Add merkle tree glossary + mermaid graph example (#298)

# Bring Back WebAssembly Support for ZeroKit

- Update minor versions of all dependencies.
- Update documentation to reflect these changes.
- ~~Vendor `wasmer` v4.4.0 in [my git
repository](https://github.com/vinhtc27/wasmer) for `ark-circom`
v0.5.0.~~
- Resolve `wasm-pack` build failures (`os error 2`) caused by a Node.js
version mismatch.
- Restore the previous CI pipeline for the `rln-wasm` feature and update
to the stable toolchain.
- ~~Use `ark-circom` with the `wasm` feature for WebAssembly
compatibility and the `rln.wasm` file for witness calculation.~~
- ~~Fix dependency issues related to `ark-circom` v0.5.0, which
currently uses `wasmer` v4.4.0 and is affected by this
[issue](https://github.com/rust-lang/rust/issues/91632#issuecomment-1477914703).~~
- Install WABT with `brew` and `apt-get` instead of cloning to fix
`wasm-strip not found` issue in the CI workflow.
- Install `wasm-pack` with `curl` instead of using `wasm-pack-action` to
fix parse exception error in the CI workflow.
- Use the `.wasm` file with JS bindings for witness calculation, which
is generated from [`iden3/circom`](https://github.com/iden3/circom)
during circuit compilation. This allows witness computation outside RLN
instance.
- Refactor the `rln` module by moving circuit-related files to the
`src/circuit` folder for better organization.
- Remove `ark-circom` and `wasmer` by cloning the
[CircomReduction](3c95ed98e2/src/circom/qap.rs (L12))
struct and the
[read_zkey](3c95ed98e2/src/zkey.rs (L53))
function into the `rln` module, which reduces the repository's build
size and speeds up compilation time and the CI workflow duration.
- These change also address
[#282](https://github.com/vacp2p/zerokit/issues/282) by removing
`wasmer` and `wasmer-wasix`, which lack x32 system support.
- Benchmark `rln-wasm` with `wasm_bindgen_test`, covering RLN instance
creation, key generation, witness calculation, proving, and
verification. Also, add them to `v0.6.1` in
[benchmark-v0.6.1](https://github.com/vacp2p/zerokit/tree/benchmark-v0.6.1)
for comparison.
- Add `arkzkey` feature for rln-wasm, including tests, benchmarks, CI
workflow updates, and related documentation.
- Benchmark rln-wasm in the browser using HTML, covering initialization,
RLN instance creation, proving, and verification; fork to the
`benchmark-v0.7.0` branch for later use
[here](https://github.com/vacp2p/zerokit/tree/benchmark-v0.7.0).
- Fix clippy error: "this `repeat().take()` can be written more
concisely" on CI workflow for `utils` module.
([error](https://github.com/vacp2p/zerokit/actions/runs/14258579070/job/39965568013))
- Update Makefile.toml to be able to run `make build`, `make test`, and
`make bench` from root and inside each modules.

.github/workflows/ci.yml

@@ -5,6 +5,7 @@ on:
     paths-ignore:
       - "**.md"
       - "!.github/workflows/*.yml"
+      - "!rln-wasm/**"
       - "!rln/src/**"
       - "!rln/resources/**"
       - "!utils/src/**"
@@ -12,6 +13,7 @@ on:
     paths-ignore:
       - "**.md"
       - "!.github/workflows/*.yml"
+      - "!rln-wasm/**"
       - "!rln/src/**"
       - "!rln/resources/**"
       - "!utils/src/**"
@@ -76,12 +78,49 @@ jobs:
           fi
         working-directory: ${{ matrix.crate }}
 
+  rln-wasm:
+    strategy:
+      matrix:
+        platform: [ ubuntu-latest, macos-latest ]
+        feature: [ "default", "arkzkey" ]
+    runs-on: ${{ matrix.platform }}
+    timeout-minutes: 60
+
+    name: test - rln-wasm - ${{ matrix.platform }} - ${{ matrix.feature }}
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install stable toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+      - uses: Swatinem/rust-cache@v2
+      - name: Install Dependencies
+        run: make installdeps
+      - name: cargo-make build
+        run: |
+          if [ ${{ matrix.feature }} == default ]; then
+            cargo make build
+          else
+            cargo make build_${{ matrix.feature }}
+          fi
+        working-directory: rln-wasm
+      - name: cargo-make test
+        run: |
+          if [ ${{ matrix.feature }} == default ]; then
+            cargo make test --release
+          else
+            cargo make test_${{ matrix.feature }} --release
+          fi
+        working-directory: rln-wasm
+
   lint:
     strategy:
       matrix:
         # we run lint tests only on ubuntu
         platform: [ ubuntu-latest ]
-        crate: [ rln, utils ]
+        crate: [ rln, rln-wasm, utils ]
     runs-on: ${{ matrix.platform }}
     timeout-minutes: 60
 
@@ -106,7 +145,7 @@ jobs:
       - name: cargo clippy
         if: success() || failure()
         run: |
-          cargo clippy --release -- -D warnings
+          cargo clippy --release
         working-directory: ${{ matrix.crate }}
 
   benchmark-utils:

.github/workflows/nightly-release.yml

@@ -84,9 +84,39 @@ jobs:
           path: ${{ matrix.target }}-${{ matrix.feature }}-rln.tar.gz
           retention-days: 2
 
+  browser-rln-wasm:
+    name: Browser build (RLN WASM)
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v3
+      - name: Install stable toolchain
+        uses: actions-rs/toolchain@v1
+        with:
+          profile: minimal
+          toolchain: stable
+          override: true
+      - uses: Swatinem/rust-cache@v2
+      - name: Install dependencies
+        run: make installdeps
+      - name: cross make build
+        run: |
+          cross make build
+          mkdir release
+          cp pkg/** release/
+          tar -czvf browser-rln-wasm.tar.gz release/
+        working-directory: rln-wasm
+
+      - name: Upload archive artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: browser-rln-wasm-archive
+          path: rln-wasm/browser-rln-wasm.tar.gz
+          retention-days: 2
+
   prepare-prerelease:
     name: Prepare pre-release
-    needs: [ linux, macos ]
+    needs: [ linux, macos, browser-rln-wasm ]
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code

.gitignore

@@ -9,7 +9,9 @@ rln-cli/database
 # will have compiled files and executables
 debug/
 target/
-wabt/
+
+# Generated by Nix
+result/
 
 # These are backup files generated by rustfmt
 **/*.rs.bk

CHANGELOG.md

@@ -1,3 +1,5 @@
+# CHANGE LOG
+
 ## 2023-02-28 v0.2
 
 This release contains:
@@ -10,7 +12,6 @@ This release contains:
 - Dual License under Apache 2.0 and MIT
 - RLN compiles as a static library, which can be consumed through a C FFI
 
-
 ## 2022-09-19 v0.1
 
 Initial beta release.

Cargo.toml

@@ -1,6 +1,6 @@
 [workspace]
-members = ["rln", "rln-cli", "utils"]
-default-members = ["rln", "rln-cli", "utils"]
+members = ["rln", "rln-cli", "rln-wasm", "utils"]
+default-members = ["rln", "rln-cli", "rln-wasm", "utils"]
 resolver = "2"
 
 # Compilation profile for any non-workspace member.

Makefile

@@ -1,4 +1,4 @@
-.PHONY: all installdeps build test clean
+.PHONY: all installdeps build test bench clean
 
 all: .pre-build build
 
@@ -13,20 +13,21 @@ endif
 
 installdeps: .pre-build
 ifeq ($(shell uname),Darwin)
-# commented due to https://github.com/orgs/Homebrew/discussions/4612
-# @brew update
+	@brew update
 	@brew install cmake ninja
-	@git -C "wabt" pull || git clone --recursive https://github.com/WebAssembly/wabt.git "wabt"
-	@cd wabt && mkdir -p build && make
 else ifeq ($(shell uname),Linux)
 	@sudo apt-get update
 	@sudo apt-get install -y cmake ninja-build
-	@git -C "wabt" pull || git clone --recursive https://github.com/WebAssembly/wabt.git "wabt"
-	@cd wabt && mkdir -p build && cd build && cmake .. -GNinja && ninja && sudo ninja install
 endif
-	# nvm already checks if it's installed, and no-ops if it is
-	@curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.7/install.sh | bash
-	@. ${HOME}/.nvm/nvm.sh && nvm install 18.20.2 && nvm use 18.20.2;
+	@if [ ! -d "$$HOME/.nvm" ]; then \
+		curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.2/install.sh | bash; \
+	fi
+	@bash -c 'export NVM_DIR="$$HOME/.nvm" && \
+		[ -s "$$NVM_DIR/nvm.sh" ] && \. "$$NVM_DIR/nvm.sh" && \
+		nvm install 22.14.0 && \
+		nvm use 22.14.0'
+	@curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
+	@echo "\033[1;32m>>> Now run this command to activate Node.js 22.14.0: \033[1;33msource $$HOME/.nvm/nvm.sh && nvm use 22.14.0\033[0m"
 
 build: .pre-build
 	@cargo make build
@@ -34,5 +35,8 @@ build: .pre-build
 test: .pre-build
 	@cargo make test
 
+bench: .pre-build
+	@cargo make bench
+
 clean:
-	@cargo clean
+	@cargo clean

flake.lock

@@ -0,0 +1,27 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1740603184,
+        "narHash": "sha256-t+VaahjQAWyA+Ctn2idyo1yxRIYpaDxMgHkgCNiMJa4=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "f44bd8ca21e026135061a0a57dcf3d0775b67a49",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "f44bd8ca21e026135061a0a57dcf3d0775b67a49",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,38 @@
+{
+  description = "A flake for building zerokit";
+
+  inputs = {
+    # Version 24.11
+    nixpkgs.url = "github:NixOS/nixpkgs?rev=f44bd8ca21e026135061a0a57dcf3d0775b67a49";
+  };
+
+  outputs = { self, nixpkgs }: 
+    let
+      stableSystems = [
+        "x86_64-linux" "aarch64-linux"
+        "x86_64-darwin" "aarch64-darwin"
+        "x86_64-windows" "i686-linux"
+        "i686-windows"
+      ];
+      forAllSystems = nixpkgs.lib.genAttrs stableSystems;
+      pkgsFor = forAllSystems (system: import nixpkgs { inherit system; });
+    in rec
+    {
+      packages = forAllSystems (system: let
+        pkgs = pkgsFor.${system};
+      in rec {
+        zerokit-android-arm64 = pkgs.callPackage ./nix/default.nix { target-platform="aarch64-android-prebuilt"; rust-target= "aarch64-linux-android"; };
+        default = zerokit-android-arm64;
+      });
+
+      devShells = forAllSystems (system: let
+        pkgs = pkgsFor.${system};
+      in {
+        default = pkgs.mkShell {
+          inputsFrom = [
+            packages.${system}.default
+          ];
+        };
+      });
+    };
+}

nix/default.nix

@@ -0,0 +1,35 @@
+{ 
+  pkgs,
+  target-platform ? "aarch64-android-prebuilt",
+  rust-target ? "aarch64-linux-android",
+}:
+
+pkgs.pkgsCross.${target-platform}.rustPlatform.buildRustPackage {
+  pname = "zerokit";
+  version = "nightly";
+
+  src = ../.;
+
+  cargoLock = {
+    lockFile = ../Cargo.lock;
+    allowBuiltinFetchGit = true;
+  };
+
+  CARGO_HOME = "/tmp";
+
+  buildPhase = ''
+    pushd rln
+    cargo rustc --crate-type=cdylib --release --lib --target=${rust-target}
+    popd
+  '';
+
+  installPhase = ''
+    mkdir -p $out/
+    cp ./target/${rust-target}/release/librln.so $out/
+  '';
+
+  meta = with pkgs.lib; {
+    description = "Zerokit";
+    license = licenses.mit;
+  };
+}

rln-cli/Cargo.toml

@@ -13,14 +13,15 @@ path = "src/examples/stateless.rs"
 required-features = ["stateless"]
 
 [dependencies]
-rln = { path = "../rln", default-features = true, features = ["pmtree-ft"] }
+rln = { path = "../rln", default-features = false }
 zerokit_utils = { path = "../utils" }
-clap = { version = "4.5.29", features = ["cargo", "derive", "env"] }
-clap_derive = { version = "4.5.28" }
-color-eyre = "0.6.2"
-serde_json = "1.0.138"
-serde = { version = "1.0.217", features = ["derive"] }
+clap = { version = "4.5.35", features = ["cargo", "derive", "env"] }
+clap_derive = { version = "4.5.32" }
+color-eyre = "0.6.3"
+serde_json = "1.0"
+serde = { version = "1.0", features = ["derive"] }
 
 [features]
+default = []
 arkzkey = ["rln/arkzkey"]
 stateless = ["rln/stateless"]

rln-cli/Makefile.toml

@@ -1,8 +1,9 @@
 [tasks.build]
 command = "cargo"
-args = ["build", "--release"]
+args = ["build"]
 
 [tasks.test]
-command = "cargo"
-args = ["test", "--release"]
+disabled = true
 
+[tasks.bench]
+disabled = true

rln-cli/src/examples/stateless.rs

@@ -127,11 +127,12 @@ impl RLNSystem {
         };
 
         let merkle_proof = self.tree.proof(user_index)?;
+        let x = hash_to_field(signal.as_bytes());
 
         let rln_witness = rln_witness_from_values(
             identity.identity_secret_hash,
             &merkle_proof,
-            hash_to_field(signal.as_bytes()),
+            x,
             external_nullifier,
             Fr::from(MESSAGE_LIMIT),
             Fr::from(message_id),
@@ -157,12 +158,12 @@ impl RLNSystem {
         let mut input_buffer = Cursor::new(proof_with_signal);
 
         let root = self.tree.root();
-        let root_serialized = fr_to_bytes_le(&root);
-        let mut root_buffer = Cursor::new(root_serialized);
+        let roots_serialized = fr_to_bytes_le(&root);
+        let mut roots_buffer = Cursor::new(roots_serialized);
 
         match self
             .rln
-            .verify_with_roots(&mut input_buffer, &mut root_buffer)
+            .verify_with_roots(&mut input_buffer, &mut roots_buffer)
         {
             Ok(true) => {
                 let nullifier = &proof_data[256..288];

rln-wasm/.gitignore

@@ -0,0 +1,6 @@
+/target
+**/*.rs.bk
+Cargo.lock
+bin/
+pkg/
+wasm-pack.log

rln-wasm/Cargo.toml

@@ -0,0 +1,39 @@
+[package]
+name = "rln-wasm"
+version = "0.1.0"
+edition = "2021"
+license = "MIT or Apache2"
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+required-features = ["stateless"]
+
+[dependencies]
+rln = { path = "../rln", default-features = false }
+num-bigint = { version = "0.4.6", default-features = false, features = [
+    "rand",
+    "serde",
+] }
+wasm-bindgen = "0.2.100"
+serde-wasm-bindgen = "0.6.5"
+js-sys = "0.3.77"
+serde_json = "1.0"
+
+# The `console_error_panic_xhook` crate provides better debugging of panics by
+# logging them with `console.error`. This is great for development, but requires
+# all the `std::fmt` and `std::panicking` infrastructure, so isn't great for
+# code size when deploying.
+console_error_panic_hook = { version = "0.1.7", optional = true }
+zerokit_utils = { path = "../utils" }
+
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+getrandom = { version = "0.2.15", features = ["js"] }
+
+[dev-dependencies]
+wasm-bindgen-test = "0.3.50"
+wasm-bindgen-futures = "0.4.50"
+
+[features]
+default = ["console_error_panic_hook"]
+stateless = ["rln/stateless"]
+arkzkey = ["rln/arkzkey"]

rln-wasm/Makefile.toml

@@ -0,0 +1,58 @@
+[tasks.build]
+clear = true
+dependencies = ["pack_build", "pack_rename"]
+
+[tasks.build_arkzkey]
+clear = true
+dependencies = ["pack_build_arkzkey", "pack_rename"]
+
+[tasks.pack_build]
+command = "wasm-pack"
+args = ["build", "--release", "--target", "web", "--scope", "waku"]
+env = { "RUSTFLAGS" = "--cfg feature=\"stateless\"" }
+
+[tasks.pack_build_arkzkey]
+command = "wasm-pack"
+args = ["build", "--release", "--target", "web", "--scope", "waku"]
+env = { "RUSTFLAGS" = "--cfg feature=\"stateless\" --cfg feature=\"arkzkey\"" }
+
+[tasks.pack_rename]
+script = "sed -i.bak 's/rln-wasm/zerokit-rln-wasm/g' pkg/package.json && rm pkg/package.json.bak"
+
+[tasks.test]
+command = "wasm-pack"
+args = [
+    "test",
+    "--release",
+    "--node",
+    "--target",
+    "wasm32-unknown-unknown",
+    "--",
+    "--nocapture",
+]
+env = { "RUSTFLAGS" = "--cfg feature=\"stateless\"" }
+
+[tasks.test_arkzkey]
+command = "wasm-pack"
+args = [
+    "test",
+    "--release",
+    "--node",
+    "--target",
+    "wasm32-unknown-unknown",
+    "--",
+    "--nocapture",
+]
+env = { "RUSTFLAGS" = "--cfg feature=\"stateless\" --cfg feature=\"arkzkey\"" }
+dependencies = ["build_arkzkey"]
+
+[tasks.bench]
+disabled = true
+
+[tasks.login]
+command = "wasm-pack"
+args = ["login"]
+
+[tasks.publish]
+command = "wasm-pack"
+args = ["publish", "--access", "public", "--target", "web"]

