Make `Debug` impl for `TransmittedNoteCiphertext` less verbose

We now print the ciphertexts as hex bytes, for which we unambiguously
encode them in RPC outputs (vs 32-byte values which are more complex).

Cargo.toml

@@ -30,6 +30,7 @@ fpe = "0.5"
 group = "0.11"
 halo2_gadgets = "=0.1.0-beta.3"
 halo2_proofs = "=0.1.0-beta.4"
+hex = "0.4"
 lazy_static = "1"
 memuse = { version = "0.2", features = ["nonempty"] }
 pasta_curves = "0.3"
@@ -48,7 +49,6 @@ plotters = { version = "0.3.0", optional = true }
 [dev-dependencies]
 criterion = "0.3"
 halo2_gadgets = { version = "=0.1.0-beta.3", features = ["test-dependencies"] }
-hex = "0.4"
 proptest = "1.0.0"
 zcash_note_encryption = { version = "0.1", features = ["pre-zip-212"] }
 

src/note.rs

@@ -1,4 +1,6 @@
 //! Data structures used for note construction.
+use std::fmt;
+
 use group::GroupEncoding;
 use pasta_curves::pallas;
 use rand::RngCore;
@@ -236,7 +238,7 @@ impl Note {
 }
 
 /// An encrypted note.
-#[derive(Debug, Clone)]
+#[derive(Clone)]
 pub struct TransmittedNoteCiphertext {
     /// The serialization of the ephemeral public key
     pub epk_bytes: [u8; 32],
@@ -247,6 +249,16 @@ pub struct TransmittedNoteCiphertext {
     pub out_ciphertext: [u8; 80],
 }
 
+impl fmt::Debug for TransmittedNoteCiphertext {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("TransmittedNoteCiphertext")
+            .field("epk_bytes", &self.epk_bytes)
+            .field("enc_ciphertext", &hex::encode(self.enc_ciphertext))
+            .field("out_ciphertext", &hex::encode(self.out_ciphertext))
+            .finish()
+    }
+}
+
 /// Generators for property testing.
 #[cfg(any(test, feature = "test-dependencies"))]
 #[cfg_attr(docsrs, doc(cfg(feature = "test-dependencies")))]