From 70e46c982655e2fbb97ad4f32c97ab0ced00685b Mon Sep 17 00:00:00 2001
From: Henry de Valence <hdevalence@hdevalence.ca>
Date: Wed, 23 Oct 2019 15:55:03 -0700
Subject: [PATCH] Fill in missing Serde impl for MontgomeryPoint.

---
 Cargo.toml        |  2 +-
 src/montgomery.rs | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/Cargo.toml b/Cargo.toml
index 64aabe2..7274867 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -42,7 +42,7 @@ byteorder = { version = "^1.2.3", default-features = false, features = ["i128"]
 digest = { version = "0.8", default-features = false }
 clear_on_drop = "=0.2.3"
 subtle = { version = "2", default-features = false }
-serde = { version = "1.0", default-features = false, optional = true }
+serde = { version = "1.0", default-features = false, optional = true, features = ["derive"] }
 packed_simd = { version = "0.3.0", features = ["into_bits"], optional = true }
 
 [features]
diff --git a/src/montgomery.rs b/src/montgomery.rs
index 8b99bb5..a89de22 100644
--- a/src/montgomery.rs
+++ b/src/montgomery.rs
@@ -64,6 +64,7 @@ use subtle::ConstantTimeEq;
 /// Holds the \\(u\\)-coordinate of a point on the Montgomery form of
 /// Curve25519 or its twist.
 #[derive(Copy, Clone, Debug)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct MontgomeryPoint(pub [u8; 32]);
 
 /// Equality of `MontgomeryPoint`s is defined mod p.
@@ -312,6 +313,22 @@ mod test {
     #[cfg(feature = "rand")]
     use rand_os::OsRng;
 
+    #[test]
+    #[cfg(feature = "serde")]
+    fn serde_bincode_basepoint_roundtrip() {
+        use bincode;
+
+        let encoded = bincode::serialize(&constants::X25519_BASEPOINT).unwrap();
+        let decoded: MontgomeryPoint = bincode::deserialize(&encoded).unwrap();
+
+        assert_eq!(encoded.len(), 32);
+        assert_eq!(decoded, constants::X25519_BASEPOINT);
+
+        let raw_bytes = constants::X25519_BASEPOINT.as_bytes();
+        let bp: MontgomeryPoint = bincode::deserialize(raw_bytes).unwrap();
+        assert_eq!(bp, constants::X25519_BASEPOINT);
+    }
+
     /// Test Montgomery -> Edwards on the X/Ed25519 basepoint
     #[test]
     fn basepoint_montgomery_to_edwards() {