rln-wasm/README.md

@@ -0,0 +1,55 @@
+# RLN for WASM
+
+This library is used in [waku-org/js-rln](https://github.com/waku-org/js-rln/)
+
+> **Note**: This project requires `wasm-pack` for compiling Rust to WebAssembly and `cargo-make` for running the build commands. Make sure both are installed before proceeding.
+
+Install `wasm-pack`:
+
+```bash
+curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh
+```
+
+Install `cargo-make`
+
+```bash
+cargo install cargo-make
+```
+
+Or install everything needed for `zerokit` at the root of the repository:
+
+```bash
+make installdeps
+```
+
+## Building the library
+
+First, navigate to the rln-wasm directory:
+
+```bash
+cd rln-wasm
+```
+
+Compile zerokit for `wasm32-unknown-unknown`:
+
+```bash
+cargo make build
+```
+
+Or compile with the **arkzkey** feature enabled
+
+```bash
+cargo make build_arkzkey
+```
+
+## Running tests and benchmarks
+
+```bash
+cargo make test
+```
+
+Or test with the **arkzkey** feature enabled
+
+```bash
+cargo make test_arkzkey
+```

rln-wasm/resources/witness_calculator.js

@@ -0,0 +1,324 @@
+module.exports = async function builder(code, options) {
+  options = options || {};
+
+  let wasmModule;
+  try {
+    wasmModule = await WebAssembly.compile(code);
+  } catch (err) {
+    console.log(err);
+    console.log(
+      "\nTry to run circom --c in order to generate c++ code instead\n"
+    );
+    throw new Error(err);
+  }
+
+  let wc;
+
+  let errStr = "";
+  let msgStr = "";
+
+  const instance = await WebAssembly.instantiate(wasmModule, {
+    runtime: {
+      exceptionHandler: function (code) {
+        let err;
+        if (code == 1) {
+          err = "Signal not found.\n";
+        } else if (code == 2) {
+          err = "Too many signals set.\n";
+        } else if (code == 3) {
+          err = "Signal already set.\n";
+        } else if (code == 4) {
+          err = "Assert Failed.\n";
+        } else if (code == 5) {
+          err = "Not enough memory.\n";
+        } else if (code == 6) {
+          err = "Input signal array access exceeds the size.\n";
+        } else {
+          err = "Unknown error.\n";
+        }
+        throw new Error(err + errStr);
+      },
+      printErrorMessage: function () {
+        errStr += getMessage() + "\n";
+        // console.error(getMessage());
+      },
+      writeBufferMessage: function () {
+        const msg = getMessage();
+        // Any calls to `log()` will always end with a `\n`, so that's when we print and reset
+        if (msg === "\n") {
+          console.log(msgStr);
+          msgStr = "";
+        } else {
+          // If we've buffered other content, put a space in between the items
+          if (msgStr !== "") {
+            msgStr += " ";
+          }
+          // Then append the message to the message we are creating
+          msgStr += msg;
+        }
+      },
+      showSharedRWMemory: function () {
+        printSharedRWMemory();
+      },
+    },
+  });
+
+  const sanityCheck = options;
+  //        options &&
+  //        (
+  //            options.sanityCheck ||
+  //            options.logGetSignal ||
+  //            options.logSetSignal ||
+  //            options.logStartComponent ||
+  //            options.logFinishComponent
+  //        );
+
+  wc = new WitnessCalculator(instance, sanityCheck);
+  return wc;
+
+  function getMessage() {
+    var message = "";
+    var c = instance.exports.getMessageChar();
+    while (c != 0) {
+      message += String.fromCharCode(c);
+      c = instance.exports.getMessageChar();
+    }
+    return message;
+  }
+
+  function printSharedRWMemory() {
+    const shared_rw_memory_size = instance.exports.getFieldNumLen32();
+    const arr = new Uint32Array(shared_rw_memory_size);
+    for (let j = 0; j < shared_rw_memory_size; j++) {
+      arr[shared_rw_memory_size - 1 - j] =
+        instance.exports.readSharedRWMemory(j);
+    }
+
+    // If we've buffered other content, put a space in between the items
+    if (msgStr !== "") {
+      msgStr += " ";
+    }
+    // Then append the value to the message we are creating
+    msgStr += fromArray32(arr).toString();
+  }
+};
+
+class WitnessCalculator {
+  constructor(instance, sanityCheck) {
+    this.instance = instance;
+
+    this.version = this.instance.exports.getVersion();
+    this.n32 = this.instance.exports.getFieldNumLen32();
+
+    this.instance.exports.getRawPrime();
+    const arr = new Uint32Array(this.n32);
+    for (let i = 0; i < this.n32; i++) {
+      arr[this.n32 - 1 - i] = this.instance.exports.readSharedRWMemory(i);
+    }
+    this.prime = fromArray32(arr);
+
+    this.witnessSize = this.instance.exports.getWitnessSize();
+
+    this.sanityCheck = sanityCheck;
+  }
+
+  circom_version() {
+    return this.instance.exports.getVersion();
+  }
+
+  async _doCalculateWitness(input, sanityCheck) {
+    //input is assumed to be a map from signals to arrays of bigints
+    this.instance.exports.init(this.sanityCheck || sanityCheck ? 1 : 0);
+    const keys = Object.keys(input);
+    var input_counter = 0;
+    keys.forEach((k) => {
+      const h = fnvHash(k);
+      const hMSB = parseInt(h.slice(0, 8), 16);
+      const hLSB = parseInt(h.slice(8, 16), 16);
+      const fArr = flatArray(input[k]);
+      let signalSize = this.instance.exports.getInputSignalSize(hMSB, hLSB);
+      if (signalSize < 0) {
+        throw new Error(`Signal ${k} not found\n`);
+      }
+      if (fArr.length < signalSize) {
+        throw new Error(`Not enough values for input signal ${k}\n`);
+      }
+      if (fArr.length > signalSize) {
+        throw new Error(`Too many values for input signal ${k}\n`);
+      }
+      for (let i = 0; i < fArr.length; i++) {
+        const arrFr = toArray32(BigInt(fArr[i]) % this.prime, this.n32);
+        for (let j = 0; j < this.n32; j++) {
+          this.instance.exports.writeSharedRWMemory(j, arrFr[this.n32 - 1 - j]);
+        }
+        try {
+          this.instance.exports.setInputSignal(hMSB, hLSB, i);
+          input_counter++;
+        } catch (err) {
+          // console.log(`After adding signal ${i} of ${k}`)
+          throw new Error(err);
+        }
+      }
+    });
+    if (input_counter < this.instance.exports.getInputSize()) {
+      throw new Error(
+        `Not all inputs have been set. Only ${input_counter} out of ${this.instance.exports.getInputSize()}`
+      );
+    }
+  }
+
+  async calculateWitness(input, sanityCheck) {
+    const w = [];
+
+    await this._doCalculateWitness(input, sanityCheck);
+
+    for (let i = 0; i < this.witnessSize; i++) {
+      this.instance.exports.getWitness(i);
+      const arr = new Uint32Array(this.n32);
+      for (let j = 0; j < this.n32; j++) {
+        arr[this.n32 - 1 - j] = this.instance.exports.readSharedRWMemory(j);
+      }
+      w.push(fromArray32(arr));
+    }
+
+    return w;
+  }
+
+  async calculateBinWitness(input, sanityCheck) {
+    const buff32 = new Uint32Array(this.witnessSize * this.n32);
+    const buff = new Uint8Array(buff32.buffer);
+    await this._doCalculateWitness(input, sanityCheck);
+
+    for (let i = 0; i < this.witnessSize; i++) {
+      this.instance.exports.getWitness(i);
+      const pos = i * this.n32;
+      for (let j = 0; j < this.n32; j++) {
+        buff32[pos + j] = this.instance.exports.readSharedRWMemory(j);
+      }
+    }
+
+    return buff;
+  }
+
+  async calculateWTNSBin(input, sanityCheck) {
+    const buff32 = new Uint32Array(this.witnessSize * this.n32 + this.n32 + 11);
+    const buff = new Uint8Array(buff32.buffer);
+    await this._doCalculateWitness(input, sanityCheck);
+
+    //"wtns"
+    buff[0] = "w".charCodeAt(0);
+    buff[1] = "t".charCodeAt(0);
+    buff[2] = "n".charCodeAt(0);
+    buff[3] = "s".charCodeAt(0);
+
+    //version 2
+    buff32[1] = 2;
+
+    //number of sections: 2
+    buff32[2] = 2;
+
+    //id section 1
+    buff32[3] = 1;
+
+    const n8 = this.n32 * 4;
+    //id section 1 length in 64bytes
+    const idSection1length = 8 + n8;
+    const idSection1lengthHex = idSection1length.toString(16);
+    buff32[4] = parseInt(idSection1lengthHex.slice(0, 8), 16);
+    buff32[5] = parseInt(idSection1lengthHex.slice(8, 16), 16);
+
+    //this.n32
+    buff32[6] = n8;
+
+    //prime number
+    this.instance.exports.getRawPrime();
+
+    var pos = 7;
+    for (let j = 0; j < this.n32; j++) {
+      buff32[pos + j] = this.instance.exports.readSharedRWMemory(j);
+    }
+    pos += this.n32;
+
+    // witness size
+    buff32[pos] = this.witnessSize;
+    pos++;
+
+    //id section 2
+    buff32[pos] = 2;
+    pos++;
+
+    // section 2 length
+    const idSection2length = n8 * this.witnessSize;
+    const idSection2lengthHex = idSection2length.toString(16);
+    buff32[pos] = parseInt(idSection2lengthHex.slice(0, 8), 16);
+    buff32[pos + 1] = parseInt(idSection2lengthHex.slice(8, 16), 16);
+
+    pos += 2;
+    for (let i = 0; i < this.witnessSize; i++) {
+      this.instance.exports.getWitness(i);
+      for (let j = 0; j < this.n32; j++) {
+        buff32[pos + j] = this.instance.exports.readSharedRWMemory(j);
+      }
+      pos += this.n32;
+    }
+
+    return buff;
+  }
+}
+
+function toArray32(rem, size) {
+  const res = []; //new Uint32Array(size); //has no unshift
+  const radix = BigInt(0x100000000);
+  while (rem) {
+    res.unshift(Number(rem % radix));
+    rem = rem / radix;
+  }
+  if (size) {
+    var i = size - res.length;
+    while (i > 0) {
+      res.unshift(0);
+      i--;
+    }
+  }
+  return res;
+}
+
+function fromArray32(arr) {
+  //returns a BigInt
+  var res = BigInt(0);
+  const radix = BigInt(0x100000000);
+  for (let i = 0; i < arr.length; i++) {
+    res = res * radix + BigInt(arr[i]);
+  }
+  return res;
+}
+
+function flatArray(a) {
+  var res = [];
+  fillArray(res, a);
+  return res;
+
+  function fillArray(res, a) {
+    if (Array.isArray(a)) {
+      for (let i = 0; i < a.length; i++) {
+        fillArray(res, a[i]);
+      }
+    } else {
+      res.push(a);
+    }
+  }
+}
+
+function fnvHash(str) {
+  const uint64_max = BigInt(2) ** BigInt(64);
+  let hash = BigInt("0xCBF29CE484222325");
+  for (var i = 0; i < str.length; i++) {
+    hash ^= BigInt(str[i].charCodeAt());
+    hash *= BigInt(0x100000001b3);
+    hash %= uint64_max;
+  }
+  let shash = hash.toString(16);
+  let n = 16 - shash.length;
+  shash = "0".repeat(n).concat(shash);
+  return shash;
+}

rln-wasm/src/lib.rs

@@ -0,0 +1,294 @@
+#![cfg(target_arch = "wasm32")]
+
+use js_sys::{BigInt as JsBigInt, Object, Uint8Array};
+use num_bigint::BigInt;
+use rln::public::{hash, poseidon_hash, RLN};
+use std::vec::Vec;
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen(js_name = initPanicHook)]
+pub fn init_panic_hook() {
+    console_error_panic_hook::set_once();
+}
+
+#[wasm_bindgen(js_name = RLN)]
+pub struct RLNWrapper {
+    // The purpose of this wrapper is to hold a RLN instance with the 'static lifetime
+    // because wasm_bindgen does not allow returning elements with lifetimes
+    instance: RLN,
+}
+
+// Macro to call methods with arbitrary amount of arguments,
+// which have the last argument is output buffer pointer
+// First argument to the macro is context,
+// second is the actual method on `RLN`
+// third is the aforementioned output buffer argument
+// rest are all other arguments to the method
+macro_rules! call_with_output_and_error_msg {
+    // this variant is needed for the case when
+    // there are zero other arguments
+    ($instance:expr, $method:ident, $error_msg:expr) => {
+        {
+            let mut output_data: Vec<u8> = Vec::new();
+            let new_instance = $instance.process();
+            if let Err(err) = new_instance.instance.$method(&mut output_data) {
+                std::mem::forget(output_data);
+                Err(format!("Msg: {:#?}, Error: {:#?}", $error_msg, err))
+            } else {
+                let result = Uint8Array::from(&output_data[..]);
+                std::mem::forget(output_data);
+                Ok(result)
+            }
+        }
+    };
+    ($instance:expr, $method:ident, $error_msg:expr, $( $arg:expr ),* ) => {
+        {
+            let mut output_data: Vec<u8> = Vec::new();
+            let new_instance = $instance.process();
+            if let Err(err) = new_instance.instance.$method($($arg.process()),*, &mut output_data) {
+                std::mem::forget(output_data);
+                Err(format!("Msg: {:#?}, Error: {:#?}", $error_msg, err))
+            } else {
+                let result = Uint8Array::from(&output_data[..]);
+                std::mem::forget(output_data);
+                Ok(result)
+            }
+        }
+    };
+}
+
+macro_rules! call {
+    ($instance:expr, $method:ident $(, $arg:expr)*) => {
+        {
+            let new_instance: &mut RLNWrapper = $instance.process();
+            new_instance.instance.$method($($arg.process()),*)
+        }
+    }
+}
+
+macro_rules! call_bool_method_with_error_msg {
+    ($instance:expr, $method:ident, $error_msg:expr $(, $arg:expr)*) => {
+        {
+            let new_instance: &RLNWrapper = $instance.process();
+            new_instance.instance.$method($($arg.process()),*).map_err(|err| format!("Msg: {:#?}, Error: {:#?}", $error_msg, err))
+        }
+    }
+}
+
+// Macro to execute a function with arbitrary amount of arguments,
+// First argument is the function to execute
+// Rest are all other arguments to the method
+macro_rules! fn_call_with_output_and_error_msg {
+    // this variant is needed for the case when
+    // there are zero other arguments
+    ($func:ident, $error_msg:expr) => {
+        {
+            let mut output_data: Vec<u8> = Vec::new();
+            if let Err(err) = $func(&mut output_data) {
+                std::mem::forget(output_data);
+                Err(format!("Msg: {:#?}, Error: {:#?}", $error_msg, err))
+            } else {
+                let result = Uint8Array::from(&output_data[..]);
+                std::mem::forget(output_data);
+                Ok(result)
+            }
+        }
+    };
+    ($func:ident, $error_msg:expr, $( $arg:expr ),* ) => {
+        {
+            let mut output_data: Vec<u8> = Vec::new();
+            if let Err(err) = $func($($arg.process()),*, &mut output_data) {
+                std::mem::forget(output_data);
+                Err(format!("Msg: {:#?}, Error: {:#?}", $error_msg, err))
+            } else {
+                let result = Uint8Array::from(&output_data[..]);
+                std::mem::forget(output_data);
+                Ok(result)
+            }
+        }
+    };
+}
+
+trait ProcessArg {
+    type ReturnType;
+    fn process(self) -> Self::ReturnType;
+}
+
+impl ProcessArg for usize {
+    type ReturnType = usize;
+    fn process(self) -> Self::ReturnType {
+        self
+    }
+}
+
+impl<T> ProcessArg for Vec<T> {
+    type ReturnType = Vec<T>;
+    fn process(self) -> Self::ReturnType {
+        self
+    }
+}
+
+impl ProcessArg for *const RLN {
+    type ReturnType = &'static RLN;
+    fn process(self) -> Self::ReturnType {
+        unsafe { &*self }
+    }
+}
+
+impl ProcessArg for *const RLNWrapper {
+    type ReturnType = &'static RLNWrapper;
+    fn process(self) -> Self::ReturnType {
+        unsafe { &*self }
+    }
+}
+
+impl ProcessArg for *mut RLNWrapper {
+    type ReturnType = &'static mut RLNWrapper;
+    fn process(self) -> Self::ReturnType {
+        unsafe { &mut *self }
+    }
+}
+
+impl<'a> ProcessArg for &'a [u8] {
+    type ReturnType = &'a [u8];
+
+    fn process(self) -> Self::ReturnType {
+        self
+    }
+}
+
+#[allow(clippy::not_unsafe_ptr_arg_deref)]
+#[wasm_bindgen(js_name = newRLN)]
+pub fn wasm_new(zkey: Uint8Array) -> Result<*mut RLNWrapper, String> {
+    let instance = RLN::new_with_params(zkey.to_vec()).map_err(|err| format!("{:#?}", err))?;
+    let wrapper = RLNWrapper { instance };
+    Ok(Box::into_raw(Box::new(wrapper)))
+}
+
+#[allow(clippy::not_unsafe_ptr_arg_deref)]
+#[wasm_bindgen(js_name = rlnWitnessToJson)]
+pub fn wasm_rln_witness_to_json(
+    ctx: *mut RLNWrapper,
+    serialized_witness: Uint8Array,
+) -> Result<Object, String> {
+    let inputs = call!(
+        ctx,
+        get_rln_witness_bigint_json,
+        &serialized_witness.to_vec()[..]
+    )
+    .map_err(|err| err.to_string())?;
+    let js_value = serde_wasm_bindgen::to_value(&inputs).map_err(|err| err.to_string())?;
+    Object::from_entries(&js_value).map_err(|err| format!("{:#?}", err))
+}
+
+#[allow(clippy::not_unsafe_ptr_arg_deref)]
+#[wasm_bindgen(js_name = generateRLNProofWithWitness)]
+pub fn wasm_generate_rln_proof_with_witness(
+    ctx: *mut RLNWrapper,
+    calculated_witness: Vec<JsBigInt>,
+    serialized_witness: Uint8Array,
+) -> Result<Uint8Array, String> {
+    let mut witness_vec: Vec<BigInt> = vec![];
+
+    for v in calculated_witness {
+        witness_vec.push(
+            v.to_string(10)
+                .map_err(|err| format!("{:#?}", err))?
+                .as_string()
+                .ok_or("not a string error")?
+                .parse::<BigInt>()
+                .map_err(|err| format!("{:#?}", err))?,
+        );
+    }
+
+    call_with_output_and_error_msg!(
+        ctx,
+        generate_rln_proof_with_witness,
+        "could not generate proof",
+        witness_vec,
+        serialized_witness.to_vec()
+    )
+}
+
+#[allow(clippy::not_unsafe_ptr_arg_deref)]
+#[wasm_bindgen(js_name = generateMembershipKey)]
+pub fn wasm_key_gen(ctx: *const RLNWrapper) -> Result<Uint8Array, String> {
+    call_with_output_and_error_msg!(ctx, key_gen, "could not generate membership keys")
+}
+
+#[allow(clippy::not_unsafe_ptr_arg_deref)]
+#[wasm_bindgen(js_name = generateExtendedMembershipKey)]
+pub fn wasm_extended_key_gen(ctx: *const RLNWrapper) -> Result<Uint8Array, String> {
+    call_with_output_and_error_msg!(ctx, extended_key_gen, "could not generate membership keys")
+}
+
+#[allow(clippy::not_unsafe_ptr_arg_deref)]
+#[wasm_bindgen(js_name = generateSeededMembershipKey)]
+pub fn wasm_seeded_key_gen(ctx: *const RLNWrapper, seed: Uint8Array) -> Result<Uint8Array, String> {
+    call_with_output_and_error_msg!(
+        ctx,
+        seeded_key_gen,
+        "could not generate membership key",
+        &seed.to_vec()[..]
+    )
+}
+
+#[allow(clippy::not_unsafe_ptr_arg_deref)]
+#[wasm_bindgen(js_name = generateSeededExtendedMembershipKey)]
+pub fn wasm_seeded_extended_key_gen(
+    ctx: *const RLNWrapper,
+    seed: Uint8Array,
+) -> Result<Uint8Array, String> {
+    call_with_output_and_error_msg!(
+        ctx,
+        seeded_extended_key_gen,
+        "could not generate membership key",
+        &seed.to_vec()[..]
+    )
+}
+
+#[allow(clippy::not_unsafe_ptr_arg_deref)]
+#[wasm_bindgen(js_name = recovedIDSecret)]
+pub fn wasm_recover_id_secret(
+    ctx: *const RLNWrapper,
+    input_proof_data_1: Uint8Array,
+    input_proof_data_2: Uint8Array,
+) -> Result<Uint8Array, String> {
+    call_with_output_and_error_msg!(
+        ctx,
+        recover_id_secret,
+        "could not recover id secret",
+        &input_proof_data_1.to_vec()[..],
+        &input_proof_data_2.to_vec()[..]
+    )
+}
+
+#[allow(clippy::not_unsafe_ptr_arg_deref)]
+#[wasm_bindgen(js_name = verifyWithRoots)]
+pub fn wasm_verify_with_roots(
+    ctx: *const RLNWrapper,
+    proof: Uint8Array,
+    roots: Uint8Array,
+) -> Result<bool, String> {
+    call_bool_method_with_error_msg!(
+        ctx,
+        verify_with_roots,
+        "error while verifying proof with roots".to_string(),
+        &proof.to_vec()[..],
+        &roots.to_vec()[..]
+    )
+}
+
+#[wasm_bindgen(js_name = hash)]
+pub fn wasm_hash(input: Uint8Array) -> Result<Uint8Array, String> {
+    fn_call_with_output_and_error_msg!(hash, "could not generate hash", &input.to_vec()[..])
+}
+
+#[wasm_bindgen(js_name = poseidonHash)]
+pub fn wasm_poseidon_hash(input: Uint8Array) -> Result<Uint8Array, String> {
+    fn_call_with_output_and_error_msg!(
+        poseidon_hash,
+        "could not generate poseidon hash",
+        &input.to_vec()[..]
+    )
+}

