Table of Contents

• Installation
• Supported Platforms
• Features
• Usage
• API
• Performance
• License

Installation

npm install @foxleys-rs/curve25519

or with Yarn / pnpm / Bun:

yarn add @foxleys-rs/curve25519
pnpm add @foxleys-rs/curve25519
bun add @foxleys-rs/curve25519

This package ships prebuilt native binaries via napi-rs for all major platforms (no Rust toolchain required).

Supported Platforms

| Operating System | Architecture | libc | Prebuilt binaries | |------------------|--------------|---------------|-------------------| | Linux | x86_64 | glibc | Yes | | Linux | x86_64 | musl | Yes | | Linux | arm64 | glibc | Yes | | Linux | arm64 | musl | Yes | | macOS | x86_64 | — | Yes | | macOS | arm64 | — | Yes | | Windows | x86_64 | — | Yes | | Windows | arm64 | — | Yes |

Features

• X25519 key pair generation and public key derivation
• ECDH shared secret computation (X25519)
• Ed25519 signing and signature verification
• Extremely fast Rust core via napi-rs
• Zero-dependency native binaries for Node.js ≥18
• Automatic pure JavaScript fallback (curve25519-js) in environments without native support (e.g., some bundlers or testing)

Usage

/*
CJS
import curve from '@foxleys-rs/curve25519';
const {
  generateKeyPair,
  getPublicFromprivKey,
  calculateAgreement,
  calculateSignature,
  verifySignature,
} = curve;
*/
// ESM
import {
	generateKeyPair,
	getPublicFromPrivateKey,
	calculateAgreement,
	calculateSignature,
	verifySignature
} from "@foxleys-rs/curve25519";

// Generate a new key pair
const { pubKey, privKey } = generateKeyPair();

console.log("Public key :", pubKey);
console.log("Private key:", privKey);

// Derive public key from an existing private key (optional)
const pubKey2 = getPublicFromPrivateKey(privKey);

// Perform ECDH key exchange
const sharedSecret = calculateAgreement(pubKey, privKey);
console.log("Shared secret:", sharedSecret);

// Sign a message (Ed25519)
const message = Buffer.from("Hello, Curve25519!");
const signature = calculateSignature(privKey, message);

// Verify signature
const isValid = verifySignature(pubKey, message, signature);
console.log("Signature valid:", isValid);

All functions accept Buffer as input.

API

| Function | Description | Returns | |---------------------------------|--------------------------------------------------|---------------------------------| | generateKeyPair() | Generates a new X25519 key pair | { privKey: Buffer, pubKey: Buffer } | | getPublicFromPrivateKey(privKey) | Derives public key from private key | Buffer (33 bytes) | | calculateAgreement(pubKey, privKey) | Computes X25519 shared secret | Buffer (32 bytes) | | calculateSignature(privKey, msg) | Signs message with Ed25519 | Buffer (64 bytes) | | verifySignature(pubKey, msg, sig)| Verifies Ed25519 signature | boolean |

Performance

Benchmarks performed on Node.js 25. Results show average latency and throughput:

| Task | Latency (avg) | Throughput (avg ops/s) | |---------------------------------|--------------------|------------------------| | Rust generateKeyPair | 75.1 μs ± 0.80% | 13,610 | | Node generateKeyPair | 237.0 μs ± 3.90% | 5,225 | | Rust getPublicFromPrivateKey | 209.1 μs ± 0.78% | 4,876 | | Node getPublicFromPrivateKey | 1,735.8 μs ± 2.84% | 606 | | Rust calculateAgreement | 205.9 μs ± 0.43% | 4,892 | | Node calculateAgreement | 379.0 μs ± 2.44% | 2,835 | | Rust calculateSignature | 134.2 μs ± 0.27% | 7,492 | | Node calculateSignature | 37,241.7 μs ± 15.48% | 35 | | Rust verifySignature | 229.6 μs ± 0.37% | 4,389 | | Node verifySignature | 30,703.2 μs ± 17.43% | 45 |

The Rust implementation is 2–5× faster than equivalent pure JavaScript implementations, especially for signing and verification.

License

This project is licensed under the MIT License – see the LICENSE file for details.

Developed with ❤️ by Foxleys.