chore(repo): refactor into 2 crates, example and sdk (#10)

* chore: refactor into 2 crates, example and sdk

* fix: cleanup

* fix: readme

.github/workflows/nightly-release.yml

@@ -39,6 +39,7 @@ jobs:
       - name: Install dependencies
         run: make deps
       - name: cross build
+        working-directory: ./sdk
         run: |
           cross build --release --target ${{ matrix.target }} --features ${{ matrix.curve }}
           mkdir release
@@ -84,6 +85,7 @@ jobs:
       - name: Install dependencies
         run: make deps
       - name: cross build
+        working-directory: ./sdk
         run: |
           cross build --release --target ${{ matrix.target }} --features ${{ matrix.curve }}
           mkdir release

Cargo.toml

@@ -1,51 +1,7 @@
-[package]
-name = "stealth_address_kit"
-version = "0.1.0"
-edition = "2021"
-description = "Stealth Address Kit: A Rust library for generating stealth addresses."
-license = "MIT"
-homepage = "https://vac.dev"
+[workspace]
 
-[lib]
-name = "stealth_address_kit"
-path = "src/lib.rs"
-crate-type = ["staticlib"]
-
-[features]
-ffi = []
-bls12_381 = []
-bls12_377 = []
-secp256k1 = []
-secp256r1 = []
-bn254 = []
-pallas = []
-vesta = []
-bw6_761 = []
-default = ["all"]
-all = ["ffi", "secp256k1", "bls12_381", "bls12_377", "bn254", "secp256r1", "pallas", "vesta", "bw6_761"]
-
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
-[dependencies]
-rln = "0.3.4"
-ark-std = "0.4.0"
-num-bigint = "0.4.3"
-num-traits = "0.2.15"
-ark-ff = "0.4.1"
-ark-bn254 = "0.4.0"
-ark-bls12-381 = "0.4.0"
-ark-bls12-377 = "0.4.0"
-ark-secp256k1 = "0.4.0"
-ark-secp256r1 = "0.4.0"
-ark-pallas = "0.4.0"
-ark-vesta = "0.4.0"
-ark-bw6-761 = "0.4.0"
-tiny-keccak = { version = "=2.0.2", features = ["keccak"] }
-ark-ec = "0.4.1"
-ark-serialize = "0.4.1"
-cfg-if = "1.0.0"
-paste = "1.0.0"
-
-[dev-dependencies]
-serde_json = "1.0.96"
-color-eyre = "0.6.2"
+members = [
+    "sdk",
+    "example"
+]
+resolver = "2"

Makefile

@@ -1,4 +1,8 @@
+.PHONY: deps clean example
+
 deps:
-	cargo install cross --git https://github.com/cross-rs/cross.git --rev 1511a28
+	@cargo install cross --git https://github.com/cross-rs/cross.git --rev 1511a28
 clean:
-	cargo clean
+	@cargo clean
+example:
+	@cargo run -p stealth_address_kit_example

README.md

@@ -1,6 +1,6 @@
 # stealth-address-kit
 
-Uses the [arkworks-rs](https://github.com/arkworks-rs/curves) suite of libraries, and utilities from [rln](https://github.com/vacp2p/zerokit)
+Uses the [arkworks-rs](https://github.com/arkworks-rs/curves) suite of libraries.
 
