update

Cargo.lock

@@ -9,20 +9,36 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c08606f8c3cbf4ce6ec8e28fb0014a2c086708fe954eaa885384a6165172e7e8"
 
 [[package]]
-name = "cfg-if"
+name = "cmov"
-version = "1.0.3"
+version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2fd1289c04a9ea8cb22300a459a72a385d7c73d3259e2ed7dcb2af674838cfa9"
+checksum = "de0758edba32d61d1fd9f4d69491b47604b91ee2f7e6b33de7e54ca4ebe55dc3"
+
+[[package]]
+name = "cpubits"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5ef0c543070d296ea414df2dd7625d1b24866ce206709d8a4a424f28377f5861"
 
 [[package]]
 name = "crypto-bigint"
-version = "0.6.1"
+version = "0.7.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "96272c2ff28b807e09250b180ad1fb7889a3258f7455759b5c3c58b719467130"
+checksum = "9fde2467e74147f492aebb834985186b2c74761927b8b9b3bd303bcb2e72199d"
 dependencies = [
+ "cpubits",
+ "ctutils",
  "num-traits",
  "rand_core",
- "subtle",
+]
+
+[[package]]
+name = "ctutils"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1005a6d4446f5120ef475ad3d2af2b30c49c2c9c6904258e3bb30219bebed5e4"
+dependencies = [
+ "cmov",
 ]
 
 [[package]]
@@ -33,23 +49,6 @@ dependencies = [
  "zeroize",
 ]
 
-[[package]]
-name = "getrandom"
-version = "0.2.16"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "335ff9f135e4384c8150d6f27c6daed433577f86b4750418338c01a1a2528592"
-dependencies = [
- "cfg-if",
- "libc",
- "wasi",
-]
-
-[[package]]
-name = "libc"
-version = "0.2.176"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "58f929b4d672ea937a23a1ab494143d968337a5f47e56d0815df1e0890ddf174"
-
 [[package]]
 name = "num-traits"
 version = "0.2.19"
@@ -61,24 +60,9 @@ dependencies = [
 
 [[package]]
 name = "rand_core"
-version = "0.6.4"
+version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+checksum = "0c8d0fd677905edcbeedbf2edb6494d676f0e98d54d5cf9bda0b061cb8fb8aba"
-dependencies = [
- "getrandom",
-]
-
-[[package]]
-name = "subtle"
-version = "2.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
-
-[[package]]
-name = "wasi"
-version = "0.11.1+wasi-snapshot-preview1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
 
 [[package]]
 name = "zeroize"

Cargo.toml

@@ -4,11 +4,11 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
-crypto-bigint = { version = "0.6.1" }
+crypto-bigint = { version = "0.7.1" }
 zeroize = { version = "1.8.2", optional = true }
 
 [features]
-rand = ["crypto-bigint/rand"]
+rand = ["crypto-bigint/rand_core"]
 edwards = []
 zeroize = ["dep:zeroize"]
 

src/lib.rs

@@ -6,13 +6,12 @@ pub mod edwards;
 pub mod montgomery;
 pub mod traits;
 
-use crypto_bigint::subtle::{Choice, ConstantTimeEq};
+pub use crypto_bigint::{Encoding, NonZero, U256};
-pub use crypto_bigint::{ConstChoice, Encoding, NonZero, U256};
-
-#[cfg(feature = "rand")]
-use crypto_bigint::{rand_core::OsRng, Random};
 
 use crate::traits::{Curve, Point};
+use crypto_bigint::{Choice, CtEq, EncodedUint};
+#[cfg(feature = "rand")]
+use crypto_bigint::{Random, rand_core::OsRng};
 pub(crate) use montgomery::*;
 
 #[derive(Debug, Clone, Copy, Eq, PartialEq)]
@@ -29,13 +28,13 @@ impl From<&Secret> for Public {
 
 impl From<[u8; 32]> for Public {
     fn from(bytes: [u8; 32]) -> Public {
-        Public(U256::from_le_bytes(bytes))
+        Public(U256::from_le_bytes(EncodedUint::from(bytes)))
     }
 }
 
 impl Public {
     pub fn as_bytes(&self) -> [u8; 32] {
-        self.0.to_le_bytes()
+        self.0.to_le_bytes().into()
     }
 }
 
@@ -53,7 +52,7 @@ impl Secret {
         let point = CURVE_25519.point(public.0);
         let p = point * self.0;
 
-        SharedSecret(p.get_x().to_le_bytes())
+        SharedSecret(p.get_x().to_le_bytes().into())
     }
 }
 
@@ -72,7 +71,7 @@ impl SharedSecret {
     }
 }
 
-impl ConstantTimeEq for SharedSecret {
+impl CtEq for SharedSecret {
     fn ct_eq(&self, other: &Self) -> Choice {
         self.0.ct_eq(&other.0)
     }
@@ -109,7 +108,7 @@ mod tests {
 
         let x_k =
             U256::from_be_hex("0933dc6ed7122bdf2a5f1b0516e218b743868769778787cfa1ac0ae2dfa89891");
-        assert_eq!(x.0, x_k.to_le_bytes());
+        assert_eq!(x.0, <[u8; 32]>::from(x_k.to_le_bytes()));
     }
 