rln-wasm/src/utils.js

@@ -0,0 +1,26 @@
+const fs = require("fs");
+
+// Utils functions for loading circom witness calculator and reading files from test
+
+module.exports = {
+  read_file: function (path) {
+    return fs.readFileSync(path);
+  },
+
+  calculateWitness: async function (circom_path, inputs) {
+    const wc = require("../resources/witness_calculator.js");
+    const wasmFile = fs.readFileSync(circom_path);
+    const wasmFileBuffer = wasmFile.slice(
+      wasmFile.byteOffset,
+      wasmFile.byteOffset + wasmFile.byteLength
+    );
+    const witnessCalculator = await wc(wasmFileBuffer);
+    const calculatedWitness = await witnessCalculator.calculateWitness(
+      inputs,
+      false
+    );
+    return JSON.stringify(calculatedWitness, (key, value) =>
+      typeof value === "bigint" ? value.toString() : value
+    );
+  },
+};

rln-wasm/tests/rln-wasm.rs

@@ -0,0 +1,289 @@
+#![cfg(target_arch = "wasm32")]
+
+#[cfg(test)]
+mod tests {
+    use js_sys::{BigInt as JsBigInt, Date, Object, Uint8Array};
+    use rln::circuit::{Fr, TEST_TREE_HEIGHT};
+    use rln::hashers::{hash_to_field, poseidon_hash};
+    use rln::poseidon_tree::PoseidonTree;
+    use rln::protocol::{prepare_verify_input, rln_witness_from_values, serialize_witness};
+    use rln::utils::{bytes_le_to_fr, fr_to_bytes_le};
+    use rln_wasm::*;
+    use wasm_bindgen::{prelude::*, JsValue};
+    use wasm_bindgen_test::wasm_bindgen_test;
+    use zerokit_utils::merkle_tree::merkle_tree::ZerokitMerkleTree;
+
+    #[wasm_bindgen(module = "src/utils.js")]
+    extern "C" {
+        #[wasm_bindgen(catch)]
+        fn read_file(path: &str) -> Result<Uint8Array, JsValue>;
+
+        #[wasm_bindgen(catch)]
+        async fn calculateWitness(circom_path: &str, input: Object) -> Result<JsValue, JsValue>;
+    }
+
+    #[cfg(feature = "arkzkey")]
+    const ZKEY_PATH: &str = "../rln/resources/tree_height_20/rln_final.arkzkey";
+    #[cfg(not(feature = "arkzkey"))]
+    const ZKEY_PATH: &str = "../rln/resources/tree_height_20/rln_final.zkey";
+
+    const CIRCOM_PATH: &str = "../rln/resources/tree_height_20/rln.wasm";
+
+    #[wasm_bindgen_test]
+    pub async fn rln_wasm_benchmark() {
+        let mut results = String::from("\nbenchmarks:\n");
+        let iterations = 10;
+
+        let zkey = read_file(&ZKEY_PATH).expect("Failed to read zkey file");
+
+        // Benchmark wasm_new
+        let start_wasm_new = Date::now();
+        for _ in 0..iterations {
+            let _ = wasm_new(zkey.clone()).expect("Failed to create RLN instance");
+        }
+        let wasm_new_result = Date::now() - start_wasm_new;
+
+        // Create RLN instance for other benchmarks
+        let rln_instance = wasm_new(zkey).expect("Failed to create RLN instance");
+        let mut tree = PoseidonTree::default(TEST_TREE_HEIGHT).expect("Failed to create tree");
+
+        // Benchmark wasm_key_gen
+        let start_wasm_key_gen = Date::now();
+        for _ in 0..iterations {
+            let _ = wasm_key_gen(rln_instance).expect("Failed to generate keys");
+        }
+        let wasm_key_gen_result = Date::now() - start_wasm_key_gen;
+
+        // Generate identity pair for other benchmarks
+        let mem_keys = wasm_key_gen(rln_instance).expect("Failed to generate keys");
+        let id_key = mem_keys.subarray(0, 32);
+        let (identity_secret_hash, _) = bytes_le_to_fr(&id_key.to_vec());
+        let (id_commitment, _) = bytes_le_to_fr(&mem_keys.subarray(32, 64).to_vec());
+
+        let epoch = hash_to_field(b"test-epoch");
+        let rln_identifier = hash_to_field(b"test-rln-identifier");
+        let external_nullifier = poseidon_hash(&[epoch, rln_identifier]);
+
+        let identity_index = tree.leaves_set();
+
+        let user_message_limit = Fr::from(100);
+
+        let rate_commitment = poseidon_hash(&[id_commitment, user_message_limit]);
+        tree.update_next(rate_commitment)
+            .expect("Failed to update tree");
+
+        let message_id = Fr::from(0);
+        let signal: [u8; 32] = [0; 32];
+        let x = hash_to_field(&signal);
+
+        let merkle_proof = tree
+            .proof(identity_index)
+            .expect("Failed to generate merkle proof");
+
+        let rln_witness = rln_witness_from_values(
+            identity_secret_hash,
+            &merkle_proof,
+            x,
+            external_nullifier,
+            user_message_limit,
+            message_id,
+        )
+        .expect("Failed to create RLN witness");
+
+        let serialized_witness =
+            serialize_witness(&rln_witness).expect("Failed to serialize witness");
+        let witness_buffer = Uint8Array::from(&serialized_witness[..]);
+
+        let json_inputs = wasm_rln_witness_to_json(rln_instance, witness_buffer.clone())
+            .expect("Failed to convert witness to JSON");
+
+        // Benchmark calculateWitness
+        let start_calculate_witness = Date::now();
+        for _ in 0..iterations {
+            let _ = calculateWitness(&CIRCOM_PATH, json_inputs.clone())
+                .await
+                .expect("Failed to calculate witness");
+        }
+        let calculate_witness_result = Date::now() - start_calculate_witness;
+
+        // Calculate witness for other benchmarks
+        let calculated_witness_json = calculateWitness(&CIRCOM_PATH, json_inputs)
+            .await
+            .expect("Failed to calculate witness")
+            .as_string()
+            .expect("Failed to convert calculated witness to string");
+        let calculated_witness_vec_str: Vec<String> =
+            serde_json::from_str(&calculated_witness_json).expect("Failed to parse JSON");
+        let calculated_witness: Vec<JsBigInt> = calculated_witness_vec_str
+            .iter()
+            .map(|x| JsBigInt::new(&x.into()).expect("Failed to create JsBigInt"))
+            .collect();
+
+        // Benchmark wasm_generate_rln_proof_with_witness
+        let start_wasm_generate_rln_proof_with_witness = Date::now();
+        for _ in 0..iterations {
+            let _ = wasm_generate_rln_proof_with_witness(
+                rln_instance,
+                calculated_witness.clone(),
+                witness_buffer.clone(),
+            )
+            .expect("Failed to generate proof");
+        }
+        let wasm_generate_rln_proof_with_witness_result =
+            Date::now() - start_wasm_generate_rln_proof_with_witness;
+
+        // Generate a proof for other benchmarks
+        let proof =
+            wasm_generate_rln_proof_with_witness(rln_instance, calculated_witness, witness_buffer)
+                .expect("Failed to generate proof");
+
+        let proof_data = proof.to_vec();
+        let verify_input = prepare_verify_input(proof_data, &signal);
+        let input_buffer = Uint8Array::from(&verify_input[..]);
+
+        let root = tree.root();
+        let roots_serialized = fr_to_bytes_le(&root);
+        let roots_buffer = Uint8Array::from(&roots_serialized[..]);
+
+        // Benchmark wasm_verify_with_roots
+        let start_wasm_verify_with_roots = Date::now();
+        for _ in 0..iterations {
+            let _ =
+                wasm_verify_with_roots(rln_instance, input_buffer.clone(), roots_buffer.clone())
+                    .expect("Failed to verify proof");
+        }
+        let wasm_verify_with_roots_result = Date::now() - start_wasm_verify_with_roots;
+
+        // Verify the proof with the root
+        let is_proof_valid = wasm_verify_with_roots(rln_instance, input_buffer, roots_buffer)
+            .expect("Failed to verify proof");
+        assert!(is_proof_valid, "verification failed");
+
+        // Format and display results
+        let format_duration = |duration_ms: f64| -> String {
+            let avg_ms = duration_ms / (iterations as f64);
+            if avg_ms >= 1000.0 {
+                format!("{:.3} s", avg_ms / 1000.0)
+            } else {
+                format!("{:.3} ms", avg_ms)
+            }
+        };
+
+        results.push_str(&format!("wasm_new: {}\n", format_duration(wasm_new_result)));
+        results.push_str(&format!(
+            "wasm_key_gen: {}\n",
+            format_duration(wasm_key_gen_result)
+        ));
+        results.push_str(&format!(
+            "calculateWitness: {}\n",
+            format_duration(calculate_witness_result)
+        ));
+        results.push_str(&format!(
+            "wasm_generate_rln_proof_with_witness: {}\n",
+            format_duration(wasm_generate_rln_proof_with_witness_result)
+        ));
+        results.push_str(&format!(
+            "wasm_verify_with_roots: {}\n",
+            format_duration(wasm_verify_with_roots_result)
+        ));
+
+        // Log the results
+        wasm_bindgen_test::console_log!("{results}");
+    }
+
+    #[wasm_bindgen_test]
+    pub async fn rln_wasm_test() {
+        // Read the zkey file
+        let zkey = read_file(&ZKEY_PATH).expect("Failed to read zkey file");
+
+        // Create RLN instance and separated tree
+        let rln_instance = wasm_new(zkey).expect("Failed to create RLN instance");
+        let mut tree = PoseidonTree::default(TEST_TREE_HEIGHT).expect("Failed to create tree");
+
+        // Setting up the epoch and rln_identifier
+        let epoch = hash_to_field(b"test-epoch");
+        let rln_identifier = hash_to_field(b"test-rln-identifier");
+        let external_nullifier = poseidon_hash(&[epoch, rln_identifier]);
+
+        // Generate identity pair
+        let mem_keys = wasm_key_gen(rln_instance).expect("Failed to generate keys");
+        let (identity_secret_hash, _) = bytes_le_to_fr(&mem_keys.subarray(0, 32).to_vec());
+        let (id_commitment, _) = bytes_le_to_fr(&mem_keys.subarray(32, 64).to_vec());
+
+        // Get index of the identity
+        let identity_index = tree.leaves_set();
+
+        // Setting up the user message limit
+        let user_message_limit = Fr::from(100);
+
+        // Updating the tree with the rate commitment
+        let rate_commitment = poseidon_hash(&[id_commitment, user_message_limit]);
+        tree.update_next(rate_commitment)
+            .expect("Failed to update tree");
+
+        // Generate merkle proof
+        let merkle_proof = tree
+            .proof(identity_index)
+            .expect("Failed to generate merkle proof");
+
+        // Create message id and signal
+        let message_id = Fr::from(0);
+        let signal: [u8; 32] = [0; 32];
+        let x = hash_to_field(&signal);
+
+        // Prepare input for witness calculation
+        let rln_witness = rln_witness_from_values(
+            identity_secret_hash,
+            &merkle_proof,
+            x,
+            external_nullifier,
+            user_message_limit,
+            message_id,
+        )
+        .expect("Failed to create RLN witness");
+
+        // Serialize the rln witness
+        let serialized_witness =
+            serialize_witness(&rln_witness).expect("Failed to serialize witness");
+        // Convert the serialized witness to a Uint8Array
+        let witness_buffer = Uint8Array::from(&serialized_witness[..]);
+
+        // Obtaining inputs that should be sent to circom witness calculator
+        let json_inputs = wasm_rln_witness_to_json(rln_instance, witness_buffer.clone())
+            .expect("Failed to convert witness to JSON");
+
+        // Calculating witness with JS
+        // (Using a JSON since wasm_bindgen does not like Result<Vec<JsBigInt>,JsValue>)
+        let calculated_witness_json = calculateWitness(&CIRCOM_PATH, json_inputs)
+            .await
+            .expect("Failed to calculate witness")
+            .as_string()
+            .expect("Failed to convert calculated witness to string");
+        let calculated_witness_vec_str: Vec<String> =
+            serde_json::from_str(&calculated_witness_json).expect("Failed to parse JSON");
+        let calculated_witness: Vec<JsBigInt> = calculated_witness_vec_str
+            .iter()
+            .map(|x| JsBigInt::new(&x.into()).expect("Failed to create JsBigInt"))
+            .collect();
+
+        // Generate a proof from the calculated witness
+        let proof =
+            wasm_generate_rln_proof_with_witness(rln_instance, calculated_witness, witness_buffer)
+                .expect("Failed to generate proof");
+
+        // Prepare the root for verification
+        let root = tree.root();
+        let roots_serialized = fr_to_bytes_le(&root);
+        let roots_buffer = Uint8Array::from(&roots_serialized[..]);
+
+        // Prepare input for proof verification
+        let proof_data = proof.to_vec();
+        let verify_input = prepare_verify_input(proof_data, &signal);
+        let input_buffer = Uint8Array::from(&verify_input[..]);
+
+        // Verify the proof with the root
+        let is_proof_valid = wasm_verify_with_roots(rln_instance, input_buffer, roots_buffer)
+            .expect("Failed to verify proof");
+        assert!(is_proof_valid, "verification failed");
+    }
+}

rln/Cargo.toml

@@ -18,78 +18,80 @@ doctest = false
 [dependencies]
 # ZKP Generation
 ark-bn254 = { version = "0.5.0", features = ["std"] }
-ark-ff = { version = "0.5.0", features = ["std", "asm"] }
-ark-serialize = { version = "0.5.0", features = ["derive"] }
-ark-ec = { version = "0.5.0", default-features = false }
-ark-std = { version = "0.5.0", default-features = false }
-ark-groth16 = { version = "0.5.0", features = [
+ark-relations = { version = "0.5.1", features = ["std"] }
+ark-ff = { version = "0.5.0", default-features = false, features = [
+    "parallel",
+] }
+ark-ec = { version = "0.5.0", default-features = false, features = [
+    "parallel",
+] }
+
+ark-std = { version = "0.5.0", default-features = false, features = [
+    "parallel",
+] }
+ark-poly = { version = "0.5.0", default-features = false, features = [
+    "parallel",
+] }
+ark-groth16 = { version = "0.5.0", default-features = false, features = [
+    "parallel",
+] }
+ark-serialize = { version = "0.5.0", default-features = false, features = [
     "parallel",
-], default-features = false }
-ark-relations = { version = "0.5.0", default-features = false, features = [
-    "std",
 ] }
-ark-circom = { version = "0.5.0" }
-ark-r1cs-std = { version = "0.5.0" }
 