 ## Existing Implementations
 
@@ -16,7 +16,7 @@ Uses the [arkworks-rs](https://github.com/arkworks-rs/curves) suite of libraries
 ## Usage
 
 ```rust
-use stealth_address_kit::{StealthAddressOnCurve};
+use stealth_address_kit::StealthAddressOnCurve;
 use ark_bn254::Bn254; // or ark_bls_12_381::Bls12_381 or ark_bls_12_377::Bls12_377, stealth_address_kit::Secp256k1, stealth_address_kit::Secp256r1, etc
 
 fn main() {
@@ -34,7 +34,7 @@ fn main() {
         panic!("View tags did not match");
     }
 
-    let derived_stealth_address = Bn254::derive_public_key(stealth_private_key_opt.unwrap());
+    let derived_stealth_address = Bn254::derive_public_key(&stealth_private_key_opt.unwrap());
     assert_eq!(derived_stealth_address, stealth_address);
 }
 ```
@@ -45,7 +45,7 @@ fn main() {
 2. Create a new module in the `src` directory, with the curve name, suffixed by `_impl.rs`
 3. Implement the `StealthAddressOnCurve` trait for the curve
 4. Define the macro `define_curve_ffi`
-5. Add the curve to the `lib.rs` file, in the `mod` declaration
+5. Add the curve to the `lib.rs` file, in the `mod` declaration, as well as re-export if required
 6. Add the curve to the README
 7. Add the curve to the nightly release workflow
 
@@ -67,5 +67,4 @@ Check out the nightly releases.
 
 ## Attribution
 
-- The original circuits for rln are located [here](https://github.com/Rate-Limting-Nullifier/circom-rln), by the PSE group
 - Inspired by the [erc-5564](https://eips.ethereum.org/EIPS/eip-5564) eip and the [poc](https://github.com/nerolation/EIP-Stealth-Address-ERC/blob/main/minimal_poc.ipynb) by Nerolation.

example/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "stealth_address_kit_example"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+stealth_address_kit = { path = "../sdk", default-features = false, features = ["secp256r1"] }

example/README.md

@@ -0,0 +1,7 @@
+# Example
+
+Feel free to play around with the `curves` that are exported by the `stealth_address_kit` crate. The following example demonstrates how to generate a stealth address using the `secp256r1` curve.
+
+Update the `Cargo.toml` file to include the features/curves that you would like to use.
+
+Supported Curves: [here](../README.md#Existing-Implementations)

example/src/main.rs

@@ -0,0 +1,78 @@
+use stealth_address_kit::Secp256r1;
+use stealth_address_kit::StealthAddressOnCurve;
+
+type Curve = Secp256r1;
+
+fn print_discriminator() {
+    println!("{}", "+".repeat(100));
+}
+
+fn main() {
+    let (spending_key, spending_public_key) = Curve::random_keypair();
+    let (viewing_key, viewing_public_key) = Curve::random_keypair();
+
+    print_discriminator();
+    println!("BOB PRE-COMPUTATION");
+    print_discriminator();
+
+    println!("Spending Key: {}", &spending_key.to_string());
+    println!("Spending Public Key: {}", &spending_public_key.to_string());
+    println!("Viewing Key: {}", &viewing_key.to_string());
+    println!("Viewing Public Key: {}", &viewing_public_key.to_string());
+
+    print_discriminator();
+
+    // generate ephemeral keypair
+    let (ephemeral_private_key, ephemeral_public_key) = Curve::random_keypair();
+
+    print_discriminator();
+    println!("ALICE COMPUTATION");
+    print_discriminator();
+
+    println!(
+        "Ephemeral Private Key: {}",
+        &ephemeral_private_key.to_string()
+    );
+    println!(
+        "Ephemeral Public Key: {}",
+        &ephemeral_public_key.to_string()
+    );
+
+    let (stealth_public_key, view_tag) = Curve::generate_stealth_address(
+        viewing_public_key,
+        spending_public_key,
+        ephemeral_private_key,
+    );
+
+    println!("Stealth Public Key: {}", &stealth_public_key.to_string());
+    println!("View Tag: {}", &view_tag.to_string());
+
+    print_discriminator();
+
+    print_discriminator();
+    println!("BOB COMPUTATION AFTER RECEIVING BROADCASTED KEY MATERIAL");
+    print_discriminator();
+
+    let stealth_private_key_opt = Curve::generate_stealth_private_key(
+        ephemeral_public_key,
+        viewing_key,
+        spending_key,
+        view_tag,
+    );
+
+    if let Some(stealth_private_key) = stealth_private_key_opt {
+        let derived_stealth_public_key = Curve::derive_public_key(&stealth_private_key);
+
+        println!(
+            "Derived Stealth Public Key: {}",
+            &derived_stealth_public_key.to_string()
+        );
+        println!("Stealth Private Key: {}", &stealth_private_key.to_string());
+
+        assert_eq!(derived_stealth_public_key, stealth_public_key);
+
+        print_discriminator();
+    } else {
+        panic!("View tags did not match");
+    };
+}

