Merge branch 'release/3.2' into main

CHANGELOG.md

@@ -5,6 +5,12 @@ major series.
 
 ## 3.x series
 
+### 3.2.0
+
+* Add support for getting the identity element for the Montgomery
+  form of curve25519, which is useful in certain protocols for
+  checking contributory behaviour in derivation of shared secrets.
+
 ### 3.1.2
 
 * Revert a commit which mistakenly removed support for `zeroize` traits
@@ -37,7 +43,7 @@ major series.
 
 ### 3.0.2
 
-* Multiple documenation typo fixes.
+* Multiple documentation typo fixes.
 * Fixes to make using `alloc`+`no_std` possible for stable Rust.
 
 ### 3.0.1

Cargo.toml

@@ -5,7 +5,7 @@ name = "curve25519-dalek"
 # - update html_root_url
 # - update README if required by semver
 # - if README was updated, also update module documentation in src/lib.rs
-version = "3.1.2"
+version = "3.2.0"
 authors = ["Isis Lovecruft <isis@patternsinthevoid.net>",
            "Henry de Valence <hdevalence@hdevalence.ca>"]
 readme = "README.md"

README.md

@@ -207,7 +207,13 @@ optimised batch inversion was contributed by Sean Bowe and Daira Hopwood.
 
 The `no_std` and `zeroize` support was contributed by Tony Arcieri.
 
-Thanks also to Ashley Hauck, Lucas Salibian, and Manish Goregaokar for their
+The formally verified backends, `fiat_u32_backend` and `fiat_u64_backend`, which
+integrate with the Rust generated by the
+[Fiat Crypto project](https://github.com/mit-plv/fiat-crypto) were contributed
+by François Garillot.
+
+Thanks also to Ashley Hauck, Lucas Salibian, Manish Goregaokar, Jack Grigg,
+Pratyush Mishra, Michael Rosenberg, and countless others for their
 contributions.
 
 [ed25519-dalek]: https://github.com/dalek-cryptography/ed25519-dalek

src/lib.rs

@@ -18,7 +18,7 @@
 #![deny(missing_docs)]
 
 #![doc(html_logo_url = "https://doc.dalek.rs/assets/dalek-logo-clear.png")]
-#![doc(html_root_url = "https://docs.rs/curve25519-dalek/3.1.2")]
+#![doc(html_root_url = "https://docs.rs/curve25519-dalek/3.2.0")]
 
 //! # curve25519-dalek [![](https://img.shields.io/crates/v/curve25519-dalek.svg)](https://crates.io/crates/curve25519-dalek) [![](https://img.shields.io/badge/dynamic/json.svg?label=docs&uri=https%3A%2F%2Fcrates.io%2Fapi%2Fv1%2Fcrates%2Fcurve25519-dalek%2Fversions&query=%24.versions%5B0%5D.num&colorB=4F74A6)](https://doc.dalek.rs) [![](https://travis-ci.org/dalek-cryptography/curve25519-dalek.svg?branch=master)](https://travis-ci.org/dalek-cryptography/curve25519-dalek)
 //!

src/montgomery.rs

@@ -94,6 +94,13 @@ impl PartialEq for MontgomeryPoint {
 
 impl Eq for MontgomeryPoint {}
 
+impl Identity for MontgomeryPoint {
+    /// Return the group identity element, which has order 4.
+    fn identity() -> MontgomeryPoint {
+        MontgomeryPoint([0u8; 32])
+    }
+}
+
 impl Zeroize for MontgomeryPoint {
     fn zeroize(&mut self) {
         self.0.zeroize();
@@ -351,6 +358,19 @@ mod test {
 
     use rand_core::OsRng;
 
+    #[test]
+    fn identity_in_different_coordinates() {
+        let id_projective = ProjectivePoint::identity();
+        let id_montgomery = id_projective.to_affine();
+
+        assert!(id_montgomery == MontgomeryPoint::identity());
+    }
+
+    #[test]
+    fn identity_in_different_models() {
+        assert!(EdwardsPoint::identity().to_montgomery() == MontgomeryPoint::identity());
+    }
+
     #[test]
     #[cfg(feature = "serde")]
     fn serde_bincode_basepoint_roundtrip() {