 # error handling
-color-eyre = "0.6.2"
-thiserror = "2.0.11"
+color-eyre = "0.6.3"
+thiserror = "2.0.12"
 
 # utilities
-byteorder = "1.4.3"
+byteorder = "1.5.0"
 cfg-if = "1.0"
 num-bigint = { version = "0.4.6", default-features = false, features = [
     "rand",
+    "std",
 ] }
 num-traits = "0.2.19"
-once_cell = "1.19.0"
-lazy_static = "1.4.0"
+once_cell = "1.21.3"
+lazy_static = "1.5.0"
 rand = "0.8.5"
 rand_chacha = "0.3.1"
-ruint = { version = "1.12.4", features = ["rand", "serde", "ark-ff-04"] }
+ruint = { version = "1.14.0", features = ["rand", "serde", "ark-ff-04"] }
 tiny-keccak = { version = "2.0.2", features = ["keccak"] }
-utils = { package = "zerokit_utils", version = "0.5.2", path = "../utils/", default-features = false }
+utils = { package = "zerokit_utils", version = "0.5.2", path = "../utils", default-features = false }
 
 # serialization
-prost = "0.13.1"
+prost = "0.13.5"
 serde_json = "1.0"
 serde = { version = "1.0", features = ["derive"] }
 
-document-features = { version = "=0.2.10", optional = true }
+document-features = { version = "0.2.11", optional = true }
 
 [dev-dependencies]
 sled = "0.34.7"
 criterion = { version = "0.4.0", features = ["html_reports"] }
 
 [features]
-default = ["parallel", "pmtree-ft"]
-parallel = [
-    "ark-ec/parallel",
-    "ark-ff/parallel",
-    "ark-std/parallel",
-    "ark-groth16/parallel",
-    "utils/parallel",
-]
+default = ["pmtree-ft"]
 fullmerkletree = ["default"]
-arkzkey = []
 stateless = []
+arkzkey = []
 
 # Note: pmtree feature is still experimental
 pmtree-ft = ["utils/pmtree-ft"]
 
-[[bench]]
-name = "pmtree_benchmark"
-harness = false
-
-[[bench]]
-name = "circuit_loading_benchmark"
-harness = false
-
 [[bench]]
 name = "circuit_loading_arkzkey_benchmark"
 harness = false
 required-features = ["arkzkey"]
 
+[[bench]]
+name = "circuit_loading_benchmark"
+harness = false
+
+[[bench]]
+name = "pmtree_benchmark"
+harness = false
+
 [[bench]]
 name = "poseidon_tree_benchmark"
 harness = false

rln/README.md

@@ -34,9 +34,9 @@ use std::io::Cursor;
 use rln::{
     circuit::Fr,
     hashers::{hash_to_field, poseidon_hash},
-    protocol::{keygen, prepare_verify_input},
+    protocol::{keygen, prepare_prove_input, prepare_verify_input},
     public::RLN,
-    utils::{fr_to_bytes_le, normalize_usize},
+    utils::fr_to_bytes_le,
 };
 use serde_json::json;
 
@@ -53,8 +53,8 @@ fn main() {
 
     // 3. Add a rate commitment to the Merkle tree
     let id_index = 10;
-    let user_message_limit = 10;
-    let rate_commitment = poseidon_hash(&[id_commitment, Fr::from(user_message_limit)]);
+    let user_message_limit = Fr::from(10);
+    let rate_commitment = poseidon_hash(&[id_commitment, user_message_limit]);
     let mut buffer = Cursor::new(fr_to_bytes_le(&rate_commitment));
     rln.set_leaf(id_index, &mut buffer).unwrap();
 
@@ -65,25 +65,28 @@ fn main() {
     // We generate rln_identifier from a date seed and we ensure is
     // mapped to a field element by hashing-to-field its content
     let rln_identifier = hash_to_field(b"test-rln-identifier");
+    // We generate a external nullifier
     let external_nullifier = poseidon_hash(&[epoch, rln_identifier]);
+    // We choose a message_id satisfy 0 <= message_id < user_message_limit
+    let message_id = Fr::from(1);
 
     // 5. Generate and verify a proof for a message
     let signal = b"RLN is awesome";
 
     // 6. Prepare input for generate_rln_proof API
     // input_data is [ identity_secret<32> | id_index<8> | external_nullifier<32> | user_message_limit<32> | message_id<32> | signal_len<8> | signal<var> ]
-    let mut serialized: Vec<u8> = Vec::new();
-    serialized.append(&mut fr_to_bytes_le(&identity_secret_hash));
-    serialized.append(&mut normalize_usize(id_index));
-    serialized.append(&mut fr_to_bytes_le(&Fr::from(user_message_limit)));
-    serialized.append(&mut fr_to_bytes_le(&Fr::from(1)));
-    serialized.append(&mut fr_to_bytes_le(&external_nullifier));
-    serialized.append(&mut normalize_usize(signal.len()));
-    serialized.append(&mut signal.to_vec());
+    let prove_input = prepare_prove_input(
+        identity_secret_hash,
+        id_index,
+        user_message_limit,
+        message_id,
+        external_nullifier,
+        signal,
+    );
 
     // 7. Generate a RLN proof
     // We generate a RLN proof for proof_input
-    let mut input_buffer = Cursor::new(serialized);
+    let mut input_buffer = Cursor::new(prove_input);
     let mut output_buffer = Cursor::new(Vec::<u8>::new());
     rln.generate_rln_proof(&mut input_buffer, &mut output_buffer)
         .unwrap();

rln/benches/circuit_loading_benchmark.rs

@@ -1,5 +1,5 @@
-use ark_circom::read_zkey;
 use criterion::{criterion_group, criterion_main, Criterion};
+use rln::circuit::zkey::read_zkey;
 use std::io::Cursor;
 
 pub fn zkey_load_benchmark(c: &mut Criterion) {

rln/benches/pmtree_benchmark.rs

@@ -21,7 +21,7 @@ pub fn pmtree_benchmark(c: &mut Criterion) {
 
     c.bench_function("Pmtree::override_range", |b| {
         b.iter(|| {
-            tree.override_range(0, leaves.clone(), [0, 1, 2, 3])
+            tree.override_range(0, leaves.clone().into_iter(), [0, 1, 2, 3].into_iter())
                 .unwrap();
         })
     });

rln/src/circuit/iden3calc/graph.rs

@@ -13,8 +13,8 @@ use std::{
     ops::{BitAnd, BitOr, BitXor, Deref, Shl, Shr},
 };
 
+use crate::circuit::iden3calc::proto;
 use crate::circuit::Fr;
-use crate::iden3calc::proto;
 
 pub const M: U256 =
     uint!(21888242871839275222246405745257275088548364400416034343698204186575808495617_U256);

rln/src/circuit/iden3calc/storage.rs

@@ -7,7 +7,7 @@ use byteorder::{LittleEndian, ReadBytesExt, WriteBytesExt};
 use prost::Message;
 use std::io::{Read, Write};
 
-use crate::iden3calc::{
+use crate::circuit::iden3calc::{
     graph,
     graph::{Operation, TresOperation, UnoOperation},
     proto, InputSignalsInfo,

rln/src/circuit/mod.rs

@@ -1,16 +1,20 @@
 // This crate provides interfaces for the zero-knowledge circuit and keys
 
+pub mod iden3calc;
+pub mod qap;
+pub mod zkey;
+
 use ::lazy_static::lazy_static;
 use ark_bn254::{
     Bn254, Fq as ArkFq, Fq2 as ArkFq2, Fr as ArkFr, G1Affine as ArkG1Affine,
     G1Projective as ArkG1Projective, G2Affine as ArkG2Affine, G2Projective as ArkG2Projective,
 };
-use ark_groth16::{ProvingKey, VerifyingKey};
+use ark_groth16::ProvingKey;
 use ark_relations::r1cs::ConstraintMatrices;
 use cfg_if::cfg_if;
 use color_eyre::{Report, Result};
 
-use crate::iden3calc::calc_witness;
+use crate::circuit::iden3calc::calc_witness;
 
 #[cfg(feature = "arkzkey")]
 use {
@@ -19,13 +23,15 @@ use {
 };
 
 #[cfg(not(feature = "arkzkey"))]
-use {ark_circom::read_zkey, std::io::Cursor};
+use {crate::circuit::zkey::read_zkey, std::io::Cursor};
 
 #[cfg(feature = "arkzkey")]
-pub const ARKZKEY_BYTES: &[u8] = include_bytes!("../resources/tree_height_20/rln_final.arkzkey");
+pub const ARKZKEY_BYTES: &[u8] = include_bytes!("../../resources/tree_height_20/rln_final.arkzkey");
 
-pub const ZKEY_BYTES: &[u8] = include_bytes!("../resources/tree_height_20/rln_final.zkey");
-const GRAPH_BYTES: &[u8] = include_bytes!("../resources/tree_height_20/graph.bin");
+pub const ZKEY_BYTES: &[u8] = include_bytes!("../../resources/tree_height_20/rln_final.zkey");
+
+#[cfg(not(target_arch = "wasm32"))]
+const GRAPH_BYTES: &[u8] = include_bytes!("../../resources/tree_height_20/graph.bin");
 
 lazy_static! {
     static ref ZKEY: (ProvingKey<Curve>, ConstraintMatrices<Fr>) = {
@@ -73,30 +79,11 @@ pub fn zkey_from_raw(zkey_data: &[u8]) -> Result<(ProvingKey<Curve>, ConstraintM
 }
 
 // Loads the proving key
+#[cfg(not(target_arch = "wasm32"))]
 pub fn zkey_from_folder() -> &'static (ProvingKey<Curve>, ConstraintMatrices<Fr>) {
     &ZKEY
 }
 
-// Loads the verification key from a bytes vector
-pub fn vk_from_raw(zkey_data: &[u8]) -> Result<VerifyingKey<Curve>> {
-    if !zkey_data.is_empty() {
-        let (proving_key, _matrices) = zkey_from_raw(zkey_data)?;
-        return Ok(proving_key.vk);
-    }
-
-    Err(Report::msg("No proving/verification key found!"))
-}
-
-// Checks verification key to be correct with respect to proving key
-pub fn check_vk_from_zkey(verifying_key: VerifyingKey<Curve>) -> Result<()> {
-    let (proving_key, _matrices) = zkey_from_folder();
-    if proving_key.vk == verifying_key {
-        Ok(())
-    } else {
-        Err(Report::msg("verifying_keys are not equal"))
-    }
-}
-
 pub fn calculate_rln_witness<I: IntoIterator<Item = (String, Vec<Fr>)>>(
     inputs: I,
     graph_data: &[u8],
@@ -104,6 +91,7 @@ pub fn calculate_rln_witness<I: IntoIterator<Item = (String, Vec<Fr>)>>(
     calc_witness(inputs, graph_data)
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 pub fn graph_from_folder() -> &'static [u8] {
     GRAPH_BYTES
 }

rln/src/circuit/qap.rs

@@ -0,0 +1,114 @@
+// This file is based on the code by arkworks. Its preimage can be found here:
+// https://github.com/arkworks-rs/circom-compat/blob/3c95ed98e23a408b4d99a53e483a9bba39685a4e/src/circom/qap.rs
+
+use ark_ff::PrimeField;
+use ark_groth16::r1cs_to_qap::{evaluate_constraint, LibsnarkReduction, R1CSToQAP};
+use ark_poly::EvaluationDomain;
+use ark_relations::r1cs::{ConstraintMatrices, ConstraintSystemRef, SynthesisError};
+use ark_std::{cfg_into_iter, cfg_iter, cfg_iter_mut, vec};
+
+/// Implements the witness map used by snarkjs. The arkworks witness map calculates the
+/// coefficients of H through computing (AB-C)/Z in the evaluation domain and going back to the
+/// coefficients domain. snarkjs instead precomputes the Lagrange form of the powers of tau bases
+/// in a domain twice as large and the witness map is computed as the odd coefficients of (AB-C)
+/// in that domain. This serves as HZ when computing the C proof element.
+pub struct CircomReduction;
+
+impl R1CSToQAP for CircomReduction {
+    #[allow(clippy::type_complexity)]
+    fn instance_map_with_evaluation<F: PrimeField, D: EvaluationDomain<F>>(
+        cs: ConstraintSystemRef<F>,
+        t: &F,
+    ) -> Result<(Vec<F>, Vec<F>, Vec<F>, F, usize, usize), SynthesisError> {
+        LibsnarkReduction::instance_map_with_evaluation::<F, D>(cs, t)
+    }
+
+    fn witness_map_from_matrices<F: PrimeField, D: EvaluationDomain<F>>(
+        matrices: &ConstraintMatrices<F>,
+        num_inputs: usize,
+        num_constraints: usize,
+        full_assignment: &[F],
+    ) -> Result<Vec<F>, SynthesisError> {
+        let zero = F::zero();
+        let domain =
+            D::new(num_constraints + num_inputs).ok_or(SynthesisError::PolynomialDegreeTooLarge)?;
+        let domain_size = domain.size();
+
+        let mut a = vec![zero; domain_size];
+        let mut b = vec![zero; domain_size];
+
+        #[allow(unexpected_cfgs)]
+        cfg_iter_mut!(a[..num_constraints])
+            .zip(cfg_iter_mut!(b[..num_constraints]))
+            .zip(cfg_iter!(&matrices.a))
+            .zip(cfg_iter!(&matrices.b))
+            .for_each(|(((a, b), at_i), bt_i)| {
+                *a = evaluate_constraint(at_i, full_assignment);
+                *b = evaluate_constraint(bt_i, full_assignment);
+            });
+
+        {
+            let start = num_constraints;
+            let end = start + num_inputs;
+            a[start..end].clone_from_slice(&full_assignment[..num_inputs]);
+        }
+
+        let mut c = vec![zero; domain_size];
+        #[allow(unexpected_cfgs)]
+        cfg_iter_mut!(c[..num_constraints])
+            .zip(&a)
+            .zip(&b)
+            .for_each(|((c_i, &a), &b)| {
+                *c_i = a * b;
+            });
+
+        domain.ifft_in_place(&mut a);
+        domain.ifft_in_place(&mut b);
+
+        let root_of_unity = {
+            let domain_size_double = 2 * domain_size;
+            let domain_double =
+                D::new(domain_size_double).ok_or(SynthesisError::PolynomialDegreeTooLarge)?;
+            domain_double.element(1)
+        };
+        D::distribute_powers_and_mul_by_const(&mut a, root_of_unity, F::one());
+        D::distribute_powers_and_mul_by_const(&mut b, root_of_unity, F::one());
+
+        domain.fft_in_place(&mut a);
+        domain.fft_in_place(&mut b);
+
+        let mut ab = domain.mul_polynomials_in_evaluation_domain(&a, &b);
+        drop(a);
+        drop(b);
+
+        domain.ifft_in_place(&mut c);
+        D::distribute_powers_and_mul_by_const(&mut c, root_of_unity, F::one());
+        domain.fft_in_place(&mut c);
+
+        #[allow(unexpected_cfgs)]
+        cfg_iter_mut!(ab)
+            .zip(c)
+            .for_each(|(ab_i, c_i)| *ab_i -= &c_i);
+
+        Ok(ab)
+    }
+
+    fn h_query_scalars<F: PrimeField, D: EvaluationDomain<F>>(
+        max_power: usize,
+        t: F,
+        _: F,
+        delta_inverse: F,
+    ) -> Result<Vec<F>, SynthesisError> {
+        // the usual H query has domain-1 powers. Z has domain powers. So HZ has 2*domain-1 powers.
+        #[allow(unexpected_cfgs)]
+        let mut scalars = cfg_into_iter!(0..2 * max_power + 1)
+            .map(|i| delta_inverse * t.pow([i as u64]))
+            .collect::<Vec<_>>();
+        let domain_size = scalars.len();
+        let domain = D::new(domain_size).ok_or(SynthesisError::PolynomialDegreeTooLarge)?;
+        // generate the lagrange coefficients
+        domain.ifft_in_place(&mut scalars);
+        #[allow(unexpected_cfgs)]
+        Ok(cfg_into_iter!(scalars).skip(1).step_by(2).collect())
+    }
+}