sdk/Cargo.toml

@@ -0,0 +1,51 @@
+[package]
+name = "stealth_address_kit"
+version = "0.1.0"
+edition = "2021"
+description = "Stealth Address Kit: A Rust library for generating stealth addresses."
+license = "MIT"
+homepage = "https://vac.dev"
+
+[lib]
+name = "stealth_address_kit"
+path = "src/lib.rs"
+crate-type = ["staticlib", "rlib"]
+
+[features]
+ffi = []
+bls12_381 = []
+bls12_377 = []
+secp256k1 = []
+secp256r1 = []
+bn254 = []
+pallas = []
+vesta = []
+bw6_761 = []
+default = ["secp256k1", "ffi"]
+all = ["ffi", "secp256k1", "bls12_381", "bls12_377", "bn254", "secp256r1", "pallas", "vesta", "bw6_761"]
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+ark-std = "0.4.0"
+num-bigint = "0.4.3"
+num-traits = "0.2.15"
+ark-ff = "0.4.1"
+ark-bn254 = "0.4.0"
+ark-bls12-381 = "0.4.0"
+ark-bls12-377 = "0.4.0"
+ark-secp256k1 = "0.4.0"
+ark-secp256r1 = "0.4.0"
+ark-pallas = "0.4.0"
+ark-vesta = "0.4.0"
+ark-bw6-761 = "0.4.0"
+tiny-keccak = { version = "=2.0.2", features = ["keccak"] }
+ark-ec = "0.4.2"
+ark-serialize = "0.4.2"
+cfg-if = "1.0.0"
+paste = "1.0.0"
+rand = { version = "0.8.5", features = ["getrandom"] }
+
+[dev-dependencies]
+serde_json = "1.0.96"
+color-eyre = "0.6.2"

sdk/src/bls12_377_impl.rs

@@ -1,5 +1,5 @@
+use crate::define_curve_tests;
 use crate::stealth_addresses::StealthAddressOnCurve;
-use crate::{define_curve_ffi, define_curve_tests};
 
 use ark_bls12_377::{Bls12_377, Fr, G1Projective};
 
@@ -8,6 +8,8 @@ impl StealthAddressOnCurve for Bls12_377 {
     type Fr = Fr;
 }
 
+#[cfg(feature = "ffi")]
+use crate::define_curve_ffi;
 #[cfg(feature = "ffi")]
 define_curve_ffi!(bls12_377, Bls12_377, Fr, G1Projective, 32, 48);
 define_curve_tests!(ark_bls12_377::Bls12_377);

sdk/src/bls12_381_impl.rs

@@ -1,5 +1,5 @@
+use crate::define_curve_tests;
 use crate::stealth_addresses::StealthAddressOnCurve;
-use crate::{define_curve_ffi, define_curve_tests};
 
 use ark_bls12_381::{Bls12_381, Fr, G1Projective};
 
@@ -8,6 +8,8 @@ impl StealthAddressOnCurve for Bls12_381 {
     type Fr = Fr;
 }
 
+#[cfg(feature = "ffi")]
+use crate::define_curve_ffi;
 #[cfg(feature = "ffi")]
 define_curve_ffi!(bls12_381, Bls12_381, Fr, G1Projective, 32, 48);
 define_curve_tests!(Bls12_381);

sdk/src/bn254_impl.rs

@@ -0,0 +1,12 @@
+use crate::stealth_addresses::StealthAddressOnCurve;
+use crate::{define_curve_ffi, define_curve_tests};
+use ark_bn254::{Bn254, Fr, G1Projective};
+
+impl StealthAddressOnCurve for Bn254 {
+    type Projective = G1Projective;
+    type Fr = Fr;
+}
+
+#[cfg(feature = "ffi")]
+define_curve_ffi!(bn254, Bn254, Fr, G1Projective, 32, 32);
+define_curve_tests!(Bn254);

sdk/src/bw6_761_impl.rs

@@ -1,5 +1,5 @@
+use crate::define_curve_tests;
 use crate::stealth_addresses::StealthAddressOnCurve;
-use crate::{define_curve_ffi, define_curve_tests};
 
 use ark_bw6_761::{Fr, G1Projective, BW6_761};
 
