From 3a9f7ba49dc0358456f23748d0782d82d631bcae Mon Sep 17 00:00:00 2001
From: dAxpeDDa <daxpedda@gmail.com>
Date: Sat, 24 Jun 2023 14:15:15 +0200
Subject: [PATCH] Bump `curve25519-dalek` to v4.0.0-rc.3

---
 Cargo.toml                           |  5 ++++-
 src/key_exchange/group/curve25519.rs | 25 ++++++++++++-------------
 2 files changed, 16 insertions(+), 14 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index f094272c..7f5538d9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -24,7 +24,7 @@ std = ["dep:getrandom"]
 argon2 = { version = "0.5", default-features = false, features = [
   "alloc",
 ], optional = true }
-curve25519-dalek = { version = "=4.0.0-rc.2", default-features = false, features = [
+curve25519-dalek = { version = "=4.0.0-rc.3", default-features = false, features = [
   "zeroize",
 ], optional = true }
 derive-where = { version = "1", features = ["zeroize-on-drop"] }
@@ -81,3 +81,6 @@ targets = []
 [[example]]
 name = "simple_login"
 required-features = ["argon2"]
+
+[patch.crates-io]
+voprf = { git = "https://github.com/khonsulabs/voprf", branch = "curve25519-dalek-4.0.0-rc.3" }
diff --git a/src/key_exchange/group/curve25519.rs b/src/key_exchange/group/curve25519.rs
index 8f7a3a4f..25a8b559 100644
--- a/src/key_exchange/group/curve25519.rs
+++ b/src/key_exchange/group/curve25519.rs
@@ -8,9 +8,8 @@
 
 //! Key Exchange group implementation for Curve25519
 
-use curve25519_dalek::constants::X25519_BASEPOINT;
 use curve25519_dalek::montgomery::MontgomeryPoint;
-use curve25519_dalek::scalar::Scalar;
+use curve25519_dalek::scalar::{self, Scalar};
 use curve25519_dalek::traits::Identity;
 use digest::core_api::BlockSizeUser;
 use digest::{FixedOutput, HashMarker, OutputSizeUser};
@@ -29,7 +28,7 @@ pub struct Curve25519;
 impl KeGroup for Curve25519 {
     type Pk = MontgomeryPoint;
     type PkLen = U32;
-    type Sk = Scalar;
+    type Sk = [u8; 32];
     type SkLen = U32;
 
     fn serialize_pk(pk: Self::Pk) -> GenericArray<u8, Self::PkLen> {
@@ -50,9 +49,9 @@ impl KeGroup for Curve25519 {
             // Sample 32 random bytes and then clamp, as described in https://cr.yp.to/ecdh.html
             let mut scalar_bytes = [0u8; 32];
             rng.fill_bytes(&mut scalar_bytes);
-            let scalar = Scalar::from_bits_clamped(scalar_bytes);
+            let scalar = scalar::clamp_integer(scalar_bytes);
 
-            if scalar != Scalar::ZERO {
+            if scalar != Scalar::ZERO.to_bytes() {
                 break scalar;
             }
         }
@@ -73,23 +72,23 @@ impl KeGroup for Curve25519 {
         <CS::Hash as OutputSizeUser>::OutputSize:
             IsLess<U256> + IsLessOrEqual<<CS::Hash as BlockSizeUser>::BlockSize>,
     {
-        Ok(Scalar::from_bits_clamped(seed.into()))
+        Ok(scalar::clamp_integer(seed.into()))
     }
 
     fn is_zero_scalar(scalar: Self::Sk) -> subtle::Choice {
-        scalar.ct_eq(&Scalar::ZERO)
+        scalar.ct_eq(&Scalar::ZERO.to_bytes())
     }
 
     fn public_key(sk: Self::Sk) -> Self::Pk {
-        X25519_BASEPOINT * sk
+        MontgomeryPoint::mul_base_clamped(sk)
     }
 
     fn diffie_hellman(pk: Self::Pk, sk: Self::Sk) -> GenericArray<u8, Self::PkLen> {
-        Self::serialize_pk(sk * pk)
+        Self::serialize_pk(pk.mul_clamped(sk))
     }
 
     fn serialize_sk(sk: Self::Sk) -> GenericArray<u8, Self::SkLen> {
-        sk.to_bytes().into()
+        sk.into()
     }
 
     fn deserialize_sk(bytes: &[u8]) -> Result<Self::Sk, InternalError> {
@@ -97,10 +96,10 @@ impl KeGroup for Curve25519 {
             .try_into()
             .ok()
             .and_then(|bytes| {
-                let scalar = Scalar::from_bits_clamped(bytes);
-                (scalar.as_bytes() == &bytes).then_some(scalar)
+                let scalar = scalar::clamp_integer(bytes);
+                (scalar == bytes).then_some(scalar)
             })
-            .filter(|scalar| scalar != &Scalar::ZERO)
+            .filter(|scalar| scalar != &Scalar::ZERO.to_bytes())
             .ok_or(InternalError::PointError)
     }
 }