rln/src/circuit/zkey.rs

@@ -0,0 +1,371 @@
+// This file is based on the code by arkworks. Its preimage can be found here:
+// https://github.com/arkworks-rs/circom-compat/blob/3c95ed98e23a408b4d99a53e483a9bba39685a4e/src/zkey.rs
+
+//! ZKey Parsing
+//!
+//! Each ZKey file is broken into sections:
+//!  Header(1)
+//!       Prover Type 1 Groth
+//!  HeaderGroth(2)
+//!       n8q
+//!       q
+//!       n8r
+//!       r
+//!       NVars
+//!       NPub
+//!       DomainSize  (multiple of 2
+//!       alpha1
+//!       beta1
+//!       delta1
+//!       beta2
+//!       gamma2
+//!       delta2
+//!  IC(3)
+//!  Coefs(4)
+//!  PointsA(5)
+//!  PointsB1(6)
+//!  PointsB2(7)
+//!  PointsC(8)
+//!  PointsH(9)
+//!  Contributions(10)
+use ark_ff::{BigInteger256, PrimeField};
+use ark_relations::r1cs::ConstraintMatrices;
+use ark_serialize::{CanonicalDeserialize, SerializationError};
+use ark_std::log2;
+use byteorder::{LittleEndian, ReadBytesExt};
+
+use std::{
+    collections::HashMap,
+    io::{Read, Seek, SeekFrom},
+};
+
+use ark_bn254::{Bn254, Fq, Fq2, Fr, G1Affine, G2Affine};
+use ark_groth16::{ProvingKey, VerifyingKey};
+use num_traits::Zero;
+
+type IoResult<T> = Result<T, SerializationError>;
+
+#[derive(Clone, Debug)]
+struct Section {
+    position: u64,
+    #[allow(dead_code)]
+    size: usize,
+}
+
+/// Reads a SnarkJS ZKey file into an Arkworks ProvingKey.
+pub fn read_zkey<R: Read + Seek>(
+    reader: &mut R,
+) -> IoResult<(ProvingKey<Bn254>, ConstraintMatrices<Fr>)> {
+    let mut binfile = BinFile::new(reader)?;
+    let proving_key = binfile.proving_key()?;
+    let matrices = binfile.matrices()?;
+    Ok((proving_key, matrices))
+}
+
+#[derive(Debug)]
+struct BinFile<'a, R> {
+    #[allow(dead_code)]
+    ftype: String,
+    #[allow(dead_code)]
+    version: u32,
+    sections: HashMap<u32, Vec<Section>>,
+    reader: &'a mut R,
+}
+
+impl<'a, R: Read + Seek> BinFile<'a, R> {
+    fn new(reader: &'a mut R) -> IoResult<Self> {
+        let mut magic = [0u8; 4];
+        reader.read_exact(&mut magic)?;
+
+        let version = reader.read_u32::<LittleEndian>()?;
+
+        let num_sections = reader.read_u32::<LittleEndian>()?;
+
+        let mut sections = HashMap::new();
+        for _ in 0..num_sections {
+            let section_id = reader.read_u32::<LittleEndian>()?;
+            let section_length = reader.read_u64::<LittleEndian>()?;
+
+            let section = sections.entry(section_id).or_insert_with(Vec::new);
+            section.push(Section {
+                position: reader.stream_position()?,
+                size: section_length as usize,
+            });
+
+            reader.seek(SeekFrom::Current(section_length as i64))?;
+        }
+
+        Ok(Self {
+            ftype: std::str::from_utf8(&magic[..]).unwrap().to_string(),
+            version,
+            sections,
+            reader,
+        })
+    }
+
+    fn proving_key(&mut self) -> IoResult<ProvingKey<Bn254>> {
+        let header = self.groth_header()?;
+        let ic = self.ic(header.n_public)?;
+
+        let a_query = self.a_query(header.n_vars)?;
+        let b_g1_query = self.b_g1_query(header.n_vars)?;
+        let b_g2_query = self.b_g2_query(header.n_vars)?;
+        let l_query = self.l_query(header.n_vars - header.n_public - 1)?;
+        let h_query = self.h_query(header.domain_size as usize)?;
+
+        let vk = VerifyingKey::<Bn254> {
+            alpha_g1: header.verifying_key.alpha_g1,
+            beta_g2: header.verifying_key.beta_g2,
+            gamma_g2: header.verifying_key.gamma_g2,
+            delta_g2: header.verifying_key.delta_g2,
+            gamma_abc_g1: ic,
+        };
+
+        let pk = ProvingKey::<Bn254> {
+            vk,
+            beta_g1: header.verifying_key.beta_g1,
+            delta_g1: header.verifying_key.delta_g1,
+            a_query,
+            b_g1_query,
+            b_g2_query,
+            h_query,
+            l_query,
+        };
+
+        Ok(pk)
+    }
+
+    fn get_section(&self, id: u32) -> Section {
+        self.sections.get(&id).unwrap()[0].clone()
+    }
+
+    fn groth_header(&mut self) -> IoResult<HeaderGroth> {
+        let section = self.get_section(2);
+        let header = HeaderGroth::new(&mut self.reader, &section)?;
+        Ok(header)
+    }
+
+    fn ic(&mut self, n_public: usize) -> IoResult<Vec<G1Affine>> {
+        // the range is non-inclusive so we do +1 to get all inputs
+        self.g1_section(n_public + 1, 3)
+    }
+
+    /// Returns the [`ConstraintMatrices`] corresponding to the zkey
+    pub fn matrices(&mut self) -> IoResult<ConstraintMatrices<Fr>> {
+        let header = self.groth_header()?;
+
+        let section = self.get_section(4);
+        self.reader.seek(SeekFrom::Start(section.position))?;
+        let num_coeffs: u32 = self.reader.read_u32::<LittleEndian>()?;
+
+        // insantiate AB
+        let mut matrices = vec![vec![vec![]; header.domain_size as usize]; 2];
+        let mut max_constraint_index = 0;
+        for _ in 0..num_coeffs {
+            let matrix: u32 = self.reader.read_u32::<LittleEndian>()?;
+            let constraint: u32 = self.reader.read_u32::<LittleEndian>()?;
+            let signal: u32 = self.reader.read_u32::<LittleEndian>()?;
+
+            let value: Fr = deserialize_field_fr(&mut self.reader)?;
+            max_constraint_index = std::cmp::max(max_constraint_index, constraint);
+            matrices[matrix as usize][constraint as usize].push((value, signal as usize));
+        }
+
+        let num_constraints = max_constraint_index as usize - header.n_public;
+        // Remove the public input constraints, Arkworks adds them later
+        matrices.iter_mut().for_each(|m| {
+            m.truncate(num_constraints);
+        });
+        // This is taken from Arkworks' to_matrices() function
+        let a = matrices[0].clone();
+        let b = matrices[1].clone();
+        let a_num_non_zero: usize = a.iter().map(|lc| lc.len()).sum();
+        let b_num_non_zero: usize = b.iter().map(|lc| lc.len()).sum();
+        let matrices = ConstraintMatrices {
+            num_instance_variables: header.n_public + 1,
+            num_witness_variables: header.n_vars - header.n_public,
+            num_constraints,
+
+            a_num_non_zero,
+            b_num_non_zero,
+            c_num_non_zero: 0,
+
+            a,
+            b,
+            c: vec![],
+        };
+
+        Ok(matrices)
+    }
+
+    fn a_query(&mut self, n_vars: usize) -> IoResult<Vec<G1Affine>> {
+        self.g1_section(n_vars, 5)
+    }
+
+    fn b_g1_query(&mut self, n_vars: usize) -> IoResult<Vec<G1Affine>> {
+        self.g1_section(n_vars, 6)
+    }
+
+    fn b_g2_query(&mut self, n_vars: usize) -> IoResult<Vec<G2Affine>> {
+        self.g2_section(n_vars, 7)
+    }
+
+    fn l_query(&mut self, n_vars: usize) -> IoResult<Vec<G1Affine>> {
+        self.g1_section(n_vars, 8)
+    }
+
+    fn h_query(&mut self, n_vars: usize) -> IoResult<Vec<G1Affine>> {
+        self.g1_section(n_vars, 9)
+    }
+
+    fn g1_section(&mut self, num: usize, section_id: usize) -> IoResult<Vec<G1Affine>> {
+        let section = self.get_section(section_id as u32);
+        self.reader.seek(SeekFrom::Start(section.position))?;
+        deserialize_g1_vec(self.reader, num as u32)
+    }
+
+    fn g2_section(&mut self, num: usize, section_id: usize) -> IoResult<Vec<G2Affine>> {
+        let section = self.get_section(section_id as u32);
+        self.reader.seek(SeekFrom::Start(section.position))?;
+        deserialize_g2_vec(self.reader, num as u32)
+    }
+}
+
+#[derive(Default, Clone, Debug, CanonicalDeserialize)]
+pub struct ZVerifyingKey {
+    alpha_g1: G1Affine,
+    beta_g1: G1Affine,
+    beta_g2: G2Affine,
+    gamma_g2: G2Affine,
+    delta_g1: G1Affine,
+    delta_g2: G2Affine,
+}
+
+impl ZVerifyingKey {
+    fn new<R: Read>(reader: &mut R) -> IoResult<Self> {
+        let alpha_g1 = deserialize_g1(reader)?;
+        let beta_g1 = deserialize_g1(reader)?;
+        let beta_g2 = deserialize_g2(reader)?;
+        let gamma_g2 = deserialize_g2(reader)?;
+        let delta_g1 = deserialize_g1(reader)?;
+        let delta_g2 = deserialize_g2(reader)?;
+
+        Ok(Self {
+            alpha_g1,
+            beta_g1,
+            beta_g2,
+            gamma_g2,
+            delta_g1,
+            delta_g2,
+        })
+    }
+}
+
+#[derive(Clone, Debug)]
+struct HeaderGroth {
+    #[allow(dead_code)]
+    n8q: u32,
+    #[allow(dead_code)]
+    q: BigInteger256,
+    #[allow(dead_code)]
+    n8r: u32,
+    #[allow(dead_code)]
+    r: BigInteger256,
+
+    n_vars: usize,
+    n_public: usize,
+
+    domain_size: u32,
+    #[allow(dead_code)]
+    power: u32,
+
+    verifying_key: ZVerifyingKey,
+}
+
+impl HeaderGroth {
+    fn new<R: Read + Seek>(reader: &mut R, section: &Section) -> IoResult<Self> {
+        reader.seek(SeekFrom::Start(section.position))?;
+        Self::read(reader)
+    }
+
+    fn read<R: Read>(mut reader: &mut R) -> IoResult<Self> {
+        // TODO: Impl From<u32> in Arkworks
+        let n8q: u32 = u32::deserialize_uncompressed(&mut reader)?;
+        // group order r of Bn254
+        let q = BigInteger256::deserialize_uncompressed(&mut reader)?;
+
+        let n8r: u32 = u32::deserialize_uncompressed(&mut reader)?;
+        // Prime field modulus
+        let r = BigInteger256::deserialize_uncompressed(&mut reader)?;
+
+        let n_vars = u32::deserialize_uncompressed(&mut reader)? as usize;
+        let n_public = u32::deserialize_uncompressed(&mut reader)? as usize;
+
+        let domain_size: u32 = u32::deserialize_uncompressed(&mut reader)?;
+        let power = log2(domain_size as usize);
+
+        let verifying_key = ZVerifyingKey::new(&mut reader)?;
+
+        Ok(Self {
+            n8q,
+            q,
+            n8r,
+            r,
+            n_vars,
+            n_public,
+            domain_size,
+            power,
+            verifying_key,
+        })
+    }
+}
+
+// need to divide by R, since snarkjs outputs the zkey with coefficients
+// multiplieid by R^2
+fn deserialize_field_fr<R: Read>(reader: &mut R) -> IoResult<Fr> {
+    let bigint = BigInteger256::deserialize_uncompressed(reader)?;
+    Ok(Fr::new_unchecked(Fr::new_unchecked(bigint).into_bigint()))
+}
+
+// skips the multiplication by R because Circom points are already in Montgomery form
+fn deserialize_field<R: Read>(reader: &mut R) -> IoResult<Fq> {
+    let bigint = BigInteger256::deserialize_uncompressed(reader)?;
+    // if you use Fq::new it multiplies by R
+    Ok(Fq::new_unchecked(bigint))
+}
+
+pub fn deserialize_field2<R: Read>(reader: &mut R) -> IoResult<Fq2> {
+    let c0 = deserialize_field(reader)?;
+    let c1 = deserialize_field(reader)?;
+    Ok(Fq2::new(c0, c1))
+}
+
+fn deserialize_g1<R: Read>(reader: &mut R) -> IoResult<G1Affine> {
+    let x = deserialize_field(reader)?;
+    let y = deserialize_field(reader)?;
+    let infinity = x.is_zero() && y.is_zero();
+    if infinity {
+        Ok(G1Affine::identity())
+    } else {
+        Ok(G1Affine::new(x, y))
+    }
+}
+
+fn deserialize_g2<R: Read>(reader: &mut R) -> IoResult<G2Affine> {
+    let f1 = deserialize_field2(reader)?;
+    let f2 = deserialize_field2(reader)?;
+    let infinity = f1.is_zero() && f2.is_zero();
+    if infinity {
+        Ok(G2Affine::identity())
+    } else {
+        Ok(G2Affine::new(f1, f2))
+    }
+}
+
+fn deserialize_g1_vec<R: Read>(reader: &mut R, n_vars: u32) -> IoResult<Vec<G1Affine>> {
+    (0..n_vars).map(|_| deserialize_g1(reader)).collect()
+}
+
+fn deserialize_g2_vec<R: Read>(reader: &mut R, n_vars: u32) -> IoResult<Vec<G2Affine>> {
+    (0..n_vars).map(|_| deserialize_g2(reader)).collect()
+}

rln/src/hashers.rs

@@ -23,7 +23,7 @@ static POSEIDON: Lazy<Poseidon<Fr>> = Lazy::new(|| Poseidon::<Fr>::from(&ROUND_P
 
 pub fn poseidon_hash(input: &[Fr]) -> Fr {
     POSEIDON
-        .hash(input.to_vec())
+        .hash(input)
         .expect("hash with fixed input size can't fail")
 }
 

rln/src/lib.rs

@@ -1,8 +1,7 @@
-#![allow(dead_code)]
-
 pub mod circuit;
+#[cfg(not(target_arch = "wasm32"))]
+pub mod ffi;
 pub mod hashers;
-pub mod iden3calc;
 #[cfg(feature = "pmtree-ft")]
 pub mod pm_tree_adapter;
 pub mod poseidon_tree;
@@ -11,5 +10,3 @@ pub mod public;
 #[cfg(test)]
 pub mod public_api_tests;
 pub mod utils;
-
-pub mod ffi;

rln/src/pm_tree_adapter.rs

@@ -244,7 +244,7 @@ impl ZerokitMerkleTree for PmTree {
             (0, 0) => Err(Report::msg("no leaves or indices to be removed")),
             (1, 0) => self.set(start, leaves[0]),
             (0, 1) => self.delete(indices[0]),
-            (_, 0) => self.set_range(start, leaves),
+            (_, 0) => self.set_range(start, leaves.into_iter()),
             (0, _) => self.remove_indices(&indices),
             (_, _) => self.remove_indices_and_set_leaves(start, leaves, &indices),
         }

rln/src/protocol.rs

@@ -1,7 +1,6 @@
 // This crate collects all the underlying primitives used to implement RLN
 
 use ark_bn254::Fr;
-use ark_circom::CircomReduction;
 use ark_groth16::{prepare_verifying_key, Groth16, Proof as ArkProof, ProvingKey, VerifyingKey};
 use ark_relations::r1cs::{ConstraintMatrices, SynthesisError};
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize};
@@ -16,7 +15,7 @@ use std::time::Instant;
 use thiserror::Error;
 use tiny_keccak::{Hasher as _, Keccak};
 
-use crate::circuit::{calculate_rln_witness, Curve};
+use crate::circuit::{calculate_rln_witness, qap::CircomReduction, Curve};
 use crate::hashers::{hash_to_field, poseidon_hash};
 use crate::poseidon_tree::*;
 use crate::public::RLN_IDENTIFIER;

rln/src/public.rs

@@ -8,16 +8,24 @@ use {
     utils::{Hasher, ZerokitMerkleProof, ZerokitMerkleTree},
 };
 