@@ -8,6 +8,8 @@ impl StealthAddressOnCurve for BW6_761 {
     type Fr = Fr;
 }
 
+#[cfg(feature = "ffi")]
+use crate::define_curve_ffi;
 #[cfg(feature = "ffi")]
 define_curve_ffi!(bw6_761, BW6_761, Fr, G1Projective, 48, 96);
 define_curve_tests!(BW6_761);

sdk/src/lib.rs

@@ -20,3 +20,13 @@ mod vesta_impl;
 
 #[cfg(feature = "ffi")]
 mod ffi;
+
+#[cfg(feature = "pallas")]
+pub use pallas_impl::Pallas;
+#[cfg(feature = "secp256k1")]
+pub use secp256k1_impl::Secp256k1;
+#[cfg(feature = "secp256r1")]
+pub use secp256r1_impl::Secp256r1;
+pub use stealth_addresses::StealthAddressOnCurve;
+#[cfg(feature = "vesta")]
+pub use vesta_impl::Vesta;

sdk/src/pallas_impl.rs

@@ -1,5 +1,5 @@
+use crate::define_curve_tests;
 use crate::stealth_addresses::StealthAddressOnCurve;
-use crate::{define_curve_ffi, define_curve_tests};
 use ark_pallas::{Fr, Projective};
 
 pub struct Pallas;
@@ -9,6 +9,8 @@ impl StealthAddressOnCurve for Pallas {
     type Fr = Fr;
 }
 
+#[cfg(feature = "ffi")]
+use crate::define_curve_ffi;
 #[cfg(feature = "ffi")]
 define_curve_ffi!(pallas, Pallas, Fr, Projective, 32, 33);
 define_curve_tests!(Pallas);

sdk/src/secp256k1_impl.rs

@@ -1,5 +1,5 @@
+use crate::define_curve_tests;
 use crate::stealth_addresses::StealthAddressOnCurve;
-use crate::{define_curve_ffi, define_curve_tests};
 use ark_secp256k1::{Fr, Projective};
 
 pub struct Secp256k1;
@@ -9,6 +9,8 @@ impl StealthAddressOnCurve for Secp256k1 {
     type Fr = Fr;
 }
 
+#[cfg(feature = "ffi")]
+use crate::define_curve_ffi;
 #[cfg(feature = "ffi")]
 define_curve_ffi!(secp256k1, Secp256k1, Fr, Projective, 32, 33);
 define_curve_tests!(Secp256k1);

sdk/src/secp256r1_impl.rs

@@ -1,5 +1,5 @@
+use crate::define_curve_tests;
 use crate::stealth_addresses::StealthAddressOnCurve;
-use crate::{define_curve_ffi, define_curve_tests};
 use ark_secp256r1::{Fr, Projective};
 
 pub struct Secp256r1;
@@ -9,6 +9,8 @@ impl StealthAddressOnCurve for Secp256r1 {
     type Fr = Fr;
 }
 
+#[cfg(feature = "ffi")]
+use crate::define_curve_ffi;
 #[cfg(feature = "ffi")]
 define_curve_ffi!(secp256r1, Secp256r1, Fr, Projective, 32, 33);
 define_curve_tests!(Secp256r1);

sdk/src/vesta_impl.rs

@@ -1,5 +1,5 @@
+use crate::define_curve_tests;
 use crate::stealth_addresses::StealthAddressOnCurve;
-use crate::{define_curve_ffi, define_curve_tests};
 use ark_vesta::{Fr, Projective};
 
 pub struct Vesta;
@@ -9,6 +9,8 @@ impl StealthAddressOnCurve for Vesta {
     type Fr = Fr;
 }
 
