From a6a3a640ca346733697bdf5fe98e1080b62820fe Mon Sep 17 00:00:00 2001
From: Deirdre Connolly <deirdre@zfnd.org>
Date: Sat, 22 Feb 2020 18:22:28 -0500
Subject: [PATCH] Tidied up some note encryption types

---
 zebra-chain/src/note_encryption.rs         |  4 +---
 zebra-chain/src/note_encryption/sapling.rs | 13 +++++++++++--
 zebra-chain/src/note_encryption/sprout.rs  |  5 ++++-
 3 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/zebra-chain/src/note_encryption.rs b/zebra-chain/src/note_encryption.rs
index bdf3125e..76027533 100644
--- a/zebra-chain/src/note_encryption.rs
+++ b/zebra-chain/src/note_encryption.rs
@@ -3,8 +3,6 @@ mod memo;
 mod sapling;
 mod sprout;
 
-#[derive(Copy, Clone, Debug, PartialEq)]
-pub struct Diversifier(pub [u8; 11]);
-
+/// The randomness used in the Pedersen Hash for note commitment.
 #[derive(Copy, Clone, Debug, PartialEq)]
 pub struct NoteCommitmentRandomness(pub [u8; 32]);
diff --git a/zebra-chain/src/note_encryption/sapling.rs b/zebra-chain/src/note_encryption/sapling.rs
index b78ab3d0..45ae8755 100644
--- a/zebra-chain/src/note_encryption/sapling.rs
+++ b/zebra-chain/src/note_encryption/sapling.rs
@@ -5,19 +5,28 @@ use proptest::{arbitrary::Arbitrary, collection::vec, prelude::*};
 
 use crate::serialization::{SerializationError, ZcashDeserialize, ZcashSerialize};
 
-use super::{Diversifier, Memo, NoteCommitmentRandomness};
+use super::*;
+
+/// A _Diversifier_, an 11 byte value used to randomize the
+/// recipient's final public shielded payment address to create a
+/// _diversified payment address_.
+///
+/// When used, this value is mapped to an affine JubJub group element.
+#[derive(Copy, Clone, Debug, PartialEq)]
+pub struct Diversifier(pub [u8; 11]);
 
 pub struct Note {
     value: u64,
     diversifier: Diversifier,
 }
 
+/// The decrypted form of encrypted Sapling notes on the blockchain.
 pub struct NotePlaintext {
     diversifier: Diversifier,
     value: u64,
     // TODO: refine as jub-jub appropriate in the base field.
     note_committment_randomness: NoteCommitmentRandomness,
-    memo: Memo,
+    memo: memo::Memo,
 }
 
 /// A ciphertext component for encrypted output notes.
diff --git a/zebra-chain/src/note_encryption/sprout.rs b/zebra-chain/src/note_encryption/sprout.rs
index ff5005e8..b248dfd5 100644
--- a/zebra-chain/src/note_encryption/sprout.rs
+++ b/zebra-chain/src/note_encryption/sprout.rs
@@ -8,15 +8,18 @@ use proptest::{collection::vec, prelude::*};
 
 use crate::serialization::{SerializationError, ZcashDeserialize, ZcashSerialize};
 
+use super::*;
+
 pub struct Note {}
 
+/// The decrypted form of encrypted Sprout notes on the blockchain.
 pub struct NotePlaintext {
     value: u64,
     // TODO: refine type
     rho: [u8; 32],
     // TODO: refine as jub-jub appropriate in the base field.
     note_committment_randomness: NoteCommitmentRandomness,
-    memo: Memo,
+    memo: memo::Memo,
 }
 
 /// A ciphertext component for encrypted output notes.