value: NoteValue,
         rho: Nullifier,