     #[test]
@@ -125,6 +124,9 @@ mod tests {
         let sa = a.diffie_hellman(&pb);
         let sb = b.diffie_hellman(&pa);
 
-        assert!(bool::from(sa.ct_eq(&sb)));
+        assert!(
+            bool::from(sa.ct_eq(&sb)),
+            "Didn't compute same shared secret"
+        );
     }
 }

src/macros.rs

@@ -1,15 +1,17 @@
+
 #[macro_export]
 macro_rules! ladder_impl {
     ($point:ident, $swap_fn:ident) => {
-        impl<N> $point<N>
+        impl<N: BitOps> $point<N>
         where
-            N: AddMod
+            N: AddMod<Output = N>
-                + SubMod
+                + SubMod<Output = N>
                 + MulMod<Output = N>
-                + InvMod<Output = N>
+                + InvertMod<Output = N>
                 + Copy
                 + Integer
                 + Div<Output = N>,
+            N: std::convert::From<u8>,
         {
             pub fn ladder(&self, rhs: &N) -> $point<N> {
                 let mut x_0 = *self;

src/montgomery.rs

@@ -1,6 +1,7 @@
 use crate::traits::{Curve, Point};
-use crypto_bigint::{AddMod, Encoding, NonZero, SubMod, U256};
+use crypto_bigint::{AddMod, EncodedUint, Encoding, InvertMod, NonZero, SubMod, U256};
-use crypto_bigint::{Integer, InvMod, MulMod};
+use crypto_bigint::{BitOps, Uint};
+use crypto_bigint::{Integer, MulMod};
 use std::fmt::{Display, Formatter};
 use std::ops::{BitXor, Div, Mul};
 
@@ -8,18 +9,23 @@ use std::ops::{BitXor, Div, Mul};
 #[derive(Clone, Copy, Debug)]
 pub struct MontgomeryCurve<N>
 where
-    N: AddMod + SubMod + MulMod + InvMod + Integer + Copy,
+    N: AddMod + SubMod + MulMod + InvertMod + Integer + Copy,
 {
     pub a: N,
     pub b: N,
-    pub p: N,
+    pub p: NonZero<N>,
 }
 
 impl<N> MontgomeryCurve<N>
 where
-    N: AddMod + SubMod + MulMod + InvMod + Copy + Integer,
+    N: AddMod<Output = N>
+        + SubMod<Output = N>
+        + MulMod<Output = N>
+        + InvertMod<Output = N>
+        + Copy
+        + Integer,
 {
-    pub const fn new(a: N, b: N, p: N) -> MontgomeryCurve<N> {
+    pub const fn new(a: N, b: N, p: NonZero<N>) -> MontgomeryCurve<N> {
         MontgomeryCurve { a, b, p }
     }
 
@@ -36,7 +42,15 @@ where
 
 impl<N> Curve<MontgomeryPoint<N>, N> for MontgomeryCurve<N>
 where
-    N: AddMod + SubMod + MulMod + InvMod<Output = N> + Copy + Integer + Div<Output = N>,
+    N: AddMod<Output = N>
+        + SubMod<Output = N>
+        + MulMod<Output = N>
+        + InvertMod<Output = N>
+        + Copy
+        + Integer
+        + Div<Output = N>
+        + std::convert::From<u8>
+        + BitOps,
 {
     /// Get the point at an x-coordinate with parameters from this curve.
     fn point(self, x: N) -> MontgomeryPoint<N> {
@@ -53,20 +67,27 @@ where
 }
 
 pub fn clamp_u256(x: U256) -> U256 {
-    let mut bytes: [u8; 32] = x.to_le_bytes();
+    let mut bytes: [u8; 32] = x.to_le_bytes().into();
 
     // clamp value
     bytes[0] &= 248;
     bytes[31] &= 127;
     bytes[31] |= 64;
 
-    U256::from_le_bytes(bytes)
+    U256::from_le_bytes(EncodedUint::from(bytes))
 }
 
