restructure: crate

Cargo.toml

@@ -1,13 +1,30 @@
 [package]
 name = "semaphore-rs"
 version = "0.1.0"
-edition = "2021"
+edition = "2024"
 
 [dependencies]
-anyhow = "1.0.95"
-ethers-core = "2.0.14"
+blake = "2.0.2"
 light-poseidon = "0.3.0"
 num-bigint = "0.4.6"
-ruint = "1.12.4"
-leanimt-rs = { git = "https://github.com/vplasencia/leanimt-rs" } 
-ark-bn254 = "0.5.0"
+thiserror = "2.0.12"
+
+# arkworks
+ark-ec = { version = "=0.5.0", default-features = false }
+ark-ed-on-bn254 = { version = "=0.5.0", default-features = false }
+ark-ff = { version = "=0.5.0", default-features = false }
+
+# zk-kit
+zk-kit-lean-imt = { git = "https://github.com/brech1/zk-kit.rust", package = "zk-kit-lean-imt", branch = "feat/generic-tree" }
+
+# serde
+serde = { version = "1", features = ["derive"], optional = true }
+serde_json = { version = "1", optional = true }
+
+[features]
+default = []
+serde = [
+    "dep:serde",
+    "serde_json",    
+    "zk-kit-lean-imt/serde"  
+]

src/baby_jubjub.rs

@@ -0,0 +1,201 @@
+//! EIP-2494 Baby Jubjub Curve
+//!
+//! This is an append to the the `ark-ed-on-bn254` crate to use the EIP-2494 defined Baby Jubjub curve parameters.
+//!
+//! - https://eips.ethereum.org/EIPS/eip-2494
+//!
+//! - Base field: q = 21888242871839275222246405745257275088548364400416034343698204186575808495617
+//! - Scalar field: r = 2736030358979909402780800718157159386076813972158567259200215660948447373041
+//! - Order: n = l * cofactor = 21888242871839275222246405745257275088614511777268538073601725287587578984328
+//! - Cofactor: 8
+//! - Subgroup order: l = 2736030358979909402780800718157159386076813972158567259200215660948447373041
+//! - Curve equation: ax² + y² = 1 + d·x²y², where
+//!    - a = 168700
+//!    - d = 168696
+//! - Generator point:
+//!   (995203441582195749578291179787384436505546430278305826713579947235728471134,
+//!   5472060717959818805561601436314318772137091100104008585924551046643952123905)
+//! - Base point:
+//!   (5299619240641551281634865583518297030282874472190772894086521144482721001553,
+//!   16950150798460657717958625567821834550301663161624707787222815936182638968203)
+
+use ark_ec::{
+    models::CurveConfig,
+    twisted_edwards::{Affine, MontCurveConfig, Projective, TECurveConfig},
+};
+use ark_ed_on_bn254::{Fq, Fr};
+use ark_ff::{Field, MontFp};
+
+pub type EdwardsAffine = Affine<BabyJubjubConfig>;
+pub type EdwardsProjective = Projective<BabyJubjubConfig>;
+
+#[derive(Clone, Default, PartialEq, Eq)]
+pub struct BabyJubjubConfig;
+
+impl CurveConfig for BabyJubjubConfig {
+    type BaseField = Fq;
+    type ScalarField = Fr;
+
+    // h = 8
+    const COFACTOR: &'static [u64] = &[8];
+
+    // h^(-1) (mod r)
+    const COFACTOR_INV: Fr =
+        MontFp!("2394026564107420727433200628387514462817212225638746351800188703329891451411");
+}
+
+// Twisted Edwards form
+// ax^2 + y^2 = 1 + dx^2y^2
+impl TECurveConfig for BabyJubjubConfig {
+    // a = 168700
+    const COEFF_A: Fq = MontFp!("168700");
+
+    #[inline(always)]
+    fn mul_by_a(elem: Self::BaseField) -> Self::BaseField {
+        elem * <BabyJubjubConfig as TECurveConfig>::COEFF_A
+    }
+
+    // d = 168696
+    const COEFF_D: Fq = MontFp!("168696");
+
+    // Base point is used as generator to operate in subgroup
+    const GENERATOR: EdwardsAffine = EdwardsAffine::new_unchecked(BASE_X, BASE_Y);
+
+    type MontCurveConfig = BabyJubjubConfig;
+}
+
+// Montgomery form
+// By^2 = x^3 + A x^2 + x
+impl MontCurveConfig for BabyJubjubConfig {
+    // A = 168698
+    const COEFF_A: Fq = MontFp!("168698");
+    // B = 1
+    const COEFF_B: Fq = Fq::ONE;
+
+    type TECurveConfig = BabyJubjubConfig;
+}
+
+/// Generator point x-coordinate
+pub const GENERATOR_X: Fq =
+    MontFp!("995203441582195749578291179787384436505546430278305826713579947235728471134");
+/// Generator point y-coordinate
+pub const GENERATOR_Y: Fq =
+    MontFp!("5472060717959818805561601436314318772137091100104008585924551046643952123905");
+
+/// Subgroup order `l`
+pub const SUBGROUP_ORDER: Fr =
+    MontFp!("2736030358979909402780800718157159386076813972158567259200215660948447373041");
+
+// Subgroup generator
+// Generates subgroup l * P = O
+
+/// Base point x-coordinate
+pub const BASE_X: Fq =
+    MontFp!("5299619240641551281634865583518297030282874472190772894086521144482721001553");
+/// Base point y-coordinate
+pub const BASE_Y: Fq =
+    MontFp!("16950150798460657717958625567821834550301663161624707787222815936182638968203");
+
+#[cfg(test)]
+mod tests {
+    //! Implementation of the tests presented in the EIP-2494
+
+    use super::*;
+    use ark_ec::CurveGroup;
+    use ark_ff::{PrimeField, Zero};
+
+    #[test]
+    fn test_addition() {
+        let p1 = EdwardsAffine::new_unchecked(
+            MontFp!(
+                "17777552123799933955779906779655732241715742912184938656739573121738514868268"
+            ),
+            MontFp!("2626589144620713026669568689430873010625803728049924121243784502389097019475"),
+        );
+
+        let p2 = EdwardsAffine::new_unchecked(
+            MontFp!(
+                "16540640123574156134436876038791482806971768689494387082833631921987005038935"
+            ),
+            MontFp!(
+                "20819045374670962167435360035096875258406992893633759881276124905556507972311"
+            ),
+        );
+
+        let result = (p1 + p2).into_affine();
+
+        assert_eq!(
+            result,
+            EdwardsAffine::new_unchecked(
+                MontFp!(
+                    "7916061937171219682591368294088513039687205273691143098332585753343424131937"
+                ),
+                MontFp!(
+                    "14035240266687799601661095864649209771790948434046947201833777492504781204499"
+                )
+            )
+        );
+    }
+
+    #[test]
+    fn test_doubling() {
+        let p1 = EdwardsAffine::new_unchecked(
+            MontFp!(
+                "17777552123799933955779906779655732241715742912184938656739573121738514868268"
+            ),
+            MontFp!("2626589144620713026669568689430873010625803728049924121243784502389097019475"),
+        );
+
+        let result = (p1 + p1).into_affine();
+
+        assert_eq!(
+            result,
+            EdwardsAffine::new_unchecked(
+                MontFp!(
+                    "6890855772600357754907169075114257697580319025794532037257385534741338397365"
+                ),
+                MontFp!(
+                    "4338620300185947561074059802482547481416142213883829469920100239455078257889"
+                )
+            )
+        );
+    }
+
+    #[test]
+    fn test_doubling_identity() {
+        let identity = EdwardsAffine::new_unchecked(Fq::zero(), Fq::ONE);
+        let result = (identity + identity).into_affine();
+
+        assert_eq!(result, identity);
+    }
+
+    #[test]
+    fn test_curve_membership() {
+        let valid_point = EdwardsAffine::new_unchecked(Fq::zero(), Fq::ONE);
+        assert!(valid_point.is_on_curve());
+
+        let invalid_point = EdwardsAffine::new_unchecked(Fq::ONE, Fq::zero());
+        assert!(!invalid_point.is_on_curve());
+    }
+
+    #[test]
+    fn test_base_point_choice() {
+        let g = EdwardsAffine::new_unchecked(GENERATOR_X, GENERATOR_Y);
+
+        let expected_base_point = EdwardsAffine::new_unchecked(BASE_X, BASE_Y);
+        let cofactor = Fr::from_be_bytes_mod_order(&[BabyJubjubConfig::COFACTOR[0] as u8]);
+        let calculated_base_point = (g * cofactor).into_affine();
+
+        assert_eq!(calculated_base_point, expected_base_point);
+    }
+
+    #[test]
+    fn test_base_point_order() {
+        let base_point = EdwardsAffine::new_unchecked(GENERATOR_X, GENERATOR_Y);
+
+        let result = (base_point * SUBGROUP_ORDER).into_affine();
+        let identity = EdwardsAffine::new_unchecked(Fq::zero(), Fq::ONE);
+
+        assert_eq!(result, identity);
+    }
+}