-use crate::circuit::{graph_from_folder, vk_from_raw, zkey_from_folder, zkey_from_raw, Curve, Fr};
+use crate::circuit::{zkey_from_raw, Curve, Fr};
 use crate::hashers::{hash_to_field, poseidon_hash as utils_poseidon_hash};
 use crate::protocol::*;
 use crate::utils::*;
+#[cfg(not(target_arch = "wasm32"))]
+use {
+    crate::circuit::{graph_from_folder, zkey_from_folder},
+    std::default::Default,
+};
 
 use ark_groth16::{Proof as ArkProof, ProvingKey, VerifyingKey};
 use ark_relations::r1cs::ConstraintMatrices;
 use ark_serialize::{CanonicalDeserialize, CanonicalSerialize, Read, Write};
 use color_eyre::{Report, Result};
-use std::{default::Default, io::Cursor};
+use std::io::Cursor;
+
+#[cfg(target_arch = "wasm32")]
+use num_bigint::BigInt;
 
 /// The application-specific RLN identifier.
 ///
@@ -32,6 +40,7 @@ pub const RLN_IDENTIFIER: &[u8] = b"zerokit/rln/010203040506070809";
 pub struct RLN {
     proving_key: (ProvingKey<Curve>, ConstraintMatrices<Fr>),
     pub(crate) verification_key: VerifyingKey<Curve>,
+    #[cfg(not(target_arch = "wasm32"))]
     pub(crate) graph_data: Vec<u8>,
     #[cfg(not(feature = "stateless"))]
     pub(crate) tree: PoseidonTree,
@@ -54,7 +63,7 @@ impl RLN {
     /// // We create a new RLN instance
     /// let mut rln = RLN::new(tree_height, input);
     /// ```
-    #[cfg(not(feature = "stateless"))]
+    #[cfg(all(not(target_arch = "wasm32"), not(feature = "stateless")))]
     pub fn new<R: Read>(tree_height: usize, mut input_data: R) -> Result<RLN> {
         // We read input
         let mut input: Vec<u8> = Vec::new();
@@ -63,9 +72,9 @@ impl RLN {
         let rln_config: Value = serde_json::from_str(&String::from_utf8(input)?)?;
         let tree_config = rln_config["tree_config"].to_string();
 
-        let proving_key = zkey_from_folder();
-        let verification_key = &proving_key.0.vk;
-        let graph_data = graph_from_folder();
+        let proving_key = zkey_from_folder().to_owned();
+        let verification_key = proving_key.0.vk.to_owned();
+        let graph_data = graph_from_folder().to_owned();
 
         let tree_config: <PoseidonTree as ZerokitMerkleTree>::Config = if tree_config.is_empty() {
             <PoseidonTree as ZerokitMerkleTree>::Config::default()
@@ -81,9 +90,9 @@ impl RLN {
         )?;
 
         Ok(RLN {
-            proving_key: proving_key.to_owned(),
-            verification_key: verification_key.to_owned(),
-            graph_data: graph_data.to_vec(),
+            proving_key,
+            verification_key,
+            graph_data,
             #[cfg(not(feature = "stateless"))]
             tree,
         })
@@ -98,16 +107,16 @@ impl RLN {
     /// let mut rln = RLN::new();
     /// ```
     #[cfg_attr(docsrs, doc(cfg(feature = "stateless")))]
-    #[cfg(feature = "stateless")]
+    #[cfg(all(not(target_arch = "wasm32"), feature = "stateless"))]
     pub fn new() -> Result<RLN> {
-        let proving_key = zkey_from_folder();
-        let verification_key = &proving_key.0.vk;
-        let graph_data = graph_from_folder();
+        let proving_key = zkey_from_folder().to_owned();
+        let verification_key = proving_key.0.vk.to_owned();
+        let graph_data = graph_from_folder().to_owned();
 
         Ok(RLN {
-            proving_key: proving_key.to_owned(),
-            verification_key: verification_key.to_owned(),
-            graph_data: graph_data.to_vec(),
+            proving_key,
+            verification_key,
+            graph_data,
         })
     }
 
@@ -116,6 +125,7 @@ impl RLN {
     /// Input parameters are
     /// - `tree_height`: the height of the internal Merkle tree
     /// - `zkey_vec`: a byte vector containing to the proving key (`rln_final.zkey`)  or (`rln_final.arkzkey`) as binary file
+    /// - `graph_data`: a byte vector containing the graph data (`graph.bin`) as binary file
     /// - `tree_config_input`: a reader for a string containing a json with the merkle tree configuration
     ///
     /// Example:
@@ -143,11 +153,10 @@ impl RLN {
     ///     tree_height,
     ///     resources[0].clone(),
     ///     resources[1].clone(),
-    ///     resources[2].clone(),
     ///     tree_config_buffer,
     /// );
     /// ```
-    #[cfg(not(feature = "stateless"))]
+    #[cfg(all(not(target_arch = "wasm32"), not(feature = "stateless")))]
     pub fn new_with_params<R: Read>(
         tree_height: usize,
         zkey_vec: Vec<u8>,
@@ -155,7 +164,7 @@ impl RLN {
         mut tree_config_input: R,
     ) -> Result<RLN> {
         let proving_key = zkey_from_raw(&zkey_vec)?;
-        let verification_key = vk_from_raw(&zkey_vec)?;
+        let verification_key = proving_key.0.vk.to_owned();
 
         let mut tree_config_vec: Vec<u8> = Vec::new();
         tree_config_input.read_to_end(&mut tree_config_vec)?;
@@ -187,6 +196,7 @@ impl RLN {
     ///
     /// Input parameters are
     /// - `zkey_vec`: a byte vector containing to the proving key (`rln_final.zkey`)  or (`rln_final.arkzkey`) as binary file
+    /// - `graph_data`: a byte vector containing the graph data (`graph.bin`) as binary file
     ///
     /// Example:
     /// ```
@@ -208,13 +218,12 @@ impl RLN {
     /// let mut rln = RLN::new_with_params(
     ///     resources[0].clone(),
     ///     resources[1].clone(),
-    ///     resources[2].clone(),
     /// );
     /// ```
-    #[cfg(feature = "stateless")]
+    #[cfg(all(not(target_arch = "wasm32"), feature = "stateless"))]
     pub fn new_with_params(zkey_vec: Vec<u8>, graph_data: Vec<u8>) -> Result<RLN> {
         let proving_key = zkey_from_raw(&zkey_vec)?;
-        let verification_key = vk_from_raw(&zkey_vec)?;
+        let verification_key = proving_key.0.vk.to_owned();
 
         Ok(RLN {
             proving_key,
@@ -223,6 +232,36 @@ impl RLN {
         })
     }
 
+    /// Creates a new stateless RLN object by passing circuit resources as a byte vector.
+    ///
+    /// Input parameters are
+    /// - `zkey_vec`: a byte vector containing the proving key (`rln_final.zkey`) or (`rln_final.arkzkey`) as binary file
+    ///
+    /// Example:
+    /// ```
+    /// use std::fs::File;
+    /// use std::io::Read;
+    ///
+    /// let zkey_path = "./resources/tree_height_20/rln_final.zkey";
+    ///
+    /// let mut file = File::open(zkey_path).expect("Failed to open file");
+    /// let metadata = std::fs::metadata(zkey_path).expect("Failed to read metadata");
+    /// let mut zkey_vec = vec![0; metadata.len() as usize];
+    /// file.read_exact(&mut zkey_vec).expect("Failed to read file");
+    ///
+    /// let mut rln = RLN::new_with_params(zkey_vec)?;
+    /// ```
+    #[cfg(all(target_arch = "wasm32", feature = "stateless"))]
+    pub fn new_with_params(zkey_vec: Vec<u8>) -> Result<RLN> {
+        let proving_key = zkey_from_raw(&zkey_vec)?;
+        let verification_key = proving_key.0.vk.to_owned();
+
+        Ok(RLN {
+            proving_key,
+            verification_key,
+        })
+    }
+
     ////////////////////////////////////////////////////////
     // Merkle-tree APIs
     ////////////////////////////////////////////////////////
@@ -346,7 +385,7 @@ impl RLN {
 
         // We set the leaves
         self.tree
-            .override_range(index, leaves, [])
+            .override_range(index, leaves.into_iter(), [].into_iter())
             .map_err(|_| Report::msg("Could not set leaves"))?;
         Ok(())
     }
@@ -429,7 +468,7 @@ impl RLN {
 
         // We set the leaves
         self.tree
-            .override_range(index, leaves, indices)
+            .override_range(index, leaves.into_iter(), indices.into_iter())
             .map_err(|e| Report::msg(format!("Could not perform the batch operation: {e}")))?;
         Ok(())
     }
@@ -698,15 +737,16 @@ impl RLN {
     /// rln.prove(&mut input_buffer, &mut output_buffer).unwrap();
     /// let zk_proof = output_buffer.into_inner();
     /// ```
+    #[cfg(not(target_arch = "wasm32"))]
     pub fn prove<R: Read, W: Write>(
         &mut self,
         mut input_data: R,
         mut output_data: W,
     ) -> Result<()> {
         // We read input RLN witness and we serialize_compressed it
-        let mut serialized: Vec<u8> = Vec::new();
-        input_data.read_to_end(&mut serialized)?;
-        let (rln_witness, _) = deserialize_witness(&serialized)?;
+        let mut serialized_witness: Vec<u8> = Vec::new();
+        input_data.read_to_end(&mut serialized_witness)?;
+        let (rln_witness, _) = deserialize_witness(&serialized_witness)?;
 
         let proof = generate_proof(&self.proving_key, &rln_witness, &self.graph_data)?;
 
@@ -818,7 +858,7 @@ impl RLN {
     /// // proof_data is [ proof<128> | root<32> | external_nullifier<32> | x<32> | y<32> | nullifier<32>]
     /// let mut proof_data = output_buffer.into_inner();
     /// ```
-    #[cfg(not(feature = "stateless"))]
+    #[cfg(all(not(target_arch = "wasm32"), not(feature = "stateless")))]
     pub fn generate_rln_proof<R: Read, W: Write>(
         &mut self,
         mut input_data: R,
@@ -840,18 +880,18 @@ impl RLN {
         Ok(())
     }
 
-    // Generate RLN Proof using a witness calculated from outside zerokit
-    //
-    // output_data is  [ proof<128> | root<32> | external_nullifier<32> | x<32> | y<32> | nullifier<32>]
-    // we skip it from documentation for now
+    /// Generate RLN Proof using a witness calculated from outside zerokit
+    ///
+    /// output_data is  [ proof<128> | root<32> | external_nullifier<32> | x<32> | y<32> | nullifier<32>]
+    #[cfg(not(target_arch = "wasm32"))]
     pub fn generate_rln_proof_with_witness<R: Read, W: Write>(
         &mut self,
         mut input_data: R,
         mut output_data: W,
     ) -> Result<()> {
-        let mut witness_byte: Vec<u8> = Vec::new();
-        input_data.read_to_end(&mut witness_byte)?;
-        let (rln_witness, _) = deserialize_witness(&witness_byte)?;
+        let mut serialized_witness: Vec<u8> = Vec::new();
+        input_data.read_to_end(&mut serialized_witness)?;
+        let (rln_witness, _) = deserialize_witness(&serialized_witness)?;
         let proof_values = proof_values_from_witness(&rln_witness)?;
 
         let proof = generate_proof(&self.proving_key, &rln_witness, &self.graph_data)?;
@@ -863,6 +903,28 @@ impl RLN {
         Ok(())
     }
 
+    /// Generate RLN Proof using a witness calculated from outside zerokit
+    ///
+    /// output_data is [ proof<128> | root<32> | external_nullifier<32> | x<32> | y<32> | nullifier<32>]
+    #[cfg(target_arch = "wasm32")]
+    pub fn generate_rln_proof_with_witness<W: Write>(
+        &mut self,
+        calculated_witness: Vec<BigInt>,
+        serialized_witness: Vec<u8>,
+        mut output_data: W,
+    ) -> Result<()> {
+        let (rln_witness, _) = deserialize_witness(&serialized_witness[..])?;
+        let proof_values = proof_values_from_witness(&rln_witness)?;
+
+        let proof = generate_proof_with_witness(calculated_witness, &self.proving_key).unwrap();
+
+        // Note: we export a serialization of ark-groth16::Proof not semaphore::Proof
+        // This proof is compressed, i.e. 128 bytes long
+        proof.serialize_compressed(&mut output_data)?;
+        output_data.write_all(&serialize_proof_values(&proof_values))?;
+        Ok(())
+    }
+
     /// Verifies a zkSNARK RLN proof against the provided proof values and the state of the internal Merkle tree.
     ///
     /// Input values are:
@@ -1301,6 +1363,7 @@ impl RLN {
     }
 }
 
+#[cfg(not(target_arch = "wasm32"))]
 impl Default for RLN {
     fn default() -> Self {
         #[cfg(not(feature = "stateless"))]

rln/src/public_api_tests.rs

@@ -486,7 +486,6 @@ mod tree_test {
         assert_eq!(received_leaf, Fr::from(0));
     }
 
-    #[allow(unused_must_use)]
     #[test]
     // This test checks if `set_leaves_from` throws an error when the index is out of bounds
     fn test_set_leaves_bad_index() {
@@ -511,6 +510,8 @@ mod tree_test {
 
         // We add leaves in a batch into the tree
         let mut buffer = Cursor::new(vec_fr_to_bytes_le(&leaves).unwrap());
+
+        #[allow(unused_must_use)]
         rln.set_leaves_from(bad_index, &mut buffer)
             .expect_err("Should throw an error");
 

rln/src/utils.rs

@@ -136,9 +136,15 @@ pub fn bytes_le_to_vec_usize(input: &[u8]) -> Result<Vec<usize>> {
     }
 }
 
+/// Normalizes a `usize` into an 8-byte array, ensuring consistency across architectures.
+/// On 32-bit systems, the result is zero-padded to 8 bytes.
+/// On 64-bit systems, it directly represents the `usize` value.
 #[inline(always)]
 pub fn normalize_usize(input: usize) -> [u8; 8] {
-    input.to_le_bytes()
+    let mut bytes = [0u8; 8];
+    let input_bytes = input.to_le_bytes();
+    bytes[..input_bytes.len()].copy_from_slice(&input_bytes);
+    bytes
 }
 
 #[inline(always)] // using for test

rln/tests/ffi.rs

@@ -156,6 +156,7 @@ mod test {
         // random number between 0..no_of_leaves
         let mut rng = thread_rng();
         let set_index = rng.gen_range(0..NO_OF_LEAVES) as usize;
+        println!("set_index: {}", set_index);
 
         // We add leaves in a batch into the tree
         set_leaves_init(rln_pointer, &leaves);
@@ -176,7 +177,10 @@ mod test {
 
         // We get the root of the tree obtained adding leaves in batch
         let root_batch_with_custom_index = get_tree_root(rln_pointer);
-        assert_eq!(root_batch_with_init, root_batch_with_custom_index);
+        assert_eq!(
+            root_batch_with_init, root_batch_with_custom_index,
+            "root batch !="
+        );
 
         // We reset the tree to default
         let success = set_tree(rln_pointer, TEST_TREE_HEIGHT);
@@ -192,7 +196,10 @@ mod test {
 
         // We get the root of the tree obtained adding leaves using the internal index
         let root_single_additions = get_tree_root(rln_pointer);
-        assert_eq!(root_batch_with_init, root_single_additions);
+        assert_eq!(
+            root_batch_with_init, root_single_additions,
+            "root single additions !="
+        );
     }
 
     #[test]

rln/tests/poseidon_tree.rs

@@ -23,6 +23,7 @@ mod test {
             assert_eq!(proof.leaf_index(), i);
 
             tree_opt.set(i, leaves[i]).unwrap();
+            assert_eq!(tree_opt.root(), tree_full.root());
             let proof = tree_opt.proof(i).expect("index should be set");
             assert_eq!(proof.leaf_index(), i);
         }
@@ -37,11 +38,11 @@ mod test {
     #[test]
     fn test_subtree_root() {
         const DEPTH: usize = 3;
-        const LEAVES_LEN: usize = 6;
+        const LEAVES_LEN: usize = 8;
 
         let mut tree = PoseidonTree::default(DEPTH).unwrap();
         let leaves: Vec<Fr> = (0..LEAVES_LEN).map(|s| Fr::from(s as i32)).collect();
-        let _ = tree.set_range(0, leaves);
+        let _ = tree.set_range(0, leaves.into_iter());
 
         for i in 0..LEAVES_LEN {
             // check leaves
@@ -78,7 +79,7 @@ mod test {
         let leaves: Vec<Fr> = (0..nof_leaves).map(|s| Fr::from(s as i32)).collect();
 
         // check set_range
-        let _ = tree.set_range(0, leaves.clone());
+        let _ = tree.set_range(0, leaves.clone().into_iter());
         assert!(tree.get_empty_leaves_indices().is_empty());
 
         let mut vec_idxs = Vec::new();
@@ -98,26 +99,28 @@ mod test {
         // check remove_indices_and_set_leaves inside override_range function
         assert!(tree.get_empty_leaves_indices().is_empty());
         let leaves_2: Vec<Fr> = (0..2).map(|s| Fr::from(s as i32)).collect();
-        tree.override_range(0, leaves_2.clone(), [0, 1, 2, 3])
+        tree.override_range(0, leaves_2.clone().into_iter(), [0, 1, 2, 3].into_iter())
             .unwrap();
         assert_eq!(tree.get_empty_leaves_indices(), vec![2, 3]);
 
