Add OrchardDomain::for_nullifier and CompactAction::from_parts

src/note_encryption.rs

@@ -92,6 +92,11 @@ impl OrchardDomain {
             rho: *act.nullifier(),
         }
     }
+
+    /// Constructs a domain from a nullifier.
+    pub fn for_nullifier<T>(nullifier: Nullifier) -> Self {
+        OrchardDomain { rho: nullifier }
+    }
 }
 
 impl Domain for OrchardDomain {
@@ -307,6 +312,23 @@ impl ShieldedOutput<OrchardDomain, COMPACT_NOTE_SIZE> for CompactAction {
     }
 }
 
+impl CompactAction {
+    /// Create a CompactAction from its constituent parts
+    pub fn from_parts(
+        nullifier: Nullifier,
+        cmx: ExtractedNoteCommitment,
+        ephemeral_key: EphemeralKeyBytes,
+        enc_ciphertext: [u8; 52],
+    ) -> Self {
+        Self {
+            nullifier,
+            cmx,
+            ephemeral_key,
+            enc_ciphertext,
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use rand::rngs::OsRng;