shh-client/client.js

The Shh.. protocol v0.0.1 Beta Tested. Keeps your messages very secure. Currently in more testing and securty.

import crypto from "crypto";

/**
 * Generate a private key or derive a public key
 * @param {'private'|'public'} type
 * @param {Buffer} [privKey] - Only needed if type === 'public'
 */
export function generateKey(type, name) {
    if (type === "private") {
        // Return private key buffer
        const ecdh = crypto.createECDH('prime256v1');
        ecdh.generateKeys();
        return ecdh.getPrivateKey();
    } else {
        throw new Error(`Use derivePublicKey() to get public key from private key`);
    }
}

/**
 * Derives a public key from a given private key
 */
export function derivePublicKey(privKey) {
    const ecdh = crypto.createECDH('prime256v1');
    ecdh.setPrivateKey(privKey);
    return ecdh.getPublicKey();
}

/**
 * Generate a shared key using own private key and peer's public key
 */
export function generateSharedKey(privKey, peerPubKey) {
    const ecdh = crypto.createECDH('prime256v1');
    ecdh.setPrivateKey(privKey);
    return ecdh.computeSecret(peerPubKey);
}

/**
 * Simple encrypt/decrypt functions (AES-256-GCM)
 */
export function enc(obj, sharedKey) {
    const iv = crypto.randomBytes(12);
    const cipher = crypto.createCipheriv('aes-256-gcm', sharedKey.slice(0, 32), iv);
    let encrypted = cipher.update(JSON.stringify(obj), 'utf8', 'hex');
    encrypted += cipher.final('hex');
    const tag = cipher.getAuthTag();
    return { iv: iv.toString('hex'), tag: tag.toString('hex'), data: encrypted };
}

export function dec(encData, sharedKey) {
    const iv = Buffer.from(encData.iv, 'hex');
    const tag = Buffer.from(encData.tag, 'hex');
    const decipher = crypto.createDecipheriv('aes-256-gcm', sharedKey.slice(0, 32), iv);
    decipher.setAuthTag(tag);
    let decrypted = decipher.update(encData.data, 'hex', 'utf8');
    decrypted += decipher.final('utf8');
    return JSON.parse(decrypted);
}

/**
 * Example sending function (stub)
 */
export function toServer(url, payload) {
    console.log(`Sending to ${url}:`, payload);
}