primefield: use const_prime_monty_params! (#1674)

Uses the built in prime modulus support in `crypto-bigint`.

We should be able to further leverage this to replace our modular square
root implementation, but for starters this just uses the new macro to
define the modulus type/constant.

Author: tarcieri

Cargo.lock

@@ -676,7 +676,7 @@ impl<C: CurveWithScalar> Scalar<C> {
 
     /// Square this scalar
     pub const fn square(&self) -> Self {
-        let value = self.scalar.square_wide();
+        let value = self.scalar.widening_square();
         Self::new(U448::rem_wide_vartime(value, ORDER.as_nz_ref()))
     }
 

ed448-goldilocks/src/field/scalar.rs

@@ -16,8 +16,13 @@ keywords = ["crypto", "ecc", "field", "prime"]
 edition = "2024"
 rust-version = "1.85"
 
+[dependencies.bigint]
+version = "0.7.0-rc.28"
+package = "crypto-bigint"
+default-features = false
+features = ["rand_core", "hybrid-array", "subtle"]
+
 [dependencies]
-bigint = { package = "crypto-bigint", version = "0.7.0-rc.27", default-features = false, features = ["rand_core", "hybrid-array", "subtle"] }
 common = { package = "crypto-common", version = "0.2", features = ["rand_core"] }
 ff = { version = "0.14.0-rc.0", package = "rustcrypto-ff", default-features = false }
 subtle = { version = "2.6", default-features = false, features = ["const-generics"] }

primefield/Cargo.toml

@@ -37,7 +37,7 @@ macro_rules! monty_field_params {
     ) => {
         use $crate::bigint::modular::ConstMontyParams;
 
-        $crate::bigint::const_monty_params!($name, $uint, $modulus_hex, $doc);
+        $crate::bigint::const_prime_monty_params!($name, $uint, $modulus_hex, $doc);
 
         impl $crate::MontyFieldParams<{ <$uint>::LIMBS }> for $name {
             type ByteSize = $crate::bigint::hybrid_array::typenum::U<