elliptic-curve: bump crypto-bigint to v0.7.0-rc.1 (#1967)

This isn't ideal but gets the crate upgraded.

I would like to experiment with changing `Curve::ORDER` to `NonZero` or
`Odd` as a better solution

Author: tarcieri

Cargo.lock

@@ -18,7 +18,7 @@ and public/secret keys composed thereof.
 
 [dependencies]
 base16ct = "0.2"
-crypto-bigint = { version = "0.7.0-rc.0", default-features = false, features = ["rand_core", "hybrid-array", "zeroize"] }
+crypto-bigint = { version = "0.7.0-rc.1", default-features = false, features = ["rand_core", "hybrid-array", "zeroize"] }
 hybrid-array = { version = "0.3", default-features = false, features = ["zeroize"] }
 rand_core = { version = "0.9.0", default-features = false }
 subtle = { version = "2.6", default-features = false }

elliptic-curve/Cargo.toml

@@ -179,6 +179,7 @@ pub trait Curve: 'static + Copy + Clone + Debug + Default + Eq + Ord + Send + Sy
 
     /// Order of this elliptic curve, i.e. number of elements in the scalar
     /// field.
+    // TODO(tarcieri): make `NonZero` or `Odd`?
     const ORDER: Self::Uint;
 }
 

elliptic-curve/src/lib.rs

@@ -62,6 +62,7 @@ where
     };
 
     /// Scalar modulus.
+    // TODO(tarcieri): make `NonZero` or `Odd`?
     pub const MODULUS: C::Uint = C::ORDER;
 
     /// Generate a random [`ScalarPrimitive`].
@@ -254,7 +255,9 @@ where
 
     fn add(self, other: &Self) -> Self {
         Self {
-            inner: self.inner.add_mod(&other.inner, &Self::MODULUS),
+            inner: self
+                .inner
+                .add_mod(&other.inner, &NonZero::new(Self::MODULUS).unwrap()),
         }
     }
 }
@@ -296,7 +299,9 @@ where
 
     fn sub(self, other: &Self) -> Self {
         Self {
-            inner: self.inner.sub_mod(&other.inner, &Self::MODULUS),
+            inner: self
+                .inner
+                .sub_mod(&other.inner, &NonZero::new(Self::MODULUS).unwrap()),
         }
     }
 }
@@ -327,7 +332,7 @@ where
 
     fn neg(self) -> Self {
         Self {
-            inner: self.inner.neg_mod(&Self::MODULUS),
+            inner: self.inner.neg_mod(&NonZero::new(Self::MODULUS).unwrap()),
         }
     }
 }