src/error.rs

@@ -0,0 +1,34 @@
+//! Error Module
+
+use thiserror::Error;
+use zk_kit_lean_imt::lean_imt::LeanIMTError;
+
+#[derive(Error, Debug, PartialEq, Eq)]
+pub enum SemaphoreError {
+    #[error("Member already removed")]
+    AlreadyRemovedMember,
+    #[error("Member value is empty")]
+    EmptyLeaf,
+    #[error("Input array of size {0} exceeds maximum allowed length of 32 bytes")]
+    InputSizeExceeded(usize),
+    #[error("LeanIMT error: {0}")]
+    LeanIMTError(LeanIMTError),
+    #[error("Message of size {0} exceeds maximum allowed length of 32 bytes")]
+    MessageSizeExceeded(usize),
+    #[error("Public key validation failed: point is not on curve")]
+    PublicKeyNotOnCurve,
+    #[error("Member has been removed")]
+    RemovedMember,
+    #[error("Signature point R is not on curve")]
+    SignaturePointNotOnCurve,
+    #[error("Signature verification failed")]
+    SignatureVerificationFailed,
+    #[error("Serialization error: {0}")]
+    SerializationError(String),
+}
+
+impl From<LeanIMTError> for SemaphoreError {
+    fn from(error: LeanIMTError) -> Self {
+        SemaphoreError::LeanIMTError(error)
+    }
+}