From 43abadfb55b92dc818fadc7c1c0b93ac89d808ba Mon Sep 17 00:00:00 2001
From: Kris Nuttycombe <kris@nutty.land>
Date: Wed, 18 Aug 2021 19:00:21 -0600
Subject: [PATCH] Adds decryption for a specific index within a bundle.

---
 src/bundle.rs | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/bundle.rs b/src/bundle.rs
index b92fdf5e..302c0fc6 100644
--- a/src/bundle.rs
+++ b/src/bundle.rs
@@ -362,7 +362,7 @@ impl<T: Authorization, V> Bundle<T, V> {
     /// Perform trial decryption of each action in the bundle with each of the
     /// specified incoming viewing keys, and return the decrypted note contents
     /// along with the index of the action from which it was derived.
-    pub fn decrypt_outputs_for_keys<'a>(
+    pub fn decrypt_outputs_for_keys(
         &self,
         keys: &[IncomingViewingKey],
     ) -> Vec<(usize, IncomingViewingKey, Note, Address, [u8; 512])> {
@@ -372,11 +372,25 @@ impl<T: Authorization, V> Bundle<T, V> {
             .filter_map(|(idx, action)| {
                 let domain = OrchardDomain::for_action(action);
                 keys.iter().find_map(move |ivk| {
-                    try_note_decryption(&domain, ivk, action).map(|(n, a, m)| (idx, ivk.clone(), n, a, m))
+                    try_note_decryption(&domain, ivk, action)
+                        .map(|(n, a, m)| (idx, ivk.clone(), n, a, m))
                 })
             })
             .collect()
     }
+
+    /// Perform trial decryption of each action at `action_idx` in the bundle with the
+    /// specified incoming viewing key, and return the decrypted note contents.
+    pub fn decrypt_output_with_key(
+        &self,
+        action_idx: usize,
+        key: &IncomingViewingKey,
+    ) -> Option<(Note, Address, [u8; 512])> {
+        self.actions.get(action_idx).and_then(move |action| {
+            let domain = OrchardDomain::for_action(action);
+            try_note_decryption(&domain, key, action)
+        })
+    }
 }
 
 impl<T: Authorization, V: Copy + Into<ValueSum>> Bundle<T, V> {