+#[cfg(feature = "ffi")]
+use crate::define_curve_ffi;
 #[cfg(feature = "ffi")]
 define_curve_ffi!(vesta, Vesta, Fr, Projective, 32, 33);
 define_curve_tests!(Vesta);

src/bn254_impl.rs

@@ -1,83 +0,0 @@
-use crate::stealth_addresses::StealthAddressOnCurve;
-use crate::{define_curve_ffi, define_curve_tests};
-use ark_bn254::{Bn254, Fr, G1Projective};
-#[allow(unused_imports)]
-use rln::ffi::*;
-use rln::hashers::{hash_to_field, poseidon_hash};
-
-impl StealthAddressOnCurve for Bn254 {
-    type Projective = G1Projective;
-    type Fr = Fr;
-
-    fn hash_to_fr(input: &[u8]) -> Self::Fr {
-        poseidon_hash(&[hash_to_field(input)])
-    }
-}
-
-#[cfg(feature = "ffi")]
-define_curve_ffi!(bn254, Bn254, Fr, G1Projective, 32, 32);
-define_curve_tests!(Bn254);
-
-#[cfg(test)]
-mod rln_tests {
-    use super::*;
-    use ark_std::rand::thread_rng;
-    use ark_std::UniformRand;
-    use color_eyre::{Report, Result};
-    use rln::public::RLN;
-    use rln::utils::fr_to_bytes_le;
-    use serde_json::json;
-    use std::io::Cursor;
-
-    type Curve = ark_bn254::Bn254;
-
-    // this can only be tested for bn254 since that is the curve supported by RLN
-    #[test]
-    fn apply_stealth_membership_from_one_tree_to_another() -> Result<()> {
-        let test_tree_height = 20;
-        let resources = Cursor::new(json!({"resources_folder": "tree_height_20"}).to_string());
-        let mut rln = RLN::new(test_tree_height, resources.clone())?;
-
-        let alice_leaf = Fr::rand(&mut thread_rng());
-        let (alice_known_spending_sk, alice_known_spending_pk) = Curve::random_keypair();
-        let alice_leaf_buffer = Cursor::new(fr_to_bytes_le(&alice_leaf));
-        rln.set_leaf(0, alice_leaf_buffer)?;
-
-        // now the application sees that a user has been inserted into the tree
-        let mut rln_app_tree = RLN::new(test_tree_height, resources)?;
-        // the application generates a stealth address for alice
-        let (ephemeral_private_key, ephemeral_public_key) = Curve::random_keypair();
-        let (alice_stealth_address, view_tag) = Curve::generate_stealth_address(
-            alice_known_spending_pk,
-            alice_known_spending_pk,
-            ephemeral_private_key,
-        );
-
-        let parts = [alice_stealth_address.x, alice_stealth_address.y];
-        let fr_parts = parts.map(|x| Fr::from(x.0));
-        let alice_stealth_address_buffer = Cursor::new(fr_to_bytes_le(&poseidon_hash(&fr_parts)));
-        rln_app_tree.set_leaf(0, alice_stealth_address_buffer)?;
-
-        // now alice's stealth address has been inserted into the tree, but alice has not
-        // yet derived the secret for it -
-        let alice_stealth_private_key_opt = Curve::generate_stealth_private_key(
-            ephemeral_public_key,
-            alice_known_spending_sk,
-            alice_known_spending_sk,
-            view_tag,
-        );
-        if alice_stealth_private_key_opt.is_none() {
-            return Err(Report::msg("Invalid view tag"));
-        }
-        let alice_stealth_private_key = alice_stealth_private_key_opt.unwrap();
-
-        assert_eq!(
-            Curve::derive_public_key(&alice_stealth_private_key),
-            alice_stealth_address
-        );
-
-        // now alice may generate valid rln proofs for the rln app tree, using a address
-        // derived from her address on the other tree
-        Ok(())
-    }
-}