ec: implement double-odd curves

curves/Cargo.toml

@@ -42,6 +42,7 @@ members = [
     "ed25519",
 
     "starkcurve",
+    "jq255s",
 ]
 resolver = "2"
 

curves/jq255s/Cargo.toml

@@ -0,0 +1,38 @@
+[package]
+name = "ark-jq255s"
+version.workspace = true
+authors.workspace = true
+description = "The do255s curve"
+homepage.workspace = true
+repository.workspace = true
+documentation = "https://docs.rs/ark-secp256r1/"
+keywords.workspace = true
+categories.workspace = true
+include.workspace = true
+license.workspace = true
+edition.workspace = true
+
+[dependencies]
+ark-ff = { workspace = true }
+ark-ec = { workspace = true }
+ark-r1cs-std = { workspace = true, optional = true }
+ark-std = { workspace = true }
+hex = "0.4.3"
+
+[dev-dependencies]
+ark-relations = { workspace = true }
+ark-serialize = { workspace = true }
+ark-algebra-test-templates = { workspace = true }
+ark-curve-constraint-tests = { path = "../curve-constraint-tests" }
+
+[features]
+default = []
+std = [ "ark-std/std", "ark-ff/std", "ark-ec/std" ]
+r1cs = [ "ark-r1cs-std" ]
+asm = [ "ark-ff/asm" ]
+
+#[patch.crates-io]
+#ark-ec = { path = "../../algebra/ec" }
+#ark-ff = { path = "../../algebra/ff" }
+#ark-poly = { path = "../../algebra/poly"  }
+#ark-serialize = {  path = "../../algebra/serialize" }

curves/jq255s/LICENSE-APACHE

@@ -0,0 +1 @@
+../LICENSE-APACHE

curves/jq255s/LICENSE-MIT

@@ -0,0 +1 @@
+../LICENSE-MIT

curves/jq255s/src/constraints/curves.rs

@@ -0,0 +1,5 @@
+use crate::{constraints::FqVar, *};
+use ark_r1cs_std::groups::curves::short_weierstrass::ProjectiveVar;
+
+/// A group element in the Jq255s curve.
+pub type GVar = ProjectiveVar<Config, FqVar>;

curves/jq255s/src/constraints/fields.rs

@@ -0,0 +1,11 @@
+use ark_r1cs_std::fields::fp::FpVar;
+
+use crate::fq::Fq;
+
+/// A variable that is the R1CS equivalent of `crate::Fq`.
+pub type FqVar = FpVar<Fq>;
+
+#[test]
+fn test() {
+    ark_curve_constraint_tests::fields::field_test::<_, _, FqVar>().unwrap();
+}

curves/jq255s/src/constraints/mod.rs

@@ -0,0 +1,7 @@
+//! This module implements the R1CS equivalent of `ark_jq255s`.
+
+mod curves;
+mod fields;
+
+pub use curves::*;
+pub use fields::*;

curves/jq255s/src/curves/mod.rs

@@ -0,0 +1,48 @@
+use ark_ec::{
+    double_odd::{self as doo, DOCurveConfig},
+    models::CurveConfig,
+};
+use ark_ff::MontFp;
+
+use crate::{fq::Fq, fr::Fr};
+
+#[cfg(test)]
+mod tests;
+
+pub type Affine = doo::Affine<Config>;
+pub type Projective = doo::Projective<Config>;
+
+#[derive(Copy, Clone, Default, PartialEq, Eq)]
+pub struct Config;
+
+impl CurveConfig for Config {
+    type BaseField = Fq;
+    type ScalarField = Fr;
+
+    /// COFACTOR = 2
+    const COFACTOR: &'static [u64] = &[2];
+
+    #[rustfmt::skip]
+    const COFACTOR_INV: Fr = MontFp!("14474011154664524427946373126085988481687200150840406918337755177497658435940");
+}
+
+impl DOCurveConfig for Config {
+    /// COEFF_A = -1
+    const COEFF_A: Fq = MontFp!("-1");
+
+    /// COEFF_B = 1/2
+    const COEFF_B: Fq =
+        MontFp!("28948022309329048855892746252171976963317496166410141009864396001978282408006");
+
+    /// GENERATOR = (G_GENERATOR_X, G_GENERATOR_Y)
+    const GENERATOR: Affine = Affine::new_unchecked(G_GENERATOR_E, G_GENERATOR_U);
+}
+
+/// G_GENERATOR_X =
+/// 0x0076aab95b2acbae4747482ba7081f7b94193dad9f96fdd2516283980459b09eaa
+pub const G_GENERATOR_E: Fq =
+    MontFp!("6929650852805837546485348833751579670837850621479164143703164723313568683024");
+
+/// G_GENERATOR_Y =
+/// 0x00b7d601b4cb25f8249b65e89b8f584a5494e592f3895d54f9002202b0530e6fbc
+pub const G_GENERATOR_U: Fq = MontFp!("3");