         // check remove_indices inside override_range function
-        tree.override_range(0, [], [0, 1]).unwrap();
+        tree.override_range(0, [].into_iter(), [0, 1].into_iter())
+            .unwrap();
         assert_eq!(tree.get_empty_leaves_indices(), vec![0, 1, 2, 3]);
 
         // check set_range inside override_range function
-        tree.override_range(0, leaves_2.clone(), []).unwrap();
+        tree.override_range(0, leaves_2.clone().into_iter(), [].into_iter())
+            .unwrap();
         assert_eq!(tree.get_empty_leaves_indices(), vec![2, 3]);
 
         let leaves_4: Vec<Fr> = (0..4).map(|s| Fr::from(s as i32)).collect();
         // check if the indexes for write and delete are the same
-        tree.override_range(0, leaves_4.clone(), [0, 1, 2, 3])
+        tree.override_range(0, leaves_4.clone().into_iter(), [0, 1, 2, 3].into_iter())
             .unwrap();
         assert!(tree.get_empty_leaves_indices().is_empty());
 
         // check if indexes for deletion are before indexes for overwriting
-        tree.override_range(4, leaves_4.clone(), [0, 1, 2, 3])
+        tree.override_range(4, leaves_4.clone().into_iter(), [0, 1, 2, 3].into_iter())
             .unwrap();
         // The result will be like this, because in the set_range function in pmtree
         // the next_index value is increased not by the number of elements to insert,
@@ -128,7 +131,7 @@ mod test {
         );
 
         // check if the indices for write and delete do not overlap completely
-        tree.override_range(2, leaves_4.clone(), [0, 1, 2, 3])
+        tree.override_range(2, leaves_4.clone().into_iter(), [0, 1, 2, 3].into_iter())
             .unwrap();
         // The result will be like this, because in the set_range function in pmtree
         // the next_index value is increased not by the number of elements to insert,

utils/Cargo.toml

@@ -12,29 +12,34 @@ repository = "https://github.com/vacp2p/zerokit"
 bench = false
 
 [dependencies]
-ark-ff = { version = "0.5.0", features = ["asm"] }
+ark-ff = { version = "0.5.0", default-features = false, features = [
+    "parallel",
+] }
 num-bigint = { version = "0.4.6", default-features = false, features = [
     "rand",
 ] }
-color-eyre = "0.6.2"
-pmtree = { package = "vacp2p_pmtree", version = "=2.0.2", optional = true }
+color-eyre = "0.6.3"
+pmtree = { package = "vacp2p_pmtree", version = "2.0.2", optional = true }
 sled = "0.34.7"
 serde = "1.0"
-lazy_static = "1.4.0"
+lazy_static = "1.5.0"
 hex = "0.4"
 
 [dev-dependencies]
 ark-bn254 = { version = "0.5.0", features = ["std"] }
 num-traits = "0.2.19"
-hex-literal = "0.3.4"
+hex-literal = "1.0.0"
 tiny-keccak = { version = "2.0.2", features = ["keccak"] }
 criterion = { version = "0.4.0", features = ["html_reports"] }
 
 [features]
-default = ["parallel"]
-parallel = ["ark-ff/parallel"]
+default = []
 pmtree-ft = ["pmtree"]
 
 [[bench]]
 name = "merkle_tree_benchmark"
 harness = false
+
+[[bench]]
+name = "poseidon_benchmark"
+harness = false

utils/Makefile.toml

@@ -8,4 +8,4 @@ args = ["test", "--release"]
 
 [tasks.bench]
 command = "cargo"
-args = ["bench"]
+args = ["bench"]

utils/README.md

@@ -20,6 +20,40 @@ The crate supports two interchangeable Merkle tree implementations:
 - **OptimalMerkleTree**
   - Only stores nodes used to prove accumulation of set leaves
 
+### Implementation notes
+
+Glossary:
+
+* depth: level of leaves if we count from levels from 0
+* number of levels: depth + 1
+* capacity (== number of leaves) -- 1 << depth
+* total number of nodes: 1 << (depth + 1)) - 1
+
+So for instance:
+* depth: 3
+* number of levels: 4
+* capacity (number of leaves): 8
+* total number of nodes: 15
+
+```mermaid
+flowchart TD
+    A[Root] --> N1
+    A[Root] --> N2
+    N1 --> N3
+    N1 --> N4
+    N2 --> N5
+    N2 --> N6
+    N3 -->|Leaf| L1
+    N3 -->|Leaf| L2
+    N4 -->|Leaf| L3
+    N4 -->|Leaf| L4
+    N5 -->|Leaf| L5
+    N5 -->|Leaf| L6
+    N6 -->|Leaf| L7
+    N6 -->|Leaf| L8
+```
+
+
 ## Poseidon Hash Implementation
 
 This crate provides an implementation to compute the Poseidon hash round constants and MDS matrices:
@@ -56,13 +90,13 @@ zerokit-utils = "0.5.1"
 
 ```bash
 # Build the crate
-cargo build
+cargo make build
 
 # Run tests
-cargo test
+cargo make test
 
 # Run benchmarks
-cargo bench
+cargo make bench
 ```
 
 To view the results of the benchmark, open the `target/criterion/report/index.html` file generated after the bench

utils/benches/merkle_tree_benchmark.rs

@@ -75,7 +75,8 @@ pub fn optimal_merkle_tree_benchmark(c: &mut Criterion) {
 
     c.bench_function("OptimalMerkleTree::override_range", |b| {
         b.iter(|| {
-            tree.override_range(0, *LEAVES, [0, 1, 2, 3]).unwrap();
+            tree.override_range(0, LEAVES.into_iter(), [0, 1, 2, 3].into_iter())
+                .unwrap();
         })
     });
 
@@ -123,7 +124,8 @@ pub fn full_merkle_tree_benchmark(c: &mut Criterion) {
 
     c.bench_function("FullMerkleTree::override_range", |b| {
         b.iter(|| {
-            tree.override_range(0, *LEAVES, [0, 1, 2, 3]).unwrap();
+            tree.override_range(0, LEAVES.into_iter(), [0, 1, 2, 3].into_iter())
+                .unwrap();
         })
     });
 

utils/benches/poseidon_benchmark.rs

@@ -0,0 +1,65 @@
+use ark_bn254::Fr;
+use criterion::{
+    black_box, criterion_group, criterion_main, BatchSize, BenchmarkId, Criterion, Throughput,
+};
+use zerokit_utils::Poseidon;
+
+const ROUND_PARAMS: [(usize, usize, usize, usize); 8] = [
+    (2, 8, 56, 0),
+    (3, 8, 57, 0),
+    (4, 8, 56, 0),
+    (5, 8, 60, 0),
+    (6, 8, 60, 0),
+    (7, 8, 63, 0),
+    (8, 8, 64, 0),
+    (9, 8, 63, 0),
+];
+
+pub fn poseidon_benchmark(c: &mut Criterion) {
+    let hasher = Poseidon::<Fr>::from(&ROUND_PARAMS);
+    let mut group = c.benchmark_group("poseidon Fr");
+
+    for size in [10u32, 100, 1000].iter() {
+        group.throughput(Throughput::Elements(*size as u64));
+
+        group.bench_with_input(BenchmarkId::new("Array hash", size), size, |b, &size| {
+            b.iter_batched(
+                // Setup: create values for each benchmark iteration
+                || {
+                    let mut values = Vec::with_capacity(size as usize);
+                    for i in 0..size {
+                        values.push([Fr::from(i)]);
+                    }
+                    values
+                },
+                // Actual benchmark
+                |values| {
+                    for v in values.iter() {
+                        let _ = hasher.hash(black_box(&v[..]));
+                    }
+                },
+                BatchSize::SmallInput,
+            )
+        });
+    }
+
+    // Benchmark single hash operation separately
+    group.bench_function("Single hash", |b| {
+        let input = [Fr::from(u64::MAX)];
+        b.iter(|| {
+            let _ = hasher.hash(black_box(&input[..]));
+        })
+    });
+
+    group.finish();
+}
+
+criterion_group! {
+    name = benches;
+    config = Criterion::default()
+        .warm_up_time(std::time::Duration::from_millis(500))
+        .measurement_time(std::time::Duration::from_secs(4))
+        .sample_size(20);
+    targets = poseidon_benchmark
+}
+criterion_main!(benches);

utils/src/merkle_tree/full_merkle_tree.rs

@@ -3,7 +3,7 @@ use color_eyre::{Report, Result};
 use std::{
     cmp::max,
     fmt::Debug,
-    iter::{once, repeat, successors},
+    iter::{once, repeat_n, successors},
     str::FromStr,
 };
 
@@ -89,7 +89,7 @@ where
             .iter()
             .rev()
             .enumerate()
-            .flat_map(|(levels, hash)| repeat(hash).take(1 << levels))
+            .flat_map(|(levels, hash)| repeat_n(hash, 1 << levels))
             .cloned()
             .collect::<Vec<_>>();
         debug_assert!(nodes.len() == (1 << (depth + 1)) - 1);
@@ -125,7 +125,6 @@ where
         self.next_index
     }
 
-    #[must_use]
     // Returns the root of the tree
     fn root(&self) -> FrOf<Self::Hasher> {
         self.nodes[0]
@@ -237,7 +236,7 @@ where
             self.cached_leaves_indices[i] = 0;
         }
 
-        self.set_range(start, set_values)
+        self.set_range(start, set_values.into_iter())
             .map_err(|e| Report::msg(e.to_string()))
     }
 
@@ -341,14 +340,12 @@ impl<H: Hasher> ZerokitMerkleProof for FullMerkleProof<H> {
     type Index = u8;
     type Hasher = H;
 
-    #[must_use]
     // Returns the length of a Merkle proof
     fn length(&self) -> usize {
         self.0.len()
     }
 
     /// Computes the leaf index corresponding to a Merkle proof
-    #[must_use]
     fn leaf_index(&self) -> usize {
         self.0.iter().rev().fold(0, |index, branch| match branch {
             FullMerkleBranch::Left(_) => index << 1,
@@ -356,7 +353,6 @@ impl<H: Hasher> ZerokitMerkleProof for FullMerkleProof<H> {
         })
     }
 
-    #[must_use]
     /// Returns the path elements forming a Merkle proof
     fn get_path_elements(&self) -> Vec<FrOf<Self::Hasher>> {
         self.0
@@ -368,7 +364,6 @@ impl<H: Hasher> ZerokitMerkleProof for FullMerkleProof<H> {
     }
 
     /// Returns the path indexes forming a Merkle proof
-    #[must_use]
     fn get_path_index(&self) -> Vec<Self::Index> {
         self.0
             .iter()
@@ -380,7 +375,6 @@ impl<H: Hasher> ZerokitMerkleProof for FullMerkleProof<H> {
     }
 
     /// Computes the Merkle root corresponding by iteratively hashing a Merkle proof with a given input leaf
-    #[must_use]
     fn compute_root_from(&self, hash: &FrOf<Self::Hasher>) -> FrOf<Self::Hasher> {
         self.0.iter().fold(*hash, |hash, branch| match branch {
             FullMerkleBranch::Left(sibling) => H::hash(&[hash, *sibling]),

utils/src/merkle_tree/merkle_tree.rs

@@ -54,13 +54,13 @@ pub trait ZerokitMerkleTree {
     fn set(&mut self, index: usize, leaf: FrOf<Self::Hasher>) -> Result<()>;
     fn set_range<I>(&mut self, start: usize, leaves: I) -> Result<()>
     where
-        I: IntoIterator<Item = FrOf<Self::Hasher>>;
+        I: ExactSizeIterator<Item = FrOf<Self::Hasher>>;
     fn get(&self, index: usize) -> Result<FrOf<Self::Hasher>>;
     fn get_empty_leaves_indices(&self) -> Vec<usize>;
     fn override_range<I, J>(&mut self, start: usize, leaves: I, to_remove_indices: J) -> Result<()>
     where
-        I: IntoIterator<Item = FrOf<Self::Hasher>>,
-        J: IntoIterator<Item = usize>;
+        I: ExactSizeIterator<Item = FrOf<Self::Hasher>>,
+        J: ExactSizeIterator<Item = usize>;
     fn update_next(&mut self, leaf: FrOf<Self::Hasher>) -> Result<()>;
     fn delete(&mut self, index: usize) -> Result<()>;
     fn proof(&self, index: usize) -> Result<Self::Proof>;

utils/src/merkle_tree/optimal_merkle_tree.rs

@@ -1,10 +1,10 @@
 use crate::merkle_tree::{Hasher, ZerokitMerkleProof, ZerokitMerkleTree};
 use crate::FrOf;
 use color_eyre::{Report, Result};
+use std::cmp::min;
 use std::collections::HashMap;
 use std::str::FromStr;
 use std::{cmp::max, fmt::Debug};
-
 ////////////////////////////////////////////////////////////
 ///// Optimal Merkle Tree Implementation
 ////////////////////////////////////////////////////////////
@@ -81,9 +81,9 @@ where
         }
         cached_nodes.reverse();
         Ok(OptimalMerkleTree {
-            cached_nodes: cached_nodes.clone(),
+            cached_nodes,
             depth,
-            nodes: HashMap::new(),
+            nodes: HashMap::with_capacity(1 << depth),
             cached_leaves_indices: vec![0; 1 << depth],
             next_index: 0,
             metadata: Vec::new(),
@@ -109,7 +109,6 @@ where
         self.next_index
     }
 
-    #[must_use]
     // Returns the root of the tree
     fn root(&self) -> H::Fr {
         self.get_node(0, 0)
@@ -137,7 +136,7 @@ where
             return Err(Report::msg("index exceeds set size"));
         }
         self.nodes.insert((self.depth, index), leaf);
-        self.recalculate_from(index)?;
+        self.update_hashes(index, 1)?;
         self.next_index = max(self.next_index, index + 1);
         self.cached_leaves_indices[index] = 1;
         Ok(())
@@ -162,25 +161,29 @@ where
     }
 
     // Sets multiple leaves from the specified tree index
-    fn set_range<I: IntoIterator<Item = H::Fr>>(&mut self, start: usize, leaves: I) -> Result<()> {
-        let leaves = leaves.into_iter().collect::<Vec<_>>();
+    fn set_range<I: ExactSizeIterator<Item = H::Fr>>(
+        &mut self,
+        start: usize,
+        leaves: I,
+    ) -> Result<()> {
         // check if the range is valid
-        if start + leaves.len() > self.capacity() {
+        let leaves_len = leaves.len();
+        if start + leaves_len > self.capacity() {
             return Err(Report::msg("provided range exceeds set size"));
         }
-        for (i, leaf) in leaves.iter().enumerate() {
-            self.nodes.insert((self.depth, start + i), *leaf);
+        for (i, leaf) in leaves.enumerate() {
+            self.nodes.insert((self.depth, start + i), leaf);
             self.cached_leaves_indices[start + i] = 1;
-            self.recalculate_from(start + i)?;
         }
-        self.next_index = max(self.next_index, start + leaves.len());
+        self.update_hashes(start, leaves_len)?;
+        self.next_index = max(self.next_index, start + leaves_len);
         Ok(())
     }
 
     fn override_range<I, J>(&mut self, start: usize, leaves: I, indices: J) -> Result<()>
     where
-        I: IntoIterator<Item = FrOf<Self::Hasher>>,
-        J: IntoIterator<Item = usize>,
+        I: ExactSizeIterator<Item = FrOf<Self::Hasher>>,
+        J: ExactSizeIterator<Item = usize>,
     {
         let indices = indices.into_iter().collect::<Vec<_>>();
         let min_index = *indices.first().unwrap();
@@ -205,7 +208,7 @@ where
             self.cached_leaves_indices[i] = 0;
         }
 
-        self.set_range(start, set_values)
+        self.set_range(start, set_values.into_iter())
             .map_err(|e| Report::msg(e.to_string()))
     }
 
@@ -317,6 +320,60 @@ where
         }
         Ok(())
     }
+
+    /// Update hashes after some leaves have been set or updated
+    /// index - first leaf index (which has been set or updated)
+    /// length - number of elements set or updated
+    fn update_hashes(&mut self, index: usize, length: usize) -> Result<()> {
+        // parent depth & index (used to store in the tree)
+        let mut parent_depth = self.depth - 1; // tree depth (or leaves depth) - 1
+        let mut parent_index = index >> 1;
+        let mut parent_index_bak = parent_index;
+        // maximum index at this depth
+        let parent_max_index_0 = (1 << parent_depth) / 2;
+        // Based on given length (number of elements we will update)
+        // we could restrict the parent_max_index
+        let current_index_max = if (index + length) % 2 == 0 {
+            index + length + 2
+        } else {
+            index + length + 1
+        };
+        let mut parent_max_index = min(current_index_max >> 1, parent_max_index_0);
+
+        // current depth & index (used to compute the hash)
+        // current depth initially == tree depth (or leaves depth)
+        let mut current_depth = self.depth;
+        let mut current_index = if index % 2 == 0 { index } else { index - 1 };
+        let mut current_index_bak = current_index;
+
+        loop {
+            // Hash 2 values at (current depth, current_index) & (current_depth, current_index + 1)
+            let n_hash = self.hash_couple(current_depth, current_index);
+            // Insert this hash at (parent_depth, parent_index)
+            self.nodes.insert((parent_depth, parent_index), n_hash);
+
+            if parent_depth == 0 {
+                // We just set the root hash of the tree - nothing to do anymore
+                break;
+            }
+            // Incr parent index
+            parent_index += 1;
+            // Incr current index (+2 because we've just hashed current index & current_index + 1)
+            current_index += 2;
+            if parent_index >= parent_max_index {
+                // reset (aka decr depth & reset indexes)
+                parent_depth -= 1;
+                parent_index = parent_index_bak >> 1;
+                parent_index_bak = parent_index;
+                parent_max_index >>= 1;
+                current_depth -= 1;
+                current_index = current_index_bak >> 1;
+                current_index_bak = current_index;
+            }
+        }
+
+        Ok(())
+    }
 }
 
 impl<H: Hasher> ZerokitMerkleProof for OptimalMerkleProof<H>
@@ -326,14 +383,12 @@ where
     type Index = u8;
     type Hasher = H;
 
