Feature: note plaintext size generalization

CHANGELOG.md

@@ -6,7 +6,28 @@ and this library adheres to Rust's notion of
 [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
-
+### Changed
+- **Breaking change:** removed the constants `COMPACT_NOTE_SIZE`,
+  `NOTE_PLAINTEXT_SIZE`, and `ENC_CIPHERTEXT_SIZE` as they are now
+  implementation spesific (located in `orchard` and `sapling-crypto` crates).
+- Generalized the note plaintext size to support variable sizes by adding the
+  abstract types `NotePlaintextBytes`, `NoteCiphertextBytes`,
+  `CompactNotePlaintextBytes`, and `CompactNoteCiphertextBytes` to the `Domain`
+  trait.
+- Removed the separate `NotePlaintextBytes` type definition (as it is now an
+  associated type).
+- Added new `parse_note_plaintext_bytes`, `parse_note_ciphertext_bytes`, and
+  `parse_compact_note_plaintext_bytes` methods to the `Domain` trait.
+- Updated the `note_plaintext_bytes` method of the `Domain` trait to return the
+  `NotePlaintextBytes` associated type.
+- Updated the `encrypt_note_plaintext` method of `NoteEncryption` to return the
+  `NoteCiphertextBytes` associated type of the `Domain` instead of the explicit
+  array.
+- Updated the `enc_ciphertext` method of the `ShieldedOutput` trait to return an
+  `Option` of a reference instead of a copy.
+- Added a new `note_bytes` module with helper trait and struct to deal with note
+  bytes data with abstracted underlying array size.
+
 ## [0.4.0] - 2023-06-06
 ### Changed
 - The `esk` and `ephemeral_key` arguments have been removed from 

src/batch.rs

@@ -4,7 +4,7 @@ use alloc::vec::Vec; // module is alloc only
 
 use crate::{
     try_compact_note_decryption_inner, try_note_decryption_inner, BatchDomain, EphemeralKeyBytes,
-    ShieldedOutput, COMPACT_NOTE_SIZE, ENC_CIPHERTEXT_SIZE,
+    ShieldedOutput,
 };
 
 /// Trial decryption of a batch of notes with a set of recipients.
@@ -16,7 +16,7 @@ use crate::{
 /// provided, along with the index in the `ivks` slice associated with
 /// the IVK that successfully decrypted the output.
 #[allow(clippy::type_complexity)]
-pub fn try_note_decryption<D: BatchDomain, Output: ShieldedOutput<D, ENC_CIPHERTEXT_SIZE>>(
+pub fn try_note_decryption<D: BatchDomain, Output: ShieldedOutput<D>>(
     ivks: &[D::IncomingViewingKey],
     outputs: &[(D, Output)],
 ) -> Vec<Option<((D::Note, D::Recipient, D::Memo), usize)>> {
@@ -32,14 +32,14 @@ pub fn try_note_decryption<D: BatchDomain, Output: ShieldedOutput<D, ENC_CIPHERT
 /// provided, along with the index in the `ivks` slice associated with
 /// the IVK that successfully decrypted the output.
 #[allow(clippy::type_complexity)]
-pub fn try_compact_note_decryption<D: BatchDomain, Output: ShieldedOutput<D, COMPACT_NOTE_SIZE>>(
+pub fn try_compact_note_decryption<D: BatchDomain, Output: ShieldedOutput<D>>(
     ivks: &[D::IncomingViewingKey],
     outputs: &[(D, Output)],
 ) -> Vec<Option<((D::Note, D::Recipient), usize)>> {
     batch_note_decryption(ivks, outputs, try_compact_note_decryption_inner)
 }
 
-fn batch_note_decryption<D: BatchDomain, Output: ShieldedOutput<D, CS>, F, FR, const CS: usize>(
+fn batch_note_decryption<D: BatchDomain, Output: ShieldedOutput<D>, F, FR>(
     ivks: &[D::IncomingViewingKey],
     outputs: &[(D, Output)],
     decrypt_inner: F,