From 0743dadcd017b60a0ac7123d04f0d6e7ce1e8016 Mon Sep 17 00:00:00 2001
From: Aditya Kulkarni <adityapk@gmail.com>
Date: Tue, 24 Sep 2019 11:14:13 -0700
Subject: [PATCH] Encode expanded spending keys

---
 zcash_client_backend/src/encoding.rs | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/zcash_client_backend/src/encoding.rs b/zcash_client_backend/src/encoding.rs
index 0bd1644..c27068c 100644
--- a/zcash_client_backend/src/encoding.rs
+++ b/zcash_client_backend/src/encoding.rs
@@ -13,6 +13,7 @@ use zcash_primitives::{
 };
 use zcash_primitives::{
     legacy::TransparentAddress,
+    keys::ExpandedSpendingKey,
     zip32::{ExtendedFullViewingKey, ExtendedSpendingKey},
     JUBJUB,
 };
@@ -38,6 +39,25 @@ where
     }
 }
 
+
+/// Writes an [`ExpandedSpendingKey`] as a Bech32-encoded string.
+///
+/// # Examples
+///
+/// ```
+/// use zcash_client_backend::{
+///     constants::testnet::{COIN_TYPE, HRP_SAPLING_EXPANDED_SPENDING_KEY},
+///     encoding::encode_expanded_spending_key,
+///     keys::spending_key,
+/// };
+///
+/// let expsk = spending_key(&[0; 32][..], COIN_TYPE, 0).expsk;
+/// let encoded = encode_expanded_spending_key(HRP_SAPLING_EXPANDED_SPENDING_KEY, &expsk);
+/// ```
+pub fn encode_expanded_spending_key(htp: &str, sk: &ExpandedSpendingKey<Bls12>) -> String {
+    bech32_encode(htp, |w| sk.write(w))
+}
+
 /// Writes an [`ExtendedSpendingKey`] as a Bech32-encoded string.
 ///
 /// # Examples