-    #[must_use]
     // Returns the length of a Merkle proof
     fn length(&self) -> usize {
         self.0.len()
     }
 
     /// Computes the leaf index corresponding to a Merkle proof
-    #[must_use]
     fn leaf_index(&self) -> usize {
         // In current implementation the path indexes in a proof correspond to the binary representation of the leaf index
         let mut binary_repr = self.get_path_index();
@@ -343,19 +398,16 @@ where
             .fold(0, |acc, digit| (acc << 1) + usize::from(digit))
     }
 
-    #[must_use]
     /// Returns the path elements forming a Merkle proof
     fn get_path_elements(&self) -> Vec<H::Fr> {
         self.0.iter().map(|x| x.0).collect()
     }
 
     /// Returns the path indexes forming a Merkle proof
-    #[must_use]
     fn get_path_index(&self) -> Vec<u8> {
         self.0.iter().map(|x| x.1).collect()
     }
 
-    #[must_use]
     /// Computes the Merkle root corresponding by iteratively hashing a Merkle proof with a given input leaf
     fn compute_root_from(&self, leaf: &H::Fr) -> H::Fr {
         let mut acc: H::Fr = *leaf;

utils/src/poseidon/poseidon_constants.rs

@@ -9,8 +9,6 @@
 
 // The following implementation was adapted from https://github.com/arkworks-rs/sponge/blob/7d9b3a474c9ddb62890014aeaefcb142ac2b3776/src/poseidon/grain_lfsr.rs
 
-#![allow(dead_code)]
-
 use ark_ff::PrimeField;
 use num_bigint::BigUint;
 
@@ -20,7 +18,6 @@ pub struct PoseidonGrainLFSR {
     pub head: usize,
 }
 
-#[allow(unused_variables)]
 impl PoseidonGrainLFSR {
     pub fn new(
         is_field: u64,

utils/src/poseidon/poseidon_hash.rs

@@ -7,7 +7,7 @@ use crate::poseidon_constants::find_poseidon_ark_and_mds;
 use ark_ff::PrimeField;
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct RoundParamenters<F: PrimeField> {
+pub struct RoundParameters<F: PrimeField> {
     pub t: usize,
     pub n_rounds_f: usize,
     pub n_rounds_p: usize,
@@ -17,16 +17,16 @@ pub struct RoundParamenters<F: PrimeField> {
 }
 
 pub struct Poseidon<F: PrimeField> {
-    round_params: Vec<RoundParamenters<F>>,
+    round_params: Vec<RoundParameters<F>>,
 }
 impl<F: PrimeField> Poseidon<F> {
     // Loads round parameters and generates round constants
     // poseidon_params is a vector containing tuples (t, RF, RP, skip_matrices)
-    // where: t is the rate (input lenght + 1), RF is the number of full rounds, RP is the number of partial rounds
+    // where: t is the rate (input length + 1), RF is the number of full rounds, RP is the number of partial rounds
     // and skip_matrices is a (temporary) parameter used to generate secure MDS matrices (see comments in the description of find_poseidon_ark_and_mds)
     // TODO: implement automatic generation of round parameters
     pub fn from(poseidon_params: &[(usize, usize, usize, usize)]) -> Self {
-        let mut read_params = Vec::<RoundParamenters<F>>::new();
+        let mut read_params = Vec::<RoundParameters<F>>::with_capacity(poseidon_params.len());
 
         for &(t, n_rounds_f, n_rounds_p, skip_matrices) in poseidon_params {
             let (ark, mds) = find_poseidon_ark_and_mds::<F>(
@@ -38,7 +38,7 @@ impl<F: PrimeField> Poseidon<F> {
                 n_rounds_p as u64,
                 skip_matrices,
             );
-            let rp = RoundParamenters {
+            let rp = RoundParameters {
                 t,
                 n_rounds_p,
                 n_rounds_f,
@@ -54,24 +54,24 @@ impl<F: PrimeField> Poseidon<F> {
         }
     }
 
-    pub fn get_parameters(&self) -> Vec<RoundParamenters<F>> {
-        self.round_params.clone()
+    pub fn get_parameters(&self) -> &Vec<RoundParameters<F>> {
+        &self.round_params
     }
 
     pub fn ark(&self, state: &mut [F], c: &[F], it: usize) {
-        for i in 0..state.len() {
-            state[i] += c[it + i];
-        }
+        state.iter_mut().enumerate().for_each(|(i, elem)| {
+            *elem += c[it + i];
+        });
     }
 
     pub fn sbox(&self, n_rounds_f: usize, n_rounds_p: usize, state: &mut [F], i: usize) {
         if (i < n_rounds_f / 2) || (i >= n_rounds_f / 2 + n_rounds_p) {
-            for current_state in &mut state.iter_mut() {
+            state.iter_mut().for_each(|current_state| {
                 let aux = *current_state;
                 *current_state *= *current_state;
                 *current_state *= *current_state;
                 *current_state *= aux;
-            }
+            })
         } else {
             let aux = state[0];
             state[0] *= state[0];
@@ -80,21 +80,20 @@ impl<F: PrimeField> Poseidon<F> {
         }
     }
 
-    pub fn mix(&self, state: &[F], m: &[Vec<F>]) -> Vec<F> {
-        let mut new_state: Vec<F> = Vec::new();
+    pub fn mix_2(&self, state: &[F], m: &[Vec<F>], state_2: &mut [F]) {
         for i in 0..state.len() {
-            new_state.push(F::zero());
-            for (j, state_item) in state.iter().enumerate() {
-                let mut mij = m[i][j];
-                mij *= state_item;
-                new_state[i] += mij;
+            // Cache the row reference
+            let row = &m[i];
+            let mut acc = F::ZERO;
+            for j in 0..state.len() {
+                acc += row[j] * state[j];
             }
+            state_2[i] = acc;
         }
-        new_state.clone()
     }
 
-    pub fn hash(&self, inp: Vec<F>) -> Result<F, String> {
-        // Note that the rate t becomes input lenght + 1, hence for lenght N we pick parameters with T = N + 1
+    pub fn hash(&self, inp: &[F]) -> Result<F, String> {
+        // Note that the rate t becomes input length + 1; hence for length N we pick parameters with T = N + 1
         let t = inp.len() + 1;
 
         // We seek the index (Poseidon's round_params is an ordered vector) for the parameters corresponding to t
@@ -106,8 +105,9 @@ impl<F: PrimeField> Poseidon<F> {
 
         let param_index = param_index.unwrap();
 
-        let mut state = vec![F::zero(); t];
-        state[1..].clone_from_slice(&inp);
+        let mut state = vec![F::ZERO; t];
+        let mut state_2 = state.clone();
+        state[1..].clone_from_slice(inp);
 
         for i in 0..(self.round_params[param_index].n_rounds_f
             + self.round_params[param_index].n_rounds_p)
@@ -123,7 +123,8 @@ impl<F: PrimeField> Poseidon<F> {
                 &mut state,
                 i,
             );
-            state = self.mix(&state, &self.round_params[param_index].m);
+            self.mix_2(&state, &self.round_params[param_index].m, &mut state_2);
+            std::mem::swap(&mut state, &mut state_2);
         }
 
         Ok(state[0])

utils/tests/merkle_tree.rs

@@ -107,7 +107,7 @@ pub mod test {
         let leaves_4: Vec<TestFr> = (0u32..4).map(TestFr::from).collect();
 
         let mut tree_full = default_full_merkle_tree(depth);
-        let _ = tree_full.set_range(0, leaves.clone());
+        let _ = tree_full.set_range(0, leaves.clone().into_iter());
         assert!(tree_full.get_empty_leaves_indices().is_empty());
 
         let mut vec_idxs = Vec::new();
@@ -125,31 +125,31 @@ pub mod test {
 
         // Check situation when the number of items to insert is less than the number of items to delete
         tree_full
-            .override_range(0, leaves_2.clone(), [0, 1, 2, 3])
+            .override_range(0, leaves_2.clone().into_iter(), [0, 1, 2, 3].into_iter())
             .unwrap();
 
         // check if the indexes for write and delete are the same
         tree_full
-            .override_range(0, leaves_4.clone(), [0, 1, 2, 3])
+            .override_range(0, leaves_4.clone().into_iter(), [0, 1, 2, 3].into_iter())
             .unwrap();
         assert_eq!(tree_full.get_empty_leaves_indices(), vec![]);
 
         // check if indexes for deletion are before indexes for overwriting
         tree_full
-            .override_range(4, leaves_4.clone(), [0, 1, 2, 3])
+            .override_range(4, leaves_4.clone().into_iter(), [0, 1, 2, 3].into_iter())
             .unwrap();
         assert_eq!(tree_full.get_empty_leaves_indices(), vec![0, 1, 2, 3]);
 
         // check if the indices for write and delete do not overlap completely
         tree_full
-            .override_range(2, leaves_4.clone(), [0, 1, 2, 3])
+            .override_range(2, leaves_4.clone().into_iter(), [0, 1, 2, 3].into_iter())
             .unwrap();
         assert_eq!(tree_full.get_empty_leaves_indices(), vec![0, 1]);
 
         //// Optimal Merkle Tree Trest
 
         let mut tree_opt = default_optimal_merkle_tree(depth);
-        let _ = tree_opt.set_range(0, leaves.clone());
+        let _ = tree_opt.set_range(0, leaves.clone().into_iter());
         assert!(tree_opt.get_empty_leaves_indices().is_empty());
 
         let mut vec_idxs = Vec::new();
@@ -166,24 +166,24 @@ pub mod test {
 
         // Check situation when the number of items to insert is less than the number of items to delete
         tree_opt
-            .override_range(0, leaves_2.clone(), [0, 1, 2, 3])
+            .override_range(0, leaves_2.clone().into_iter(), [0, 1, 2, 3].into_iter())
             .unwrap();
 
         // check if the indexes for write and delete are the same
         tree_opt
-            .override_range(0, leaves_4.clone(), [0, 1, 2, 3])
+            .override_range(0, leaves_4.clone().into_iter(), [0, 1, 2, 3].into_iter())
             .unwrap();
         assert_eq!(tree_opt.get_empty_leaves_indices(), vec![]);
 
         // check if indexes for deletion are before indexes for overwriting
         tree_opt
-            .override_range(4, leaves_4.clone(), [0, 1, 2, 3])
+            .override_range(4, leaves_4.clone().into_iter(), [0, 1, 2, 3].into_iter())
             .unwrap();
         assert_eq!(tree_opt.get_empty_leaves_indices(), vec![0, 1, 2, 3]);
 
         // check if the indices for write and delete do not overlap completely
         tree_opt
-            .override_range(2, leaves_4.clone(), [0, 1, 2, 3])
+            .override_range(2, leaves_4.clone().into_iter(), [0, 1, 2, 3].into_iter())
             .unwrap();
         assert_eq!(tree_opt.get_empty_leaves_indices(), vec![0, 1]);
     }
@@ -191,7 +191,7 @@ pub mod test {
     #[test]
     fn test_subtree_root() {
         let depth = 3;
-        let nof_leaves: usize = 6;
+        let nof_leaves: usize = 4;
         let leaves: Vec<TestFr> = (0..nof_leaves as u32).map(TestFr::from).collect();
 
         let mut tree_full = default_optimal_merkle_tree(depth);

utils/tests/poseidon_constants.rs

@@ -3530,7 +3530,8 @@ mod test {
         {
             // We check if the round constants and matrices correspond to the one generated when instantiating Poseidon with ROUND_PARAMS
             let (loaded_c, loaded_m) = load_constants();
-            let poseidon_parameters = Poseidon::<Fr>::from(&ROUND_PARAMS).get_parameters();
+            let poseidon_hasher = Poseidon::<Fr>::from(&ROUND_PARAMS);
+            let poseidon_parameters = poseidon_hasher.get_parameters();
             for i in 0..poseidon_parameters.len() {
                 assert_eq!(loaded_c[i], poseidon_parameters[i].c);
                 assert_eq!(loaded_m[i], poseidon_parameters[i].m);

utils/tests/poseidon_hash_test.rs

@@ -0,0 +1,131 @@
+#[cfg(test)]
+mod test {
+    use ark_bn254::Fr;
+    use ark_ff::{AdditiveGroup, Field};
+    use std::collections::HashMap;
+    use std::str::FromStr;
+    use zerokit_utils::poseidon_hash::Poseidon;
+
+    const ROUND_PARAMS: [(usize, usize, usize, usize); 8] = [
+        (2, 8, 56, 0),
+        (3, 8, 57, 0),
+        (4, 8, 56, 0),
+        (5, 8, 60, 0),
+        (6, 8, 60, 0),
+        (7, 8, 63, 0),
+        (8, 8, 64, 0),
+        (9, 8, 63, 0),
+    ];
+
+    #[test]
+    fn test_poseidon_hash_basic() {
+        let map = HashMap::from([
+            (
+                Fr::ZERO,
+                Fr::from_str(
+                    "19014214495641488759237505126948346942972912379615652741039992445865937985820",
+                )
+                .unwrap(),
+            ),
+            (
+                Fr::ONE,
+                Fr::from_str(
+                    "18586133768512220936620570745912940619677854269274689475585506675881198879027",
+                )
+                .unwrap(),
+            ),
+            (
+                Fr::from(255),
+                Fr::from_str(
+                    "20026131459732984724454933360292530547665726761019872861025481903072111625788",
+                )
+                .unwrap(),
+            ),
+            (
+                Fr::from(u16::MAX),
+                Fr::from_str(
+                    "12358868638722666642632413418981275677998688723398440898957566982787708451243",
+                )
+                .unwrap(),
+            ),
+            (
+                Fr::from(u64::MAX),
+                Fr::from_str(
+                    "17449307747295017006142981453320720946812828330895590310359634430146721583189",
+                )
+                .unwrap(),
+            ),
+        ]);
+
+        // map (key: what to hash, value: expected value)
+        for (k, v) in map.into_iter() {
+            let hasher = Poseidon::<Fr>::from(&ROUND_PARAMS);
+            let h = hasher.hash(&[k]);
+            assert_eq!(h.unwrap(), v);
+        }
+    }
+
+    #[test]
+    fn test_poseidon_hash_multi() {
+        // All hashes done in a merkle tree (with leaves: [0, 1, 2, 3, 4, 5, 6, 7])
+
+        // ~ leaves
+        let fr_0 = Fr::ZERO;
+        let fr_1 = Fr::ONE;
+        let fr_2 = Fr::from(2);
+        let fr_3 = Fr::from(3);
+        let fr_4 = Fr::from(4);
+        let fr_5 = Fr::from(5);
+        let fr_6 = Fr::from(6);
+        let fr_7 = Fr::from(7);
+
+        let fr_0_1 = Fr::from_str(
+            "12583541437132735734108669866114103169564651237895298778035846191048104863326",
+        )
+        .unwrap();
+        let fr_2_3 = Fr::from_str(
+            "17197790661637433027297685226742709599380837544520340689137581733613433332983",
+        )
+        .unwrap();
+        let fr_4_5 = Fr::from_str(
+            "756592041685769348226045093946546956867261766023639881791475046640232555043",
+        )
+        .unwrap();
+        let fr_6_7 = Fr::from_str(
+            "5558359459771725727593826278265342308584225092343962757289948761260561575479",
+        )
+        .unwrap();
+
+        let fr_0_3 = Fr::from_str(
+            "3720616653028013822312861221679392249031832781774563366107458835261883914924",
+        )
+        .unwrap();
+        let fr_4_7 = Fr::from_str(
+            "7960741062684589801276390367952372418815534638314682948141519164356522829957",
+        )
+        .unwrap();
+
+        // ~ root
+        let fr_0_7 = Fr::from_str(
+            "11780650233517635876913804110234352847867393797952240856403268682492028497284",
+        )
+        .unwrap();
+
+        // map (key: what to hash, value: expected value)
+        let map = HashMap::from([
+            ((fr_0, fr_1), fr_0_1),
+            ((fr_2, fr_3), fr_2_3),
+            ((fr_4, fr_5), fr_4_5),
+            ((fr_6, fr_7), fr_6_7),
+            ((fr_0_1, fr_2_3), fr_0_3),
+            ((fr_4_5, fr_6_7), fr_4_7),
+            ((fr_0_3, fr_4_7), fr_0_7),
+        ]);
+
+        for (k, v) in map.into_iter() {
+            let hasher = Poseidon::<Fr>::from(&ROUND_PARAMS);
+            let h = hasher.hash(&[k.0, k.1]);
+            assert_eq!(h.unwrap(), v);
+        }
+    }
+}