 #[derive(Copy, Debug, Clone)]
 pub struct MontgomeryPoint<N>
 where
-    N: AddMod + SubMod + Div<Output = N> + MulMod<Output = N> + InvMod<Output = N> + Copy + Integer,
+    N: AddMod<Output = N>
+        + SubMod<Output = N>
+        + Div<Output = N>
+        + MulMod<Output = N>
+        + InvertMod<Output = N>
+        + Copy
+        + Integer
+        + From<u8>,
 {
     pub x: N,
     pub z: N,
@@ -76,24 +97,23 @@ where
 
 impl<N> Point<N> for MontgomeryPoint<N>
 where
-    N: AddMod
+    N: AddMod<Output = N>
-        + SubMod
+        + SubMod<Output = N>
         + Div<Output = N>
         + MulMod<Output = N>
-        + InvMod<Output = N>
+        + InvertMod<Output = N>
         + Copy
         + Integer
-        + From<u8>,
+        + From<u8>
+        + BitOps,
 {
     fn get_x(self) -> N {
-        self.x.mul_mod(
+        self.x
-            &self.z.inv_mod(&self.curve.p).unwrap(),
+            .mul_mod(&self.z.invert_mod(&self.curve.p).unwrap(), &self.curve.p)
-            &NonZero::new(self.curve.p).unwrap(),
-        )
     }
 
     fn add(&self, rhs: &Self, neg: &Self) -> Self {
-        let p = &NonZero::new(self.curve.p).unwrap();
+        let p = &self.curve.p;
 
         let mut v_0 = self.x.add_mod(&self.z, p); // 1: V_0 = X_P + Z_P
         let mut v_1 = rhs.x.sub_mod(&rhs.z, p); // 2: V_1 = X_Q - Z_Q
@@ -120,7 +140,7 @@ where
     }
 
     fn double(&self) -> MontgomeryPoint<N> {
-        let p = &NonZero::new(self.curve.p).unwrap();
+        let p = &self.curve.p;
 
         let mut v_1 = self.x.add_mod(&self.z, p);
         v_1 = v_1.mul_mod(&v_1, p);
@@ -162,7 +182,16 @@ ladder_impl!(MontgomeryPoint, swap_montgomery);
 
 fn swap_montgomery<N>(a: &mut MontgomeryPoint<N>, b: &mut MontgomeryPoint<N>, c: u8, max: N)
 where
-    N: BitXor + Copy + Mul<Output = N> + From<u8> + Div<Output = N> + Integer + InvMod<Output = N>,
+    N: BitXor
+        + Copy
+        + Mul<Output = N>
+        + From<u8>
+        + Div<Output = N>
+        + Integer
+        + InvertMod<Output = N>
+        + AddMod<Output = N>
+        + MulMod<Output = N>
+        + SubMod<Output = N>,
 {
     let m = max * N::from(c);
 
@@ -178,14 +207,15 @@ where
 
 impl<N> Display for MontgomeryPoint<N>
 where
-    N: AddMod
+    N: AddMod<Output = N>
-        + SubMod
+        + SubMod<Output = N>
-        + MulMod
+        + MulMod<Output = N>
-        + InvMod<Output = N>
+        + InvertMod<Output = N>
         + Copy
         + Integer
         + Display
-        + std::ops::Div<Output = N>,
+        + Div<Output = N>
+        + From<u8>,
 {
     fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
         f.write_fmt(format_args!("({} : {})", self.x, self.z))
@@ -194,7 +224,15 @@ where
 
 impl<N> Mul<N> for MontgomeryPoint<N>
 where
-    N: AddMod + SubMod + MulMod + InvMod<Output = N> + Copy + Integer + std::ops::Div<Output = N>,
+    N: AddMod<Output = N>
+        + SubMod<Output = N>
+        + MulMod<Output = N>
+        + InvertMod<Output = N>
+        + Copy
+        + Integer
+        + Div<Output = N>
+        + std::convert::From<u8>
+        + BitOps,
 {
     type Output = MontgomeryPoint<N>;
 
@@ -211,7 +249,10 @@ where
 pub const CURVE_25519: MontgomeryCurve<U256> = MontgomeryCurve::new(
     U256::from_u32(486662u32),
     U256::ONE,
-    U256::ONE.shl(255).sub_mod(&U256::from_u8(19), &U256::MAX),
+    NonZero::<Uint<4>>::new_unwrap(U256::ONE.shl(255).sub_mod(
+        &U256::from_u8(19),
+        &NonZero::<Uint<4>>::new_unwrap(U256::MAX),
+    )),
 );
 
 #[cfg(test)]

src/traits.rs

@@ -1,9 +1,9 @@
-use crypto_bigint::{AddMod, InvMod, MulMod, SubMod};
+use crypto_bigint::{AddMod, InvertMod, MulMod, SubMod};
 
 pub trait Curve<T, N>
 where
     T: Point<N>,
-    N: AddMod<Output = N> + SubMod<Output = N> + MulMod<Output = N> + InvMod<Output = N> + Copy,
+    N: AddMod<Output = N> + SubMod<Output = N> + MulMod<Output = N> + InvertMod<Output = N> + Copy,
 {
     fn point(self, x: N) -> T;
     fn generator(self) -> T;
@@ -11,7 +11,7 @@ where
 
 pub trait Point<N>
 where
-    N: AddMod + SubMod + MulMod + InvMod + Copy,
+    N: AddMod<Output = N> + SubMod<Output = N> + MulMod<Output = N> + InvertMod<Output = N> + Copy,
 {
     fn get_x(self) -> N;